ITS#4308 slapd-bdb/hdb cache sched fix

CHANGES

@@ -5,6 +5,7 @@ OpenLDAP 2.3.16 Engineering
 	Fixed slapd-monitor connection search crash (ITS#4300)
 	Flapd slapd cn=config bad ACL syntax modfy crash (ITS#4306)
 	Fixed slapd ACL/suffix configuration issue (ITS#4307)
+	Fixed slapd-bdb/hdb cache issue (ITS#4308)
 	Build environment
 		Replace sched_yield(2) on Linux with select(2) (ITS#3950)
 	Documentation

servers/slapd/back-bdb/back-bdb.h

@@ -150,6 +150,9 @@ struct bdb_db_info {
 	DB			*bdi_db;
 };
 
+/* From ldap_rq.h */
+struct re_s;
+
 struct bdb_info {
 	DB_ENV		*bi_dbenv;
 
@@ -175,9 +178,9 @@ struct bdb_info {
 	int			bi_txn_cp;
 	u_int32_t	bi_txn_cp_min;
 	u_int32_t	bi_txn_cp_kbyte;
-	void		*bi_txn_cp_task;
-	void		*bi_index_task;
- 	void		*bi_cache_task;
+	struct re_s		*bi_txn_cp_task;
+	struct re_s		*bi_index_task;
+ 	struct re_s		*bi_cache_task;
 
 	int			bi_lock_detect;
 	long		bi_shm_key;

servers/slapd/back-bdb/cache.c

@@ -643,11 +643,16 @@ bdb_cache_lru_add(
 			ldap_pvt_thread_mutex_lock( &slapd_rq.rq_mutex );
 			if ( bdb->bi_cache_task ) {
 				if ( !ldap_pvt_runqueue_isrunning( &slapd_rq,
-					bdb->bi_cache_task ))
+					bdb->bi_cache_task )) {
+					/* We want it to start right now */
+					bdb->bi_cache_task->interval.tv_sec = 0;
 					ldap_pvt_runqueue_resched( &slapd_rq, bdb->bi_cache_task,
 						0 );
+					/* But don't try to reschedule it while it's running */
+					bdb->bi_cache_task->interval.tv_sec = 3600;
+				}
 			} else {
-				bdb->bi_cache_task = ldap_pvt_runqueue_insert( &slapd_rq, 0,
+				bdb->bi_cache_task = ldap_pvt_runqueue_insert( &slapd_rq, 3600,
 					bdb_cache_lru_purge, bdb, "bdb_cache_lru_purge",
 					bdb->bi_dbenv_home );
 			}