win32/win32.c

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/*
 *  Copyright (c) 1993, Intergraph Corporation
 *
 *  You may distribute under the terms of either the GNU General Public
 *  License or the Artistic License, as specified in the perl README file.
 *
 *  Various Unix compatibility functions and NT specific functions.
 *
 *  Some of this code was derived from the MSDOS port(s) and the OS/2 port.
 *
 */

#include "ruby/ruby.h"
#include "ruby/encoding.h"
#include "dln.h"
#include <fcntl.h>
#include <process.h>
#include <sys/stat.h>
/* #include <sys/wait.h> */
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <assert.h>
#include <ctype.h>

#include <windows.h>
#include <winbase.h>
#include <wincon.h>
#include <share.h>
#include <shlobj.h>
#include <mbstring.h>
#if _MSC_VER >= 1400
#include <crtdbg.h>
#include <rtcapi.h>
#endif
#ifdef __MINGW32__
#include <mswsock.h>
#endif
#include "ruby/win32.h"
#include "win32/dir.h"
#define isdirsep(x) ((x) == '/' || (x) == '\\')

#undef stat
#undef fclose
#undef close
#undef setsockopt

#if defined __BORLANDC__
#  define _filbuf _fgetc
#  define _flsbuf _fputc
#  define enough_to_get(n) (--(n) >= 0)
#  define enough_to_put(n) (++(n) < 0)
#else
#  define enough_to_get(n) (--(n) >= 0)
#  define enough_to_put(n) (--(n) >= 0)
#endif

#ifdef WIN32_DEBUG
#define Debug(something) something
#else
#define Debug(something) /* nothing */
#endif

#define TO_SOCKET(x)    _get_osfhandle(x)

static struct ChildRecord *CreateChild(const WCHAR *, const WCHAR *, SECURITY_ATTRIBUTES *, HANDLE, HANDLE, HANDLE, DWORD);
static int has_redirection(const char *);
int rb_w32_wait_events(HANDLE *events, int num, DWORD timeout);
static int rb_w32_open_osfhandle(intptr_t osfhandle, int flags);
static int wstati64(const WCHAR *path, struct stati64 *st);
VALUE rb_w32_conv_from_wchar(const WCHAR *wstr, rb_encoding *enc);

#define RUBY_CRITICAL(expr) do { expr; } while (0)

/* errno mapping */
static struct {
    DWORD winerr;
    int err;
} errmap[] = {
    {   ERROR_INVALID_FUNCTION,         EINVAL          },
    {   ERROR_FILE_NOT_FOUND,           ENOENT          },
    {   ERROR_PATH_NOT_FOUND,           ENOENT          },
    {   ERROR_TOO_MANY_OPEN_FILES,      EMFILE          },
    {   ERROR_ACCESS_DENIED,            EACCES          },
    {   ERROR_INVALID_HANDLE,           EBADF           },
    {   ERROR_ARENA_TRASHED,            ENOMEM          },
    {   ERROR_NOT_ENOUGH_MEMORY,        ENOMEM          },
    {   ERROR_INVALID_BLOCK,            ENOMEM          },
    {   ERROR_BAD_ENVIRONMENT,          E2BIG           },
    {   ERROR_BAD_FORMAT,               ENOEXEC         },
    {   ERROR_INVALID_ACCESS,           EINVAL          },
    {   ERROR_INVALID_DATA,             EINVAL          },
    {   ERROR_INVALID_DRIVE,            ENOENT          },
    {   ERROR_CURRENT_DIRECTORY,        EACCES          },
    {   ERROR_NOT_SAME_DEVICE,          EXDEV           },
    {   ERROR_NO_MORE_FILES,            ENOENT          },
    {   ERROR_WRITE_PROTECT,            EROFS           },
    {   ERROR_BAD_UNIT,                 ENODEV          },
    {   ERROR_NOT_READY,                ENXIO           },
    {   ERROR_BAD_COMMAND,              EACCES          },
    {   ERROR_CRC,                      EACCES          },
    {   ERROR_BAD_LENGTH,               EACCES          },
    {   ERROR_SEEK,                     EIO             },
    {   ERROR_NOT_DOS_DISK,             EACCES          },
    {   ERROR_SECTOR_NOT_FOUND,         EACCES          },
    {   ERROR_OUT_OF_PAPER,             EACCES          },
    {   ERROR_WRITE_FAULT,              EIO             },
    {   ERROR_READ_FAULT,               EIO             },
    {   ERROR_GEN_FAILURE,              EACCES          },
    {   ERROR_LOCK_VIOLATION,           EACCES          },
    {   ERROR_SHARING_VIOLATION,        EACCES          },
    {   ERROR_WRONG_DISK,               EACCES          },
    {   ERROR_SHARING_BUFFER_EXCEEDED,  EACCES          },
    {   ERROR_BAD_NETPATH,              ENOENT          },
    {   ERROR_NETWORK_ACCESS_DENIED,    EACCES          },
    {   ERROR_BAD_NET_NAME,             ENOENT          },
    {   ERROR_FILE_EXISTS,              EEXIST          },
    {   ERROR_CANNOT_MAKE,              EACCES          },
    {   ERROR_FAIL_I24,                 EACCES          },
    {   ERROR_INVALID_PARAMETER,        EINVAL          },
    {   ERROR_NO_PROC_SLOTS,            EAGAIN          },
    {   ERROR_DRIVE_LOCKED,             EACCES          },
    {   ERROR_BROKEN_PIPE,              EPIPE           },
    {   ERROR_DISK_FULL,                ENOSPC          },
    {   ERROR_INVALID_TARGET_HANDLE,    EBADF           },
    {   ERROR_INVALID_HANDLE,           EINVAL          },
    {   ERROR_WAIT_NO_CHILDREN,         ECHILD          },
    {   ERROR_CHILD_NOT_COMPLETE,       ECHILD          },
    {   ERROR_DIRECT_ACCESS_HANDLE,     EBADF           },
    {   ERROR_NEGATIVE_SEEK,            EINVAL          },
    {   ERROR_SEEK_ON_DEVICE,           EACCES          },
    {   ERROR_DIR_NOT_EMPTY,            ENOTEMPTY       },
    {   ERROR_DIRECTORY,                ENOTDIR         },
    {   ERROR_NOT_LOCKED,               EACCES          },
    {   ERROR_BAD_PATHNAME,             ENOENT          },
    {   ERROR_MAX_THRDS_REACHED,        EAGAIN          },
    {   ERROR_LOCK_FAILED,              EACCES          },
    {   ERROR_ALREADY_EXISTS,           EEXIST          },
    {   ERROR_INVALID_STARTING_CODESEG, ENOEXEC         },
    {   ERROR_INVALID_STACKSEG,         ENOEXEC         },
    {   ERROR_INVALID_MODULETYPE,       ENOEXEC         },
    {   ERROR_INVALID_EXE_SIGNATURE,    ENOEXEC         },
    {   ERROR_EXE_MARKED_INVALID,       ENOEXEC         },
    {   ERROR_BAD_EXE_FORMAT,           ENOEXEC         },
    {   ERROR_ITERATED_DATA_EXCEEDS_64k,ENOEXEC         },
    {   ERROR_INVALID_MINALLOCSIZE,     ENOEXEC         },
    {   ERROR_DYNLINK_FROM_INVALID_RING,ENOEXEC         },
    {   ERROR_IOPL_NOT_ENABLED,         ENOEXEC         },
    {   ERROR_INVALID_SEGDPL,           ENOEXEC         },
    {   ERROR_AUTODATASEG_EXCEEDS_64k,  ENOEXEC         },
    {   ERROR_RING2SEG_MUST_BE_MOVABLE, ENOEXEC         },
    {   ERROR_RELOC_CHAIN_XEEDS_SEGLIM, ENOEXEC         },
    {   ERROR_INFLOOP_IN_RELOC_CHAIN,   ENOEXEC         },
    {   ERROR_FILENAME_EXCED_RANGE,     ENOENT          },
    {   ERROR_NESTING_NOT_ALLOWED,      EAGAIN          },
#ifndef ERROR_PIPE_LOCAL
#define ERROR_PIPE_LOCAL        229L
#endif
    {   ERROR_PIPE_LOCAL,               EPIPE           },
    {   ERROR_BAD_PIPE,                 EPIPE           },
    {   ERROR_PIPE_BUSY,                EAGAIN          },
    {   ERROR_NO_DATA,                  EPIPE           },
    {   ERROR_PIPE_NOT_CONNECTED,       EPIPE           },
    {   ERROR_OPERATION_ABORTED,        EINTR           },
    {   ERROR_NOT_ENOUGH_QUOTA,         ENOMEM          },
    {   ERROR_MOD_NOT_FOUND,            ENOENT          },
    {   WSAEINTR,                       EINTR           },
    {   WSAEBADF,                       EBADF           },
    {   WSAEACCES,                      EACCES          },
    {   WSAEFAULT,                      EFAULT          },
    {   WSAEINVAL,                      EINVAL          },
    {   WSAEMFILE,                      EMFILE          },
    {   WSAEWOULDBLOCK,                 EWOULDBLOCK     },
    {   WSAEINPROGRESS,                 EINPROGRESS     },
    {   WSAEALREADY,                    EALREADY        },
    {   WSAENOTSOCK,                    ENOTSOCK        },
    {   WSAEDESTADDRREQ,                EDESTADDRREQ    },
    {   WSAEMSGSIZE,                    EMSGSIZE        },
    {   WSAEPROTOTYPE,                  EPROTOTYPE      },
    {   WSAENOPROTOOPT,                 ENOPROTOOPT     },
    {   WSAEPROTONOSUPPORT,             EPROTONOSUPPORT },
    {   WSAESOCKTNOSUPPORT,             ESOCKTNOSUPPORT },
    {   WSAEOPNOTSUPP,                  EOPNOTSUPP      },
    {   WSAEPFNOSUPPORT,                EPFNOSUPPORT    },
    {   WSAEAFNOSUPPORT,                EAFNOSUPPORT    },
    {   WSAEADDRINUSE,                  EADDRINUSE      },
    {   WSAEADDRNOTAVAIL,               EADDRNOTAVAIL   },
    {   WSAENETDOWN,                    ENETDOWN        },
    {   WSAENETUNREACH,                 ENETUNREACH     },
    {   WSAENETRESET,                   ENETRESET       },
    {   WSAECONNABORTED,                ECONNABORTED    },
    {   WSAECONNRESET,                  ECONNRESET      },
    {   WSAENOBUFS,                     ENOBUFS         },
    {   WSAEISCONN,                     EISCONN         },
    {   WSAENOTCONN,                    ENOTCONN        },
    {   WSAESHUTDOWN,                   ESHUTDOWN       },
    {   WSAETOOMANYREFS,                ETOOMANYREFS    },
    {   WSAETIMEDOUT,                   ETIMEDOUT       },
    {   WSAECONNREFUSED,                ECONNREFUSED    },
    {   WSAELOOP,                       ELOOP           },
    {   WSAENAMETOOLONG,                ENAMETOOLONG    },
    {   WSAEHOSTDOWN,                   EHOSTDOWN       },
    {   WSAEHOSTUNREACH,                EHOSTUNREACH    },
    {   WSAEPROCLIM,                    EPROCLIM        },
    {   WSAENOTEMPTY,                   ENOTEMPTY       },
    {   WSAEUSERS,                      EUSERS          },
    {   WSAEDQUOT,                      EDQUOT          },
    {   WSAESTALE,                      ESTALE          },
    {   WSAEREMOTE,                     EREMOTE         },
};

int
rb_w32_map_errno(DWORD winerr)
{
    int i;

    if (winerr == 0) {
        return 0;
    }

    for (i = 0; i < (int)(sizeof(errmap) / sizeof(*errmap)); i++) {
        if (errmap[i].winerr == winerr) {
            return errmap[i].err;
        }
    }

    if (winerr >= WSABASEERR) {
        return winerr;
    }
    return EINVAL;
}

#define map_errno rb_w32_map_errno

static const char *NTLoginName;

static OSVERSIONINFO osver;

static void
get_version(void)
{
    memset(&osver, 0, sizeof(OSVERSIONINFO));
    osver.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
    GetVersionEx(&osver);
}

#ifdef _M_IX86
DWORD
rb_w32_osid(void)
{
    return osver.dwPlatformId;
}
#endif

DWORD
rb_w32_osver(void)
{
    return osver.dwMajorVersion;
}

#define IsWinNT() rb_w32_iswinnt()
#define IsWin95() rb_w32_iswin95()
#ifdef WIN95
#define IfWin95(win95, winnt) (IsWin95() ? (win95) : (winnt))
#else
#define IfWin95(win95, winnt) (winnt)
#endif

HANDLE
GetCurrentThreadHandle(void)
{
    static HANDLE current_process_handle = NULL;
    HANDLE h;

    if (!current_process_handle)
        current_process_handle = GetCurrentProcess();
    if (!DuplicateHandle(current_process_handle, GetCurrentThread(),
                         current_process_handle, &h,
                         0, FALSE, DUPLICATE_SAME_ACCESS))
        return NULL;
    return h;
}

/* simulate flock by locking a range on the file */


#define LK_ERR(f,i) \
    do {                                                                \
        if (f)                                                          \
            i = 0;                                                      \
        else {                                                          \
            DWORD err = GetLastError();                                 \
            if (err == ERROR_LOCK_VIOLATION || err == ERROR_IO_PENDING) \
                errno = EWOULDBLOCK;                                    \
            else if (err == ERROR_NOT_LOCKED)                           \
                i = 0;                                                  \
            else                                                        \
                errno = map_errno(err);                                 \
        }                                                               \
    } while (0)
#define LK_LEN      ULONG_MAX

static uintptr_t
flock_winnt(uintptr_t self, int argc, uintptr_t* argv)
{
    OVERLAPPED o;
    int i = -1;
    const HANDLE fh = (HANDLE)self;
    const int oper = argc;

    memset(&o, 0, sizeof(o));

    switch(oper) {
      case LOCK_SH:             /* shared lock */
        LK_ERR(LockFileEx(fh, 0, 0, LK_LEN, LK_LEN, &o), i);
        break;
      case LOCK_EX:             /* exclusive lock */
        LK_ERR(LockFileEx(fh, LOCKFILE_EXCLUSIVE_LOCK, 0, LK_LEN, LK_LEN, &o), i);
        break;
      case LOCK_SH|LOCK_NB:     /* non-blocking shared lock */
        LK_ERR(LockFileEx(fh, LOCKFILE_FAIL_IMMEDIATELY, 0, LK_LEN, LK_LEN, &o), i);
        break;
      case LOCK_EX|LOCK_NB:     /* non-blocking exclusive lock */
        LK_ERR(LockFileEx(fh,
                          LOCKFILE_EXCLUSIVE_LOCK|LOCKFILE_FAIL_IMMEDIATELY,
                          0, LK_LEN, LK_LEN, &o), i);
        break;
      case LOCK_UN:             /* unlock lock */
      case LOCK_UN|LOCK_NB:     /* unlock is always non-blocking, I hope */
        LK_ERR(UnlockFileEx(fh, 0, LK_LEN, LK_LEN, &o), i);
        break;
      default:            /* unknown */
        errno = EINVAL;
        break;
    }
    return i;
}

#ifdef WIN95
static uintptr_t
flock_win95(uintptr_t self, int argc, uintptr_t* argv)
{
    int i = -1;
    const HANDLE fh = (HANDLE)self;
    const int oper = argc;

    switch(oper) {
      case LOCK_EX:
        do {
            LK_ERR(LockFile(fh, 0, 0, LK_LEN, LK_LEN), i);
        } while (i && errno == EWOULDBLOCK);
        break;
      case LOCK_EX|LOCK_NB:
        LK_ERR(LockFile(fh, 0, 0, LK_LEN, LK_LEN), i);
        break;
      case LOCK_UN:
      case LOCK_UN|LOCK_NB:
        LK_ERR(UnlockFile(fh, 0, 0, LK_LEN, LK_LEN), i);
        break;
      default:
        errno = EINVAL;
        break;
    }
    return i;
}
#endif

#undef LK_ERR

int
flock(int fd, int oper)
{
#ifdef WIN95
    static asynchronous_func_t locker = NULL;

    if (!locker) {
        if (IsWinNT())
            locker = flock_winnt;
        else
            locker = flock_win95;
    }
#else
    const asynchronous_func_t locker = flock_winnt;
#endif

    return rb_w32_asynchronize(locker,
                              (VALUE)_get_osfhandle(fd), oper, NULL,
                              (DWORD)-1);
}

static inline WCHAR *
translate_wchar(WCHAR *p, int from, int to)
{
    for (; *p; p++) {
        if (*p == from)
            *p = to;
    }
    return p;
}

static inline char *
translate_char(char *p, int from, int to)
{
    while (*p) {
        if ((unsigned char)*p == from)
            *p = to;
        p = CharNext(p);
    }
    return p;
}

#ifndef CSIDL_LOCAL_APPDATA
#define CSIDL_LOCAL_APPDATA 28
#endif
#ifndef CSIDL_COMMON_APPDATA
#define CSIDL_COMMON_APPDATA 35
#endif
#ifndef CSIDL_WINDOWS
#define CSIDL_WINDOWS   36
#endif
#ifndef CSIDL_SYSTEM
#define CSIDL_SYSTEM    37
#endif
#ifndef CSIDL_PROFILE
#define CSIDL_PROFILE 40
#endif

static BOOL
get_special_folder(int n, WCHAR *env)
{
    LPITEMIDLIST pidl;
    LPMALLOC alloc;
    BOOL f = FALSE;
    if (SHGetSpecialFolderLocation(NULL, n, &pidl) == 0) {
        f = SHGetPathFromIDListW(pidl, env);
        SHGetMalloc(&alloc);
        alloc->lpVtbl->Free(alloc, pidl);
        alloc->lpVtbl->Release(alloc);
    }
    return f;
}

static void
regulate_path(WCHAR *path)
{
    WCHAR *p = translate_wchar(path, L'\\', L'/');
    if (p - path == 2 && path[1] == L':') {
        *p++ = L'/';
        *p = L'\0';
    }
}

static FARPROC
get_proc_address(const char *module, const char *func, HANDLE *mh)
{
    HANDLE h;
    FARPROC ptr;

    if (mh)
        h = LoadLibrary(module);
    else
        h = GetModuleHandle(module);
    if (!h)
        return NULL;

    ptr = GetProcAddress(h, func);
    if (mh) {
        if (ptr)
            *mh = h;
        else
            FreeLibrary(h);
    }
    return ptr;
}

static UINT
get_system_directory(WCHAR *path, UINT len)
{
    typedef UINT WINAPI wgetdir_func(WCHAR*, UINT);
    FARPROC ptr =
        get_proc_address("kernel32", "GetSystemWindowsDirectoryW", NULL);
    if (ptr)
        return (*(wgetdir_func *)ptr)(path, len);
    return GetWindowsDirectoryW(path, len);
}

#define numberof(array) (sizeof(array) / sizeof(*array))

VALUE
rb_w32_special_folder(int type)
{
    WCHAR path[_MAX_PATH];

    if (!get_special_folder(type, path)) return Qnil;
    regulate_path(path);
    return rb_w32_conv_from_wchar(path, rb_filesystem_encoding());
}

UINT
rb_w32_system_tmpdir(WCHAR *path, UINT len)
{
    static const WCHAR temp[] = L"temp";
    WCHAR *p;

    if (!get_special_folder(CSIDL_LOCAL_APPDATA, path)) {
        if (get_system_directory(path, len)) return 0;
    }
    p = translate_wchar(path, L'\\', L'/');
    if (*(p - 1) != L'/') *p++ = L'/';
    if (p - path + numberof(temp) >= len) return 0;
    memcpy(p, temp, sizeof(temp));
    return p - path + numberof(temp) - 1;
}

static void
init_env(void)
{
    static const WCHAR TMPDIR[] = L"TMPDIR";
    struct {WCHAR name[6], eq, val[_MAX_PATH];} wk;
    DWORD len;
    BOOL f;
#define env wk.val
#define set_env_val(vname) do { \
        typedef char namesizecheck[numberof(wk.name) < numberof(vname) - 1 ? -1 : 1]; \
        WCHAR *const buf = wk.name + numberof(wk.name) - numberof(vname) + 1; \
        MEMCPY(buf, vname, WCHAR, numberof(vname) - 1); \
        _wputenv(buf); \
    } while (0)

    wk.eq = L'=';

    if (!GetEnvironmentVariableW(L"HOME", env, numberof(env))) {
        f = FALSE;
        if (GetEnvironmentVariableW(L"HOMEDRIVE", env, numberof(env)))
            len = lstrlenW(env);
        else
            len = 0;
        if (GetEnvironmentVariableW(L"HOMEPATH", env + len, numberof(env) - len) || len) {
            f = TRUE;
        }
        else if (GetEnvironmentVariableW(L"USERPROFILE", env, numberof(env))) {
            f = TRUE;
        }
        else if (get_special_folder(CSIDL_PROFILE, env)) {
            f = TRUE;
        }
        else if (get_special_folder(CSIDL_PERSONAL, env)) {
            f = TRUE;
        }
        if (f) {
            regulate_path(env);
            set_env_val(L"HOME");
        }
    }

    if (!GetEnvironmentVariableW(L"USER", env, numberof(env))) {
        if (!GetEnvironmentVariableW(L"USERNAME", env, numberof(env)) &&
            !GetUserNameW(env, (len = numberof(env), &len))) {
            NTLoginName = "<Unknown>";
            return;
        }
        set_env_val(L"USER");
    }
    NTLoginName = strdup(rb_w32_getenv("USER"));

    if (!GetEnvironmentVariableW(TMPDIR, env, numberof(env)) &&
        !GetEnvironmentVariableW(L"TMP", env, numberof(env)) &&
        !GetEnvironmentVariableW(L"TEMP", env, numberof(env)) &&
        rb_w32_system_tmpdir(env, numberof(env))) {
        set_env_val(TMPDIR);
    }

#undef env
#undef set_env_val
}


typedef BOOL (WINAPI *cancel_io_t)(HANDLE);
static cancel_io_t cancel_io = NULL;

static void
init_func(void)
{
    if (!cancel_io)
        cancel_io = (cancel_io_t)get_proc_address("kernel32", "CancelIo", NULL);
}

static void init_stdhandle(void);

#if RT_VER >= 80
static void
invalid_parameter(const wchar_t *expr, const wchar_t *func, const wchar_t *file, unsigned int line, uintptr_t dummy)
{
    // nothing to do
}

int ruby_w32_rtc_error;

static int __cdecl
rtc_error_handler(int e, const char *src, int line, const char *exe, const char *fmt, ...)
{
    va_list ap;
    VALUE str;

    if (!ruby_w32_rtc_error) return 0;
    str = rb_sprintf("%s:%d: ", src, line);
    va_start(ap, fmt);
    rb_str_vcatf(str, fmt, ap);
    va_end(ap);
    rb_str_cat(str, "\n", 1);
    rb_write_error2(RSTRING_PTR(str), RSTRING_LEN(str));
    return 0;
}
#endif

static CRITICAL_SECTION select_mutex;
static int NtSocketsInitialized = 0;
static st_table *socklist = NULL;
static char *envarea;

static void
exit_handler(void)
{
    if (NtSocketsInitialized) {
        WSACleanup();
        st_free_table(socklist);
        socklist = NULL;
        NtSocketsInitialized = 0;
    }
    if (envarea) {
        FreeEnvironmentStrings(envarea);
        envarea = NULL;
    }
    DeleteCriticalSection(&select_mutex);
}

static void
StartSockets(void)
{
    WORD version;
    WSADATA retdata;

    //
    // initalize the winsock interface and insure that it's
    // cleaned up at exit.
    //
    version = MAKEWORD(2, 0);
    if (WSAStartup(version, &retdata))
        rb_fatal ("Unable to locate winsock library!\n");
    if (LOBYTE(retdata.wVersion) != 2)
        rb_fatal("could not find version 2 of winsock dll\n");

    socklist = st_init_numtable();

    NtSocketsInitialized = 1;
}

//
// Initialization stuff
//
void
rb_w32_sysinit(int *argc, char ***argv)
{
#if RT_VER >= 80
    static void set_pioinfo_extra(void);

    _CrtSetReportMode(_CRT_ASSERT, 0);
    _set_invalid_parameter_handler(invalid_parameter);
    _RTC_SetErrorFunc(rtc_error_handler);
    set_pioinfo_extra();
#else
    SetErrorMode(SEM_FAILCRITICALERRORS|SEM_NOGPFAULTERRORBOX);
#endif

    get_version();

    //
    // subvert cmd.exe's feeble attempt at command line parsing
    //
    *argc = rb_w32_cmdvector(GetCommandLine(), argv);

    //
    // Now set up the correct time stuff
    //

    tzset();

    init_env();

    init_func();

    init_stdhandle();

    InitializeCriticalSection(&select_mutex);

    atexit(exit_handler);

    // Initialize Winsock
    StartSockets();
}

char *
getlogin(void)
{
    return (char *)NTLoginName;
}

#define MAXCHILDNUM 256 /* max num of child processes */

static struct ChildRecord {
    HANDLE hProcess;    /* process handle */
    rb_pid_t pid;       /* process id */
} ChildRecord[MAXCHILDNUM];

#define FOREACH_CHILD(v) do { \
    struct ChildRecord* v; \
    for (v = ChildRecord; v < ChildRecord + sizeof(ChildRecord) / sizeof(ChildRecord[0]); ++v)
#define END_FOREACH_CHILD } while (0)

static struct ChildRecord *
FindChildSlot(rb_pid_t pid)
{

    FOREACH_CHILD(child) {
        if (child->pid == pid) {
            return child;
        }
    } END_FOREACH_CHILD;
    return NULL;
}

static struct ChildRecord *
FindChildSlotByHandle(HANDLE h)
{

    FOREACH_CHILD(child) {
        if (child->hProcess == h) {
            return child;
        }
    } END_FOREACH_CHILD;
    return NULL;
}

static void
CloseChildHandle(struct ChildRecord *child)
{
    HANDLE h = child->hProcess;
    child->hProcess = NULL;
    child->pid = 0;
    CloseHandle(h);
}

static struct ChildRecord *
FindFreeChildSlot(void)
{
    FOREACH_CHILD(child) {
        if (!child->pid) {
            child->pid = -1;    /* lock the slot */
            child->hProcess = NULL;
            return child;
        }
    } END_FOREACH_CHILD;
    return NULL;
}


/*
  ruby -lne 'BEGIN{$cmds = Hash.new(0); $mask = 1}'
   -e '$cmds[$_.downcase] |= $mask' -e '$mask <<= 1 if ARGF.eof'
   -e 'END{$cmds.sort.each{|n,f|puts "    \"\\#{f.to_s(8)}\" #{n.dump} + 1,"}}'
   98cmd ntcmd
 */
static const char *const szInternalCmds[] = {
    "\2" "assoc" + 1,
    "\3" "break" + 1,
    "\3" "call" + 1,
    "\3" "cd" + 1,
    "\1" "chcp" + 1,
    "\3" "chdir" + 1,
    "\3" "cls" + 1,
    "\2" "color" + 1,
    "\3" "copy" + 1,
    "\1" "ctty" + 1,
    "\3" "date" + 1,
    "\3" "del" + 1,
    "\3" "dir" + 1,
    "\3" "echo" + 1,
    "\2" "endlocal" + 1,
    "\3" "erase" + 1,
    "\3" "exit" + 1,
    "\3" "for" + 1,
    "\2" "ftype" + 1,
    "\3" "goto" + 1,
    "\3" "if" + 1,
    "\1" "lfnfor" + 1,
    "\1" "lh" + 1,
    "\1" "lock" + 1,
    "\3" "md" + 1,
    "\3" "mkdir" + 1,
    "\2" "move" + 1,
    "\3" "path" + 1,
    "\3" "pause" + 1,
    "\2" "popd" + 1,
    "\3" "prompt" + 1,
    "\2" "pushd" + 1,
    "\3" "rd" + 1,
    "\3" "rem" + 1,
    "\3" "ren" + 1,
    "\3" "rename" + 1,
    "\3" "rmdir" + 1,
    "\3" "set" + 1,
    "\2" "setlocal" + 1,
    "\3" "shift" + 1,
    "\2" "start" + 1,
    "\3" "time" + 1,
    "\2" "title" + 1,
    "\1" "truename" + 1,
    "\3" "type" + 1,
    "\1" "unlock" + 1,
    "\3" "ver" + 1,
    "\3" "verify" + 1,
    "\3" "vol" + 1,
};

static int
internal_match(const void *key, const void *elem)
{
    return strcmp(key, *(const char *const *)elem);
}

static int
is_command_com(const char *interp)
{
    int i = strlen(interp) - 11;

    if ((i == 0 || i > 0 && isdirsep(interp[i-1])) &&
        strcasecmp(interp+i, "command.com") == 0) {
        return 1;
    }
    return 0;
}

static int internal_cmd_match(const char *cmdname, int nt);

static int
is_internal_cmd(const char *cmd, int nt)
{
    char cmdname[9], *b = cmdname, c;

    do {
        if (!(c = *cmd++)) return 0;
    } while (isspace(c));
    if (c == '@')
        return 1;
    while (isalpha(c)) {
        *b++ = tolower(c);
        if (b == cmdname + sizeof(cmdname)) return 0;
        c = *cmd++;
    }
    if (c == '.') c = *cmd;
    switch (c) {
      case '<': case '>': case '|':
        return 1;
      case '\0': case ' ': case '\t': case '\n':
        break;
      default:
        return 0;
    }
    *b = 0;
    return internal_cmd_match(cmdname, nt);
}

static int
internal_cmd_match(const char *cmdname, int nt)
{
    char **nm;

    nm = bsearch(cmdname, szInternalCmds,
                 sizeof(szInternalCmds) / sizeof(*szInternalCmds),
                 sizeof(*szInternalCmds),
                 internal_match);
    if (!nm || !(nm[0][-1] & (nt ? 2 : 1)))
        return 0;
    return 1;
}

SOCKET
rb_w32_get_osfhandle(int fh)
{
    return _get_osfhandle(fh);
}

static int
join_argv(char *cmd, char *const *argv, BOOL escape)
{
    const char *p, *s;
    char *q, *const *t;
    int len, n, bs, quote;

    for (t = argv, q = cmd, len = 0; p = *t; t++) {
        quote = 0;
        s = p;
        if (!*p || strpbrk(p, " \t\"'")) {
            quote = 1;
            len++;
            if (q) *q++ = '"';
        }
        for (bs = 0; *p; ++p) {
            switch (*p) {
              case '\\':
                ++bs;
                break;
              case '"':
                len += n = p - s;
                if (q) {
                    memcpy(q, s, n);
                    q += n;
                }
                s = p;
                len += ++bs;
                if (q) {
                    memset(q, '\\', bs);
                    q += bs;
                }
                bs = 0;
                break;
              case '<': case '>': case '|': case '^':
                if (escape && !quote) {
                    len += (n = p - s) + 1;
                    if (q) {
                        memcpy(q, s, n);
                        q += n;
                        *q++ = '^';
                    }
                    s = p;
                    break;
                }
              default:
                bs = 0;
                p = CharNext(p) - 1;
                break;
            }
        }
        len += (n = p - s) + 1;
        if (quote) len++;
        if (q) {
            memcpy(q, s, n);
            q += n;
            if (quote) *q++ = '"';
            *q++ = ' ';
        }
    }
    if (q > cmd) --len;
    if (q) {
        if (q > cmd) --q;
        *q = '\0';
    }
    return len;
}

#ifdef HAVE_SYS_PARAM_H
# include <sys/param.h>
#else
# define MAXPATHLEN 512
#endif

#define STRNDUPV(ptr, v, src, len)                                      \
    (((char *)memcpy(((ptr) = ALLOCV((v), (len) + 1)), (src), (len)))[len] = 0)

static int
check_spawn_mode(int mode)
{
    switch (mode) {
      case P_NOWAIT:
      case P_OVERLAY:
        return 0;
      default:
        errno = EINVAL;
        return -1;
    }
}

static rb_pid_t
child_result(struct ChildRecord *child, int mode)
{
    DWORD exitcode;

    if (!child) {
        return -1;
    }

    switch (mode) {
      case P_NOWAIT:
        return child->pid;
      case P_OVERLAY:
        WaitForSingleObject(child->hProcess, INFINITE);
        GetExitCodeProcess(child->hProcess, &exitcode);
        CloseChildHandle(child);
        _exit(exitcode);
      default:
        return -1;      /* not reached */
    }
}

static struct ChildRecord *
CreateChild(const WCHAR *cmd, const WCHAR *prog, SECURITY_ATTRIBUTES *psa,
            HANDLE hInput, HANDLE hOutput, HANDLE hError, DWORD dwCreationFlags)
{
    BOOL fRet;
    STARTUPINFOW aStartupInfo;
    PROCESS_INFORMATION aProcessInformation;
    SECURITY_ATTRIBUTES sa;
    struct ChildRecord *child;

    if (!cmd && !prog) {
        errno = EFAULT;
        return NULL;
    }

    child = FindFreeChildSlot();
    if (!child) {
        errno = EAGAIN;
        return NULL;
    }

    if (!psa) {
        sa.nLength              = sizeof (SECURITY_ATTRIBUTES);
        sa.lpSecurityDescriptor = NULL;
        sa.bInheritHandle       = TRUE;
        psa = &sa;
    }

    memset(&aStartupInfo, 0, sizeof(aStartupInfo));
    memset(&aProcessInformation, 0, sizeof(aProcessInformation));
    aStartupInfo.cb = sizeof(aStartupInfo);
    aStartupInfo.dwFlags = STARTF_USESTDHANDLES;
    if (hInput) {
        aStartupInfo.hStdInput  = hInput;
    }
    else {
        aStartupInfo.hStdInput  = GetStdHandle(STD_INPUT_HANDLE);
    }
    if (hOutput) {
        aStartupInfo.hStdOutput = hOutput;
    }
    else {
        aStartupInfo.hStdOutput = GetStdHandle(STD_OUTPUT_HANDLE);
    }
    if (hError) {
        aStartupInfo.hStdError = hError;
    }
    else {
        aStartupInfo.hStdError = GetStdHandle(STD_ERROR_HANDLE);
    }

    dwCreationFlags |= NORMAL_PRIORITY_CLASS;

    if (lstrlenW(cmd) > 32767) {
        child->pid = 0;         /* release the slot */
        errno = E2BIG;
        return NULL;
    }

    RUBY_CRITICAL({
        fRet = CreateProcessW(prog, (WCHAR *)cmd, psa, psa,
                              psa->bInheritHandle, dwCreationFlags, NULL, NULL,
                              &aStartupInfo, &aProcessInformation);
        errno = map_errno(GetLastError());
    });

    if (!fRet) {
        child->pid = 0;         /* release the slot */
        return NULL;
    }

    CloseHandle(aProcessInformation.hThread);

    child->hProcess = aProcessInformation.hProcess;
    child->pid = (rb_pid_t)aProcessInformation.dwProcessId;

    if (!IsWinNT()) {
        /* On Win9x, make pid positive similarly to cygwin and perl */
        child->pid = -child->pid;
    }

    return child;
}

static int
is_batch(const char *cmd)
{
    int len = strlen(cmd);
    if (len <= 4) return 0;
    cmd += len - 4;
    if (*cmd++ != '.') return 0;
    if (strcasecmp(cmd, "bat") == 0) return 1;
    if (strcasecmp(cmd, "cmd") == 0) return 1;
    return 0;
}

static UINT filecp(void);
static WCHAR *mbstr_to_wstr(UINT, const char *, int, long *);
static char *wstr_to_mbstr(UINT, const WCHAR *, int, long *);
#define acp_to_wstr(str, plen) mbstr_to_wstr(CP_ACP, str, -1, plen)
#define wstr_to_acp(str, plen) wstr_to_mbstr(CP_ACP, str, -1, plen)
#define filecp_to_wstr(str, plen) mbstr_to_wstr(filecp(), str, -1, plen)
#define wstr_to_filecp(str, plen) wstr_to_mbstr(filecp(), str, -1, plen)
#define utf8_to_wstr(str, plen) mbstr_to_wstr(CP_UTF8, str, -1, plen)
#define wstr_to_utf8(str, plen) wstr_to_mbstr(CP_UTF8, str, -1, plen)

rb_pid_t
rb_w32_spawn(int mode, const char *cmd, const char *prog)
{
    char fbuf[MAXPATHLEN];
    char *p = NULL;
    const char *shell = NULL;
    WCHAR *wcmd, *wshell;
    rb_pid_t ret;
    VALUE v = 0;
    VALUE v2 = 0;

    if (check_spawn_mode(mode)) return -1;

    if (prog) {
        if (!(p = dln_find_exe_r(prog, NULL, fbuf, sizeof(fbuf)))) {
            shell = prog;
        }
        else {
            shell = p;
            translate_char(p, '/', '\\');
        }
    }
    else {
        int redir = -1;
        int nt;
        while (ISSPACE(*cmd)) cmd++;
        if ((shell = getenv("RUBYSHELL")) && (redir = has_redirection(cmd))) {
            char *tmp = ALLOCV(v, strlen(shell) + strlen(cmd) + sizeof(" -c ") + 2);
            sprintf(tmp, "%s -c \"%s\"", shell, cmd);
            cmd = tmp;
        }
        else if ((shell = getenv("COMSPEC")) &&
                 (nt = !is_command_com(shell),
                  (redir < 0 ? has_redirection(cmd) : redir) ||
                  is_internal_cmd(cmd, nt))) {
            char *tmp = ALLOCV(v, strlen(shell) + strlen(cmd) + sizeof(" /c ") + (nt ? 2 : 0));
            sprintf(tmp, nt ? "%s /c \"%s\"" : "%s /c %s", shell, cmd);
            cmd = tmp;
        }
        else {
            int len = 0, quote = (*cmd == '"') ? '"' : (*cmd == '\'') ? '\'' : 0;
            for (prog = cmd + !!quote;; prog = CharNext(prog)) {
                if (!*prog) {
                    len = prog - cmd;
                    shell = cmd;
                    break;
                }
                if ((unsigned char)*prog == quote) {
                    len = prog++ - cmd - 1;
                    STRNDUPV(p, v2, cmd + 1, len);
                    shell = p;
                    break;
                }
                if (quote) continue;
                if (ISSPACE(*prog) || strchr("<>|*?\"", *prog)) {
                    len = prog - cmd;
                    STRNDUPV(p, v2, cmd, len);
                    shell = p;
                    break;
                }
            }
            shell = dln_find_exe_r(shell, NULL, fbuf, sizeof(fbuf));
            if (!shell) {
                shell = p ? p : cmd;
            }
            else {
                len = strlen(shell);
                if (strchr(shell, ' ')) quote = -1;
                if (shell == fbuf) {
                    p = fbuf;
                }
                else if (shell != p && strchr(shell, '/')) {
                    STRNDUPV(p, v2, shell, len);
                    shell = p;
                }
                if (p) translate_char(p, '/', '\\');
                if (is_batch(shell)) {
                    int alen = strlen(prog);
                    cmd = p = ALLOCV(v, len + alen + (quote ? 2 : 0) + 1);
                    if (quote) *p++ = '"';
                    memcpy(p, shell, len);
                    p += len;
                    if (quote) *p++ = '"';
                    memcpy(p, prog, alen + 1);
                    shell = 0;
                }
            }
        }
    }

    /* assume ACP */
    wcmd = cmd ? acp_to_wstr(cmd, NULL) : NULL;
    if (v) ALLOCV_END(v);
    wshell = shell ? acp_to_wstr(shell, NULL) : NULL;
    if (v2) ALLOCV_END(v2);

    ret = child_result(CreateChild(wcmd, wshell, NULL, NULL, NULL, NULL, 0), mode);
    free(wshell);
    free(wcmd);
    return ret;
}

rb_pid_t
rb_w32_aspawn_flags(int mode, const char *prog, char *const *argv, DWORD flags)
{
    int c_switch = 0;
    size_t len;
    BOOL ntcmd = FALSE, tmpnt;
    const char *shell;
    char *cmd, fbuf[MAXPATHLEN];
    WCHAR *wcmd, *wprog;
    rb_pid_t ret;
    VALUE v = 0;

    if (check_spawn_mode(mode)) return -1;

    if (!prog) prog = argv[0];
    if ((shell = getenv("COMSPEC")) &&
        internal_cmd_match(prog, tmpnt = !is_command_com(shell))) {
        ntcmd = tmpnt;
        prog = shell;
        c_switch = 1;
    }
    else if ((cmd = dln_find_exe_r(prog, NULL, fbuf, sizeof(fbuf)))) {
        if (cmd == prog) strlcpy(cmd = fbuf, prog, sizeof(fbuf));
        translate_char(cmd, '/', '\\');
        prog = cmd;
    }
    else if (strchr(prog, '/')) {
        len = strlen(prog);
        if (len < sizeof(fbuf))
            strlcpy(cmd = fbuf, prog, sizeof(fbuf));
        else
            STRNDUPV(cmd, v, prog, len);
        translate_char(cmd, '/', '\\');
        prog = cmd;
    }
    if (c_switch || is_batch(prog)) {
        char *progs[2];
        progs[0] = (char *)prog;
        progs[1] = NULL;
        len = join_argv(NULL, progs, ntcmd);
        if (c_switch) len += 3;
        else ++argv;
        if (argv[0]) len += join_argv(NULL, argv, ntcmd);
        cmd = ALLOCV(v, len);
        join_argv(cmd, progs, ntcmd);
        if (c_switch) strlcat(cmd, " /c", len);
        if (argv[0]) join_argv(cmd + strlcat(cmd, " ", len), argv, ntcmd);
        prog = c_switch ? shell : 0;
    }
    else {
        len = join_argv(NULL, argv, FALSE);
        cmd = ALLOCV(v, len);
        join_argv(cmd, argv, FALSE);
    }

    /* assume ACP */
    wcmd = cmd ? acp_to_wstr(cmd, NULL) : NULL;
    if (v) ALLOCV_END(v);
    wprog = prog ? acp_to_wstr(prog, NULL) : NULL;

    ret = child_result(CreateChild(wcmd, wprog, NULL, NULL, NULL, NULL, flags), mode);
    free(wprog);
    free(wcmd);
    return ret;
}

rb_pid_t
rb_w32_aspawn(int mode, const char *prog, char *const *argv)
{
    return rb_w32_aspawn_flags(mode, prog, argv, 0);
}

/* License: Artistic or GPL */
typedef struct _NtCmdLineElement {
    struct _NtCmdLineElement *next;
    char *str;
    int len;
    int flags;
} NtCmdLineElement;

//
// Possible values for flags
//

#define NTGLOB   0x1    // element contains a wildcard
#define NTMALLOC 0x2    // string in element was malloc'ed
#define NTSTRING 0x4    // element contains a quoted string

static int
insert(const char *path, VALUE vinfo, void *enc)
{
    NtCmdLineElement *tmpcurr;
    NtCmdLineElement ***tail = (NtCmdLineElement ***)vinfo;

    tmpcurr = (NtCmdLineElement *)malloc(sizeof(NtCmdLineElement));
    if (!tmpcurr) return -1;
    MEMZERO(tmpcurr, NtCmdLineElement, 1);
    tmpcurr->len = strlen(path);
    tmpcurr->str = strdup(path);
    if (!tmpcurr->str) return -1;
    tmpcurr->flags |= NTMALLOC;
    **tail = tmpcurr;
    *tail = &tmpcurr->next;

    return 0;
}


static NtCmdLineElement **
cmdglob(NtCmdLineElement *patt, NtCmdLineElement **tail)
{
    char buffer[MAXPATHLEN], *buf = buffer;
    char *p;
    NtCmdLineElement **last = tail;
    int status;

    if (patt->len >= MAXPATHLEN)
        if (!(buf = malloc(patt->len + 1))) return 0;

    strlcpy(buf, patt->str, patt->len + 1);
    buf[patt->len] = '\0';
    for (p = buf; *p; p = CharNext(p))
        if (*p == '\\')
            *p = '/';
    status = ruby_brace_glob(buf, 0, insert, (VALUE)&tail);
    if (buf != buffer)
        free(buf);

    if (status || last == tail) return 0;
    if (patt->flags & NTMALLOC)
        free(patt->str);
    free(patt);
    return tail;
}

//
// Check a command string to determine if it has I/O redirection
// characters that require it to be executed by a command interpreter
//

static int
has_redirection(const char *cmd)
{
    char quote = '\0';
    const char *ptr;

    //
    // Scan the string, looking for redirection characters (< or >), pipe
    // character (|) or newline (\n) that are not in a quoted string
    //

    for (ptr = cmd; *ptr;) {
        switch (*ptr) {
          case '\'':
          case '\"':
            if (!quote)
                quote = *ptr;
            else if (quote == *ptr)
                quote = '\0';
            ptr++;
            break;

          case '>':
          case '<':
          case '|':
          case '&':
          case '\n':
            if (!quote)
                return TRUE;
            ptr++;
            break;

          case '%':
            if (*++ptr != '_' && !ISALPHA(*ptr)) break;
            while (*++ptr == '_' || ISALNUM(*ptr));
            if (*ptr++ == '%') return TRUE;
            break;

          case '\\':
            ptr++;
          default:
            ptr = CharNext(ptr);
            break;
        }
    }
    return FALSE;
}

static inline char *
skipspace(char *ptr)
{
    while (ISSPACE(*ptr))
        ptr++;
    return ptr;
}

int
rb_w32_cmdvector(const char *cmd, char ***vec)
{
    int globbing, len;
    int elements, strsz, done;
    int slashes, escape;
    char *ptr, *base, *buffer, *cmdline;
    char **vptr;
    char quote;
    NtCmdLineElement *curr, **tail;
    NtCmdLineElement *cmdhead = NULL, **cmdtail = &cmdhead;

    //
    // just return if we don't have a command line
    //

    while (ISSPACE(*cmd))
        cmd++;
    if (!*cmd) {
        *vec = NULL;
        return 0;
    }

    ptr = cmdline = strdup(cmd);

    //
    // Ok, parse the command line, building a list of CmdLineElements.
    // When we've finished, and it's an input command (meaning that it's
    // the processes argv), we'll do globing and then build the argument
    // vector.
    // The outer loop does one interation for each element seen.
    // The inner loop does one interation for each character in the element.
    //

    while (*(ptr = skipspace(ptr))) {
        base = ptr;
        quote = slashes = globbing = escape = 0;
        for (done = 0; !done && *ptr; ) {
            //
            // Switch on the current character. We only care about the
            // white-space characters, the  wild-card characters, and the
            // quote characters.
            //

            switch (*ptr) {
              case '\\':
                if (quote != '\'') slashes++;
                break;

              case ' ':
              case '\t':
              case '\n':
                //
                // if we're not in a string, then we're finished with this
                // element
                //

                if (!quote) {
                    *ptr = 0;
                    done = 1;
                }
                break;

              case '*':
              case '?':
              case '[':
              case '{':
                //
                // record the fact that this element has a wildcard character
                // N.B. Don't glob if inside a single quoted string
                //

                if (quote != '\'')
                    globbing++;
                slashes = 0;
                break;

              case '\'':
              case '\"':
                //
                // if we're already in a string, see if this is the
                // terminating close-quote. If it is, we're finished with
                // the string, but not neccessarily with the element.
                // If we're not already in a string, start one.
                //

                if (!(slashes & 1)) {
                    if (!quote)
                        quote = *ptr;
                    else if (quote == *ptr) {
                        if (quote == '"' && quote == ptr[1])
                            ptr++;
                        quote = '\0';
                    }
                }
                escape++;
                slashes = 0;
                break;

              default:
                ptr = CharNext(ptr);
                slashes = 0;
                continue;
            }
            ptr++;
        }

        //
        // when we get here, we've got a pair of pointers to the element,
        // base and ptr. Base points to the start of the element while ptr
        // points to the character following the element.
        //

        len = ptr - base;
        if (done) --len;

        //
        // if it's an input vector element and it's enclosed by quotes,
        // we can remove them.
        //

        if (escape) {
            char *p = base, c;
            slashes = quote = 0;
            while (p < base + len) {
                switch (c = *p) {
                  case '\\':
                    p++;
                    if (quote != '\'') slashes++;
                    break;

                  case '\'':
                  case '"':
                    if (!(slashes & 1) && quote && quote != c) {
                        p++;
                        slashes = 0;
                        break;
                    }
                    memcpy(p - ((slashes + 1) >> 1), p + (~slashes & 1),
                           base + len - p);
                    len -= ((slashes + 1) >> 1) + (~slashes & 1);
                    p -= (slashes + 1) >> 1;
                    if (!(slashes & 1)) {
                        if (quote) {
                            if (quote == '"' && quote == *p)
                                p++;
                            quote = '\0';
                        }
                        else
                            quote = c;
                    }
                    else
                        p++;
                    slashes = 0;
                    break;

                  default:
                    p = CharNext(p);
                    slashes = 0;
                    break;
                }
            }
        }

        curr = (NtCmdLineElement *)calloc(sizeof(NtCmdLineElement), 1);
        if (!curr) goto do_nothing;
        curr->str = base;
        curr->len = len;

        if (globbing && (tail = cmdglob(curr, cmdtail))) {
            cmdtail = tail;
        }
        else {
            *cmdtail = curr;
            cmdtail = &curr->next;
        }
    }

    //
    // Almost done!
    // Count up the elements, then allocate space for a vector of pointers
    // (argv) and a string table for the elements.
    //

    for (elements = 0, strsz = 0, curr = cmdhead; curr; curr = curr->next) {
        elements++;
        strsz += (curr->len + 1);
    }

    len = (elements+1)*sizeof(char *) + strsz;
    buffer = (char *)malloc(len);
    if (!buffer) {
      do_nothing:
        while (curr = cmdhead) {
            cmdhead = curr->next;
            if (curr->flags & NTMALLOC) free(curr->str);
            free(curr);
        }
        free(cmdline);
        for (vptr = *vec; *vptr; ++vptr);
        return vptr - *vec;
    }

    //
    // make vptr point to the start of the buffer
    // and ptr point to the area we'll consider the string table.
    //
    //   buffer (*vec)
    //   |
    //   V       ^---------------------V
    //   +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    //   |   |       | ....  | NULL  |   | ..... |\0 |   | ..... |\0 |...
    //   +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    //   |-  elements+1             -| ^ 1st element   ^ 2nd element

    vptr = (char **) buffer;

    ptr = buffer + (elements+1) * sizeof(char *);

    while (curr = cmdhead) {
        strlcpy(ptr, curr->str, curr->len + 1);
        *vptr++ = ptr;
        ptr += curr->len + 1;
        cmdhead = curr->next;
        if (curr->flags & NTMALLOC) free(curr->str);
        free(curr);
    }
    *vptr = 0;

    *vec = (char **) buffer;
    free(cmdline);
    return elements;
}

//
// UNIX compatible directory access functions for NT
//

#define PATHLEN 1024

//
// The idea here is to read all the directory names into a string table
// (separated by nulls) and when one of the other dir functions is called
// return the pointer to the current file name.
//

#define GetBit(bits, i) ((bits)[(i) / CHAR_BIT] &  (1 << (i) % CHAR_BIT))
#define SetBit(bits, i) ((bits)[(i) / CHAR_BIT] |= (1 << (i) % CHAR_BIT))

#define BitOfIsDir(n) ((n) * 2)
#define BitOfIsRep(n) ((n) * 2 + 1)
#define DIRENT_PER_CHAR (CHAR_BIT / 2)

static HANDLE
open_dir_handle(const WCHAR *filename, WIN32_FIND_DATAW *fd)
{
    HANDLE fh;
    static const WCHAR wildcard[] = L"\\*";
    WCHAR *scanname;
    WCHAR *p;
    int len;
    VALUE v;

    //
    // Create the search pattern
    //
    len = lstrlenW(filename);
    scanname = ALLOCV_N(WCHAR, v, len + sizeof(wildcard) / sizeof(WCHAR));
    lstrcpyW(scanname, filename);
    p = CharPrevW(scanname, scanname + len);
    if (*p == L'/' || *p == L'\\' || *p == L':')
        lstrcatW(scanname, wildcard + 1);
    else
        lstrcatW(scanname, wildcard);

    //
    // do the FindFirstFile call
    //
    fh = FindFirstFileW(scanname, fd);
    ALLOCV_END(v);
    if (fh == INVALID_HANDLE_VALUE) {
        errno = map_errno(GetLastError());
    }
    return fh;
}

static DIR *
opendir_internal(WCHAR *wpath, const char *filename)
{
    struct stati64 sbuf;
    WIN32_FIND_DATAW fd;
    HANDLE fh;
    DIR *p;
    long len;
    long idx;
    WCHAR *tmpW;
    char *tmp;

    //
    // check to see if we've got a directory
    //
    if (wstati64(wpath, &sbuf) < 0) {
        return NULL;
    }
    if (!(sbuf.st_mode & S_IFDIR) &&
        (!ISALPHA(filename[0]) || filename[1] != ':' || filename[2] != '\0' ||
         ((1 << ((filename[0] & 0x5f) - 'A')) & GetLogicalDrives()) == 0)) {
        errno = ENOTDIR;
        return NULL;
    }
    fh = open_dir_handle(wpath, &fd);
    if (fh == INVALID_HANDLE_VALUE) {
        return NULL;
    }

    //
    // Get us a DIR structure
    //
    p = calloc(sizeof(DIR), 1);
    if (p == NULL)
        return NULL;

    idx = 0;

    //
    // loop finding all the files that match the wildcard
    // (which should be all of them in this directory!).
    // the variable idx should point one past the null terminator
    // of the previous string found.
    //
    do {
        len = lstrlenW(fd.cFileName) + 1;

        //
        // bump the string table size by enough for the
        // new name and it's null terminator
        //
        tmpW = realloc(p->start, (idx + len) * sizeof(WCHAR));
        if (!tmpW) {
          error:
            rb_w32_closedir(p);
            FindClose(fh);
            errno = ENOMEM;
            return NULL;
        }

        p->start = tmpW;
        memcpy(&p->start[idx], fd.cFileName, len * sizeof(WCHAR));

        if (p->nfiles % DIRENT_PER_CHAR == 0) {
            tmp = realloc(p->bits, p->nfiles / DIRENT_PER_CHAR + 1);
            if (!tmp)
                goto error;
            p->bits = tmp;
            p->bits[p->nfiles / DIRENT_PER_CHAR] = 0;
        }
        if (fd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
            SetBit(p->bits, BitOfIsDir(p->nfiles));
        if (fd.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)
            SetBit(p->bits, BitOfIsRep(p->nfiles));

        p->nfiles++;
        idx += len;
    } while (FindNextFileW(fh, &fd));
    FindClose(fh);
    p->size = idx;
    p->curr = p->start;
    return p;
}

static inline UINT
filecp(void)
{
    UINT cp = AreFileApisANSI() ? CP_ACP : CP_OEMCP;
    return cp;
}

static char *
wstr_to_mbstr(UINT cp, const WCHAR *wstr, int clen, long *plen)
{
    char *ptr;
    int len = WideCharToMultiByte(cp, 0, wstr, clen, NULL, 0, NULL, NULL) - 1;
    if (!(ptr = malloc(len + 1))) return 0;
    WideCharToMultiByte(cp, 0, wstr, clen, ptr, len + 1, NULL, NULL);
    if (plen) *plen = len;
    return ptr;
}

static WCHAR *
mbstr_to_wstr(UINT cp, const char *str, int clen, long *plen)
{
    WCHAR *ptr;
    int len = MultiByteToWideChar(cp, 0, str, clen, NULL, 0) - 1;
    if (!(ptr = malloc(sizeof(WCHAR) * (len + 1)))) return 0;
    MultiByteToWideChar(cp, 0, str, clen, ptr, len + 1);
    if (plen) *plen = len;
    return ptr;
}

DIR *
rb_w32_opendir(const char *filename)
{
    DIR *ret;
    WCHAR *wpath = filecp_to_wstr(filename, NULL);
    if (!wpath)
        return NULL;
    ret = opendir_internal(wpath, filename);
    free(wpath);
    return ret;
}

DIR *
rb_w32_uopendir(const char *filename)
{
    DIR *ret;
    WCHAR *wpath = utf8_to_wstr(filename, NULL);
    if (!wpath)
        return NULL;
    ret = opendir_internal(wpath, filename);
    free(wpath);
    return ret;
}

//
// Move to next entry
//

static void
move_to_next_entry(DIR *dirp)
{
    if (dirp->curr) {
        dirp->loc++;
        dirp->curr += lstrlenW(dirp->curr) + 1;
        if (dirp->curr >= (dirp->start + dirp->size)) {
            dirp->curr = NULL;
        }
    }
}

//
// Readdir just returns the current string pointer and bumps the
// string pointer to the next entry.
//
static BOOL
win32_direct_conv(const WCHAR *file, struct direct *entry, rb_encoding *dummy)
{
    if (!(entry->d_name = wstr_to_filecp(file, &entry->d_namlen)))
        return FALSE;
    return TRUE;
}

VALUE
rb_w32_conv_from_wchar(const WCHAR *wstr, rb_encoding *enc)
{
    static rb_encoding *utf16 = (rb_encoding *)-1;
    VALUE src;

    if (utf16 == (rb_encoding *)-1) {
        utf16 = rb_enc_find("UTF-16LE");
        if (utf16 == rb_ascii8bit_encoding())
            utf16 = NULL;
    }
    if (!utf16)
        /* maybe miniruby */
        return Qnil;

    src = rb_enc_str_new((char *)wstr, lstrlenW(wstr) * sizeof(WCHAR), utf16);
    return rb_str_encode(src, rb_enc_from_encoding(enc), ECONV_UNDEF_REPLACE, Qnil);
}

char *
rb_w32_conv_from_wstr(const WCHAR *wstr, long *lenp, rb_encoding *enc)
{
    VALUE str = rb_w32_conv_from_wchar(wstr, enc);
    long len;
    char *ptr;

    if (NIL_P(str)) return wstr_to_filecp(wstr, lenp);
    *lenp = len = RSTRING_LEN(str);
    memcpy(ptr = malloc(len + 1), RSTRING_PTR(str), len);
    ptr[len] = '\0';
    return ptr;
}

static BOOL
ruby_direct_conv(const WCHAR *file, struct direct *entry, rb_encoding *enc)
{
    if (!(entry->d_name = rb_w32_conv_from_wstr(file, &entry->d_namlen, enc)))
        return FALSE;
    return TRUE;
}

static struct direct *
readdir_internal(DIR *dirp, BOOL (*conv)(const WCHAR *, struct direct *, rb_encoding *), rb_encoding *enc)
{
    static int dummy = 0;

    if (dirp->curr) {

        //
        // first set up the structure to return
        //
        if (dirp->dirstr.d_name)
            free(dirp->dirstr.d_name);
        conv(dirp->curr, &dirp->dirstr, enc);

        //
        // Fake inode
        //
        dirp->dirstr.d_ino = dummy++;

        //
        // Attributes
        //
        dirp->dirstr.d_isdir = GetBit(dirp->bits, BitOfIsDir(dirp->loc));
        dirp->dirstr.d_isrep = GetBit(dirp->bits, BitOfIsRep(dirp->loc));

        //
        // Now set up for the next call to readdir
        //

        move_to_next_entry(dirp);

        return &(dirp->dirstr);

    }
    else
        return NULL;
}

struct direct  *
rb_w32_readdir(DIR *dirp)
{
    return readdir_internal(dirp, win32_direct_conv, NULL);
}

struct direct  *
rb_w32_readdir_with_enc(DIR *dirp, rb_encoding *enc)
{
    if (enc == rb_ascii8bit_encoding())
        return readdir_internal(dirp, win32_direct_conv, NULL);
    else
        return readdir_internal(dirp, ruby_direct_conv, enc);
}

//
// Telldir returns the current string pointer position
//

long
rb_w32_telldir(DIR *dirp)
{
    return dirp->loc;
}

//
// Seekdir moves the string pointer to a previously saved position
// (Saved by telldir).

void
rb_w32_seekdir(DIR *dirp, long loc)
{
    if (dirp->loc > loc) rb_w32_rewinddir(dirp);

    while (dirp->curr && dirp->loc < loc) {
        move_to_next_entry(dirp);
    }
}

//
// Rewinddir resets the string pointer to the start
//

void
rb_w32_rewinddir(DIR *dirp)
{
    dirp->curr = dirp->start;
    dirp->loc = 0;
}

//
// This just free's the memory allocated by opendir
//

void
rb_w32_closedir(DIR *dirp)
{
    if (dirp) {
        if (dirp->dirstr.d_name)
            free(dirp->dirstr.d_name);
        if (dirp->start)
            free(dirp->start);
        if (dirp->bits)
            free(dirp->bits);
        free(dirp);
    }
}

#if (defined _MT || defined __MSVCRT__) && !defined __BORLANDC__
#define MSVCRT_THREADS
#endif
#ifdef MSVCRT_THREADS
# define MTHREAD_ONLY(x) x
# define STHREAD_ONLY(x)
#elif defined(__BORLANDC__)
# define MTHREAD_ONLY(x)
# define STHREAD_ONLY(x)
#else
# define MTHREAD_ONLY(x)
# define STHREAD_ONLY(x) x
#endif

typedef struct  {
    intptr_t osfhnd;    /* underlying OS file HANDLE */
    char osfile;        /* attributes of file (e.g., open in text mode?) */
    char pipech;        /* one char buffer for handles opened on pipes */
#ifdef MSVCRT_THREADS
    int lockinitflag;
    CRITICAL_SECTION lock;
#endif
#if RT_VER >= 80
    char textmode;
    char pipech2[2];
#endif
}       ioinfo;

#if !defined _CRTIMP || defined __MINGW32__
#undef _CRTIMP
#define _CRTIMP __declspec(dllimport)
#endif

#if !defined(__BORLANDC__)
EXTERN_C _CRTIMP ioinfo * __pioinfo[];

#define IOINFO_L2E                      5
#define IOINFO_ARRAY_ELTS       (1 << IOINFO_L2E)
#define _pioinfo(i)     ((ioinfo*)((char*)(__pioinfo[i >> IOINFO_L2E]) + (i & (IOINFO_ARRAY_ELTS - 1)) * (sizeof(ioinfo) + pioinfo_extra)))
#define _osfhnd(i)  (_pioinfo(i)->osfhnd)
#define _osfile(i)  (_pioinfo(i)->osfile)
#define _pipech(i)  (_pioinfo(i)->pipech)

#if RT_VER >= 80
static size_t pioinfo_extra = 0;        /* workaround for VC++8 SP1 */

static void
set_pioinfo_extra(void)
{
    int fd;

    fd = _open("NUL", O_RDONLY);
    for (pioinfo_extra = 0; pioinfo_extra <= 64; pioinfo_extra += sizeof(void *)) {
        if (_osfhnd(fd) == _get_osfhandle(fd)) {
            break;
        }
    }
    _close(fd);

    if (pioinfo_extra > 64) {
        /* not found, maybe something wrong... */
        pioinfo_extra = 0;
    }
}
#else
#define pioinfo_extra 0
#endif

#define _set_osfhnd(fh, osfh) (void)(_osfhnd(fh) = osfh)
#define _set_osflags(fh, flags) (_osfile(fh) = (flags))

#define FOPEN                   0x01    /* file handle open */
#define FEOFLAG                 0x02    /* end of file has been encountered */
#define FPIPE                   0x08    /* file handle refers to a pipe */
#define FNOINHERIT              0x10    /* file handle opened O_NOINHERIT */
#define FAPPEND                 0x20    /* file handle opened O_APPEND */
#define FDEV                    0x40    /* file handle refers to device */
#define FTEXT                   0x80    /* file handle is in text mode */

static int is_socket(SOCKET);
static int is_console(SOCKET);

int
rb_w32_io_cancelable_p(int fd)
{
    return cancel_io != NULL && (is_socket(TO_SOCKET(fd)) || !is_console(TO_SOCKET(fd)));
}

static int
rb_w32_open_osfhandle(intptr_t osfhandle, int flags)
{
    int fh;
    char fileflags;             /* _osfile flags */
    HANDLE hF;

    /* copy relevant flags from second parameter */
    fileflags = FDEV;

    if (flags & O_APPEND)
        fileflags |= FAPPEND;

    if (flags & O_TEXT)
        fileflags |= FTEXT;

    if (flags & O_NOINHERIT)
        fileflags |= FNOINHERIT;

    /* attempt to allocate a C Runtime file handle */
    hF = CreateFile("NUL", 0, 0, NULL, OPEN_ALWAYS, 0, NULL);
    fh = _open_osfhandle((intptr_t)hF, 0);
    CloseHandle(hF);
    if (fh == -1) {
        errno = EMFILE;         /* too many open files */
        _doserrno = 0L;         /* not an OS error */
    }
    else {

        MTHREAD_ONLY(EnterCriticalSection(&(_pioinfo(fh)->lock)));
        /* the file is open. now, set the info in _osfhnd array */
        _set_osfhnd(fh, osfhandle);

        fileflags |= FOPEN;             /* mark as open */

        _set_osflags(fh, fileflags); /* set osfile entry */
        MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fh)->lock));
    }
    return fh;                  /* return handle */
}

static void
init_stdhandle(void)
{
    int nullfd = -1;
    int keep = 0;
#define open_null(fd)                                           \
    (((nullfd < 0) ?                                            \
      (nullfd = open("NUL", O_RDWR)) : 0),              \
     ((nullfd == (fd)) ? (keep = 1) : dup2(nullfd, fd)),        \
     (fd))

    if (fileno(stdin) < 0) {
        stdin->_file = open_null(0);
    }
    else {
        setmode(fileno(stdin), O_BINARY);
    }
    if (fileno(stdout) < 0) {
        stdout->_file = open_null(1);
    }
    if (fileno(stderr) < 0) {
        stderr->_file = open_null(2);
    }
    if (nullfd >= 0 && !keep) close(nullfd);
    setvbuf(stderr, NULL, _IONBF, 0);
}
#else

#define _set_osfhnd(fh, osfh) (void)((fh), (osfh))
#define _set_osflags(fh, flags) (void)((fh), (flags))

static void
init_stdhandle(void)
{
}
#endif

#ifdef __BORLANDC__
static int
rb_w32_open_osfhandle(intptr_t osfhandle, int flags)
{
    int fd = _open_osfhandle(osfhandle, flags);
    if (fd == -1) {
        errno = EMFILE;         /* too many open files */
        _doserrno = 0L;         /* not an OS error */
    }
    return fd;
}
#endif

#undef getsockopt

static int
is_socket(SOCKET sock)
{
    if (st_lookup(socklist, (st_data_t)sock, NULL))
        return TRUE;
    else
        return FALSE;
}

int
rb_w32_is_socket(int fd)
{
    return is_socket(TO_SOCKET(fd));
}

//
// Since the errors returned by the socket error function
// WSAGetLastError() are not known by the library routine strerror
// we have to roll our own.
//

#undef strerror

char *
rb_w32_strerror(int e)
{
    static char buffer[512];
    DWORD source = 0;
    char *p;

#if defined __BORLANDC__ && defined ENOTEMPTY // _sys_errlist is broken
    switch (e) {
      case ENAMETOOLONG:
        return "Filename too long";
      case ENOTEMPTY:
        return "Directory not empty";
    }
#endif

    if (e < 0 || e > sys_nerr) {
        if (e < 0)
            e = GetLastError();
#if WSAEWOULDBLOCK != EWOULDBLOCK
        else if (e >= EADDRINUSE && e <= EWOULDBLOCK) {
            static int s = -1;
            int i;
            if (s < 0)
                for (s = 0; s < (int)(sizeof(errmap)/sizeof(*errmap)); s++)
                    if (errmap[s].winerr == WSAEWOULDBLOCK)
                        break;
            for (i = s; i < (int)(sizeof(errmap)/sizeof(*errmap)); i++)
                if (errmap[i].err == e) {
                    e = errmap[i].winerr;
                    break;
                }
        }
#endif
        if (FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
                          FORMAT_MESSAGE_IGNORE_INSERTS, &source, e,
                          MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US),
                          buffer, sizeof(buffer), NULL) == 0 &&
            FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
                          FORMAT_MESSAGE_IGNORE_INSERTS, &source, e, 0,
                          buffer, sizeof(buffer), NULL) == 0)
            strlcpy(buffer, "Unknown Error", sizeof(buffer));
    }
    else
        strlcpy(buffer, strerror(e), sizeof(buffer));

    p = buffer;
    while ((p = strpbrk(p, "\r\n")) != NULL) {
        memmove(p, p + 1, strlen(p));
    }
    return buffer;
}

//
// various stubs
//


// Ownership
//
// Just pretend that everyone is a superuser. NT will let us know if
// we don't really have permission to do something.
//

#define ROOT_UID        0
#define ROOT_GID        0

rb_uid_t
getuid(void)
{
        return ROOT_UID;
}

rb_uid_t
geteuid(void)
{
        return ROOT_UID;
}

rb_gid_t
getgid(void)
{
        return ROOT_GID;
}

rb_gid_t
getegid(void)
{
    return ROOT_GID;
}

int
setuid(rb_uid_t uid)
{
    return (uid == ROOT_UID ? 0 : -1);
}

int
setgid(rb_gid_t gid)
{
    return (gid == ROOT_GID ? 0 : -1);
}

//
// File system stuff
//

int
ioctl(int i, int u, ...)
{
    errno = EINVAL;
    return -1;
}

void
rb_w32_fdset(int fd, fd_set *set)
{
    FD_SET(fd, set);
}

#undef FD_CLR

void
rb_w32_fdclr(int fd, fd_set *set)
{
    unsigned int i;
    SOCKET s = TO_SOCKET(fd);

    for (i = 0; i < set->fd_count; i++) {
        if (set->fd_array[i] == s) {
            memmove(&set->fd_array[i], &set->fd_array[i+1],
                    sizeof(set->fd_array[0]) * (--set->fd_count - i));
            break;
        }
    }
}

#undef FD_ISSET

int
rb_w32_fdisset(int fd, fd_set *set)
{
    int ret;
    SOCKET s = TO_SOCKET(fd);
    if (s == (SOCKET)INVALID_HANDLE_VALUE)
        return 0;
    RUBY_CRITICAL(ret = __WSAFDIsSet(s, set));
    return ret;
}

void
rb_w32_fd_copy(rb_fdset_t *dst, const fd_set *src, int max)
{
    max = min(src->fd_count, (UINT)max);
    if ((UINT)dst->capa < (UINT)max) {
        dst->capa = (src->fd_count / FD_SETSIZE + 1) * FD_SETSIZE;
        dst->fdset = xrealloc(dst->fdset, sizeof(unsigned int) + sizeof(SOCKET) * dst->capa);
    }

    memcpy(dst->fdset->fd_array, src->fd_array,
           max * sizeof(src->fd_array[0]));
    dst->fdset->fd_count = src->fd_count;
}

/* License: Ruby's */
void
rb_w32_fd_dup(rb_fdset_t *dst, const rb_fdset_t *src)
{
    if ((UINT)dst->capa < src->fdset->fd_count) {
        dst->capa = (src->fdset->fd_count / FD_SETSIZE + 1) * FD_SETSIZE;
        dst->fdset = xrealloc(dst->fdset, sizeof(unsigned int) + sizeof(SOCKET) * dst->capa);
    }

    memcpy(dst->fdset->fd_array, src->fdset->fd_array,
           src->fdset->fd_count * sizeof(src->fdset->fd_array[0]));
    dst->fdset->fd_count = src->fdset->fd_count;
}

//
// Networking trampolines
// These are used to avoid socket startup/shutdown overhead in case
// the socket routines aren't used.
//

#undef select

static int
extract_fd(rb_fdset_t *dst, fd_set *src, int (*func)(SOCKET))
{
    unsigned int s = 0;
    unsigned int m = 0;
    if (!src) return 0;

    while (s < src->fd_count) {
        SOCKET fd = src->fd_array[s];

        if (!func || (*func)(fd)) {
            if (dst) { /* move it to dst */
                unsigned int d;

                for (d = 0; d < dst->fdset->fd_count; d++) {
                    if (dst->fdset->fd_array[d] == fd)
                        break;
                }
                if (d == dst->fdset->fd_count) {
                    if ((int)dst->fdset->fd_count >= dst->capa) {
                        dst->capa = (dst->fdset->fd_count / FD_SETSIZE + 1) * FD_SETSIZE;
                        dst->fdset = xrealloc(dst->fdset, sizeof(unsigned int) + sizeof(SOCKET) * dst->capa);
                    }
                    dst->fdset->fd_array[dst->fdset->fd_count++] = fd;
                }
                memmove(
                    &src->fd_array[s],
                    &src->fd_array[s+1],
                    sizeof(src->fd_array[0]) * (--src->fd_count - s));
            }
            else {
                m++;
                s++;
            }
        }
        else s++;
    }

    return dst ? dst->fdset->fd_count : m;
}

static int
copy_fd(fd_set *dst, fd_set *src)
{
    unsigned int s;
    if (!src || !dst) return 0;

    for (s = 0; s < src->fd_count; ++s) {
        SOCKET fd = src->fd_array[s];
        unsigned int d;
        for (d = 0; d < dst->fd_count; ++d) {
            if (dst->fd_array[d] == fd)
                break;
        }
        if (d == dst->fd_count && d < FD_SETSIZE) {
            dst->fd_array[dst->fd_count++] = fd;
        }
    }

    return dst->fd_count;
}

static int
is_not_socket(SOCKET sock)
{
    return !is_socket(sock);
}

static int
is_pipe(SOCKET sock) /* DONT call this for SOCKET! it clains it is PIPE. */
{
    int ret;

    RUBY_CRITICAL({
        ret = (GetFileType((HANDLE)sock) == FILE_TYPE_PIPE);
    });

    return ret;
}

static int
is_readable_pipe(SOCKET sock) /* call this for pipe only */
{
    int ret;
    DWORD n = 0;

    RUBY_CRITICAL(
        if (PeekNamedPipe((HANDLE)sock, NULL, 0, NULL, &n, NULL)) {
            ret = (n > 0);
        }
        else {
            ret = (GetLastError() == ERROR_BROKEN_PIPE); /* pipe was closed */
        }
    );

    return ret;
}

static int
is_console(SOCKET sock) /* DONT call this for SOCKET! */
{
    int ret;
    DWORD n = 0;
    INPUT_RECORD ir;

    RUBY_CRITICAL(
        ret = (PeekConsoleInput((HANDLE)sock, &ir, 1, &n))
    );

    return ret;
}

static int
is_readable_console(SOCKET sock) /* call this for console only */
{
    int ret = 0;
    DWORD n = 0;
    INPUT_RECORD ir;

    RUBY_CRITICAL(
        if (PeekConsoleInput((HANDLE)sock, &ir, 1, &n) && n > 0) {
            if (ir.EventType == KEY_EVENT && ir.Event.KeyEvent.bKeyDown &&
                ir.Event.KeyEvent.uChar.AsciiChar) {
                ret = 1;
            }
            else {
                ReadConsoleInput((HANDLE)sock, &ir, 1, &n);
            }
        }
    );

    return ret;
}

static int
is_invalid_handle(SOCKET sock)
{
    return (HANDLE)sock == INVALID_HANDLE_VALUE;
}

static int
do_select(int nfds, fd_set *rd, fd_set *wr, fd_set *ex,
            struct timeval *timeout)
{
    int r = 0;

    if (nfds == 0) {
        if (timeout)
            rb_w32_sleep(timeout->tv_sec * 1000 + timeout->tv_usec / 1000);
        else
            rb_w32_sleep(INFINITE);
    }
    else {
        RUBY_CRITICAL(
            EnterCriticalSection(&select_mutex);
            r = select(nfds, rd, wr, ex, timeout);
            LeaveCriticalSection(&select_mutex);
            if (r == SOCKET_ERROR) {
                errno = map_errno(WSAGetLastError());
                r = -1;
            }
        );
    }

    return r;
}

/*
 * rest -= wait
 * return 0 if rest is smaller than wait.
 */
int
rb_w32_time_subtract(struct timeval *rest, const struct timeval *wait)
{
    if (rest->tv_sec < wait->tv_sec) {
        return 0;
    }
    while (rest->tv_usec < wait->tv_usec) {
        if (rest->tv_sec <= wait->tv_sec) {
            return 0;
        }
        rest->tv_sec -= 1;
        rest->tv_usec += 1000 * 1000;
    }
    rest->tv_sec -= wait->tv_sec;
    rest->tv_usec -= wait->tv_usec;
    return rest->tv_sec != 0 || rest->tv_usec != 0;
}

static inline int
compare(const struct timeval *t1, const struct timeval *t2)
{
    if (t1->tv_sec < t2->tv_sec)
        return -1;
    if (t1->tv_sec > t2->tv_sec)
        return 1;
    if (t1->tv_usec < t2->tv_usec)
        return -1;
    if (t1->tv_usec > t2->tv_usec)
        return 1;
    return 0;
}

#undef Sleep

int rb_w32_check_interrupt(void *);     /* @internal */

/* @internal */
int
rb_w32_select_with_thread(int nfds, fd_set *rd, fd_set *wr, fd_set *ex,
                          struct timeval *timeout, void *th)
{
    int r;
    rb_fdset_t pipe_rd;
    rb_fdset_t cons_rd;
    rb_fdset_t else_rd;
    rb_fdset_t else_wr;
    rb_fdset_t except;
    int nonsock = 0;
    struct timeval limit = {0, 0};

    if (nfds < 0 || (timeout && (timeout->tv_sec < 0 || timeout->tv_usec < 0))) {
        errno = EINVAL;
        return -1;
    }

    if (timeout) {
        if (timeout->tv_sec < 0 ||
            timeout->tv_usec < 0 ||
            timeout->tv_usec >= 1000000) {
            errno = EINVAL;
            return -1;
        }
        gettimeofday(&limit, NULL);
        limit.tv_sec += timeout->tv_sec;
        limit.tv_usec += timeout->tv_usec;
        if (limit.tv_usec >= 1000000) {
            limit.tv_usec -= 1000000;
            limit.tv_sec++;
        }
    }

    if (!NtSocketsInitialized) {
        StartSockets();
    }

    // assume else_{rd,wr} (other than socket, pipe reader, console reader)
    // are always readable/writable. but this implementation still has
    // problem. if pipe's buffer is full, writing to pipe will block
    // until some data is read from pipe. but ruby is single threaded system,
    // so whole system will be blocked forever.

    rb_fd_init(&else_rd);
    nonsock += extract_fd(&else_rd, rd, is_not_socket);

    rb_fd_init(&else_wr);
    nonsock += extract_fd(&else_wr, wr, is_not_socket);

    // check invalid handles
    if (extract_fd(NULL, else_rd.fdset, is_invalid_handle) > 0 ||
        extract_fd(NULL, else_wr.fdset, is_invalid_handle) > 0) {
        rb_fd_term(&else_wr);
        rb_fd_term(&else_rd);
        errno = EBADF;
        return -1;
    }

    rb_fd_init(&pipe_rd);
    extract_fd(&pipe_rd, else_rd.fdset, is_pipe); // should not call is_pipe for socket

    rb_fd_init(&cons_rd);
    extract_fd(&cons_rd, else_rd.fdset, is_console); // ditto

    rb_fd_init(&except);
    extract_fd(&except, ex, is_not_socket); // drop only

    r = 0;
    if (rd && (int)rd->fd_count > r) r = (int)rd->fd_count;
    if (wr && (int)wr->fd_count > r) r = (int)wr->fd_count;
    if (ex && (int)ex->fd_count > r) r = (int)ex->fd_count;
    if (nfds > r) nfds = r;

    {
        struct timeval rest;
        struct timeval wait;
        struct timeval zero;
        wait.tv_sec = 0; wait.tv_usec = 10 * 1000; // 10ms
        zero.tv_sec = 0; zero.tv_usec = 0;         //  0ms
        for (;;) {
            if (th && rb_w32_check_interrupt(th) != WAIT_TIMEOUT) {
                r = -1;
                break;
            }
            if (nonsock) {
                // modifying {else,pipe,cons}_rd is safe because
                // if they are modified, function returns immediately.
                extract_fd(&else_rd, pipe_rd.fdset, is_readable_pipe);
                extract_fd(&else_rd, cons_rd.fdset, is_readable_console);
            }

            if (else_rd.fdset->fd_count || else_wr.fdset->fd_count) {
                r = do_select(nfds, rd, wr, ex, &zero); // polling
                if (r < 0) break; // XXX: should I ignore error and return signaled handles?
                r += copy_fd(rd, else_rd.fdset);
                r += copy_fd(wr, else_wr.fdset);
                if (ex)
                    r += ex->fd_count;
                break;
            }
            else {
                struct timeval *dowait = &wait;

                fd_set orig_rd;
                fd_set orig_wr;
                fd_set orig_ex;

                FD_ZERO(&orig_rd);
                FD_ZERO(&orig_wr);
                FD_ZERO(&orig_ex);

                if (rd) copy_fd(&orig_rd, rd);
                if (wr) copy_fd(&orig_wr, wr);
                if (ex) copy_fd(&orig_ex, ex);
                r = do_select(nfds, rd, wr, ex, &zero); // polling
                if (r != 0) break; // signaled or error
                if (rd) copy_fd(rd, &orig_rd);
                if (wr) copy_fd(wr, &orig_wr);
                if (ex) copy_fd(ex, &orig_ex);

                if (timeout) {
                    struct timeval now;
                    gettimeofday(&now, NULL);
                    rest = limit;
                    if (!rb_w32_time_subtract(&rest, &now)) break;
                    if (compare(&rest, &wait) < 0) dowait = &rest;
                }
                Sleep(dowait->tv_sec * 1000 + dowait->tv_usec / 1000);
            }
        }
    }

    rb_fd_term(&except);
    rb_fd_term(&cons_rd);
    rb_fd_term(&pipe_rd);
    rb_fd_term(&else_wr);
    rb_fd_term(&else_rd);

    return r;
}

int WSAAPI
rb_w32_select(int nfds, fd_set *rd, fd_set *wr, fd_set *ex,
              struct timeval *timeout)
{
    return rb_w32_select_with_thread(nfds, rd, wr, ex, timeout, 0);
}

static FARPROC
get_wsa_extension_function(SOCKET s, GUID *guid)
{
    DWORD dmy;
    FARPROC ptr = NULL;

    WSAIoctl(s, SIO_GET_EXTENSION_FUNCTION_POINTER, guid, sizeof(*guid),
             &ptr, sizeof(ptr), &dmy, NULL, NULL);
    if (!ptr)
        errno = ENOSYS;
    return ptr;
}

#undef accept

int WSAAPI
rb_w32_accept(int s, struct sockaddr *addr, int *addrlen)
{
    SOCKET r;
    int fd;

    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        HANDLE h = CreateFile("NUL", 0, 0, NULL, OPEN_ALWAYS, 0, NULL);
        fd = rb_w32_open_osfhandle((intptr_t)h, O_RDWR|O_BINARY|O_NOINHERIT);
        if (fd != -1) {
            r = accept(TO_SOCKET(s), addr, addrlen);
            if (r != INVALID_SOCKET) {
                MTHREAD_ONLY(EnterCriticalSection(&(_pioinfo(fd)->lock)));
                _set_osfhnd(fd, r);
                MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));
                CloseHandle(h);
                st_insert(socklist, (st_data_t)r, (st_data_t)0);
            }
            else {
                errno = map_errno(WSAGetLastError());
                close(fd);
                fd = -1;
            }
        }
        else
            CloseHandle(h);
    });
    return fd;
}

#undef bind

int WSAAPI
rb_w32_bind(int s, const struct sockaddr *addr, int addrlen)
{
    int r;

    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        r = bind(TO_SOCKET(s), addr, addrlen);
        if (r == SOCKET_ERROR)
            errno = map_errno(WSAGetLastError());
    });
    return r;
}

#undef connect

int WSAAPI
rb_w32_connect(int s, const struct sockaddr *addr, int addrlen)
{
    int r;
    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        r = connect(TO_SOCKET(s), addr, addrlen);
        if (r == SOCKET_ERROR) {
            int err = WSAGetLastError();
            if (err != WSAEWOULDBLOCK)
                errno = map_errno(err);
            else
                errno = EINPROGRESS;
        }
    });
    return r;
}


#undef getpeername

int WSAAPI
rb_w32_getpeername(int s, struct sockaddr *addr, int *addrlen)
{
    int r;
    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        r = getpeername(TO_SOCKET(s), addr, addrlen);
        if (r == SOCKET_ERROR)
            errno = map_errno(WSAGetLastError());
    });
    return r;
}

#undef getsockname

int WSAAPI
rb_w32_getsockname(int s, struct sockaddr *addr, int *addrlen)
{
    int r;
    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        r = getsockname(TO_SOCKET(s), addr, addrlen);
        if (r == SOCKET_ERROR)
            errno = map_errno(WSAGetLastError());
    });
    return r;
}

int WSAAPI
rb_w32_getsockopt(int s, int level, int optname, char *optval, int *optlen)
{
    int r;
    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        r = getsockopt(TO_SOCKET(s), level, optname, optval, optlen);
        if (r == SOCKET_ERROR)
            errno = map_errno(WSAGetLastError());
    });
    return r;
}

#undef ioctlsocket

int WSAAPI
rb_w32_ioctlsocket(int s, long cmd, u_long *argp)
{
    int r;
    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        r = ioctlsocket(TO_SOCKET(s), cmd, argp);
        if (r == SOCKET_ERROR)
            errno = map_errno(WSAGetLastError());
    });
    return r;
}

#undef listen

int WSAAPI
rb_w32_listen(int s, int backlog)
{
    int r;
    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        r = listen(TO_SOCKET(s), backlog);
        if (r == SOCKET_ERROR)
            errno = map_errno(WSAGetLastError());
    });
    return r;
}

#undef recv
#undef recvfrom
#undef send
#undef sendto

static int
finish_overlapped_socket(SOCKET s, WSAOVERLAPPED *wol, int result, DWORD *len, DWORD size)
{
    DWORD flg;
    int err;

    if (result != SOCKET_ERROR)
        *len = size;
    else if ((err = WSAGetLastError()) == WSA_IO_PENDING) {
        switch (rb_w32_wait_events_blocking(&wol->hEvent, 1, INFINITE)) {
          case WAIT_OBJECT_0:
            RUBY_CRITICAL(
                result = WSAGetOverlappedResult(s, wol, &size, TRUE, &flg)
                );
            if (result) {
                *len = size;
                break;
            }
            /* thru */
          default:
            errno = map_errno(WSAGetLastError());
            /* thru */
          case WAIT_OBJECT_0 + 1:
            /* interrupted */
            *len = -1;
            cancel_io((HANDLE)s);
            break;
        }
    }
    else {
        errno = map_errno(err);
        *len = -1;
    }
    CloseHandle(wol->hEvent);

    return result;
}

static int
overlapped_socket_io(BOOL input, int fd, char *buf, int len, int flags,
                     struct sockaddr *addr, int *addrlen)
{
    int r;
    int ret;
    int mode;
    st_data_t data;
    DWORD flg;
    WSAOVERLAPPED wol;
    WSABUF wbuf;
    SOCKET s;

    if (!NtSocketsInitialized)
        StartSockets();

    s = TO_SOCKET(fd);
    st_lookup(socklist, (st_data_t)s, &data);
    mode = (int)data;
    if (!cancel_io || (mode & O_NONBLOCK)) {
        RUBY_CRITICAL({
            if (input) {
                if (addr && addrlen)
                    r = recvfrom(s, buf, len, flags, addr, addrlen);
                else
                    r = recv(s, buf, len, flags);
            }
            else {
                if (addr && addrlen)
                    r = sendto(s, buf, len, flags, addr, *addrlen);
                else
                    r = send(s, buf, len, flags);
            }
            if (r == SOCKET_ERROR)
                errno = map_errno(WSAGetLastError());
        });
    }
    else {
        DWORD size;
        DWORD rlen;
        wbuf.len = len;
        wbuf.buf = buf;
        memset(&wol, 0, sizeof(wol));
        RUBY_CRITICAL({
            wol.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
            if (input) {
                flg = flags;
                if (addr && addrlen)
                    ret = WSARecvFrom(s, &wbuf, 1, &size, &flg, addr, addrlen,
                                      &wol, NULL);
                else
                    ret = WSARecv(s, &wbuf, 1, &size, &flg, &wol, NULL);
            }
            else {
                if (addr && addrlen)
                    ret = WSASendTo(s, &wbuf, 1, &size, flags, addr, *addrlen,
                                    &wol, NULL);
                else
                    ret = WSASend(s, &wbuf, 1, &size, flags, &wol, NULL);
            }
        });

        finish_overlapped_socket(s, &wol, ret, &rlen, size);
        r = (int)rlen;
    }

    return r;
}

int WSAAPI
rb_w32_recv(int fd, char *buf, int len, int flags)
{
    return overlapped_socket_io(TRUE, fd, buf, len, flags, NULL, NULL);
}

int WSAAPI
rb_w32_recvfrom(int fd, char *buf, int len, int flags,
                struct sockaddr *from, int *fromlen)
{
    return overlapped_socket_io(TRUE, fd, buf, len, flags, from, fromlen);
}

int WSAAPI
rb_w32_send(int fd, const char *buf, int len, int flags)
{
    return overlapped_socket_io(FALSE, fd, (char *)buf, len, flags, NULL, NULL);
}

int WSAAPI
rb_w32_sendto(int fd, const char *buf, int len, int flags,
              const struct sockaddr *to, int tolen)
{
    return overlapped_socket_io(FALSE, fd, (char *)buf, len, flags,
                                (struct sockaddr *)to, &tolen);
}

#if !defined(MSG_TRUNC) && !defined(__MINGW32__)
typedef struct {
    SOCKADDR *name;
    int namelen;
    WSABUF *lpBuffers;
    DWORD dwBufferCount;
    WSABUF Control;
    DWORD dwFlags;
} WSAMSG;
#endif
#ifndef WSAID_WSARECVMSG
#define WSAID_WSARECVMSG {0xf689d7c8,0x6f1f,0x436b,{0x8a,0x53,0xe5,0x4f,0xe3,0x51,0xc3,0x22}}
#endif
#ifndef WSAID_WSASENDMSG
#define WSAID_WSASENDMSG {0xa441e712,0x754f,0x43ca,{0x84,0xa7,0x0d,0xee,0x44,0xcf,0x60,0x6d}}
#endif

#define msghdr_to_wsamsg(msg, wsamsg) \
    do { \
        int i; \
        (wsamsg)->name = (msg)->msg_name; \
        (wsamsg)->namelen = (msg)->msg_namelen; \
        (wsamsg)->lpBuffers = ALLOCA_N(WSABUF, (msg)->msg_iovlen); \
        (wsamsg)->dwBufferCount = (msg)->msg_iovlen; \
        for (i = 0; i < (msg)->msg_iovlen; ++i) { \
            (wsamsg)->lpBuffers[i].buf = (msg)->msg_iov[i].iov_base; \
            (wsamsg)->lpBuffers[i].len = (msg)->msg_iov[i].iov_len; \
        } \
        (wsamsg)->Control.buf = (msg)->msg_control; \
        (wsamsg)->Control.len = (msg)->msg_controllen; \
        (wsamsg)->dwFlags = (msg)->msg_flags; \
    } while (0)

int
recvmsg(int fd, struct msghdr *msg, int flags)
{
    typedef int (WSAAPI *WSARecvMsg_t)(SOCKET, WSAMSG *, DWORD *, WSAOVERLAPPED *, LPWSAOVERLAPPED_COMPLETION_ROUTINE);
    static WSARecvMsg_t pWSARecvMsg = NULL;
    WSAMSG wsamsg;
    SOCKET s;
    st_data_t data;
    int mode;
    DWORD len;
    int ret;

    if (!NtSocketsInitialized)
        StartSockets();

    s = TO_SOCKET(fd);

    if (!pWSARecvMsg) {
        static GUID guid = WSAID_WSARECVMSG;
        pWSARecvMsg = (WSARecvMsg_t)get_wsa_extension_function(s, &guid);
        if (!pWSARecvMsg)
            return -1;
    }

    msghdr_to_wsamsg(msg, &wsamsg);
    wsamsg.dwFlags |= flags;

    st_lookup(socklist, (st_data_t)s, &data);
    mode = (int)data;
    if (!cancel_io || (mode & O_NONBLOCK)) {
        RUBY_CRITICAL({
            if ((ret = pWSARecvMsg(s, &wsamsg, &len, NULL, NULL)) == SOCKET_ERROR) {
                errno = map_errno(WSAGetLastError());
                len = -1;
            }
        });
    }
    else {
        DWORD size;
        WSAOVERLAPPED wol;
        memset(&wol, 0, sizeof(wol));
        RUBY_CRITICAL({
            wol.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
            ret = pWSARecvMsg(s, &wsamsg, &size, &wol, NULL);
        });

        ret = finish_overlapped_socket(s, &wol, ret, &len, size);
    }
    if (ret == SOCKET_ERROR)
        return -1;

    /* WSAMSG to msghdr */
    msg->msg_name = wsamsg.name;
    msg->msg_namelen = wsamsg.namelen;
    msg->msg_flags = wsamsg.dwFlags;

    return len;
}

int
sendmsg(int fd, const struct msghdr *msg, int flags)
{
    typedef int (WSAAPI *WSASendMsg_t)(SOCKET, const WSAMSG *, DWORD, DWORD *, WSAOVERLAPPED *, LPWSAOVERLAPPED_COMPLETION_ROUTINE);
    static WSASendMsg_t pWSASendMsg = NULL;
    WSAMSG wsamsg;
    SOCKET s;
    st_data_t data;
    int mode;
    DWORD len;
    int ret;

    if (!NtSocketsInitialized)
        StartSockets();

    s = TO_SOCKET(fd);

    if (!pWSASendMsg) {
        static GUID guid = WSAID_WSASENDMSG;
        pWSASendMsg = (WSASendMsg_t)get_wsa_extension_function(s, &guid);
        if (!pWSASendMsg)
            return -1;
    }

    msghdr_to_wsamsg(msg, &wsamsg);

    st_lookup(socklist, (st_data_t)s, &data);
    mode = (int)data;
    if (!cancel_io || (mode & O_NONBLOCK)) {
        RUBY_CRITICAL({
            if ((ret = pWSASendMsg(s, &wsamsg, flags, &len, NULL, NULL)) == SOCKET_ERROR) {
                errno = map_errno(WSAGetLastError());
                len = -1;
            }
        });
    }
    else {
        DWORD size;
        WSAOVERLAPPED wol;
        memset(&wol, 0, sizeof(wol));
        RUBY_CRITICAL({
            wol.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
            ret = pWSASendMsg(s, &wsamsg, flags, &size, &wol, NULL);
        });

        finish_overlapped_socket(s, &wol, ret, &len, size);
    }

    return len;
}

#undef setsockopt

int WSAAPI
rb_w32_setsockopt(int s, int level, int optname, const char *optval, int optlen)
{
    int r;
    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        r = setsockopt(TO_SOCKET(s), level, optname, optval, optlen);
        if (r == SOCKET_ERROR)
            errno = map_errno(WSAGetLastError());
    });
    return r;
}

#undef shutdown

int WSAAPI
rb_w32_shutdown(int s, int how)
{
    int r;
    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        r = shutdown(TO_SOCKET(s), how);
        if (r == SOCKET_ERROR)
            errno = map_errno(WSAGetLastError());
    });
    return r;
}

static SOCKET
open_ifs_socket(int af, int type, int protocol)
{
    unsigned long proto_buffers_len = 0;
    int error_code;
    SOCKET out = INVALID_SOCKET;

    if (WSAEnumProtocols(NULL, NULL, &proto_buffers_len) == SOCKET_ERROR) {
        error_code = WSAGetLastError();
        if (error_code == WSAENOBUFS) {
            WSAPROTOCOL_INFO *proto_buffers;
            int protocols_available = 0;

            proto_buffers = (WSAPROTOCOL_INFO *)malloc(proto_buffers_len);
            if (!proto_buffers) {
                WSASetLastError(WSA_NOT_ENOUGH_MEMORY);
                return INVALID_SOCKET;
            }

            protocols_available =
                WSAEnumProtocols(NULL, proto_buffers, &proto_buffers_len);
            if (protocols_available != SOCKET_ERROR) {
                int i;
                for (i = 0; i < protocols_available; i++) {
                    if ((af != AF_UNSPEC && af != proto_buffers[i].iAddressFamily) ||
                        (type != proto_buffers[i].iSocketType) ||
                        (protocol != 0 && protocol != proto_buffers[i].iProtocol))
                        continue;

                    if ((proto_buffers[i].dwServiceFlags1 & XP1_IFS_HANDLES) == 0)
                        continue;

                    out = WSASocket(af, type, protocol, &(proto_buffers[i]), 0,
                                    WSA_FLAG_OVERLAPPED);
                    break;
                }
                if (out == INVALID_SOCKET)
                    out = WSASocket(af, type, protocol, NULL, 0, 0);
            }

            free(proto_buffers);
        }
    }

    return out;
}

#undef socket

int WSAAPI
rb_w32_socket(int af, int type, int protocol)
{
    SOCKET s;
    int fd;

    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        s = open_ifs_socket(af, type, protocol);
        if (s == INVALID_SOCKET) {
            errno = map_errno(WSAGetLastError());
            fd = -1;
        }
        else {
            fd = rb_w32_open_osfhandle(s, O_RDWR|O_BINARY|O_NOINHERIT);
            if (fd != -1)
                st_insert(socklist, (st_data_t)s, (st_data_t)0);
            else
                closesocket(s);
        }
    });
    return fd;
}

#undef gethostbyaddr

struct hostent * WSAAPI
rb_w32_gethostbyaddr(const char *addr, int len, int type)
{
    struct hostent *r;
    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        r = gethostbyaddr(addr, len, type);
        if (r == NULL)
            errno = map_errno(WSAGetLastError());
    });
    return r;
}

#undef gethostbyname

struct hostent * WSAAPI
rb_w32_gethostbyname(const char *name)
{
    struct hostent *r;
    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        r = gethostbyname(name);
        if (r == NULL)
            errno = map_errno(WSAGetLastError());
    });
    return r;
}

#undef gethostname

int WSAAPI
rb_w32_gethostname(char *name, int len)
{
    int r;
    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        r = gethostname(name, len);
        if (r == SOCKET_ERROR)
            errno = map_errno(WSAGetLastError());
    });
    return r;
}

#undef getprotobyname

struct protoent * WSAAPI
rb_w32_getprotobyname(const char *name)
{
    struct protoent *r;
    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        r = getprotobyname(name);
        if (r == NULL)
            errno = map_errno(WSAGetLastError());
    });
    return r;
}

#undef getprotobynumber

struct protoent * WSAAPI
rb_w32_getprotobynumber(int num)
{
    struct protoent *r;
    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        r = getprotobynumber(num);
        if (r == NULL)
            errno = map_errno(WSAGetLastError());
    });
    return r;
}

#undef getservbyname

struct servent * WSAAPI
rb_w32_getservbyname(const char *name, const char *proto)
{
    struct servent *r;
    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        r = getservbyname(name, proto);
        if (r == NULL)
            errno = map_errno(WSAGetLastError());
    });
    return r;
}

#undef getservbyport

struct servent * WSAAPI
rb_w32_getservbyport(int port, const char *proto)
{
    struct servent *r;
    if (!NtSocketsInitialized) {
        StartSockets();
    }
    RUBY_CRITICAL({
        r = getservbyport(port, proto);
        if (r == NULL)
            errno = map_errno(WSAGetLastError());
    });
    return r;
}

static int
socketpair_internal(int af, int type, int protocol, SOCKET *sv)
{
    SOCKET svr = INVALID_SOCKET, r = INVALID_SOCKET, w = INVALID_SOCKET;
    struct sockaddr_in sock_in4;
#ifdef INET6
    struct sockaddr_in6 sock_in6;
#endif
    struct sockaddr *addr;
    int ret = -1;
    int len;

    if (!NtSocketsInitialized) {
        StartSockets();
    }

    switch (af) {
      case AF_INET:
#if defined PF_INET && PF_INET != AF_INET
      case PF_INET:
#endif
        sock_in4.sin_family = AF_INET;
        sock_in4.sin_port = 0;
        sock_in4.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
        addr = (struct sockaddr *)&sock_in4;
        len = sizeof(sock_in4);
        break;
#ifdef INET6
      case AF_INET6:
        memset(&sock_in6, 0, sizeof(sock_in6));
        sock_in6.sin6_family = AF_INET6;
        sock_in6.sin6_addr = IN6ADDR_LOOPBACK_INIT;
        addr = (struct sockaddr *)&sock_in6;
        len = sizeof(sock_in6);
        break;
#endif
      default:
        errno = EAFNOSUPPORT;
        return -1;
    }
    if (type != SOCK_STREAM) {
        errno = EPROTOTYPE;
        return -1;
    }

    sv[0] = (SOCKET)INVALID_HANDLE_VALUE;
    sv[1] = (SOCKET)INVALID_HANDLE_VALUE;
    RUBY_CRITICAL({
        do {
            svr = open_ifs_socket(af, type, protocol);
            if (svr == INVALID_SOCKET)
                break;
            if (bind(svr, addr, len) < 0)
                break;
            if (getsockname(svr, addr, &len) < 0)
                break;
            if (type == SOCK_STREAM)
                listen(svr, 5);

            w = open_ifs_socket(af, type, protocol);
            if (w == INVALID_SOCKET)
                break;
            if (connect(w, addr, len) < 0)
                break;

            r = accept(svr, addr, &len);
            if (r == INVALID_SOCKET)
                break;

            ret = 0;
        } while (0);

        if (ret < 0) {
            errno = map_errno(WSAGetLastError());
            if (r != INVALID_SOCKET)
                closesocket(r);
            if (w != INVALID_SOCKET)
                closesocket(w);
        }
        else {
            sv[0] = r;
            sv[1] = w;
        }
        if (svr != INVALID_SOCKET)
            closesocket(svr);
    });

    return ret;
}

int
rb_w32_socketpair(int af, int type, int protocol, int *sv)
{
    SOCKET pair[2];

    if (socketpair_internal(af, type, protocol, pair) < 0)
        return -1;
    sv[0] = rb_w32_open_osfhandle(pair[0], O_RDWR|O_BINARY|O_NOINHERIT);
    if (sv[0] == -1) {
        closesocket(pair[0]);
        closesocket(pair[1]);
        return -1;
    }
    sv[1] = rb_w32_open_osfhandle(pair[1], O_RDWR|O_BINARY|O_NOINHERIT);
    if (sv[1] == -1) {
        rb_w32_close(sv[0]);
        closesocket(pair[1]);
        return -1;
    }
    st_insert(socklist, (st_data_t)pair[0], (st_data_t)0);
    st_insert(socklist, (st_data_t)pair[1], (st_data_t)0);

    return 0;
}

//
// Networking stubs
//

void endhostent(void) {}
void endnetent(void) {}
void endprotoent(void) {}
void endservent(void) {}

struct netent *getnetent (void) {return (struct netent *) NULL;}

struct netent *getnetbyaddr(long net, int type) {return (struct netent *)NULL;}

struct netent *getnetbyname(const char *name) {return (struct netent *)NULL;}

struct protoent *getprotoent (void) {return (struct protoent *) NULL;}

struct servent *getservent (void) {return (struct servent *) NULL;}

void sethostent (int stayopen) {}

void setnetent (int stayopen) {}

void setprotoent (int stayopen) {}

void setservent (int stayopen) {}

int
fcntl(int fd, int cmd, ...)
{
    SOCKET sock = TO_SOCKET(fd);
    va_list va;
    int arg;
    int ret;
    int flag = 0;
    st_data_t data;
    u_long ioctlArg;

    if (!is_socket(sock)) {
        errno = EBADF;
        return -1;
    }
    if (cmd != F_SETFL) {
        errno = EINVAL;
        return -1;
    }

    va_start(va, cmd);
    arg = va_arg(va, int);
    va_end(va);
    st_lookup(socklist, (st_data_t)sock, &data);
    flag = (int)data;
    if (arg & O_NONBLOCK) {
        flag |= O_NONBLOCK;
        ioctlArg = 1;
    }
    else {
        flag &= ~O_NONBLOCK;
        ioctlArg = 0;
    }
    RUBY_CRITICAL({
        ret = ioctlsocket(sock, FIONBIO, &ioctlArg);
        if (ret == 0)
            st_insert(socklist, (st_data_t)sock, (st_data_t)flag);
        else
            errno = map_errno(WSAGetLastError());
    });

    return ret;
}

#ifndef WNOHANG
#define WNOHANG -1
#endif

static rb_pid_t
poll_child_status(struct ChildRecord *child, int *stat_loc)
{
    DWORD exitcode;
    DWORD err;

    if (!GetExitCodeProcess(child->hProcess, &exitcode)) {
        /* If an error occured, return immediatly. */
    error_exit:
        err = GetLastError();
        if (err == ERROR_INVALID_PARAMETER)
            errno = ECHILD;
        else {
            if (GetLastError() == ERROR_INVALID_HANDLE)
                errno = EINVAL;
            else
                errno = map_errno(GetLastError());
        }
        CloseChildHandle(child);
        return -1;
    }
    if (exitcode != STILL_ACTIVE) {
        rb_pid_t pid;
        /* If already died, wait process's real termination. */
        if (rb_w32_wait_events_blocking(&child->hProcess, 1, INFINITE) != WAIT_OBJECT_0) {
            goto error_exit;
        }
        pid = child->pid;
        CloseChildHandle(child);
        if (stat_loc) *stat_loc = exitcode << 8;
        return pid;
    }
    return 0;
}

rb_pid_t
waitpid(rb_pid_t pid, int *stat_loc, int options)
{
    DWORD timeout;

    if (options == WNOHANG) {
        timeout = 0;
    }
    else {
        timeout = INFINITE;
    }

    if (pid == -1) {
        int count = 0;
        int ret;
        HANDLE events[MAXCHILDNUM];

        FOREACH_CHILD(child) {
            if (!child->pid || child->pid < 0) continue;
            if ((pid = poll_child_status(child, stat_loc))) return pid;
            events[count++] = child->hProcess;
        } END_FOREACH_CHILD;
        if (!count) {
            errno = ECHILD;
            return -1;
        }

        ret = rb_w32_wait_events_blocking(events, count, timeout);
        if (ret == WAIT_TIMEOUT) return 0;
        if ((ret -= WAIT_OBJECT_0) == count) {
            return -1;
        }
        if (ret > count) {
            errno = map_errno(GetLastError());
            return -1;
        }

        return poll_child_status(FindChildSlotByHandle(events[ret]), stat_loc);
    }
    else {
        struct ChildRecord* child = FindChildSlot(pid);
        if (!child) {
            errno = ECHILD;
            return -1;
        }

        while (!(pid = poll_child_status(child, stat_loc))) {
            /* wait... */
            if (rb_w32_wait_events_blocking(&child->hProcess, 1, timeout) != WAIT_OBJECT_0) {
                /* still active */
                pid = 0;
                break;
            }
        }
    }

    return pid;
}

#include <sys/timeb.h>

static int
filetime_to_timeval(const FILETIME* ft, struct timeval *tv)
{
    ULARGE_INTEGER tmp;
    unsigned LONG_LONG lt;

    tmp.LowPart = ft->dwLowDateTime;
    tmp.HighPart = ft->dwHighDateTime;
    lt = tmp.QuadPart;

    /* lt is now 100-nanosec intervals since 1601/01/01 00:00:00 UTC,
       convert it into UNIX time (since 1970/01/01 00:00:00 UTC).
       the first leap second is at 1972/06/30, so we doesn't need to think
       about it. */
    lt /= 10;   /* to usec */
    lt -= (LONG_LONG)((1970-1601)*365.2425) * 24 * 60 * 60 * 1000 * 1000;

    tv->tv_sec = (long)(lt / (1000 * 1000));
    tv->tv_usec = (long)(lt % (1000 * 1000));

    return tv->tv_sec > 0 ? 0 : -1;
}

int _cdecl
gettimeofday(struct timeval *tv, struct timezone *tz)
{
    FILETIME ft;

    GetSystemTimeAsFileTime(&ft);
    filetime_to_timeval(&ft, tv);

    return 0;
}

char *
rb_w32_getcwd(char *buffer, int size)
{
    char *p = buffer;
    int len;

    len = GetCurrentDirectory(0, NULL);
    if (!len) {
        errno = map_errno(GetLastError());
        return NULL;
    }

    if (p) {
        if (size < len) {
            errno = ERANGE;
            return NULL;
        }
    }
    else {
        p = malloc(len);
        size = len;
        if (!p) {
            errno = ENOMEM;
            return NULL;
        }
    }

    if (!GetCurrentDirectory(size, p)) {
        errno = map_errno(GetLastError());
        if (!buffer)
            free(p);
        return NULL;
    }

    translate_char(p, '\\', '/');

    return p;
}

int
chown(const char *path, int owner, int group)
{
    return 0;
}

int
rb_w32_uchown(const char *path, int owner, int group)
{
    return 0;
}

int
kill(int pid, int sig)
{
    int ret = 0;
    DWORD err;

    if (pid < 0 || pid == 0 && sig != SIGINT) {
        errno = EINVAL;
        return -1;
    }

    (void)IfWin95(pid = -pid, 0);
    if ((unsigned int)pid == GetCurrentProcessId() &&
        (sig != 0 && sig != SIGKILL)) {
        if ((ret = raise(sig)) != 0) {
            /* MSVCRT doesn't set errno... */
            errno = EINVAL;
        }
        return ret;
    }

    switch (sig) {
      case 0:
        RUBY_CRITICAL({
            HANDLE hProc =
                OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, (DWORD)pid);
            if (hProc == NULL || hProc == INVALID_HANDLE_VALUE) {
                if (GetLastError() == ERROR_INVALID_PARAMETER) {
                    errno = ESRCH;
                }
                else {
                    errno = EPERM;
                }
                ret = -1;
            }
            else {
                CloseHandle(hProc);
            }
        });
        break;

      case SIGINT:
        RUBY_CRITICAL({
            DWORD ctrlEvent = CTRL_C_EVENT;
            if (pid != 0) {
                /* CTRL+C signal cannot be generated for process groups.
                 * Instead, we use CTRL+BREAK signal. */
                ctrlEvent = CTRL_BREAK_EVENT;
            }
            if (!GenerateConsoleCtrlEvent(ctrlEvent, (DWORD)pid)) {
                if ((err = GetLastError()) == 0)
                    errno = EPERM;
                else
                    errno = map_errno(GetLastError());
                ret = -1;
            }
        });
        break;

      case SIGKILL:
        RUBY_CRITICAL({
            HANDLE hProc;
            struct ChildRecord* child = FindChildSlot(pid);
            if (child) {
                hProc = child->hProcess;
            }
            else {
                hProc = OpenProcess(PROCESS_TERMINATE | PROCESS_QUERY_INFORMATION, FALSE, (DWORD)pid);
            }
            if (hProc == NULL || hProc == INVALID_HANDLE_VALUE) {
                if (GetLastError() == ERROR_INVALID_PARAMETER) {
                    errno = ESRCH;
                }
                else {
                    errno = EPERM;
                }
                ret = -1;
            }
            else {
                DWORD status;
                if (!GetExitCodeProcess(hProc, &status)) {
                    errno = map_errno(GetLastError());
                    ret = -1;
                }
                else if (status == STILL_ACTIVE) {
                    if (!TerminateProcess(hProc, 0)) {
                        errno = EPERM;
                        ret = -1;
                    }
                }
                else {
                    errno = ESRCH;
                    ret = -1;
                }
                if (!child) {
                    CloseHandle(hProc);
                }
            }
        });
        break;

      default:
        errno = EINVAL;
        ret = -1;
        break;
    }

    return ret;
}

static int
wlink(const WCHAR *from, const WCHAR *to)
{
    typedef BOOL (WINAPI link_func)(LPCWSTR, LPCWSTR, LPSECURITY_ATTRIBUTES);
    static link_func *pCreateHardLinkW = NULL;
    static int myerrno = 0;

    if (!pCreateHardLinkW && !myerrno) {
        pCreateHardLinkW = (link_func *)get_proc_address("kernel32", "CreateHardLinkW", NULL);
        if (!pCreateHardLinkW)
            myerrno = ENOSYS;
    }
    if (!pCreateHardLinkW) {
        errno = myerrno;
        return -1;
    }

    if (!pCreateHardLinkW(to, from, NULL)) {
        errno = map_errno(GetLastError());
        return -1;
    }

    return 0;
}

int
rb_w32_ulink(const char *from, const char *to)
{
    WCHAR *wfrom;
    WCHAR *wto;
    int ret;

    if (!(wfrom = utf8_to_wstr(from, NULL)))
        return -1;
    if (!(wto = utf8_to_wstr(to, NULL))) {
        free(wfrom);
        return -1;
    }
    ret = wlink(wfrom, wto);
    free(wto);
    free(wfrom);
    return ret;
}

int
link(const char *from, const char *to)
{
    WCHAR *wfrom;
    WCHAR *wto;
    int ret;

    if (!(wfrom = filecp_to_wstr(from, NULL)))
        return -1;
    if (!(wto = filecp_to_wstr(to, NULL))) {
        free(wfrom);
        return -1;
    }
    ret = wlink(wfrom, wto);
    free(wto);
    free(wfrom);
    return ret;
}

int
wait(int *status)
{
    return waitpid(-1, status, 0);
}

char *
rb_w32_getenv(const char *name)
{
    int len = strlen(name);
    char *env;

    if (len == 0) return NULL;
    if (envarea) FreeEnvironmentStrings(envarea);
    envarea = GetEnvironmentStrings();
    if (!envarea) {
        map_errno(GetLastError());
        return NULL;
    }

    for (env = envarea; *env; env += strlen(env) + 1)
        if (strncasecmp(env, name, len) == 0 && *(env + len) == '=')
            return env + len + 1;

    return NULL;
}

static int
wrename(const WCHAR *oldpath, const WCHAR *newpath)
{
    int res = 0;
    int oldatts;
    int newatts;

    oldatts = GetFileAttributesW(oldpath);
    newatts = GetFileAttributesW(newpath);

    if (oldatts == -1) {
        errno = map_errno(GetLastError());
        return -1;
    }

    RUBY_CRITICAL({
        if (newatts != -1 && newatts & FILE_ATTRIBUTE_READONLY)
            SetFileAttributesW(newpath, newatts & ~ FILE_ATTRIBUTE_READONLY);

        if (IsWinNT()) {
            if (!MoveFileExW(oldpath, newpath, MOVEFILE_REPLACE_EXISTING | MOVEFILE_COPY_ALLOWED))
                res = -1;
        }
        else {
            if (!MoveFileW(oldpath, newpath))
                res = -1;

            if (res) {
                switch (GetLastError()) {
                  case ERROR_ALREADY_EXISTS:
                  case ERROR_FILE_EXISTS:
                    for (;;) {
                        if (!DeleteFileW(newpath) && GetLastError() != ERROR_FILE_NOT_FOUND)
                            break;
                        else if (MoveFileW(oldpath, newpath)) {
                            res = 0;
                            break;
                        }
                    }
                }
            }
        }

        if (res)
            errno = map_errno(GetLastError());
        else
            SetFileAttributesW(newpath, oldatts);
    });

    return res;
}

int rb_w32_urename(const char *from, const char *to)
{
    WCHAR *wfrom;
    WCHAR *wto;
    int ret = -1;

    if (!(wfrom = utf8_to_wstr(from, NULL)))
        return -1;
    if (!(wto = utf8_to_wstr(to, NULL))) {
        free(wfrom);
        return -1;
    }
    ret = wrename(wfrom, wto);
    free(wto);
    free(wfrom);
    return ret;
}

int rb_w32_rename(const char *from, const char *to)
{
    WCHAR *wfrom;
    WCHAR *wto;
    int ret = -1;

    if (!(wfrom = filecp_to_wstr(from, NULL)))
        return -1;
    if (!(wto = filecp_to_wstr(to, NULL))) {
        free(wfrom);
        return -1;
    }
    ret = wrename(wfrom, wto);
    free(wto);
    free(wfrom);
    return ret;
}

static int
isUNCRoot(const WCHAR *path)
{
    if (path[0] == L'\\' && path[1] == L'\\') {
        const WCHAR *p;
        for (p = path + 2; *p; p++) {
            if (*p == L'\\')
                break;
        }
        if (p[0] && p[1]) {
            for (p++; *p; p++) {
                if (*p == L'\\')
                    break;
            }
            if (!p[0] || !p[1] || (p[1] == L'.' && !p[2]))
                return 1;
        }
    }
    return 0;
}

#define COPY_STAT(src, dest, size_cast) do {    \
        (dest).st_dev   = (src).st_dev;         \
        (dest).st_ino   = (src).st_ino;         \
        (dest).st_mode  = (src).st_mode;        \
        (dest).st_nlink = (src).st_nlink;       \
        (dest).st_uid   = (src).st_uid;         \
        (dest).st_gid   = (src).st_gid;         \
        (dest).st_rdev  = (src).st_rdev;        \
        (dest).st_size  = size_cast(src).st_size; \
        (dest).st_atime = (src).st_atime;       \
        (dest).st_mtime = (src).st_mtime;       \
        (dest).st_ctime = (src).st_ctime;       \
    } while (0)

static time_t filetime_to_unixtime(const FILETIME *ft);

#undef fstat
int
rb_w32_fstat(int fd, struct stat *st)
{
    BY_HANDLE_FILE_INFORMATION info;
    int ret = fstat(fd, st);

    if (ret) return ret;
#ifdef __BORLANDC__
    st->st_mode &= ~(S_IWGRP | S_IWOTH);
#endif
    if (GetFileInformationByHandle((HANDLE)_get_osfhandle(fd), &info)) {
#ifdef __BORLANDC__
        if (!(info.dwFileAttributes & FILE_ATTRIBUTE_READONLY)) {
            st->st_mode |= S_IWUSR;
        }
#endif
        st->st_atime = filetime_to_unixtime(&info.ftLastAccessTime);
        st->st_mtime = filetime_to_unixtime(&info.ftLastWriteTime);
        st->st_ctime = filetime_to_unixtime(&info.ftCreationTime);
    }
    return ret;
}

int
rb_w32_fstati64(int fd, struct stati64 *st)
{
    BY_HANDLE_FILE_INFORMATION info;
    struct stat tmp;
    int ret = fstat(fd, &tmp);

    if (ret) return ret;
#ifdef __BORLANDC__
    tmp.st_mode &= ~(S_IWGRP | S_IWOTH);
#endif
    COPY_STAT(tmp, *st, +);
    if (GetFileInformationByHandle((HANDLE)_get_osfhandle(fd), &info)) {
#ifdef __BORLANDC__
        if (!(info.dwFileAttributes & FILE_ATTRIBUTE_READONLY)) {
            st->st_mode |= S_IWUSR;
        }
#endif
        st->st_size = ((__int64)info.nFileSizeHigh << 32) | info.nFileSizeLow;
        st->st_atime = filetime_to_unixtime(&info.ftLastAccessTime);
        st->st_mtime = filetime_to_unixtime(&info.ftLastWriteTime);
        st->st_ctime = filetime_to_unixtime(&info.ftCreationTime);
    }
    return ret;
}

static time_t
filetime_to_unixtime(const FILETIME *ft)
{
    struct timeval tv;

    if (filetime_to_timeval(ft, &tv) == (time_t)-1)
        return 0;
    else
        return tv.tv_sec;
}

static unsigned
fileattr_to_unixmode(DWORD attr, const WCHAR *path)
{
    unsigned mode = 0;

    if (attr & FILE_ATTRIBUTE_READONLY) {
        mode |= S_IREAD;
    }
    else {
        mode |= S_IREAD | S_IWRITE | S_IWUSR;
    }

    if (attr & FILE_ATTRIBUTE_DIRECTORY) {
        mode |= S_IFDIR | S_IEXEC;
    }
    else {
        mode |= S_IFREG;
    }

    if (path && (mode & S_IFREG)) {
        const WCHAR *end = path + lstrlenW(path);
        while (path < end) {
            end = CharPrevW(path, end);
            if (*end == L'.') {
                if ((_wcsicmp(end, L".bat") == 0) ||
                    (_wcsicmp(end, L".cmd") == 0) ||
                    (_wcsicmp(end, L".com") == 0) ||
                    (_wcsicmp(end, L".exe") == 0)) {
                    mode |= S_IEXEC;
                }
                break;
            }
        }
    }

    mode |= (mode & 0700) >> 3;
    mode |= (mode & 0700) >> 6;

    return mode;
}

static int
check_valid_dir(const WCHAR *path)
{
    WIN32_FIND_DATAW fd;
    HANDLE fh;

    /* GetFileAttributes() determines "..." as directory. */
    /* We recheck it by FindFirstFile(). */
    if (wcsstr(path, L"...") == NULL)
        return 0;

    fh = open_dir_handle(path, &fd);
    if (fh == INVALID_HANDLE_VALUE)
        return -1;
    FindClose(fh);
    return 0;
}

static int
winnt_stat(const WCHAR *path, struct stati64 *st)
{
    HANDLE h;
    WIN32_FIND_DATAW wfd;
    WIN32_FILE_ATTRIBUTE_DATA wfa;

    memset(st, 0, sizeof(*st));
    st->st_nlink = 1;

    if (wcspbrk(path, L"?*")) {
        errno = ENOENT;
        return -1;
    }
    if (GetFileAttributesExW(path, GetFileExInfoStandard, (void*)&wfa)) {
        if (wfa.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
            if (check_valid_dir(path)) return -1;
            st->st_size = 0;
        }
        else {
            st->st_size = ((__int64)wfa.nFileSizeHigh << 32) | wfa.nFileSizeLow;
        }
        st->st_mode  = fileattr_to_unixmode(wfa.dwFileAttributes, path);
        st->st_atime = filetime_to_unixtime(&wfa.ftLastAccessTime);
        st->st_mtime = filetime_to_unixtime(&wfa.ftLastWriteTime);
        st->st_ctime = filetime_to_unixtime(&wfa.ftCreationTime);
    }
    else {
        /* GetFileAttributesEx failed; check why. */
        int e = GetLastError();

        if ((e == ERROR_FILE_NOT_FOUND) || (e == ERROR_INVALID_NAME)
            || (e == ERROR_PATH_NOT_FOUND || (e == ERROR_BAD_NETPATH))) {
            errno = map_errno(e);
            return -1;
        }

        /* Fall back to FindFirstFile for ERROR_SHARING_VIOLATION */
        h = FindFirstFileW(path, &wfd);
        if (h != INVALID_HANDLE_VALUE) {
            FindClose(h);
            st->st_mode  = fileattr_to_unixmode(wfd.dwFileAttributes, path);
            st->st_atime = filetime_to_unixtime(&wfd.ftLastAccessTime);
            st->st_mtime = filetime_to_unixtime(&wfd.ftLastWriteTime);
            st->st_ctime = filetime_to_unixtime(&wfd.ftCreationTime);
            st->st_size = ((__int64)wfd.nFileSizeHigh << 32) | wfd.nFileSizeLow;
        }
        else {
            errno = map_errno(GetLastError());
            return -1;
        }
    }

    st->st_dev = st->st_rdev = (iswalpha(path[0]) && path[1] == L':') ?
        towupper(path[0]) - L'A' : _getdrive() - 1;

    return 0;
}

#ifdef WIN95
static int
win95_stat(const WCHAR *path, struct stati64 *st)
{
    int ret = _wstati64(path, st);
    if (ret) return ret;
    if (st->st_mode & S_IFDIR) {
        return check_valid_dir(path);
    }
    return 0;
}
#else
#define win95_stat(path, st) -1
#endif

int
rb_w32_stat(const char *path, struct stat *st)
{
    struct stati64 tmp;

    if (rb_w32_stati64(path, &tmp)) return -1;
    COPY_STAT(tmp, *st, (_off_t));
    return 0;
}

static int
wstati64(const WCHAR *path, struct stati64 *st)
{
    const WCHAR *p;
    WCHAR *buf1, *s, *end;
    int len, size;
    int ret;
    VALUE v;

    if (!path || !st) {
        errno = EFAULT;
        return -1;
    }
    size = lstrlenW(path) + 2;
    buf1 = ALLOCV_N(WCHAR, v, size);
    for (p = path, s = buf1; *p; p++, s++) {
        if (*p == L'/')
            *s = L'\\';
        else
            *s = *p;
    }
    *s = '\0';
    len = s - buf1;
    if (!len || L'\"' == *(--s)) {
        errno = ENOENT;
        return -1;
    }
    end = buf1 + len - 1;

    if (isUNCRoot(buf1)) {
        if (*end == L'.')
            *end = L'\0';
        else if (*end != L'\\')
            lstrcatW(buf1, L"\\");
    }
    else if (*end == L'\\' || (buf1 + 1 == end && *end == L':'))
        lstrcatW(buf1, L".");

    ret = IsWinNT() ? winnt_stat(buf1, st) : win95_stat(buf1, st);
    if (ret == 0) {
        st->st_mode &= ~(S_IWGRP | S_IWOTH);
    }
    if (v)
        ALLOCV_END(v);

    return ret;
}

int
rb_w32_ustati64(const char *path, struct stati64 *st)
{
    WCHAR *wpath;
    int ret;

    if (!(wpath = utf8_to_wstr(path, NULL)))
        return -1;
    ret = wstati64(wpath, st);
    free(wpath);
    return ret;
}

int
rb_w32_stati64(const char *path, struct stati64 *st)
{
    WCHAR *wpath;
    int ret;

    if (!(wpath = filecp_to_wstr(path, NULL)))
        return -1;
    ret = wstati64(wpath, st);
    free(wpath);
    return ret;
}

int
rb_w32_access(const char *path, int mode)
{
    struct stati64 stat;
    if (rb_w32_stati64(path, &stat) != 0)
        return -1;
    mode <<= 6;
    if ((stat.st_mode & mode) != mode) {
        errno = EACCES;
        return -1;
    }
    return 0;
}

int
rb_w32_uaccess(const char *path, int mode)
{
    struct stati64 stat;
    if (rb_w32_ustati64(path, &stat) != 0)
        return -1;
    mode <<= 6;
    if ((stat.st_mode & mode) != mode) {
        errno = EACCES;
        return -1;
    }
    return 0;
}

static int
rb_chsize(HANDLE h, off_t size)
{
    long upos, lpos, usize, lsize, uend, lend;
    off_t end;
    int ret = -1;
    DWORD e;

    if (((lpos = SetFilePointer(h, 0, (upos = 0, &upos), SEEK_CUR)) == -1L &&
         (e = GetLastError())) ||
        ((lend = GetFileSize(h, (DWORD *)&uend)) == -1L && (e = GetLastError()))) {
        errno = map_errno(e);
        return -1;
    }
    end = ((off_t)uend << 32) | (unsigned long)lend;
    usize = (long)(size >> 32);
    lsize = (long)size;
    if (SetFilePointer(h, lsize, &usize, SEEK_SET) == (DWORD)-1L &&
        (e = GetLastError())) {
        errno = map_errno(e);
    }
    else if (!SetEndOfFile(h)) {
        errno = map_errno(GetLastError());
    }
    else {
        ret = 0;
    }
    SetFilePointer(h, lpos, &upos, SEEK_SET);
    return ret;
}

int
rb_w32_truncate(const char *path, off_t length)
{
    HANDLE h;
    int ret;
#ifdef WIN95
    if (IsWin95()) {
        int fd = open(path, O_WRONLY), e = 0;
        if (fd == -1) return -1;
        ret = chsize(fd, (unsigned long)length);
        if (ret == -1) e = errno;
        close(fd);
        if (ret == -1) errno = e;
        return ret;
    }
#endif
    h = CreateFile(path, GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);
    if (h == INVALID_HANDLE_VALUE) {
        errno = map_errno(GetLastError());
        return -1;
    }
    ret = rb_chsize(h, length);
    CloseHandle(h);
    return ret;
}

int
rb_w32_ftruncate(int fd, off_t length)
{
    HANDLE h;

#ifdef WIN95
    if (IsWin95()) {
        return chsize(fd, (unsigned long)length);
    }
#endif
    h = (HANDLE)_get_osfhandle(fd);
    if (h == (HANDLE)-1) return -1;
    return rb_chsize(h, length);
}

#ifdef __BORLANDC__
off_t
_filelengthi64(int fd)
{
    DWORD u, l;
    int e;

    l = GetFileSize((HANDLE)_get_osfhandle(fd), &u);
    if (l == (DWORD)-1L && (e = GetLastError())) {
        errno = map_errno(e);
        return (off_t)-1;
    }
    return ((off_t)u << 32) | l;
}

off_t
_lseeki64(int fd, off_t offset, int whence)
{
    long u, l;
    int e;
    HANDLE h = (HANDLE)_get_osfhandle(fd);

    if (!h) {
        errno = EBADF;
        return -1;
    }
    u = (long)(offset >> 32);
    if ((l = SetFilePointer(h, (long)offset, &u, whence)) == -1L &&
        (e = GetLastError())) {
        errno = map_errno(e);
        return -1;
    }
    return ((off_t)u << 32) | l;
}
#endif

int
fseeko(FILE *stream, off_t offset, int whence)
{
    off_t pos;
    switch (whence) {
      case SEEK_CUR:
        if (fgetpos(stream, (fpos_t *)&pos))
            return -1;
        pos += offset;
        break;
      case SEEK_END:
        if ((pos = _filelengthi64(fileno(stream))) == (off_t)-1)
            return -1;
        pos += offset;
        break;
      default:
        pos = offset;
        break;
    }
    return fsetpos(stream, (fpos_t *)&pos);
}

off_t
rb_w32_ftello(FILE *stream)
{
    off_t pos;
    if (fgetpos(stream, (fpos_t *)&pos)) return (off_t)-1;
    return pos;
}

static long
filetime_to_clock(FILETIME *ft)
{
    __int64 qw = ft->dwHighDateTime;
    qw <<= 32;
    qw |= ft->dwLowDateTime;
    qw /= 10000;  /* File time ticks at 0.1uS, clock at 1mS */
    return (long) qw;
}

int
rb_w32_times(struct tms *tmbuf)
{
    FILETIME create, exit, kernel, user;

    if (GetProcessTimes(GetCurrentProcess(),&create, &exit, &kernel, &user)) {
        tmbuf->tms_utime = filetime_to_clock(&user);
        tmbuf->tms_stime = filetime_to_clock(&kernel);
        tmbuf->tms_cutime = 0;
        tmbuf->tms_cstime = 0;
    }
    else {
        tmbuf->tms_utime = clock();
        tmbuf->tms_stime = 0;
        tmbuf->tms_cutime = 0;
        tmbuf->tms_cstime = 0;
    }
    return 0;
}

#define yield_once() Sleep(0)
#define yield_until(condition) do yield_once(); while (!(condition))

static void
catch_interrupt(void)
{
    yield_once();
    RUBY_CRITICAL(rb_w32_wait_events(NULL, 0, 0));
}

#if defined __BORLANDC__
#undef read
int
read(int fd, void *buf, size_t size)
{
    int ret = _read(fd, buf, size);
    if ((ret < 0) && (errno == EPIPE)) {
        errno = 0;
        ret = 0;
    }
    catch_interrupt();
    return ret;
}
#endif

#undef fgetc
int
rb_w32_getc(FILE* stream)
{
    int c;
    if (enough_to_get(stream->FILE_COUNT)) {
        c = (unsigned char)*stream->FILE_READPTR++;
    }
    else {
        c = _filbuf(stream);
#if defined __BORLANDC__
        if ((c == EOF) && (errno == EPIPE)) {
            clearerr(stream);
        }
#endif
        catch_interrupt();
    }
    return c;
}

#undef fputc
int
rb_w32_putc(int c, FILE* stream)
{
    if (enough_to_put(stream->FILE_COUNT)) {
        c = (unsigned char)(*stream->FILE_READPTR++ = (char)c);
    }
    else {
        c = _flsbuf(c, stream);
        catch_interrupt();
    }
    return c;
}

struct asynchronous_arg_t {
    /* output field */
    void* stackaddr;
    int errnum;

    /* input field */
    uintptr_t (*func)(uintptr_t self, int argc, uintptr_t* argv);
    uintptr_t self;
    int argc;
    uintptr_t* argv;
};

static DWORD WINAPI
call_asynchronous(PVOID argp)
{
    DWORD ret;
    struct asynchronous_arg_t *arg = argp;
    arg->stackaddr = &argp;
    ret = (DWORD)arg->func(arg->self, arg->argc, arg->argv);
    arg->errnum = errno;
    return ret;
}

uintptr_t
rb_w32_asynchronize(asynchronous_func_t func, uintptr_t self,
                    int argc, uintptr_t* argv, uintptr_t intrval)
{
    DWORD val;
    BOOL interrupted = FALSE;
    HANDLE thr;

    RUBY_CRITICAL({
        struct asynchronous_arg_t arg;

        arg.stackaddr = NULL;
        arg.errnum = 0;
        arg.func = func;
        arg.self = self;
        arg.argc = argc;
        arg.argv = argv;

        thr = CreateThread(NULL, 0, call_asynchronous, &arg, 0, &val);

        if (thr) {
            yield_until(arg.stackaddr);

            if (rb_w32_wait_events_blocking(&thr, 1, INFINITE) != WAIT_OBJECT_0) {
                interrupted = TRUE;

                if (TerminateThread(thr, intrval)) {
                    yield_once();
                }
            }

            GetExitCodeThread(thr, &val);
            CloseHandle(thr);

            if (interrupted) {
                /* must release stack of killed thread, why doesn't Windows? */
                MEMORY_BASIC_INFORMATION m;

                memset(&m, 0, sizeof(m));
                if (!VirtualQuery(arg.stackaddr, &m, sizeof(m))) {
                    Debug(fprintf(stderr, "couldn't get stack base:%p:%d\n",
                                  arg.stackaddr, GetLastError()));
                }
                else if (!VirtualFree(m.AllocationBase, 0, MEM_RELEASE)) {
                    Debug(fprintf(stderr, "couldn't release stack:%p:%d\n",
                                  m.AllocationBase, GetLastError()));
                }
                errno = EINTR;
            }
            else {
                errno = arg.errnum;
            }
        }
    });

    if (!thr) {
        rb_fatal("failed to launch waiter thread:%ld", GetLastError());
    }

    return val;
}

char **
rb_w32_get_environ(void)
{
    char *envtop, *env;
    char **myenvtop, **myenv;
    int num;

    /*
     * We avoid values started with `='. If you want to deal those values,
     * change this function, and some functions in hash.c which recognize
     * `=' as delimiter or rb_w32_getenv() and ruby_setenv().
     * CygWin deals these values by changing first `=' to '!'. But we don't
     * use such trick and follow cmd.exe's way that just doesn't show these
     * values.
     * (U.N. 2001-11-15)
     */
    envtop = GetEnvironmentStrings();
    for (env = envtop, num = 0; *env; env += strlen(env) + 1)
        if (*env != '=') num++;

    myenvtop = (char **)malloc(sizeof(char *) * (num + 1));
    for (env = envtop, myenv = myenvtop; *env; env += strlen(env) + 1) {
        if (*env != '=') {
            if (!(*myenv = strdup(env))) {
                break;
            }
            myenv++;
        }
    }
    *myenv = NULL;
    FreeEnvironmentStrings(envtop);

    return myenvtop;
}

void
rb_w32_free_environ(char **env)
{
    char **t = env;

    while (*t) free(*t++);
    free(env);
}

rb_pid_t
rb_w32_getpid(void)
{
    rb_pid_t pid;

    pid = GetCurrentProcessId();

    (void)IfWin95(pid = -pid, 0);

    return pid;
}


rb_pid_t
rb_w32_getppid(void)
{
    typedef long (WINAPI query_func)(HANDLE, int, void *, ULONG, ULONG *);
    static query_func *pNtQueryInformationProcess = NULL;
    rb_pid_t ppid = 0;

    if (!IsWin95() && rb_w32_osver() >= 5) {
        if (!pNtQueryInformationProcess)
            pNtQueryInformationProcess = (query_func *)get_proc_address("ntdll.dll", "NtQueryInformationProcess", NULL);
        if (pNtQueryInformationProcess) {
            struct {
                long ExitStatus;
                void* PebBaseAddress;
                uintptr_t AffinityMask;
                uintptr_t BasePriority;
                uintptr_t UniqueProcessId;
                uintptr_t ParentProcessId;
            } pbi;
            ULONG len;
            long ret = pNtQueryInformationProcess(GetCurrentProcess(), 0, &pbi, sizeof(pbi), &len);
            if (!ret) {
                ppid = pbi.ParentProcessId;
            }
        }
    }

    return ppid;
}

int
rb_w32_uopen(const char *file, int oflag, ...)
{
    WCHAR *wfile;
    int ret;
    int pmode;

    va_list arg;
    va_start(arg, oflag);
    pmode = va_arg(arg, int);
    va_end(arg);

    if (!(wfile = utf8_to_wstr(file, NULL)))
        return -1;
    ret = rb_w32_wopen(wfile, oflag, pmode);
    free(wfile);
    return ret;
}

int
rb_w32_open(const char *file, int oflag, ...)
{
    WCHAR *wfile;
    int ret;
    int pmode;

    va_list arg;
    va_start(arg, oflag);
    pmode = va_arg(arg, int);
    va_end(arg);

    if ((oflag & O_TEXT) || !(oflag & O_BINARY))
        return _open(file, oflag, pmode);

    if (!(wfile = filecp_to_wstr(file, NULL)))
        return -1;
    ret = rb_w32_wopen(wfile, oflag, pmode);
    free(wfile);
    return ret;
}

int
rb_w32_wopen(const WCHAR *file, int oflag, ...)
{
    char flags = 0;
    int fd;
    DWORD access;
    DWORD create;
    DWORD attr = FILE_ATTRIBUTE_NORMAL;
    SECURITY_ATTRIBUTES sec;
    HANDLE h;

    if ((oflag & O_TEXT) || !(oflag & O_BINARY)) {
        va_list arg;
        int pmode;
        va_start(arg, oflag);
        pmode = va_arg(arg, int);
        va_end(arg);
        return _wopen(file, oflag, pmode);
    }

    sec.nLength = sizeof(sec);
    sec.lpSecurityDescriptor = NULL;
    if (oflag & O_NOINHERIT) {
        sec.bInheritHandle = FALSE;
        flags |= FNOINHERIT;
    }
    else {
        sec.bInheritHandle = TRUE;
    }
    oflag &= ~O_NOINHERIT;

    /* always open with binary mode */
    oflag &= ~(O_BINARY | O_TEXT);

    switch (oflag & (O_RDWR | O_RDONLY | O_WRONLY)) {
      case O_RDWR:
        access = GENERIC_READ | GENERIC_WRITE;
        break;
      case O_RDONLY:
        access = GENERIC_READ;
        break;
      case O_WRONLY:
        access = GENERIC_WRITE;
        break;
      default:
        errno = EINVAL;
        return -1;
    }
    oflag &= ~(O_RDWR | O_RDONLY | O_WRONLY);

    switch (oflag & (O_CREAT | O_EXCL | O_TRUNC)) {
      case O_CREAT:
        create = OPEN_ALWAYS;
        break;
      case 0:
      case O_EXCL:
        create = OPEN_EXISTING;
        break;
      case O_CREAT | O_EXCL:
      case O_CREAT | O_EXCL | O_TRUNC:
        create = CREATE_NEW;
        break;
      case O_TRUNC:
      case O_TRUNC | O_EXCL:
        create = TRUNCATE_EXISTING;
        break;
      case O_CREAT | O_TRUNC:
        create = CREATE_ALWAYS;
        break;
      default:
        errno = EINVAL;
        return -1;
    }
    if (oflag & O_CREAT) {
        va_list arg;
        int pmode;
        va_start(arg, oflag);
        pmode = va_arg(arg, int);
        va_end(arg);
        /* TODO: we need to check umask here, but it's not exported... */
        if (!(pmode & S_IWRITE))
            attr = FILE_ATTRIBUTE_READONLY;
    }
    oflag &= ~(O_CREAT | O_EXCL | O_TRUNC);

    if (oflag & O_TEMPORARY) {
        attr |= FILE_FLAG_DELETE_ON_CLOSE;
        access |= DELETE;
    }
    oflag &= ~O_TEMPORARY;

    if (oflag & _O_SHORT_LIVED)
        attr |= FILE_ATTRIBUTE_TEMPORARY;
    oflag &= ~_O_SHORT_LIVED;

    switch (oflag & (O_SEQUENTIAL | O_RANDOM)) {
      case 0:
        break;
      case O_SEQUENTIAL:
        attr |= FILE_FLAG_SEQUENTIAL_SCAN;
        break;
      case O_RANDOM:
        attr |= FILE_FLAG_RANDOM_ACCESS;
        break;
      default:
        errno = EINVAL;
        return -1;
    }
    oflag &= ~(O_SEQUENTIAL | O_RANDOM);

    if (oflag & ~O_APPEND) {
        errno = EINVAL;
        return -1;
    }

    /* allocate a C Runtime file handle */
    RUBY_CRITICAL({
        h = CreateFile("NUL", 0, 0, NULL, OPEN_ALWAYS, 0, NULL);
        fd = _open_osfhandle((intptr_t)h, 0);
        CloseHandle(h);
    });
    if (fd == -1) {
        errno = EMFILE;
        return -1;
    }
    RUBY_CRITICAL({
        MTHREAD_ONLY(EnterCriticalSection(&(_pioinfo(fd)->lock)));
        _set_osfhnd(fd, (intptr_t)INVALID_HANDLE_VALUE);
        _set_osflags(fd, 0);

        h = CreateFileW(file, access, FILE_SHARE_READ | FILE_SHARE_WRITE, &sec,
                        create, attr, NULL);
        if (h == INVALID_HANDLE_VALUE) {
            errno = map_errno(GetLastError());
            MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));
            fd = -1;
            goto quit;
        }

        switch (GetFileType(h)) {
          case FILE_TYPE_CHAR:
            flags |= FDEV;
            break;
          case FILE_TYPE_PIPE:
            flags |= FPIPE;
            break;
          case FILE_TYPE_UNKNOWN:
            errno = map_errno(GetLastError());
            CloseHandle(h);
            MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));
            fd = -1;
            goto quit;
        }
        if (!(flags & (FDEV | FPIPE)) && (oflag & O_APPEND))
            flags |= FAPPEND;

        _set_osfhnd(fd, (intptr_t)h);
        _osfile(fd) = flags | FOPEN;

        MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));
      quit:
        ;
    });

    return fd;
}

int
rb_w32_fclose(FILE *fp)
{
    int fd = fileno(fp);
    SOCKET sock = TO_SOCKET(fd);
    int save_errno = errno;

    if (fflush(fp)) return -1;
    if (!is_socket(sock)) {
        UnlockFile((HANDLE)sock, 0, 0, LK_LEN, LK_LEN);
        return fclose(fp);
    }
    _set_osfhnd(fd, (SOCKET)INVALID_HANDLE_VALUE);
    fclose(fp);
    errno = save_errno;
    if (closesocket(sock) == SOCKET_ERROR) {
        errno = map_errno(WSAGetLastError());
        return -1;
    }
    return 0;
}

int
rb_w32_pipe(int fds[2])
{
    static DWORD serial = 0;
    char name[] = "\\\\.\\pipe\\ruby0000000000000000-0000000000000000";
    char *p;
    SECURITY_ATTRIBUTES sec;
    HANDLE hRead, hWrite, h;
    int fdRead, fdWrite;
    int ret;

    /* if doesn't have CancelIo, use default pipe function */
    if (!cancel_io)
        return _pipe(fds, 65536L, _O_NOINHERIT);

    p = strchr(name, '0');
    snprintf(p, strlen(p) + 1, "%"PRI_PIDT_PREFIX"x-%lx", rb_w32_getpid(), serial++);

    sec.nLength = sizeof(sec);
    sec.lpSecurityDescriptor = NULL;
    sec.bInheritHandle = FALSE;

    RUBY_CRITICAL({
        hRead = CreateNamedPipe(name, PIPE_ACCESS_DUPLEX | FILE_FLAG_OVERLAPPED,
                                0, 2, 65536, 65536, 0, &sec);
    });
    if (hRead == INVALID_HANDLE_VALUE) {
        DWORD err = GetLastError();
        if (err == ERROR_PIPE_BUSY)
            errno = EMFILE;
        else
            errno = map_errno(GetLastError());
        return -1;
    }

    RUBY_CRITICAL({
        hWrite = CreateFile(name, GENERIC_READ | GENERIC_WRITE, 0, &sec,
                            OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
    });
    if (hWrite == INVALID_HANDLE_VALUE) {
        errno = map_errno(GetLastError());
        CloseHandle(hRead);
        return -1;
    }

    RUBY_CRITICAL(do {
        ret = 0;
        h = CreateFile("NUL", 0, 0, NULL, OPEN_ALWAYS, 0, NULL);
        fdRead = _open_osfhandle((intptr_t)h, 0);
        CloseHandle(h);
        if (fdRead == -1) {
            errno = EMFILE;
            CloseHandle(hWrite);
            CloseHandle(hRead);
            ret = -1;
            break;
        }

        MTHREAD_ONLY(EnterCriticalSection(&(_pioinfo(fdRead)->lock)));
        _set_osfhnd(fdRead, (intptr_t)hRead);
        _set_osflags(fdRead, FOPEN | FPIPE | FNOINHERIT);
        MTHREAD_ONLY(LeaveCriticalSection(&(_pioinfo(fdRead)->lock)));
    } while (0));
    if (ret)
        return ret;

    RUBY_CRITICAL(do {
        h = CreateFile("NUL", 0, 0, NULL, OPEN_ALWAYS, 0, NULL);
        fdWrite = _open_osfhandle((intptr_t)h, 0);
        CloseHandle(h);
        if (fdWrite == -1) {
            errno = EMFILE;
            CloseHandle(hWrite);
            ret = -1;
            break;
        }
        MTHREAD_ONLY(EnterCriticalSection(&(_pioinfo(fdWrite)->lock)));
        _set_osfhnd(fdWrite, (intptr_t)hWrite);
        _set_osflags(fdWrite, FOPEN | FPIPE | FNOINHERIT);
        MTHREAD_ONLY(LeaveCriticalSection(&(_pioinfo(fdWrite)->lock)));
    } while (0));
    if (ret) {
        rb_w32_close(fdRead);
        return ret;
    }

    fds[0] = fdRead;
    fds[1] = fdWrite;

    return 0;
}

int
rb_w32_close(int fd)
{
    SOCKET sock = TO_SOCKET(fd);
    int save_errno = errno;
    st_data_t key;

    if (!is_socket(sock)) {
        UnlockFile((HANDLE)sock, 0, 0, LK_LEN, LK_LEN);
        return _close(fd);
    }
    _set_osfhnd(fd, (SOCKET)INVALID_HANDLE_VALUE);
    key = (st_data_t)sock;
    st_delete(socklist, &key, NULL);
    sock = (SOCKET)key;
    _close(fd);
    errno = save_errno;
    if (closesocket(sock) == SOCKET_ERROR) {
        errno = map_errno(WSAGetLastError());
        return -1;
    }
    return 0;
}

static int
setup_overlapped(OVERLAPPED *ol, int fd)
{
    memset(ol, 0, sizeof(*ol));
    if (!(_osfile(fd) & (FDEV | FPIPE))) {
        LONG high = 0;
        DWORD method = _osfile(fd) & FAPPEND ? FILE_END : FILE_CURRENT;
        DWORD low = SetFilePointer((HANDLE)_osfhnd(fd), 0, &high, method);
#ifndef INVALID_SET_FILE_POINTER
#define INVALID_SET_FILE_POINTER ((DWORD)-1)
#endif
        if (low == INVALID_SET_FILE_POINTER) {
            DWORD err = GetLastError();
            if (err != NO_ERROR) {
                errno = map_errno(err);
                return -1;
            }
        }
        ol->Offset = low;
        ol->OffsetHigh = high;
    }
    ol->hEvent = CreateEvent(NULL, TRUE, TRUE, NULL);
    if (!ol->hEvent) {
        errno = map_errno(GetLastError());
        return -1;
    }
    return 0;
}

static void
finish_overlapped(OVERLAPPED *ol, int fd, DWORD size)
{
    CloseHandle(ol->hEvent);

    if (!(_osfile(fd) & (FDEV | FPIPE))) {
        LONG high = ol->OffsetHigh;
        DWORD low = ol->Offset + size;
        if (low < ol->Offset)
            ++high;
        SetFilePointer((HANDLE)_osfhnd(fd), low, &high, FILE_BEGIN);
    }
}

#undef read
ssize_t
rb_w32_read(int fd, void *buf, size_t size)
{
    SOCKET sock = TO_SOCKET(fd);
    DWORD read;
    DWORD wait;
    DWORD err;
    size_t len;
    size_t ret;
    OVERLAPPED ol, *pol = NULL;
    BOOL isconsole;
    BOOL islineinput = FALSE;
    int start = 0;

    if (is_socket(sock))
        return rb_w32_recv(fd, buf, size, 0);

    // validate fd by using _get_osfhandle() because we cannot access _nhandle
    if (_get_osfhandle(fd) == -1) {
        return -1;
    }

    if (_osfile(fd) & FTEXT) {
        return _read(fd, buf, size);
    }

    MTHREAD_ONLY(EnterCriticalSection(&(_pioinfo(fd)->lock)));

    if (!size || _osfile(fd) & FEOFLAG) {
        _set_osflags(fd, _osfile(fd) & ~FEOFLAG);
        MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));
        return 0;
    }

    ret = 0;
    isconsole = is_console(_osfhnd(fd)) && (osver.dwMajorVersion < 6 || (osver.dwMajorVersion == 6 && osver.dwMinorVersion < 2));
    if (isconsole) {
        DWORD mode;
        GetConsoleMode((HANDLE)_osfhnd(fd),&mode);
        islineinput = (mode & ENABLE_LINE_INPUT) != 0;
    }
  retry:
    /* get rid of console reading bug */
    if (isconsole) {
        if (start)
            len = 1;
        else {
            len = 0;
            start = 1;
        }
    }
    else
        len = size;
    size -= len;

    /* if have cancel_io, use Overlapped I/O */
    if (cancel_io) {
        if (setup_overlapped(&ol, fd)) {
            MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));
            return -1;
        }

        pol = &ol;
    }

    if (!ReadFile((HANDLE)_osfhnd(fd), buf, len, &read, pol)) {
        err = GetLastError();
        if (err != ERROR_IO_PENDING) {
            if (pol) CloseHandle(ol.hEvent);
            if (err == ERROR_ACCESS_DENIED)
                errno = EBADF;
            else if (err == ERROR_BROKEN_PIPE || err == ERROR_HANDLE_EOF) {
                MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));
                return 0;
            }
            else
                errno = map_errno(err);

            MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));
            return -1;
        }

        if (pol) {
            wait = rb_w32_wait_events_blocking(&ol.hEvent, 1, INFINITE);
            if (wait != WAIT_OBJECT_0) {
                if (wait == WAIT_OBJECT_0 + 1)
                    errno = EINTR;
                else
                    errno = map_errno(GetLastError());
                CloseHandle(ol.hEvent);
                cancel_io((HANDLE)_osfhnd(fd));
                MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));
                return -1;
            }

            if (!GetOverlappedResult((HANDLE)_osfhnd(fd), &ol, &read, TRUE) &&
                (err = GetLastError()) != ERROR_HANDLE_EOF) {
                int ret = 0;
                if (err != ERROR_BROKEN_PIPE) {
                    errno = map_errno(err);
                    ret = -1;
                }
                CloseHandle(ol.hEvent);
                cancel_io((HANDLE)_osfhnd(fd));
                MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));
                return ret;
            }
        }
    }

    if (pol) {
        finish_overlapped(&ol, fd, read);
    }

    ret += read;
    if (read >= len) {
        buf = (char *)buf + read;
        if (!(isconsole && len == 1 && (!islineinput || *((char *)buf - 1) == '\n')) && size > 0)
            goto retry;
    }
    if (read == 0)
        _set_osflags(fd, _osfile(fd) | FEOFLAG);


    MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));

    return ret;
}

#undef write
ssize_t
rb_w32_write(int fd, const void *buf, size_t size)
{
    SOCKET sock = TO_SOCKET(fd);
    DWORD written;
    DWORD wait;
    DWORD err;
    size_t len;
    size_t ret;
    OVERLAPPED ol, *pol = NULL;

    if (is_socket(sock))
        return rb_w32_send(fd, buf, size, 0);

    // validate fd by using _get_osfhandle() because we cannot access _nhandle
    if (_get_osfhandle(fd) == -1) {
        return -1;
    }

    if ((_osfile(fd) & FTEXT) &&
        (!(_osfile(fd) & FPIPE) || fd == fileno(stdout) || fd == fileno(stderr))) {
        return _write(fd, buf, size);
    }

    MTHREAD_ONLY(EnterCriticalSection(&(_pioinfo(fd)->lock)));

    if (!size || _osfile(fd) & FEOFLAG) {
        MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));
        return 0;
    }

    ret = 0;
  retry:
    /* get rid of console writing bug */
    len = (_osfile(fd) & FDEV) ? min(32 * 1024, size) : size;
    size -= len;

    /* if have cancel_io, use Overlapped I/O */
    if (cancel_io) {
        if (setup_overlapped(&ol, fd)) {
            MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));
            return -1;
        }

        pol = &ol;
    }

    if (!WriteFile((HANDLE)_osfhnd(fd), buf, len, &written, pol)) {
        err = GetLastError();
        if (err != ERROR_IO_PENDING) {
            if (pol) CloseHandle(ol.hEvent);
            if (err == ERROR_ACCESS_DENIED)
                errno = EBADF;
            else
                errno = map_errno(err);

            MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));
            return -1;
        }

        if (pol) {
            wait = rb_w32_wait_events_blocking(&ol.hEvent, 1, INFINITE);
            if (wait != WAIT_OBJECT_0) {
                if (wait == WAIT_OBJECT_0 + 1)
                    errno = EINTR;
                else
                    errno = map_errno(GetLastError());
                CloseHandle(ol.hEvent);
                cancel_io((HANDLE)_osfhnd(fd));
                MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));
                return -1;
            }

            if (!GetOverlappedResult((HANDLE)_osfhnd(fd), &ol, &written,
                                     TRUE)) {
                errno = map_errno(err);
                CloseHandle(ol.hEvent);
                cancel_io((HANDLE)_osfhnd(fd));
                MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));
                return -1;
            }
        }
    }

    if (pol) {
        finish_overlapped(&ol, fd, written);
    }

    ret += written;
    if (written == len) {
        buf = (const char *)buf + len;
        if (size > 0)
            goto retry;
    }

    MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));

    return ret;
}

long
rb_w32_write_console(uintptr_t strarg, int fd)
{
    static int disable;
    HANDLE handle;
    DWORD dwMode, reslen;
    VALUE str = strarg;

    if (disable) return -1L;
    handle = (HANDLE)_osfhnd(fd);
    if (!GetConsoleMode(handle, &dwMode) ||
        !rb_econv_has_convpath_p(rb_enc_name(rb_enc_get(str)), "UTF-16LE"))
        return -1L;

    str = rb_str_encode(str, rb_enc_from_encoding(rb_enc_find("UTF-16LE")),
                        ECONV_INVALID_REPLACE|ECONV_UNDEF_REPLACE, Qnil);
    if (!WriteConsoleW(handle, (LPWSTR)RSTRING_PTR(str), RSTRING_LEN(str)/2,
                       &reslen, NULL)) {
        if (GetLastError() == ERROR_CALL_NOT_IMPLEMENTED)
            disable = TRUE;
        return -1L;
    }
    return (long)reslen;
}

static int
unixtime_to_filetime(time_t time, FILETIME *ft)
{
    ULARGE_INTEGER tmp;

    tmp.QuadPart = ((LONG_LONG)time + (LONG_LONG)((1970-1601)*365.2425) * 24 * 60 * 60) * 10 * 1000 * 1000;
    ft->dwLowDateTime = tmp.LowPart;
    ft->dwHighDateTime = tmp.HighPart;
    return 0;
}

static int
wutime(const WCHAR *path, const struct utimbuf *times)
{
    HANDLE hFile;
    FILETIME atime, mtime;
    struct stati64 stat;
    int ret = 0;

    if (wstati64(path, &stat)) {
        return -1;
    }

    if (times) {
        if (unixtime_to_filetime(times->actime, &atime)) {
            return -1;
        }
        if (unixtime_to_filetime(times->modtime, &mtime)) {
            return -1;
        }
    }
    else {
        GetSystemTimeAsFileTime(&atime);
        mtime = atime;
    }

    RUBY_CRITICAL({
        const DWORD attr = GetFileAttributesW(path);
        if (attr != (DWORD)-1 && (attr & FILE_ATTRIBUTE_READONLY))
            SetFileAttributesW(path, attr & ~FILE_ATTRIBUTE_READONLY);
        hFile = CreateFileW(path, GENERIC_WRITE, 0, 0, OPEN_EXISTING,
                            IsWin95() ? 0 : FILE_FLAG_BACKUP_SEMANTICS, 0);
        if (hFile == INVALID_HANDLE_VALUE) {
            errno = map_errno(GetLastError());
            ret = -1;
        }
        else {
            if (!SetFileTime(hFile, NULL, &atime, &mtime)) {
                errno = map_errno(GetLastError());
                ret = -1;
            }
            CloseHandle(hFile);
        }
        if (attr != (DWORD)-1 && (attr & FILE_ATTRIBUTE_READONLY))
            SetFileAttributesW(path, attr);
    });

    return ret;
}

int
rb_w32_uutime(const char *path, const struct utimbuf *times)
{
    WCHAR *wpath;
    int ret;

    if (!(wpath = utf8_to_wstr(path, NULL)))
        return -1;
    ret = wutime(wpath, times);
    free(wpath);
    return ret;
}

int
rb_w32_utime(const char *path, const struct utimbuf *times)
{
    WCHAR *wpath;
    int ret;

    if (!(wpath = filecp_to_wstr(path, NULL)))
        return -1;
    ret = wutime(wpath, times);
    free(wpath);
    return ret;
}

int
rb_w32_uchdir(const char *path)
{
    WCHAR *wpath;
    int ret;

    if (!(wpath = utf8_to_wstr(path, NULL)))
        return -1;
    ret = _wchdir(wpath);
    free(wpath);
    return ret;
}

static int
wmkdir(const WCHAR *wpath, int mode)
{
    int ret = -1;

    RUBY_CRITICAL(do {
        if (CreateDirectoryW(wpath, NULL) == FALSE) {
            errno = map_errno(GetLastError());
            break;
        }
        if (_wchmod(wpath, mode) == -1) {
            RemoveDirectoryW(wpath);
            break;
        }
        ret = 0;
    } while (0));
    return ret;
}

int
rb_w32_umkdir(const char *path, int mode)
{
    WCHAR *wpath;
    int ret;

    if (!(wpath = utf8_to_wstr(path, NULL)))
        return -1;
    ret = wmkdir(wpath, mode);
    free(wpath);
    return ret;
}

int
rb_w32_mkdir(const char *path, int mode)
{
    WCHAR *wpath;
    int ret;

    if (!(wpath = filecp_to_wstr(path, NULL)))
        return -1;
    ret = wmkdir(wpath, mode);
    free(wpath);
    return ret;
}

static int
wrmdir(const WCHAR *wpath)
{
    int ret = 0;
    RUBY_CRITICAL({
        const DWORD attr = GetFileAttributesW(wpath);
        if (attr != (DWORD)-1 && (attr & FILE_ATTRIBUTE_READONLY)) {
            SetFileAttributesW(wpath, attr & ~FILE_ATTRIBUTE_READONLY);
        }
        if (RemoveDirectoryW(wpath) == FALSE) {
            errno = map_errno(GetLastError());
            ret = -1;
            if (attr != (DWORD)-1 && (attr & FILE_ATTRIBUTE_READONLY)) {
                SetFileAttributesW(wpath, attr);
            }
        }
    });
    return ret;
}

int
rb_w32_rmdir(const char *path)
{
    WCHAR *wpath;
    int ret;

    if (!(wpath = filecp_to_wstr(path, NULL)))
        return -1;
    ret = wrmdir(wpath);
    free(wpath);
    return ret;
}

int
rb_w32_urmdir(const char *path)
{
    WCHAR *wpath;
    int ret;

    if (!(wpath = utf8_to_wstr(path, NULL)))
        return -1;
    ret = wrmdir(wpath);
    free(wpath);
    return ret;
}

static int
wunlink(const WCHAR *path)
{
    int ret = 0;
    RUBY_CRITICAL({
        const DWORD attr = GetFileAttributesW(path);
        if (attr != (DWORD)-1 && (attr & FILE_ATTRIBUTE_READONLY)) {
            SetFileAttributesW(path, attr & ~FILE_ATTRIBUTE_READONLY);
        }
        if (!DeleteFileW(path)) {
            errno = map_errno(GetLastError());
            ret = -1;
            if (attr != (DWORD)-1 && (attr & FILE_ATTRIBUTE_READONLY)) {
                SetFileAttributesW(path, attr);
            }
        }
    });
    return ret;
}

int
rb_w32_uunlink(const char *path)
{
    WCHAR *wpath;
    int ret;

    if (!(wpath = utf8_to_wstr(path, NULL)))
        return -1;
    ret = wunlink(wpath);
    free(wpath);
    return ret;
}

int
rb_w32_unlink(const char *path)
{
    WCHAR *wpath;
    int ret;

    if (!(wpath = filecp_to_wstr(path, NULL)))
        return -1;
    ret = wunlink(wpath);
    free(wpath);
    return ret;
}

int
rb_w32_uchmod(const char *path, int mode)
{
    WCHAR *wpath;
    int ret;

    if (!(wpath = utf8_to_wstr(path, NULL)))
        return -1;
    ret = _wchmod(wpath, mode);
    free(wpath);
    return ret;
}

#if !defined(__BORLANDC__)
int
rb_w32_isatty(int fd)
{
    DWORD mode;

    // validate fd by using _get_osfhandle() because we cannot access _nhandle
    if (_get_osfhandle(fd) == -1) {
        return 0;
    }
    if (!GetConsoleMode((HANDLE)_osfhnd(fd), &mode)) {
        errno = ENOTTY;
        return 0;
    }
    return 1;
}
#endif

//
// Fix bcc32's stdio bug
//

#ifdef __BORLANDC__
static int
too_many_files(void)
{
    FILE *f;
    for (f = _streams; f < _streams + _nfile; f++) {
        if (f->fd < 0) return 0;
    }
    return 1;
}

#undef fopen
FILE *
rb_w32_fopen(const char *path, const char *mode)
{
    FILE *f = (errno = 0, fopen(path, mode));
    if (f == NULL && errno == 0) {
        if (too_many_files())
            errno = EMFILE;
    }
    return f;
}

FILE *
rb_w32_fdopen(int handle, const char *type)
{
    FILE *f = (errno = 0, _fdopen(handle, (char *)type));
    if (f == NULL && errno == 0) {
        if (handle < 0)
            errno = EBADF;
        else if (too_many_files())
            errno = EMFILE;
    }
    return f;
}

FILE *
rb_w32_fsopen(const char *path, const char *mode, int shflags)
{
    FILE *f = (errno = 0, _fsopen(path, mode, shflags));
    if (f == NULL && errno == 0) {
        if (too_many_files())
            errno = EMFILE;
    }
    return f;
}
#endif

#if defined(_MSC_VER) && RT_VER <= 60
extern long _ftol(double);
long
_ftol2(double d)
{
    return _ftol(d);
}
long
_ftol2_sse(double d)
{
    return _ftol(d);
}
#endif

#ifndef signbit
int
signbit(double x)
{
    int *ip = (int *)(&x + 1) - 1;
    return *ip < 0;
}
#endif

char * WSAAPI
rb_w32_inet_ntop(int af, void *addr, char *numaddr, size_t numaddr_len)
{
    typedef char *(WSAAPI inet_ntop_t)(int, void *, char *, size_t);
    inet_ntop_t *pInetNtop;
    pInetNtop = (inet_ntop_t *)get_proc_address("ws2_32", "inet_ntop", NULL);
    if(pInetNtop){
       return pInetNtop(af,addr,numaddr,numaddr_len);
    }else{
       struct in_addr in;
       memcpy(&in.s_addr, addr, sizeof(in.s_addr));
       snprintf(numaddr, numaddr_len, "%s", inet_ntoa(in));
    }
    return numaddr;
}

char
rb_w32_fd_is_text(int fd) {
    return _osfile(fd) & FTEXT;
}

---