freebsd-dev/lib/libc_r/uthread/uthread_suspend_np.c
Daniel Eischen e5106342c6 Add weak definitions for wrapped system calls. In general:
_foo - wrapped system call
	foo - weak definition to _foo

and for cancellation points:

	_foo - wrapped system call
	__foo - enter cancellation point, call _foo(), leave
	        cancellation point
	foo - weak definition to __foo

Change use of global _thread_run to call a function to get the
currently running thread.

Make all pthread_foo functions weak definitions to _pthread_foo,
where _pthread_foo is the implementation.  This allows an application
to provide its own pthread functions.

Provide slightly different versions of pthread_mutex_lock and
pthread_mutex_init so that we can tell the difference between
a libc mutex and an application mutex.  Threads holding mutexes
internal to libc should never be allowed to exit, call signal
handlers, or cancel.

Approved by:	-arch
2001-01-24 13:03:38 +00:00

155 lines
4.5 KiB
C

/*
* Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by John Birrell.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <errno.h>
#include <pthread.h>
#include "pthread_private.h"
static void finish_suspension(void *arg);
#pragma weak pthread_suspend_np=_pthread_suspend_np
/* Suspend a thread: */
int
_pthread_suspend_np(pthread_t thread)
{
int ret;
/* Find the thread in the list of active threads: */
if ((ret = _find_thread(thread)) == 0) {
/*
* Defer signals to protect the scheduling queues from
* access by the signal handler:
*/
_thread_kern_sig_defer();
switch (thread->state) {
case PS_RUNNING:
/*
* Remove the thread from the priority queue and
* set the state to suspended:
*/
PTHREAD_PRIOQ_REMOVE(thread);
PTHREAD_SET_STATE(thread, PS_SUSPENDED);
break;
case PS_SPINBLOCK:
case PS_FDR_WAIT:
case PS_FDW_WAIT:
case PS_POLL_WAIT:
case PS_SELECT_WAIT:
/*
* Remove these threads from the work queue
* and mark the operation as interrupted:
*/
if ((thread->flags & PTHREAD_FLAGS_IN_WORKQ) != 0)
PTHREAD_WORKQ_REMOVE(thread);
_thread_seterrno(thread,EINTR);
thread->interrupted = 1;
/* FALLTHROUGH */
case PS_SIGTHREAD:
case PS_SLEEP_WAIT:
case PS_WAIT_WAIT:
case PS_SIGSUSPEND:
case PS_SIGWAIT:
/*
* Remove these threads from the waiting queue and
* set their state to suspended:
*/
PTHREAD_WAITQ_REMOVE(thread);
PTHREAD_SET_STATE(thread, PS_SUSPENDED);
break;
case PS_MUTEX_WAIT:
/* Mark the thread as suspended and still in a queue. */
thread->suspended = SUSP_MUTEX_WAIT;
PTHREAD_SET_STATE(thread, PS_SUSPENDED);
break;
case PS_COND_WAIT:
/* Mark the thread as suspended and still in a queue. */
thread->suspended = SUSP_COND_WAIT;
PTHREAD_SET_STATE(thread, PS_SUSPENDED);
break;
case PS_FDLR_WAIT:
case PS_FDLW_WAIT:
case PS_FILE_WAIT:
case PS_JOIN:
/* Mark the thread as suspended: */
thread->suspended = SUSP_YES;
/*
* Threads in these states may be in queues.
* In order to preserve queue integrity, the
* cancelled thread must remove itself from the
* queue. Mark the thread as interrupted and
* set the state to running. When the thread
* resumes, it will remove itself from the queue
* and call the suspension completion routine.
*/
thread->interrupted = 1;
_thread_seterrno(thread, EINTR);
PTHREAD_NEW_STATE(thread, PS_RUNNING);
thread->continuation = finish_suspension;
break;
case PS_DEAD:
case PS_DEADLOCK:
case PS_STATE_MAX:
case PS_SUSPENDED:
/* Nothing needs to be done: */
break;
}
/*
* Undefer and handle pending signals, yielding if
* necessary:
*/
_thread_kern_sig_undefer();
}
return(ret);
}
static void
finish_suspension(void *arg)
{
struct pthread *curthread = _get_curthread();
if (curthread->suspended != SUSP_NO)
_thread_kern_sched_state(PS_SUSPENDED, __FILE__, __LINE__);
}