/* now define version that doesn't lock/unlock, validate fh */
int __cdecl _close_lk (
int fh
)
{
DWORD dosretval;
#else
/* now define normal version */
int __cdecl _close (
int fh
)
{
DWORD dosretval;
/* validate file handle */
if ( ((unsigned)fh >= (unsigned)_nhandle) ||
!(_osfile(fh) & FOPEN) )
{
/* bad file handle, set errno and abort */
errno = EBADF;
_doserrno = 0; /* no o.s. error */
return -1;
}
#endif
/*
* Close the underlying OS file handle. Note that if fh is STDOUT
* or STDERR, and if STDOUT and STDERR are mapped to the same OS
* file handle, the close is skipped (without error). STDOUT and
* STDERR are the only handles for which this support is provided.
* Other handles are mapped to the same OS file handle only at the
* programmer's risk.
*/
if ( ( ((fh == 1) || (fh == 2)) &&
(_get_osfhandle(1) == _get_osfhandle(2)) ) ||
CloseHandle( (HANDLE)_get_osfhandle(fh) ) )
{
dosretval = 0L;
}
else
dosretval = GetLastError();
_free_osfhnd(fh);
if (dosretval) {
/* OS error */
_dosmaperr(dosretval);
return -1;
}
_osfile(fh) = 0; /* clear file flags */
return 0; /* good return */
}
int
WIN32_Close_FD_Socket(int fd)
{
int result = 0;
if (closesocket(_get_osfhandle(fd)) == SOCKET_ERROR) {
errno = WSAGetLastError();
result = 1;
}
_free_osfhnd(fd);
_osfile(fd) = 0;
return result;
}
extern "C" int __cdecl _close_nolock(int const fh)
{
DWORD const close_os_handle_error = close_os_handle_nolock(fh);
_free_osfhnd(fh);
_osfile(fh) = 0;
if (close_os_handle_error != 0)
{
__acrt_errno_map_os_error(close_os_handle_error);
return -1;
}
return 0;
}
int close(int fh) {
if (folly::portability::sockets::is_fh_socket(fh)) {
SOCKET h = (SOCKET)_get_osfhandle(fh);
// If we were to just call _close on the descriptor, it would
// close the HANDLE, but it wouldn't free any of the resources
// associated to the SOCKET, and we can't call _close after
// calling closesocket, because closesocket has already closed
// the HANDLE, and _close would attempt to close the HANDLE
// again, resulting in a double free.
// Luckily though, there is a function in the internals of the
// CRT that is used to free only the file descriptor, so we
// can call that to avoid leaking the file descriptor itself.
auto c = closesocket(h);
_free_osfhnd(fh);
return c;
}
return _close(fh);
}
FILE * __cdecl _tpopen (
const _TSCHAR *cmdstring,
const _TSCHAR *type
)
{
int phdls[2]; /* I/O handles for pipe */
int ph_open[2]; /* flags, set if correspond phdls is open */
int i1; /* index into phdls[] */
int i2; /* index into phdls[] */
int tm = 0; /* flag indicating text or binary mode */
int stdhdl; /* either STDIN or STDOUT */
HANDLE osfhndsv1; /* used to save _osfhnd(stdhdl) */
long osfhndsv2; /* used to save _osfhnd(phdls[i2]) */
char osfilesv1; /* used to save _osfile(stdhdl) */
char osfilesv2; /* used to save _osfile(phdls[i2]) */
HANDLE oldhnd; /* used to hold OS file handle values... */
HANDLE newhnd; /* ...in calls to DuplicateHandle API */
FILE *pstream; /* stream to be associated with pipe */
HANDLE prochnd; /* handle for current process */
_TSCHAR *cmdexe; /* pathname for the command processor */
int childhnd; /* handle for child process (cmd.exe) */
IDpair *locidpair; /* pointer to IDpair table entry */
/* first check for errors in the arguments
*/
if ( (cmdstring == NULL) || (type == NULL) || ((*type != 'w') &&
(*type != _T('r'))) )
goto error1;
/* do the _pipe(). note that neither of the resulting handles will
* be inheritable.
*/
if ( *(type + 1) == _T('t') )
tm = _O_TEXT;
else if ( *(type + 1) == _T('b') )
tm = _O_BINARY;
tm |= _O_NOINHERIT;
if ( _pipe( phdls, PSIZE, tm ) == -1 )
goto error1;
/* test *type and set stdhdl, i1 and i2 accordingly.
*/
if ( *type == _T('w') ) {
stdhdl = STDIN;
i1 = 0;
i2 = 1;
}
else {
stdhdl = STDOUT;
i1 = 1;
i2 = 0;
}
/* the pipe now exists. the following steps must be carried out before
* the child process (cmd.exe) may be spawned:
*
* 1. save a non-inheritable dup of stdhdl
*
* 2. force stdhdl to be a dup of ph[i1]. close both ph[i1] and
* the original OS handle underlying stdhdl
*
* 3. associate a stdio-level stream with ph[i2].
*/
/* set flags to indicate pipe handles are open. note, these are only
* used for error recovery.
*/
ph_open[ 0 ] = ph_open[ 1 ] = 1;
/* get the process handle, it will be needed in some API calls
*/
prochnd = GetCurrentProcess();
/* MULTI-THREAD: ASSERT LOCK ON STDHDL HERE!!!!
*/
_lock_fh( stdhdl );
/* save a non-inheritable copy of stdhdl for later restoration.
*/
oldhnd = (HANDLE)_osfhnd( stdhdl );
if ( (oldhnd == INVALID_HANDLE_VALUE) ||
!DuplicateHandle( prochnd,
oldhnd,
prochnd,
&osfhndsv1,
0L,
FALSE, /* non-inheritable */
DUPLICATE_SAME_ACCESS )
) {
goto error2;
}
osfilesv1 = _osfile( stdhdl );
/* force stdhdl to an inheritable dup of phdls[i1] (i.e., force
* STDIN to the pipe read handle or STDOUT to the pipe write handle)
* and close phdls[i1] (so there won't be a stray open handle on the
* pipe after a _pclose). also, clear ph_open[i1] flag so that error
* recovery won't try to close it again.
*/
if ( !DuplicateHandle( prochnd,
(HANDLE)_osfhnd( phdls[i1] ),
prochnd,
&newhnd,
0L,
TRUE, /* inheritable */
DUPLICATE_SAME_ACCESS )
) {
goto error3;
}
(void)CloseHandle( (HANDLE)_osfhnd(stdhdl) );
_free_osfhnd( stdhdl );
_set_osfhnd( stdhdl, (long)newhnd );
_osfile( stdhdl ) = _osfile( phdls[i1] );
(void)_close( phdls[i1] );
ph_open[ i1 ] = 0;
/* associate a stream with phdls[i2]. note that if there are no
* errors, pstream is the return value to the caller.
*/
if ( (pstream = _tfdopen( phdls[i2], type )) == NULL )
goto error4;
/* MULTI-THREAD: ASSERT LOCK ON IDPAIRS HERE!!!!
*/
_mlock( _POPEN_LOCK );
/* next, set locidpair to a free entry in the idpairs table.
*/
if ( (locidpair = idtab( NULL )) == NULL )
goto error5;
/* temporarily change the osfhnd and osfile entries so that
* the child doesn't get any entries for phdls[i2].
*/
osfhndsv2 = _osfhnd( phdls[i2] );
_osfhnd( phdls[i2] ) = (long)INVALID_HANDLE_VALUE;
osfilesv2 = _osfile( phdls[i2] );
_osfile( phdls[i2] ) = 0;
/* spawn the child copy of cmd.exe. the algorithm is adapted from
* SYSTEM.C, and behaves the same way.
*/
if ( ((cmdexe = _tgetenv(_T("COMSPEC"))) == NULL) ||
(((childhnd = _tspawnl( _P_NOWAIT,
cmdexe,
cmdexe,
_T("/c"),
cmdstring,
NULL ))
== -1) && ((errno == ENOENT) || (errno == EACCES))) ) {
/*
* either COMSPEC wasn't defined, or the spawn failed because
* cmdexe wasn't found or was inaccessible. in either case, try to
* spawn "cmd.exe" (Windows NT) or "command.com" (Windows 95) instead
* Note that spawnlp is used here so that the path is searched.
*/
cmdexe = ( _osver & 0x8000 ) ? _T("command.com") : _T("cmd.exe");
childhnd = _tspawnlp( _P_NOWAIT,
cmdexe,
cmdexe,
_T("/c"),
cmdstring,
NULL);
}
_osfhnd( phdls[i2] ) = osfhndsv2;
_osfile( phdls[i2] ) = osfilesv2;
/* check if the last (perhaps only) spawn attempt was successful
*/
if ( childhnd == -1 )
goto error6;
/* restore stdhdl for the current process, set value of *locidpair,
* close osfhndsv1 (note that CloseHandle must be used instead of close)
* and return pstream to the caller
*/
(void)DuplicateHandle( prochnd,
osfhndsv1,
prochnd,
&newhnd,
0L,
TRUE, /* inheritable */
DUPLICATE_CLOSE_SOURCE | /* close osfhndsv1 */
DUPLICATE_SAME_ACCESS );
(void)CloseHandle( (HANDLE)_osfhnd(stdhdl) );
_free_osfhnd( stdhdl );
_set_osfhnd( stdhdl, (long)newhnd );
_osfile(stdhdl) = osfilesv1;
/* MULTI-THREAD: RELEASE LOCK ON STDHDL HERE!!!!
*/
_unlock_fh( stdhdl );
locidpair->prochnd = childhnd;
locidpair->stream = pstream;
/* MULTI-THREAD: RELEASE LOCK ON IDPAIRS HERE!!!!
*/
_munlock( _POPEN_LOCK );
/* all successful calls to _popen return to the caller via this return
* statement!
*/
return( pstream );
/**
* error handling code. all detected errors end up here, entering
* via a goto one of the labels. note that the logic is currently
* a straight fall-thru scheme (e.g., if entered at error5, the
* code for error5, error4,...,error1 is all executed).
**********************************************************************/
error6: /* make sure locidpair is reusable
*/
locidpair->stream = NULL;
error5: /* close pstream (also, clear ph_open[i2] since the stream
* close will also close the pipe handle)
*/
(void)fclose( pstream );
ph_open[ i2 ] = 0;
/* MULTI-THREAD: RELEASE LOCK ON IDPAIRS HERE!!!!
*/
_munlock(_POPEN_LOCK);
error4: /* restore stdhdl
*/
(void)DuplicateHandle( prochnd,
osfhndsv1,
prochnd,
&newhnd,
0L,
TRUE,
DUPLICATE_SAME_ACCESS );
(void)CloseHandle( (HANDLE)_osfhnd(stdhdl) );
_free_osfhnd( stdhdl );
_set_osfhnd( stdhdl, (long)newhnd );
_osfile( stdhdl ) = osfilesv1;
/* MULTI-THREAD: RELEASE LOCK ON STDHDL HERE!!!!
*/
_unlock_fh( stdhdl );
error3: /* close osfhndsv1
*/
CloseHandle( osfhndsv1 );
error2: /* close handles on pipe (if they are still open)
*/
if ( ph_open[i1] )
_close( phdls[i1] );
if ( ph_open[i2] )
_close( phdls[i2] );
error1: /* return NULL to the caller indicating failure
*/
return( NULL );
}
