ITS#8486 Don't keep sl_mutex locked when playing the sessionlog

diff --git a/servers/slapd/overlays/syncprov.c b/servers/slapd/overlays/syncprov.c
index e4d363d36b5742f6d17083877de154368988a1b8..a0c6e9aa8f14dbf806d30b6005240c01e0fd2dfe 100644 (file)
--- a/servers/slapd/overlays/syncprov.c
+++ b/servers/slapd/overlays/syncprov.c
@@ -130,6 +130,7 @@ typedef struct sessionlog {
        int             sl_numcsns;
        int             sl_num;
        int             sl_size;
+       int             sl_playing;
        slog_entry *sl_head;
        slog_entry *sl_tail;
        ldap_pvt_thread_mutex_t sl_mutex;
@@ -1540,12 +1541,15 @@ syncprov_add_slog( Operation *op )
                         * wipe out anything in the log if we see them.
                         */
                        ldap_pvt_thread_mutex_lock( &sl->sl_mutex );
+                       /* can only do this if no one else is reading the log at the moment */
+                       if (!sl->sl_playing) {
                        while ( se = sl->sl_head ) {
                                sl->sl_head = se->se_next;
                                ch_free( se );
                        }
                        sl->sl_tail = NULL;
                        sl->sl_num = 0;
+                       }
                        ldap_pvt_thread_mutex_unlock( &sl->sl_mutex );
                        return;
                }
@@ -1596,6 +1600,7 @@ syncprov_add_slog( Operation *op )
                        }
                }
                sl->sl_num++;
+               if (!sl->sl_playing) {
                while ( sl->sl_num > sl->sl_size ) {
                        int i;
                        se = sl->sl_head;
@@ -1612,6 +1617,7 @@ syncprov_add_slog( Operation *op )
                        ch_free( se );
                        sl->sl_num--;
                }
+               }
                ldap_pvt_thread_mutex_unlock( &sl->sl_mutex );
        }
 }
@@ -1646,6 +1652,8 @@ syncprov_playlog( Operation *op, SlapReply *rs, sessionlog *sl,
        num = sl->sl_num;
        i = 0;
        nmods = 0;
+       sl->sl_playing++;
+       ldap_pvt_thread_mutex_unlock( &sl->sl_mutex );
 
        uuids = op->o_tmpalloc( (num+1) * sizeof( struct berval ) +
                num * UUID_LEN, op->o_tmpmemctx );
@@ -1702,6 +1710,8 @@ syncprov_playlog( Operation *op, SlapReply *rs, sessionlog *sl,
                AC_MEMCPY(uuids[j].bv_val, se->se_uuid.bv_val, UUID_LEN);
                uuids[j].bv_len = UUID_LEN;
        }
+       ldap_pvt_thread_mutex_lock( &sl->sl_mutex );
+       sl->sl_playing--;
        ldap_pvt_thread_mutex_unlock( &sl->sl_mutex );
 
        ndel = i;