NetBSD/lib/libpthread/pthreads/pthread.c

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/* ==== pthread.c ============================================================
* Copyright (c) 1993, 1994 by Chris Provenzano, proven@mit.edu
1993-12-20 22:31:06 +03:00
* 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 Chris Provenzano.
* 4. The name of Chris Provenzano may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY CHRIS PROVENZANO ``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 CHRIS PROVENZANO 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.
*
* Description : Pthread functions.
*
* 1.00 93/07/26 proven
* -Started coding this file.
*/
#ifndef lint
static const char rcsid[] = "$Id: pthread.c,v 1.3 1994/02/07 22:04:22 proven Exp $ $provenid: pthread.c,v 1.16 1994/02/07 02:19:06 proven Exp $";
#endif
#include "pthread.h"
#include <signal.h>
#include <errno.h>
/*
* These first functions really should not be called by the user.
*/
/* ==========================================================================
* pthread_init()
*
* This function should be called in crt0.o before main() is called.
* But on some systems It may not be possible to change crt0.o so currently
* I'm requiring this function to be called first thing after main.
* Actually I'm assuming it is, because I do no locking here.
*/
void pthread_init(void)
{
struct machdep_pthread machdep_data = MACHDEP_PTHREAD_INIT;
/* Initialize the first thread */
if (pthread_initial = (pthread_t)malloc(sizeof(struct pthread))) {
memcpy(&(pthread_initial->machdep_data), &machdep_data, sizeof(machdep_data));
pthread_initial->state = PS_RUNNING;
pthread_initial->queue = NULL;
pthread_initial->next = NULL;
pthread_initial->pll = NULL;
pthread_initial->lock = SEMAPHORE_CLEAR;
pthread_initial->error = 0;
pthread_link_list = pthread_initial;
pthread_run = pthread_initial;
/* Initialize the signal handler. */
sig_init();
/* Initialize the fd table. */
fd_init();
return;
}
PANIC();
}
/* ==========================================================================
* pthread_yield()
*/
void pthread_yield()
{
sig_handler_fake(SIGVTALRM);
}
/* ======================================================================= */
/* ==========================================================================
* pthread_self()
*/
pthread_t pthread_self()
{
return(pthread_run);
}
/* ==========================================================================
* pthread_equal()
*/
int pthread_equal(pthread_t t1, pthread_t t2)
{
return(t1 == t2);
}
/* ==========================================================================
* pthread_exit()
*/
void pthread_exit(void *status)
{
semaphore *lock, *plock;
pthread_t pthread;
lock = &pthread_run->lock;
if (SEMAPHORE_TEST_AND_SET(lock)) {
pthread_yield();
}
/* Save return value */
pthread_run->ret = status;
/* First execute all cleanup handlers */
/*
* Are there any threads joined to this one,
* if so wake them and let them detach this thread.
*/
if (pthread = pthread_queue_get(&(pthread_run->join_queue))) {
/* The current thread pthread_run can't be detached */
plock = &(pthread->lock);
while (SEMAPHORE_TEST_AND_SET(plock)) {
pthread_yield();
}
(void)pthread_queue_deq(&(pthread_run->join_queue));
pthread->state = PS_RUNNING;
/* Thread will unlock itself in pthread_join() */
}
/* This thread will never run again */
reschedule(PS_DEAD);
PANIC();
}
/* ==========================================================================
* pthread_create()
*
* After the new thread structure is allocated and set up, it is added to
* pthread_run_next_queue, which requires a sig_prevent(),
* sig_check_and_resume()
*/
int pthread_create(pthread_t *thread, const pthread_attr_t *attr,
void * (*start_routine)(void *), void *arg)
{
long nsec = 100000000;
void *stack;
if ((*thread) = (pthread_t)malloc(sizeof(struct pthread))) {
if (! attr) { attr = &pthread_default_attr; }
/* Get a stack, if necessary */
if ((stack = attr->stackaddr_attr) ||
(stack = (void *)malloc(attr->stacksize_attr))) {
machdep_pthread_create(&((*thread)->machdep_data),
start_routine, arg, 65536, stack, nsec);
memcpy(&(*thread)->attr, attr, sizeof(pthread_attr_t));
(*thread)->queue = NULL;
(*thread)->next = NULL;
(*thread)->lock = SEMAPHORE_CLEAR;
(*thread)->error = 0;
sig_prevent();
/* Add to the link list of all threads. */
(*thread)->pll = pthread_link_list;
pthread_link_list = (*thread);
(*thread)->state = PS_RUNNING;
sig_check_and_resume();
return(OK);
}
free((*thread));
}
return(ENOMEM);
}
/* ==========================================================================
* pthread_cancel()
*
* This routine will also require a sig_prevent/sig_check_and_resume()
*/