GPCS4/3rdParty/pthreads4w/errno.c
2019-06-23 06:00:43 +08:00

103 lines
2.6 KiB
C

/*
* errno.c
*
* Description:
* This translation unit implements routines associated with spawning a new
* thread.
*
* --------------------------------------------------------------------------
*
* Pthreads4w - POSIX Threads for Windows
* Copyright 1998 John E. Bossom
* Copyright 1999-2018, Pthreads4w contributors
*
* Homepage: https://sourceforge.net/projects/pthreads4w/
*
* The current list of contributors is contained
* in the file CONTRIBUTORS included with the source
* code distribution. The list can also be seen at the
* following World Wide Web location:
*
* https://sourceforge.net/p/pthreads4w/wiki/Contributors/
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#if defined(NEED_ERRNO)
#include "pthread.h"
#include "implement.h"
static int reallyBad = ENOMEM;
/*
* Re-entrant errno.
*
* Each thread has it's own errno variable in pthread_t.
*
* The benefit of using the pthread_t structure
* instead of another TSD key is TSD keys are limited
* on Win32 to 64 per process. Secondly, to implement
* it properly without using pthread_t you'd need
* to dynamically allocate an int on starting the thread
* and store it manually into TLS and then ensure that you free
* it on thread termination. We get all that for free
* by simply storing the errno on the pthread_t structure.
*
* MSVC and Mingw32 already have their own thread-safe errno.
*
* #if defined( _REENTRANT ) || defined( _MT )
* #define errno *_errno()
*
* int *_errno( void );
* #else
* extern int errno;
* #endif
*
*/
int *
_errno (void)
{
pthread_t self;
int *result;
if ((self = pthread_self ()).p == NULL)
{
/*
* Yikes! unable to allocate a thread!
* Throw an exception? return an error?
*/
result = &reallyBad;
}
else
{
result = (int *)(&((__ptw32_thread_t *)self.p)->exitStatus);
}
return (result);
} /* _errno */
#endif /* (NEED_ERRNO) */
#if ! defined (__PTW32_BUILD_INLINED)
/*
* Avoid "translation unit is empty" warnings
*/
typedef int foo;
#endif