reslist: follow up to r1828289: adjust maintenance top too.

Also, clarify in doxygen when apr_reslist_fifo_set() should be called.

[Reverted by r1829102]


git-svn-id: https://svn.apache.org/repos/asf/apr/apr/trunk@1828369 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 13 insertions, 2 deletions

diff --git a/include/apr_reslist.h b/include/apr_reslist.h
index 291cc5593..d1947944a 100644
--- a/include/apr_reslist.h
+++ b/include/apr_reslist.h
@@ -134,11 +134,17 @@ APR_DECLARE(apr_status_t) apr_reslist_release(apr_reslist_t *reslist,
  */
 APR_DECLARE(void) apr_reslist_timeout_set(apr_reslist_t *reslist,
                                           apr_interval_time_t timeout);
+
 /**
  * Set whether the reslist reuses resources as FIFO (First In First Out) or
  * LIFO (Last In First Out).
  * @param reslist The resource list.
  * @param fifo Set as FIFO (non zero) or LIFO (zero).
+ * @remark This function should be called before any resource is in the
+ * the reslist, otherwise maintenance optimizations based on the expiration
+ * time relative to the order of insertion (i.e. position in the list) won't
+ * work as expected.
+ *
  */
 APR_DECLARE(void) apr_reslist_fifo_set(apr_reslist_t *reslist, int fifo);
 
diff --git a/util-misc/apr_reslist.c b/util-misc/apr_reslist.c
index 48c4d36ce..ddc9eb5ea 100644
--- a/util-misc/apr_reslist.c
+++ b/util-misc/apr_reslist.c
@@ -229,8 +229,13 @@ APR_DECLARE(apr_status_t) apr_reslist_maintain(apr_reslist_t *reslist)
     /* Check if we need to expire old resources */
     now = apr_time_now();
     while (reslist->nidle > reslist->smax && reslist->nidle > 0) {
-        /* Peak at the last resource in the list */
-        res = APR_RING_LAST(&reslist->avail_list);
+        /* Peek at the next expiring resource in the list */
+        if (reslist->fifo) {
+            res = APR_RING_FIRST(&reslist->avail_list);
+        }
+        else {
+            res = APR_RING_LAST(&reslist->avail_list);
+        }
         /* See if the oldest entry should be expired */
         if (now - res->freed < reslist->ttl) {
             /* If this entry is too young, none of the others