ITS#5364: introduce ltp_work_list, drop 1st ltp_pause loop in pool_wrapper().

diff --git a/libraries/libldap_r/tpool.c b/libraries/libldap_r/tpool.c
index 9d51e0afbbc1f5d8ede6a82f340bbb7661f453d3..e8536010af356d942eb086d4acaec79623c5f7f5 100644 (file)
--- a/libraries/libldap_r/tpool.c
+++ b/libraries/libldap_r/tpool.c
@@ -86,6 +86,8 @@ typedef struct ldap_int_thread_task_s {
        void *ltt_arg;
 } ldap_int_thread_task_t;
 
+typedef LDAP_STAILQ_HEAD(tcq, ldap_int_thread_task_s) ldap_int_tpool_plist_t;
+
 struct ldap_int_thread_pool_s {
        LDAP_STAILQ_ENTRY(ldap_int_thread_pool_s) ltp_next;
 
@@ -99,7 +101,7 @@ struct ldap_int_thread_pool_s {
        ldap_pvt_thread_cond_t ltp_pcond;
 
        /* pending tasks, and unused task objects */
-       LDAP_STAILQ_HEAD(tcq, ldap_int_thread_task_s) ltp_pending_list;
+       ldap_int_tpool_plist_t ltp_pending_list;
        LDAP_SLIST_HEAD(tcl, ldap_int_thread_task_s) ltp_free_list;
 
        /* The pool is finishing, waiting for its threads to close.
@@ -129,6 +131,9 @@ struct ldap_int_thread_pool_s {
         * in ldap_pvt_thread_pool_<submit/wrapper>().
         */
 
+       /* ltp_pause == 0 ? &ltp_pending_list : &empty_pending_list */
+       ldap_int_tpool_plist_t *ltp_work_list;
+
        /* >0 if paused or we may open a thread, <0 if we should close a thread. */
        /* Updated when ltp_<finishing/pause/max_count/open_count> change. */
        int ltp_vary_open_count;
@@ -140,6 +145,9 @@ struct ldap_int_thread_pool_s {
                 - (pool)->ltp_open_count)
 };
 
+static ldap_int_tpool_plist_t empty_pending_list =
+       LDAP_STAILQ_HEAD_INITIALIZER(empty_pending_list);
+
 static int ldap_int_has_thread_pool = 0;
 static LDAP_STAILQ_HEAD(tpq, ldap_int_thread_pool_s)
        ldap_int_thread_pool_list =
@@ -217,7 +225,9 @@ ldap_pvt_thread_pool_init (
        pool->ltp_max_pending = max_pending;
 
        LDAP_STAILQ_INIT(&pool->ltp_pending_list);
+       pool->ltp_work_list = &pool->ltp_pending_list;
        LDAP_SLIST_INIT(&pool->ltp_free_list);
+
        ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
        LDAP_STAILQ_INSERT_TAIL(&ldap_int_thread_pool_list, pool, ltp_next);
        ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
@@ -620,11 +630,8 @@ ldap_int_thread_pool_wrapper (
        pool->ltp_starting--;
 
        for (;;) {
-               while (pool->ltp_pause)
-                       ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
-
-               task = LDAP_STAILQ_FIRST(&pool->ltp_pending_list);
-               if (task == NULL) {
+               task = LDAP_STAILQ_FIRST(pool->ltp_work_list);
+               if (task == NULL) {     /* paused or no pending tasks */
                        if (pool->ltp_vary_open_count < 0) {
                                /* not paused, and either finishing or too many
                                 * threads running (can happen if ltp_max_count
@@ -718,6 +725,8 @@ ldap_pvt_thread_pool_pause (
        /* Wait for everyone else to pause or finish */
        pool->ltp_pause = 1;
        SET_VARY_OPEN_COUNT(pool);
+       /* Hide pending tasks from ldap_pvt_thread_pool_wrapper() */
+       pool->ltp_work_list = &empty_pending_list;
 
        while (pool->ltp_active_count > 1) {
                ldap_pvt_thread_cond_wait(&pool->ltp_pcond, &pool->ltp_mutex);
@@ -743,10 +752,14 @@ ldap_pvt_thread_pool_resume (
                return(0);
 
        ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
+
        pool->ltp_pause = 0;
        SET_VARY_OPEN_COUNT(pool);
+       pool->ltp_work_list = &pool->ltp_pending_list;
+
        if (!pool->ltp_finishing)
                ldap_pvt_thread_cond_broadcast(&pool->ltp_cond);
+
        ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
        return(0);
 }