From: Stefan Fritsch <sf@apache.org>
Date: Sun, 15 Jul 2012 19:31:49 +0000 (+0000)
Subject: Simplify handling of MaxConnectionsPerChild
X-Git-Tag: 2.5.0-alpha~6650
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7482abb7f2d05902c0bac8d4f0072aa812769564;p=thirdparty%2Fapache%2Fhttpd.git

Simplify handling of MaxConnectionsPerChild

If we decrement the counter at accept time and not at close time,
we only need to access the counter in the listener thread and the
code gets much simpler.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1361766 13f79535-47bb-0310-9956-ffa450edef68
---

diff --git a/server/mpm/event/event.c b/server/mpm/event/event.c
index f228a25db58..14d41b30441 100644
--- a/server/mpm/event/event.c
+++ b/server/mpm/event/event.c
@@ -176,14 +176,9 @@ static int workers_may_exit = 0;
 static int start_thread_may_exit = 0;
 static int listener_may_exit = 0;
 static int num_listensocks = 0;
-/*
- * As we don't have APR atomic functions for apr_int32_t, we use apr_uint32_t
- * to actually store a signed value. This works as long as the platform uses
- * two's complement representation. This assumption is also made in other
- * parts of the code (e.g. fdqueue.c).
- */
-static apr_uint32_t conns_this_child;
-static apr_uint32_t connection_count = 0;
+static apr_int32_t conns_this_child;        /* MaxConnectionsPerChild, only access
+                                               in listener thread */
+static apr_uint32_t connection_count = 0;   /* Number of open connections */
 static int resource_shortage = 0;
 static fd_queue_t *worker_queue;
 static fd_queue_info_t *worker_queue_info;
@@ -615,7 +610,6 @@ static int volatile restart_pending;
 
 static apr_status_t decrement_connection_count(void *dummy) {
     apr_atomic_dec32(&connection_count);
-    apr_atomic_dec32(&conns_this_child);
     return APR_SUCCESS;
 }
 
@@ -901,7 +895,6 @@ static void process_socket(apr_thread_t *thd, apr_pool_t * p, apr_socket_t * soc
             apr_bucket_alloc_destroy(cs->bucket_alloc);
             apr_pool_clear(p);
             ap_push_pool(worker_queue_info, p);
-            apr_atomic_dec32(&conns_this_child);
             return;
         }
         apr_atomic_inc32(&connection_count);
@@ -1067,7 +1060,7 @@ static void check_infinite_requests(void)
     }
     else {
         /* keep going */
-        apr_atomic_set32(&conns_this_child, APR_INT32_MAX);
+        conns_this_child = APR_INT32_MAX;
     }
 }
 
@@ -1456,9 +1449,8 @@ static void * APR_THREAD_FUNC listener_thread(apr_thread_t * thd, void *dummy)
                 break;
         }
 
-        if (((apr_int32_t)apr_atomic_read32(&conns_this_child)) <= 0) {
+        if (conns_this_child <= 0)
             check_infinite_requests();
-        }
 
         now = apr_time_now();
         if (APLOGtrace6(ap_server_conf)) {
@@ -1667,6 +1659,7 @@ static void * APR_THREAD_FUNC listener_thread(apr_thread_t * thd, void *dummy)
                     }
 
                     if (csd != NULL) {
+                        conns_this_child--;
                         rc = ap_queue_push(worker_queue, csd, NULL, ptrans);
                         if (rc != APR_SUCCESS) {
                             /* trash the connection; we couldn't queue the connected
@@ -2154,11 +2147,11 @@ static void child_main(int child_num_arg)
     }
 
     if (ap_max_requests_per_child) {
-        apr_atomic_set32(&conns_this_child, (apr_uint32_t)ap_max_requests_per_child);
+        conns_this_child = ap_max_requests_per_child;
     }
     else {
         /* coding a value of zero means infinity */
-        apr_atomic_set32(&conns_this_child, APR_INT32_MAX);
+        conns_this_child = APR_INT32_MAX;
     }
 
     /* Setup worker threads */