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Simplify pthread_join(). Knocks about 5% off pthread_create/join in a loop.

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This commit is contained in:
ad 2007-08-15 22:48:52 +00:00
parent 56accd1ffe
commit c94f5a91bc
1 changed files with 36 additions and 41 deletions
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77
lib/libpthread/pthread.c
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@ -1,4 +1,4 @@
/* $NetBSD: pthread.c,v 1.73 2007/08/07 19:58:30 ad Exp $ */
/* $NetBSD: pthread.c,v 1.74 2007/08/15 22:48:52 ad Exp $ */
/*-
* Copyright (c) 2001, 2002, 2003, 2006, 2007 The NetBSD Foundation, Inc.
@ -37,7 +37,7 @@
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: pthread.c,v 1.73 2007/08/07 19:58:30 ad Exp $");
__RCSID("$NetBSD: pthread.c,v 1.74 2007/08/15 22:48:52 ad Exp $");
#include <err.h>
#include <errno.h>
@ -87,7 +87,8 @@ enum {
static int pthread__diagassert = DIAGASSERT_ABORT | DIAGASSERT_STDERR;
int pthread__concurrency, pthread__maxconcurrency, pthread__nspins;
int pthread__concurrency;
int pthread__nspins;
int pthread__unpark_max = PTHREAD__UNPARK_MAX;
int pthread__osrev;
@ -514,7 +515,6 @@ pthread_join(pthread_t thread, void **valptr)
{
pthread_t self;
char *name;
int num, retval;
self = pthread__self();
SDPRINTF(("(pthread_join %p) Joining %p.\n", self, thread));
@ -528,46 +528,41 @@ pthread_join(pthread_t thread, void **valptr)
if (thread == self)
return EDEADLK;
retval = 0;
name = NULL;
again:
pthread_spinlock(self, &thread->pt_lock);
switch (thread->pt_state) {
case PT_STATE_RUNNING:
pthread_spinunlock(self, &thread->pt_lock);
/*
* IEEE Std 1003.1, 2004 Edition:
*
* "The pthread_join() function shall not
* return an error code of [EINTR]."
*/
if (_lwp_wait(thread->pt_lid, &num) != 0 && errno != EINTR)
/*
* IEEE Std 1003.1, 2004 Edition:
*
* "The pthread_join() function shall not return an
* error code of [EINTR]."
*/
while (_lwp_wait(thread->pt_lid, NULL) != 0) {
if (errno != EINTR)
return errno;
goto again;
case PT_STATE_ZOMBIE:
if (valptr != NULL)
*valptr = thread->pt_exitval;
if (retval == 0) {
name = thread->pt_name;
thread->pt_name = NULL;
}
thread->pt_state = PT_STATE_DEAD;
pthread_spinlock(self, &pthread__queue_lock);
PTQ_REMOVE(&pthread__allqueue, thread, pt_allq);
PTQ_INSERT_HEAD(&pthread__deadqueue, thread, pt_allq);
pthread_spinunlock(self, &pthread__queue_lock);
pthread_spinunlock(self, &thread->pt_lock);
SDPRINTF(("(pthread_join %p) Joined %p.\n", self, thread));
if (name != NULL)
free(name);
(void)_lwp_detach(thread->pt_lid);
return retval;
default:
pthread_spinunlock(self, &thread->pt_lock);
return EINVAL;
}
/*
* No need to lock - nothing else should (legally) be
* interested in the thread's state at this point.
*
* _lwp_wait() provides a barrier, so the user level
* thread state will be visible to us at this point.
*/
if (thread->pt_state != PT_STATE_ZOMBIE) {
pthread__errorfunc(__FILE__, __LINE__, __func__,
"not a zombie");
}
if (valptr != NULL)
*valptr = thread->pt_exitval;
name = thread->pt_name;
thread->pt_name = NULL;
thread->pt_state = PT_STATE_DEAD;
pthread_spinlock(self, &pthread__queue_lock);
PTQ_REMOVE(&pthread__allqueue, thread, pt_allq);
PTQ_INSERT_HEAD(&pthread__deadqueue, thread, pt_allq);
pthread_spinunlock(self, &pthread__queue_lock);
SDPRINTF(("(pthread_join %p) Joined %p.\n", self, thread));
if (name != NULL)
free(name);
return 0;
}