From 451bb0670ddd5f5c0606410f2b5f51733119645d Mon Sep 17 00:00:00 2001 From: rpj Date: Sat, 3 Apr 1999 22:05:39 +0000 Subject: ./ChangeLog Sun Apr 4 11:05:57 1999 Ross Johnson * sched.c (sched.h): Include. * sched.h: New file for POSIX 1b scheduling. * pthread.h: Move opaque structures to implement.h; move sched_* prototypes out and into sched.h. * implement.h: Add opaque structures from pthread.h. * sched.c (sched_yield): New function. * condvar.c (_pthread_sem_*): Rename to sem_*; except for _pthread_sem_timedwait which is an private function. Sat Apr 3 23:28:00 1999 Ross Johnson * Makefile.in (OBJS): Add errno.o. Fri Apr 2 11:08:50 1999 Ross Johnson * implement.h (_pthread_sem_*): Remove prototypes now defined in semaphore.h. * pthread.h (sempahore.h): Include. * semaphore.h: New file for POSIX 1b semaphores. * pthread.h (_pthread_sem_t): Change to sem_t. * semaphore.c (_pthread_sem_*): Change to sem_*; these functions will be exported from the library; set errno on error. - John Bossom (_pthread_sem_timedwait): Moved to private.c. * private.c (_pthread_sem_timedwait): Moved from semaphore.c; set errno on error. * errno.c (_errno): New file. New function. - John Bossom * pthread.h (pthread_t_): Add per-thread errno element. tests/ChangeLog Sun Apr 4 12:04:28 1999 Ross Johnson * tsd1.c (mythread): Change Sleep(0) to sched_yield(). (sched.h): Include. * condvar3.c (mythread): Remove redundant Sleep(). * runtest.bat: Re-organised to make more informative. --- errno.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 87 insertions(+) create mode 100644 errno.c (limited to 'errno.c') diff --git a/errno.c b/errno.c new file mode 100644 index 0000000..e6cf5e7 --- /dev/null +++ b/errno.c @@ -0,0 +1,87 @@ +/* + * errno.c + * + * Description: + * This translation unit implements routines associated with spawning a new + * thread. + * + * Pthreads-win32 - POSIX Threads Library for Win32 + * Copyright (C) 1998 + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, + * MA 02111-1307, USA + */ + +#if defined( _REENTRANT ) || defined( _MT ) + +#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. + * + * Relies on the following being defined in errno.h: + * (true for MSVC and Mingw32 I think) + * + * #if defined( _REENTRANT ) || defined( _MT ) + * #define errno *_errno() + * + * int *_errno( void ); + * #else + * extern int errno; + * #endif /* _REENTRANT */ + * + */ + +int * _errno( void ) +{ + pthread_t *self; + int *result; + + if( ( self = pthread_self() ) == NULL ) + { + /* + * Yikes! unable to allocate a thread! + * Throw an exception? return an error? + */ + result = &reallyBad; + } + else + { + result = &(self->ptErrno); + } + + return( result ); + +} /* _errno */ + +#else + +#error "errno: Not thread-safe." + +#endif /* _REENTRANT || _MT */ -- cgit v1.2.3