reactos/sdk/lib/ucrt/conio/pipe.cpp
2025-01-16 14:18:53 +02:00

115 lines
3.4 KiB
C++

//
// pipe.cpp
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// Defines _pipe(), which creates a pipe.
//
#include <corecrt_internal_lowio.h>
#include <stdlib.h>
// Creates a pipe. The phandles pointer must be a pointer to an array of two
// int objects. Upon successful return, phandles[0] is the read handle, and
// phandles[1] is the write handle for the pipe. On success, 0 is returned; on
// failure, -1 is returned and errno is set.
//
// The psize is the amount of memory, in bytes, to ask the OS to reserve for the
// pipe. The textmode is the text mode that will be given to the pipe.
extern "C" int __cdecl _pipe(int* const phandles, unsigned const psize, int const textmode)
{
_VALIDATE_CLEAR_OSSERR_RETURN(phandles != nullptr, EINVAL, -1);
phandles[0] = phandles[1] = -1;
_VALIDATE_CLEAR_OSSERR_RETURN((textmode & ~(_O_NOINHERIT | _O_BINARY | _O_TEXT)) == 0, EINVAL, -1);
_VALIDATE_CLEAR_OSSERR_RETURN((textmode & (_O_BINARY | _O_TEXT)) != (_O_BINARY | _O_TEXT), EINVAL, -1);
SECURITY_ATTRIBUTES security_attributes;
security_attributes.nLength = sizeof(security_attributes);
security_attributes.lpSecurityDescriptor = nullptr;
security_attributes.bInheritHandle = (textmode & _O_NOINHERIT) == 0;
// Create the pipe:
HANDLE read_handle, write_handle;
if (!CreatePipe(&read_handle, &write_handle, &security_attributes, psize))
{
__acrt_errno_map_os_error(GetLastError());
return -1;
}
// Create the CRT read handle for the pipe:
int const crt_read_handle = _alloc_osfhnd();
if (crt_read_handle == -1)
{
errno = EMFILE;
_doserrno = 0;
CloseHandle(read_handle);
CloseHandle(write_handle);
return -1;
}
__try
{
_osfile(crt_read_handle) = FOPEN | FPIPE | FTEXT;
_textmode(crt_read_handle) = __crt_lowio_text_mode::ansi;
_tm_unicode(crt_read_handle) = false;
}
__finally
{
__acrt_lowio_unlock_fh(crt_read_handle);
}
__endtry
// Create the CRT write handle for the pipe:
int const crt_write_handle = _alloc_osfhnd();
if (crt_write_handle == -1)
{
_osfile(crt_read_handle) = 0;
errno = EMFILE;
_doserrno = 0;
CloseHandle(read_handle);
CloseHandle(write_handle);
return -1;
}
__try
{
_osfile(crt_write_handle) = FOPEN | FPIPE | FTEXT;
_textmode(crt_write_handle) = __crt_lowio_text_mode::ansi;
_tm_unicode(crt_write_handle) = false;
}
__finally
{
__acrt_lowio_unlock_fh(crt_write_handle);
}
__endtry
// Figure out which textmode the file gets:
int fmode = 0;
_ERRCHECK(_get_fmode(&fmode));
// The pipe gets binary mode if (a) binary was requested or (b) the
// global default fmode was changed to binary.
if ((textmode & _O_BINARY) || ((textmode & _O_TEXT) == 0 && fmode == _O_BINARY))
{
_osfile(crt_read_handle) &= ~FTEXT;
_osfile(crt_write_handle) &= ~FTEXT;
}
if (textmode & _O_NOINHERIT)
{
_osfile(crt_read_handle) |= FNOINHERIT;
_osfile(crt_write_handle) |= FNOINHERIT;
}
__acrt_lowio_set_os_handle(crt_read_handle, reinterpret_cast<intptr_t>(read_handle));
__acrt_lowio_set_os_handle(crt_write_handle, reinterpret_cast<intptr_t>(write_handle));
phandles[0] = crt_read_handle;
phandles[1] = crt_write_handle;
return 0;
}