In pool_submit():

- Move problematic mutex_unlock()-mutex_lock() into the unused #ifdef
  LDAP_PVT_THREAD_POOL_SEM_LOAD_CONTROL and add a FIXME comment inside.
- Delay ltp_starting--; until pool_wrapper().  Nonzero value could otherwise
  no longer be exposed when !defined LDAP_PVT_THREAD_POOL_SEM_LOAD_CONTROL.

diff --git a/libraries/libldap_r/tpool.c b/libraries/libldap_r/tpool.c
index ac4f791432fdb688327e9664c9c8fd2346a24902..c3e5686ca4ee206325267986d5a300dee5494331 100644 (file)
--- a/libraries/libldap_r/tpool.c
+++ b/libraries/libldap_r/tpool.c
@@ -393,24 +393,27 @@ ldap_pvt_thread_pool_submit (
                pool->ltp_starting++;
                need_thread = 1;
        }
-       ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 
 #ifdef LDAP_PVT_THREAD_POOL_SEM_LOAD_CONTROL
+       ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
        ldap_lazy_sem_op_submit( thread_pool_sem );
+       /* FIXME:  Another thread can now handle and release ctx, after
+        * which a newly submitted op can reuse ctx.  Then it is wrong for
+        * the "if (pool->ltp_open_count == 0)" code below to release ctx.
+        */
 #endif
 
        if (need_thread) {
-               int rc;
-
-               ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
-
-               rc = ldap_pvt_thread_create( &thr, 1,
-                       ldap_int_thread_pool_wrapper, pool );
-               pool->ltp_starting--;
-               if (rc != 0) {
+               if (0 != ldap_pvt_thread_create(
+                       &thr, 1, ldap_int_thread_pool_wrapper, pool))
+               {
                        /* couldn't create thread.  back out of
                         * ltp_open_count and check for even worse things.
                         */
+#ifdef LDAP_PVT_THREAD_POOL_SEM_LOAD_CONTROL
+                       ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
+#endif
+                       pool->ltp_starting--;
                        pool->ltp_open_count--;
                        if (pool->ltp_open_count == 0) {
                                /* no open threads at all?!?
@@ -435,15 +438,21 @@ ldap_pvt_thread_pool_submit (
                                        return(-1);
                                }
                        }
+#ifdef LDAP_PVT_THREAD_POOL_SEM_LOAD_CONTROL
+                       ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
+#endif
                        /* there is another open thread, so this
                         * context will be handled eventually.
                         * continue on, we have signalled that
                         * the context is waiting.
                         */
                }
-               ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
        }
 
+#ifndef LDAP_PVT_THREAD_POOL_SEM_LOAD_CONTROL
+       ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
+#endif
+
        return(0);
 }
 
@@ -675,6 +684,8 @@ ldap_int_thread_pool_wrapper (
        thread_keys[keyslot].ctx = &uctx;
        ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
 
+       pool->ltp_starting--;
+
        for (;;) {
                while (pool->ltp_pause)
                        ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);