glibc/nptl/pthread_cancel.c
Ulrich Drepper db54f488ee Update.
2003-07-07  Ulrich Drepper  <drepper@redhat.com>

	* descr.h (struct pthread): Add pid field.
	* allocatestack.c (allocate_stack): Initialize pid field in descriptor.
	(__reclaim_stacks): Likewise.
	* init.c (sigcancel_handler): If __ASSUME_CORRECT_SI_PID is defined
	also check for PID of the signal source.
	(__pthread_initialize_minimal_internal): Also initialize pid field
	of initial thread's descriptor.
	* pthread_cancel.c: Use tgkill instead of tkill if possible.
	* sysdeps/unix/sysv/linux/fork.c: Likewise.
	* sysdeps/unix/sysv/linux/pt-raise.c: Likewise.
	* sysdeps/unix/sysv/linux/pthread_kill.c: Likewise.
	* sysdeps/unix/sysv/linux/raise.c: Likewise.
2003-07-08 03:40:49 +00:00

94 lines
2.8 KiB
C

/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <signal.h>
#include "pthreadP.h"
#include "atomic.h"
#include <sysdep.h>
#include <kernel-features.h>
int
pthread_cancel (th)
pthread_t th;
{
volatile struct pthread *pd = (volatile struct pthread *) th;
/* Make sure the descriptor is valid. */
if (INVALID_TD_P (pd))
/* Not a valid thread handle. */
return ESRCH;
int result = 0;
int oldval;
int newval;
do
{
oldval = pd->cancelhandling;
newval = oldval | CANCELING_BITMASK | CANCELED_BITMASK;
/* Avoid doing unnecessary work. The atomic operation can
potentially be expensive if the bug has to be locked and
remote cache lines have to be invalidated. */
if (oldval == newval)
break;
/* If the cancellation is handled asynchronously just send a
signal. We avoid this if possible since it's more
expensive. */
if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval))
{
/* Mark the cancellation as "in progress". */
atomic_bit_set (&pd->cancelhandling, CANCELING_BIT);
/* The cancellation handler will take care of marking the
thread as canceled. */
INTERNAL_SYSCALL_DECL (err);
int val;
#if __ASSUME_TGKILL
val = INTERNAL_SYSCALL (tgkill, err, 3,
THREAD_GETMEM (THREAD_SELF, pid), pd->tid,
SIGCANCEL);
#else
# ifdef __NR_tgkill
val = INTERNAL_SYSCALL (tgkill, err, 3,
THREAD_GETMEM (THREAD_SELF, pid), pd->tid,
SIGCANCEL);
if (INTERNAL_SYSCALL_ERROR_P (val, err)
&& INTERNAL_SYSCALL_ERRNO (val, err) == ENOSYS)
# endif
val = INTERNAL_SYSCALL (tkill, err, 2, pd->tid, SIGCANCEL);
#endif
if (INTERNAL_SYSCALL_ERROR_P (val, err))
result = INTERNAL_SYSCALL_ERRNO (val, err);
break;
}
}
/* Mark the thread as canceled. This has to be done
atomically since other bits could be modified as well. */
while (atomic_compare_and_exchange_bool_acq (&pd->cancelhandling, newval,
oldval));
return result;
}