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/*
* 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.
*/
#include "config.h"
#include "umem_base.h"
#include "vmem_base.h"
#ifndef _WIN32
#include <unistd.h>
/*
* The following functions are for pre- and post-fork1(2) handling. See
* "Lock Ordering" in lib/libumem/common/umem.c for the lock ordering used.
*/
static void
umem_lockup_cache(umem_cache_t *cp)
{
int idx;
int ncpus = cp->cache_cpu_mask + 1;
for (idx = 0; idx < ncpus; idx++)
(void) mutex_lock(&cp->cache_cpu[idx].cc_lock);
(void) mutex_lock(&cp->cache_depot_lock);
(void) mutex_lock(&cp->cache_lock);
}
static void
umem_release_cache(umem_cache_t *cp)
{
int idx;
int ncpus = cp->cache_cpu_mask + 1;
(void) mutex_unlock(&cp->cache_lock);
(void) mutex_unlock(&cp->cache_depot_lock);
for (idx = 0; idx < ncpus; idx++)
(void) mutex_unlock(&cp->cache_cpu[idx].cc_lock);
}
static void
umem_lockup_log_header(umem_log_header_t *lhp)
{
int idx;
if (lhp == NULL)
return;
for (idx = 0; idx < umem_max_ncpus; idx++)
(void) mutex_lock(&lhp->lh_cpu[idx].clh_lock);
(void) mutex_lock(&lhp->lh_lock);
}
static void
umem_release_log_header(umem_log_header_t *lhp)
{
int idx;
if (lhp == NULL)
return;
(void) mutex_unlock(&lhp->lh_lock);
for (idx = 0; idx < umem_max_ncpus; idx++)
(void) mutex_unlock(&lhp->lh_cpu[idx].clh_lock);
}
static void
umem_lockup(void)
{
umem_cache_t *cp;
(void) mutex_lock(&umem_init_lock);
/*
* If another thread is busy initializing the library, we must
* wait for it to complete (by calling umem_init()) before allowing
* the fork() to proceed.
*/
if (umem_ready == UMEM_READY_INITING && umem_init_thr != thr_self()) {
(void) mutex_unlock(&umem_init_lock);
(void) umem_init();
(void) mutex_lock(&umem_init_lock);
}
vmem_lockup();
vmem_sbrk_lockup();
(void) mutex_lock(&umem_cache_lock);
(void) mutex_lock(&umem_update_lock);
(void) mutex_lock(&umem_flags_lock);
umem_lockup_cache(&umem_null_cache);
for (cp = umem_null_cache.cache_prev; cp != &umem_null_cache;
cp = cp->cache_prev)
umem_lockup_cache(cp);
umem_lockup_log_header(umem_transaction_log);
umem_lockup_log_header(umem_content_log);
umem_lockup_log_header(umem_failure_log);
umem_lockup_log_header(umem_slab_log);
(void) cond_broadcast(&umem_update_cv);
}
static void
umem_do_release(int as_child)
{
umem_cache_t *cp;
int cleanup_update = 0;
/*
* Clean up the update state if we are the child process and
* another thread was processing updates.
*/
if (as_child) {
if (umem_update_thr != thr_self()) {
umem_update_thr = 0;
cleanup_update = 1;
}
if (umem_st_update_thr != thr_self()) {
umem_st_update_thr = 0;
cleanup_update = 1;
}
}
if (cleanup_update) {
umem_reaping = UMEM_REAP_DONE;
for (cp = umem_null_cache.cache_next; cp != &umem_null_cache;
cp = cp->cache_next) {
if (cp->cache_uflags & UMU_NOTIFY)
cp->cache_uflags &= ~UMU_NOTIFY;
/*
* If the cache is active, we just re-add it to
* the update list. This will re-do any active
* updates on the cache, but that won't break
* anything.
*
* The worst that can happen is a cache has
* its magazines rescaled twice, instead of once.
*/
if (cp->cache_uflags & UMU_ACTIVE) {
umem_cache_t *cnext, *cprev;
ASSERT(cp->cache_unext == NULL &&
cp->cache_uprev == NULL);
cp->cache_uflags &= ~UMU_ACTIVE;
cp->cache_unext = cnext = &umem_null_cache;
cp->cache_uprev = cprev =
umem_null_cache.cache_uprev;
cnext->cache_uprev = cp;
cprev->cache_unext = cp;
}
}
}
umem_release_log_header(umem_slab_log);
umem_release_log_header(umem_failure_log);
umem_release_log_header(umem_content_log);
umem_release_log_header(umem_transaction_log);
for (cp = umem_null_cache.cache_next; cp != &umem_null_cache;
cp = cp->cache_next)
umem_release_cache(cp);
umem_release_cache(&umem_null_cache);
(void) mutex_unlock(&umem_flags_lock);
(void) mutex_unlock(&umem_update_lock);
(void) mutex_unlock(&umem_cache_lock);
vmem_sbrk_release();
vmem_release();
(void) mutex_unlock(&umem_init_lock);
}
static void
umem_release(void)
{
umem_do_release(0);
}
static void
umem_release_child(void)
{
umem_do_release(1);
}
#endif
void
umem_forkhandler_init(void)
{
#ifndef _WIN32
/*
* There is no way to unregister these atfork functions,
* but we don't need to. The dynamic linker and libc take
* care of unregistering them if/when the library is unloaded.
*/
(void) pthread_atfork(umem_lockup, umem_release, umem_release_child);
#endif
}
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