glibc/sysdeps/htl/pt-mutex-trylock.c
Samuel Thibault 33574c17ee hurd: Add hurd thread library
Contributed by

Agustina Arzille <avarzille@riseup.net>
Amos Jeffries <squid3@treenet.co.nz>
David Michael <fedora.dm0@gmail.com>
Marco Gerards <marco@gnu.org>
Marcus Brinkmann <marcus@gnu.org>
Neal H. Walfield <neal@gnu.org>
Pino Toscano <toscano.pino@tiscali.it>
Richard Braun <rbraun@sceen.net>
Roland McGrath <roland@gnu.org>
Samuel Thibault <samuel.thibault@ens-lyon.org>
Thomas DiModica <ricinwich@yahoo.com>
Thomas Schwinge <tschwinge@gnu.org>

	* htl: New directory.
	* sysdeps/htl: New directory.
	* sysdeps/hurd/htl: New directory.
	* sysdeps/i386/htl: New directory.
	* sysdeps/mach/htl: New directory.
	* sysdeps/mach/hurd/htl: New directory.
	* sysdeps/mach/hurd/i386/htl: New directory.
	* nscd/Depend, resolv/Depend, rt/Depend: Add htl dependency.
	* sysdeps/mach/hurd/i386/Implies: Add mach/hurd/i386/htl imply.
	* sysdeps/mach/hurd/i386/libpthread.abilist: New file.
2018-04-02 01:44:14 +02:00

112 lines
2.8 KiB
C

/* Try to Lock a mutex. Generic version.
Copyright (C) 2002-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C 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.
The GNU C 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 the GNU C Library; see the file COPYING.LIB. If
not, see <http://www.gnu.org/licenses/>. */
#include <pthread.h>
#include <pt-internal.h>
#define LOSE do { * (int *) 0 = 0; } while (1)
/* Lock MUTEX, return EBUSY if we can't get it. */
int
__pthread_mutex_trylock (struct __pthread_mutex *mutex)
{
int err;
struct __pthread *self;
const struct __pthread_mutexattr *attr = mutex->__attr;
if (attr == __PTHREAD_ERRORCHECK_MUTEXATTR)
attr = &__pthread_errorcheck_mutexattr;
if (attr == __PTHREAD_RECURSIVE_MUTEXATTR)
attr = &__pthread_recursive_mutexattr;
__pthread_spin_lock (&mutex->__lock);
if (__pthread_spin_trylock (&mutex->__held) == 0)
/* Acquired the lock. */
{
#if defined(ALWAYS_TRACK_MUTEX_OWNER)
# ifndef NDEBUG
self = _pthread_self ();
if (self != NULL)
/* The main thread may take a lock before the library is fully
initialized, in particular, before the main thread has a
TCB. */
{
assert (mutex->__owner == NULL);
mutex->__owner = _pthread_self ();
}
# endif
#endif
if (attr != NULL)
switch (attr->__mutex_type)
{
case PTHREAD_MUTEX_NORMAL:
break;
case PTHREAD_MUTEX_RECURSIVE:
mutex->__locks = 1;
case PTHREAD_MUTEX_ERRORCHECK:
mutex->__owner = _pthread_self ();
break;
default:
LOSE;
}
__pthread_spin_unlock (&mutex->__lock);
return 0;
}
err = EBUSY;
if (attr != NULL)
{
self = _pthread_self ();
switch (attr->__mutex_type)
{
case PTHREAD_MUTEX_NORMAL:
break;
case PTHREAD_MUTEX_ERRORCHECK:
/* We could check if MUTEX->OWNER is SELF, however, POSIX
does not permit pthread_mutex_trylock to return EDEADLK
instead of EBUSY, only pthread_mutex_lock. */
break;
case PTHREAD_MUTEX_RECURSIVE:
if (mutex->__owner == self)
{
mutex->__locks++;
err = 0;
}
break;
default:
LOSE;
}
}
__pthread_spin_unlock (&mutex->__lock);
return err;
}
strong_alias (__pthread_mutex_trylock, _pthread_mutex_trylock);
strong_alias (__pthread_mutex_trylock, pthread_mutex_trylock);