libumem/umem_update_thread.c

221 lines
5.8 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*
* Portions Copyright 2006-2008 Message Systems, Inc. All rights reserved.
*/
/* #pragma ident "@(#)umem_update_thread.c 1.2 05/06/08 SMI" */
#include "config.h"
#include "umem_base.h"
#include "vmem_base.h"
#include <signal.h>
struct umem_suspend_signal_object {
/* locked by creating thread; unlocked when umem_update_thread
* can proceed */
pthread_mutex_t mtx;
/* lock associated with the condition variable */
pthread_mutex_t cmtx;
/* condition variable is signalled by umem_update_thread when
* it has obtained the mtx; it is then safe for the creating
* thread to clean up its stack (on which this object resides) */
pthread_cond_t cond;
int flag;
};
/*ARGSUSED*/
static THR_RETURN
THR_API umem_update_thread(void *arg)
{
struct timeval now;
int in_update = 0;
struct umem_suspend_signal_object *obj = arg;
pthread_mutex_lock(&obj->mtx);
obj->flag = 1;
pthread_cond_signal(&obj->cond);
obj = NULL;
(void) mutex_lock(&umem_update_lock);
ASSERT(umem_update_thr == thr_self());
ASSERT(umem_st_update_thr == 0);
for (;;) {
umem_process_updates();
if (in_update) {
in_update = 0;
/*
* we wait until now to set the next update time
* so that the updates are self-throttling
*/
(void) gettimeofday(&umem_update_next, NULL);
umem_update_next.tv_sec += umem_reap_interval;
}
switch (umem_reaping) {
case UMEM_REAP_DONE:
case UMEM_REAP_ADDING:
break;
case UMEM_REAP_ACTIVE:
umem_reap_next = gethrtime() +
(hrtime_t)umem_reap_interval * NANOSEC;
umem_reaping = UMEM_REAP_DONE;
break;
default:
ASSERT(umem_reaping == UMEM_REAP_DONE ||
umem_reaping == UMEM_REAP_ADDING ||
umem_reaping == UMEM_REAP_ACTIVE);
break;
}
(void) gettimeofday(&now, NULL);
if (now.tv_sec > umem_update_next.tv_sec ||
(now.tv_sec == umem_update_next.tv_sec &&
now.tv_usec >= umem_update_next.tv_usec)) {
/*
* Time to run an update
*/
(void) mutex_unlock(&umem_update_lock);
vmem_update(NULL);
/*
* umem_cache_update can use umem_add_update to
* request further work. The update is not complete
* until all such work is finished.
*/
umem_cache_applyall(umem_cache_update);
(void) mutex_lock(&umem_update_lock);
in_update = 1;
continue; /* start processing immediately */
}
/*
* if there is no work to do, we wait until it is time for
* next update, or someone wakes us.
*/
if (umem_null_cache.cache_unext == &umem_null_cache) {
int cancel_state;
timespec_t abs_time;
abs_time.tv_sec = umem_update_next.tv_sec;
abs_time.tv_nsec = umem_update_next.tv_usec * 1000;
(void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE,
&cancel_state);
(void) cond_timedwait(&umem_update_cv,
&umem_update_lock, &abs_time);
(void) pthread_setcancelstate(cancel_state, NULL);
}
}
/* LINTED no return statement */
}
int
umem_create_update_thread(void)
{
#ifndef _WIN32
sigset_t sigmask, oldmask;
#endif
pthread_t newthread;
pthread_attr_t attr;
struct umem_suspend_signal_object obj;
int cancel_state;
ASSERT(MUTEX_HELD(&umem_update_lock));
ASSERT(umem_update_thr == 0);
#ifndef _WIN32
/*
* The update thread handles no signals
*/
(void) sigfillset(&sigmask);
(void) pthread_sigmask(SIG_BLOCK, &sigmask, &oldmask);
#endif
/*
* drop the umem_update_lock; we cannot hold locks acquired in
* pre-fork handler while calling thr_create or thr_continue().
*/
(void) mutex_unlock(&umem_update_lock);
pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
pthread_mutex_init(&obj.mtx, NULL);
pthread_mutex_init(&obj.cmtx, NULL);
pthread_cond_init(&obj.cond, NULL);
obj.flag = 0;
pthread_mutex_lock(&obj.mtx);
if (pthread_create(&newthread, &attr, umem_update_thread, &obj) == 0) {
#ifndef _WIN32
(void) pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
#endif
(void) mutex_lock(&umem_update_lock);
/*
* due to the locking in umem_reap(), only one thread can
* ever call umem_create_update_thread() at a time. This
* must be the case for this code to work.
*/
ASSERT(umem_update_thr == 0);
umem_update_thr = newthread;
(void) mutex_unlock(&umem_update_lock);
/* tell the thread to continue */
pthread_mutex_unlock(&obj.mtx);
pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cancel_state);
/* wait for it to be done with obj */
pthread_mutex_lock(&obj.cmtx);
do {
if (obj.flag) {
break;
}
ASSERT(pthread_cond_wait(&obj.cond, &obj.cmtx) == 0);
} while (1);
pthread_setcancelstate(cancel_state, NULL);
pthread_mutex_destroy(&obj.mtx);
pthread_mutex_destroy(&obj.cmtx);
pthread_cond_destroy(&obj.cond);
(void) mutex_lock(&umem_update_lock);
return (1);
} else { /* thr_create failed */
(void) thr_sigsetmask(SIG_SETMASK, &oldmask, NULL);
(void) mutex_lock(&umem_update_lock);
pthread_mutex_destroy(&obj.mtx);
pthread_mutex_destroy(&obj.cmtx);
pthread_cond_destroy(&obj.cond);
}
return (0);
}