Add a comment explaining the start mutex.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@723675 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/modules/cluster/mod_heartmonitor.c b/modules/cluster/mod_heartmonitor.c
index 41cba183ab216296fb1c7a5222e69530ec30796e..8097adc37144e85843c1a0a63251121c20fd65f4 100644 (file)
--- a/modules/cluster/mod_heartmonitor.c
+++ b/modules/cluster/mod_heartmonitor.c
@@ -392,6 +392,9 @@ static void start_hm_worker(apr_pool_t *p, hm_ctx_t *ctx)
         return;
     }
 
+    /* This mutex fixes problems with a fast start/fast end, where the pool 
+     * cleanup was being invoked before the thread completely spawned. 
+     */
     apr_thread_mutex_lock(ctx->start_mtx);
 
     apr_pool_cleanup_register(p, ctx, hm_pool_cleanup, apr_pool_cleanup_null);