/* $OpenLDAP$ */
/*
- * Copyright 1998-2000 The OpenLDAP Foundation, Redwood City, California, USA
+ * Copyright 1998-2002 The OpenLDAP Foundation, Redwood City, California, USA
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted only
#include "portable.h"
#include <stdio.h>
-#include <stdarg.h>
+#include <ac/stdarg.h>
#include <ac/stdlib.h>
#include <ac/string.h>
#include <ac/time.h>
#include "ldap-int.h"
#include "ldap_pvt_thread.h"
+#include "ldap_queue.h"
#ifndef LDAP_THREAD_HAVE_TPOOL
LDAP_INT_THREAD_POOL_STOPPING
};
-typedef struct ldap_int_thread_list_element_s {
- struct ldap_int_thread_list_element_s *next;
-} ldap_int_thread_list_element_t, *ldap_int_thread_list_t;
+typedef struct ldap_int_thread_ctx_s {
+ union {
+ LDAP_STAILQ_ENTRY(ldap_int_thread_ctx_s) q;
+ LDAP_SLIST_ENTRY(ldap_int_thread_ctx_s) l;
+ } ltc_next;
+ void *(*ltc_start_routine)( void *);
+ void *ltc_arg;
+} ldap_int_thread_ctx_t;
struct ldap_int_thread_pool_s {
- struct ldap_int_thread_pool_s *ltp_next;
+ LDAP_STAILQ_ENTRY(ldap_int_thread_pool_s) ltp_next;
ldap_pvt_thread_mutex_t ltp_mutex;
ldap_pvt_thread_cond_t ltp_cond;
- ldap_int_thread_list_t ltp_pending_list;
+ LDAP_STAILQ_HEAD(tcq, ldap_int_thread_ctx_s) ltp_pending_list;
+ LDAP_SLIST_HEAD(tcl, ldap_int_thread_ctx_s) ltp_free_list;
long ltp_state;
long ltp_max_count;
long ltp_max_pending;
long ltp_pending_count;
long ltp_active_count;
long ltp_open_count;
+ long ltp_starting;
};
-typedef struct ldap_int_thread_ctx_s {
- struct ldap_int_thread_ctx_s *ltc_next;
- void *(*ltc_start_routine)( void *);
- void *ltc_arg;
-} ldap_int_thread_ctx_t;
+static LDAP_STAILQ_HEAD(tpq, ldap_int_thread_pool_s)
+ ldap_int_thread_pool_list =
+ LDAP_STAILQ_HEAD_INITIALIZER(ldap_int_thread_pool_list);
-static ldap_int_thread_list_t ldap_int_thread_pool_list = NULL;
static ldap_pvt_thread_mutex_t ldap_pvt_thread_pool_mutex;
-static void *ldap_int_thread_pool_wrapper(
- struct ldap_int_thread_pool_s *pool );
-
-static void *ldap_int_thread_enlist( ldap_int_thread_list_t *list, void *elem );
-static void *ldap_int_thread_delist( ldap_int_thread_list_t *list, void *elem );
-static void *ldap_int_thread_onlist( ldap_int_thread_list_t *list, void *elem );
+static void *ldap_int_thread_pool_wrapper( void *pool );
int
ldap_int_thread_pool_startup ( void )
int
ldap_int_thread_pool_shutdown ( void )
{
- while (ldap_int_thread_pool_list != NULL) {
- struct ldap_int_thread_pool_s *pool =
- (struct ldap_int_thread_pool_s *) ldap_int_thread_pool_list;
+ struct ldap_int_thread_pool_s *pool;
+ while ((pool = LDAP_STAILQ_FIRST(&ldap_int_thread_pool_list)) != NULL) {
+ LDAP_STAILQ_REMOVE_HEAD(&ldap_int_thread_pool_list, ltp_next);
ldap_pvt_thread_pool_destroy( &pool, 0);
}
ldap_pvt_thread_mutex_destroy(&ldap_pvt_thread_pool_mutex);
int
ldap_pvt_thread_pool_init (
ldap_pvt_thread_pool_t *tpool,
- int max_concurrency,
+ int max_threads,
int max_pending )
{
- int rc;
ldap_pvt_thread_pool_t pool;
- ldap_pvt_thread_t thr;
+ int rc;
*tpool = NULL;
pool = (ldap_pvt_thread_pool_t) LDAP_CALLOC(1,
if (pool == NULL) return(-1);
- ldap_pvt_thread_mutex_init(&pool->ltp_mutex);
- ldap_pvt_thread_cond_init(&pool->ltp_cond);
+ rc = ldap_pvt_thread_mutex_init(&pool->ltp_mutex);
+ if (rc != 0)
+ return(rc);
+ rc = ldap_pvt_thread_cond_init(&pool->ltp_cond);
+ if (rc != 0)
+ return(rc);
pool->ltp_state = LDAP_INT_THREAD_POOL_RUNNING;
- pool->ltp_max_count = max_concurrency;
+ pool->ltp_max_count = max_threads;
pool->ltp_max_pending = max_pending;
+ LDAP_STAILQ_INIT(&pool->ltp_pending_list);
+ LDAP_SLIST_INIT(&pool->ltp_free_list);
ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
- ldap_int_thread_enlist(&ldap_int_thread_pool_list, pool);
+ LDAP_STAILQ_INSERT_TAIL(&ldap_int_thread_pool_list, pool, ltp_next);
ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
- /* start up one thread, just so there is one */
+#if 0
+ /* THIS WILL NOT WORK on some systems. If the process
+ * forks after starting a thread, there is no guarantee
+ * that the thread will survive the fork. For example,
+ * slapd forks in order to daemonize, and does so after
+ * calling ldap_pvt_thread_pool_init. On some systems,
+ * this initial thread does not run in the child process,
+ * but ltp_open_count == 1, so two things happen:
+ * 1) the first client connection fails, and 2) when
+ * slapd is kill'ed, it never terminates since it waits
+ * for all worker threads to exit. */
+
+ /* start up one thread, just so there is one. no need to
+ * lock the mutex right now, since no threads are running.
+ */
pool->ltp_open_count++;
- rc = ldap_pvt_thread_create( &thr, 1,
- (void *) ldap_int_thread_pool_wrapper, pool );
+ ldap_pvt_thread_t thr;
+ rc = ldap_pvt_thread_create( &thr, 1, ldap_int_thread_pool_wrapper, pool );
if( rc != 0) {
/* couldn't start one? then don't start any */
ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
- ldap_int_thread_delist(&ldap_int_thread_pool_list, pool);
+ LDAP_STAILQ_REMOVE(ldap_int_thread_pool_list, pool,
+ ldap_int_thread_pool_s, ltp_next);
ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
ldap_pvt_thread_cond_destroy(&pool->ltp_cond);
ldap_pvt_thread_mutex_destroy(&pool->ltp_mutex);
- free(pool);
+ LDAP_FREE(pool);
return(-1);
}
+#endif
*tpool = pool;
return(0);
if (pool == NULL)
return(-1);
- ctx = (ldap_int_thread_ctx_t *) LDAP_CALLOC(1,
- sizeof(ldap_int_thread_ctx_t));
-
- if (ctx == NULL) return(-1);
-
- ctx->ltc_start_routine = start_routine;
- ctx->ltc_arg = arg;
-
ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
if (pool->ltp_state != LDAP_INT_THREAD_POOL_RUNNING
|| (pool->ltp_max_pending > 0
&& pool->ltp_pending_count >= pool->ltp_max_pending))
{
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
- free(ctx);
return(-1);
}
+ ctx = LDAP_SLIST_FIRST(&pool->ltp_free_list);
+ if (ctx) {
+ LDAP_SLIST_REMOVE_HEAD(&pool->ltp_free_list, ltc_next.l);
+ } else {
+ ctx = (ldap_int_thread_ctx_t *) LDAP_MALLOC(
+ sizeof(ldap_int_thread_ctx_t));
+ if (ctx == NULL) {
+ ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
+ return(-1);
+ }
+ }
+
+ ctx->ltc_start_routine = start_routine;
+ ctx->ltc_arg = arg;
+
pool->ltp_pending_count++;
- ldap_int_thread_enlist(&pool->ltp_pending_list, ctx);
+ LDAP_STAILQ_INSERT_TAIL(&pool->ltp_pending_list, ctx, ltc_next.q);
ldap_pvt_thread_cond_signal(&pool->ltp_cond);
if ((pool->ltp_open_count <= 0
|| pool->ltp_pending_count > 1
|| pool->ltp_open_count < pool->ltp_max_count))
{
pool->ltp_open_count++;
+ pool->ltp_starting++;
need_thread = 1;
}
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
if (need_thread) {
int rc = ldap_pvt_thread_create( &thr, 1,
- (void *)ldap_int_thread_pool_wrapper, pool );
- if (rc != 0) {
+ ldap_int_thread_pool_wrapper, pool );
+ ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
+ if (rc == 0) {
+ pool->ltp_starting--;
+ } else {
/* couldn't create thread. back out of
* ltp_open_count and check for even worse things.
*/
- ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
pool->ltp_open_count--;
+ pool->ltp_starting--;
if (pool->ltp_open_count == 0) {
- /* no open threads at all?!? this will never happen
- * because we always leave at least one thread open.
+ /* no open threads at all?!?
*/
- if (ldap_int_thread_delist(&pool->ltp_pending_list, ctx)) {
+ ldap_int_thread_ctx_t *ptr;
+ LDAP_STAILQ_FOREACH(ptr, &pool->ltp_pending_list, ltc_next.q)
+ if (ptr == ctx) break;
+ if (ptr == ctx) {
/* no open threads, context not handled, so
* back out of ltp_pending_count, free the context,
* report the error.
*/
+ LDAP_STAILQ_REMOVE(&pool->ltp_pending_list, ctx,
+ ldap_int_thread_ctx_s, ltc_next.q);
pool->ltp_pending_count++;
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
- free(ctx);
+ LDAP_FREE(ctx);
return(-1);
}
}
- ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
/* there is another open thread, so this
* context will be handled eventually.
* continue on and signal that the context
* is waiting.
*/
}
+ ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
}
return(0);
}
+int
+ldap_pvt_thread_pool_maxthreads ( ldap_pvt_thread_pool_t *tpool, int max_threads )
+{
+ struct ldap_int_thread_pool_s *pool;
+
+ if (tpool == NULL)
+ return(-1);
+
+ pool = *tpool;
+
+ if (pool == NULL)
+ return(-1);
+
+ ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
+ pool->ltp_max_count = max_threads;
+ ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
+ return(0);
+}
+
int
ldap_pvt_thread_pool_backload ( ldap_pvt_thread_pool_t *tpool )
{
int
ldap_pvt_thread_pool_destroy ( ldap_pvt_thread_pool_t *tpool, int run_pending )
{
- struct ldap_int_thread_pool_s *pool;
+ struct ldap_int_thread_pool_s *pool, *pptr;
long waiting;
ldap_int_thread_ctx_t *ctx;
if (pool == NULL) return(-1);
ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
- pool = ldap_int_thread_delist(&ldap_int_thread_pool_list, pool);
+ LDAP_STAILQ_FOREACH(pptr, &ldap_int_thread_pool_list, ltp_next)
+ if (pptr == pool) break;
+ if (pptr == pool)
+ LDAP_STAILQ_REMOVE(&ldap_int_thread_pool_list, pool,
+ ldap_int_thread_pool_s, ltp_next);
ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
- if (pool == NULL) return(-1);
+ if (pool != pptr) return(-1);
ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
pool->ltp_state = run_pending
? LDAP_INT_THREAD_POOL_FINISHING
: LDAP_INT_THREAD_POOL_STOPPING;
waiting = pool->ltp_open_count;
- ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
/* broadcast could be used here, but only after
* it is fixed in the NT thread implementation
while (--waiting >= 0) {
ldap_pvt_thread_cond_signal(&pool->ltp_cond);
}
+ ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
do {
ldap_pvt_thread_yield();
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
} while (waiting > 0);
- while (ctx = (ldap_int_thread_ctx_t *)ldap_int_thread_delist(
- &pool->ltp_pending_list, NULL))
+ while ((ctx = LDAP_STAILQ_FIRST(&pool->ltp_pending_list)) != NULL)
{
- free(ctx);
+ LDAP_STAILQ_REMOVE_HEAD(&pool->ltp_pending_list, ltc_next.q);
+ LDAP_FREE(ctx);
+ }
+
+ while ((ctx = LDAP_SLIST_FIRST(&pool->ltp_free_list)) != NULL)
+ {
+ LDAP_SLIST_REMOVE_HEAD(&pool->ltp_free_list, ltc_next.l);
+ LDAP_FREE(ctx);
}
ldap_pvt_thread_cond_destroy(&pool->ltp_cond);
ldap_pvt_thread_mutex_destroy(&pool->ltp_mutex);
- free(pool);
+ LDAP_FREE(pool);
return(0);
}
static void *
ldap_int_thread_pool_wrapper (
- struct ldap_int_thread_pool_s *pool )
+ void *xpool )
{
+ struct ldap_int_thread_pool_s *pool = xpool;
ldap_int_thread_ctx_t *ctx;
if (pool == NULL)
ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
while (pool->ltp_state != LDAP_INT_THREAD_POOL_STOPPING) {
-
- ctx = ldap_int_thread_delist(&pool->ltp_pending_list, NULL);
- if (ctx == NULL) {
+ ctx = LDAP_STAILQ_FIRST(&pool->ltp_pending_list);
+ if (ctx) {
+ LDAP_STAILQ_REMOVE_HEAD(&pool->ltp_pending_list, ltc_next.q);
+ } else {
if (pool->ltp_state == LDAP_INT_THREAD_POOL_FINISHING)
break;
+ if (pool->ltp_max_count > 0
+ && pool->ltp_open_count > pool->ltp_max_count)
+ {
+ /* too many threads running (can happen if the
+ * maximum threads value is set during ongoing
+ * operation using ldap_pvt_thread_pool_maxthreads)
+ * so let this thread die.
+ */
+ break;
+ }
+
/* we could check an idle timer here, and let the
* thread die if it has been inactive for a while.
* only die if there are other open threads (i.e.,
- * always have at least one thread open).
+ * always have at least one thread open). the check
+ * should be like this:
+ * if (pool->ltp_open_count > 1 && pool->ltp_starting == 0)
+ * check timer, leave thread (break;)
*/
if (pool->ltp_state == LDAP_INT_THREAD_POOL_RUNNING)
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
(ctx->ltc_start_routine)(ctx->ltc_arg);
- free(ctx);
+ LDAP_SLIST_INSERT_HEAD(&pool->ltp_free_list, ctx, ltc_next.l);
ldap_pvt_thread_yield();
/* if we use an idle timer, here's
ldap_pvt_thread_exit(NULL);
return(NULL);
}
-
-static void *
-ldap_int_thread_enlist( ldap_int_thread_list_t *list, void *elem )
-{
- ldap_int_thread_list_element_t *prev;
-
- if (elem == NULL) return(NULL);
-
- ((ldap_int_thread_list_element_t *)elem)->next = NULL;
- if (*list == NULL) {
- *list = elem;
- return(elem);
- }
-
- for (prev = *list ; prev->next != NULL; prev = prev->next) ;
- prev->next = elem;
- return(elem);
-}
-
-static void *
-ldap_int_thread_delist( ldap_int_thread_list_t *list, void *elem )
-{
- ldap_int_thread_list_element_t *prev;
-
- if (*list == NULL) return(NULL);
-
- if (elem == NULL) elem = *list;
-
- if (*list == elem) {
- *list = ((ldap_int_thread_list_element_t *)elem)->next;
- return(elem);
- }
-
- for (prev = *list ; prev->next != NULL; prev = prev->next) {
- if (prev->next == elem) {
- prev->next = ((ldap_int_thread_list_element_t *)elem)->next;
- return(elem);
- }
- }
- return(NULL);
-}
-
-static void *
-ldap_int_thread_onlist( ldap_int_thread_list_t *list, void *elem )
-{
- ldap_int_thread_list_element_t *prev;
-
- if (elem == NULL || *list == NULL) return(NULL);
-
- for (prev = *list ; prev != NULL; prev = prev->next) {
- if (prev == elem)
- return(elem);
- }
-
- return(NULL);
-}
-
#endif /* LDAP_HAVE_THREAD_POOL */
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