consistency sweep

Author: machine-moon

CHANGES

@@ -1,8 +1,12 @@
                                                          -*- coding: utf-8 -*-
 Changes with Apache 2.5.1
 
-  *) mpm_event, mpm_worker, mpm_winnt, mpm_prefork: Add optional hooks to
-     account for connections managed outside the MPM accept loop (e.g., UDP).
+  *) mpm_event, mpm_worker, mpm_winnt, mpm_prefork: Add the optional functions
+     ap_mpm_note_extra_connection_added() and
+     ap_mpm_note_extra_connection_removed() to account for connections managed
+     outside the MPM accept loop (e.g., UDP).  On graceful stop a child waits
+     for those connections no longer than max(Timeout,
+     GracefulShutdownTimeout), then warns and exits.
      [Tarek Ibrahim <tareki@pulsarxtech.com> <t1br4h1m@gmail.com>]
 
   * mod_ssl: Add support for OpenSSL provider based certificate

include/ap_mmn.h

@@ -737,7 +737,9 @@
  * 20211221.29 (2.5.1-dev) Add ap_set_time_process_request() to scoreboard.h
  * 20211221.30 (2.5.1-dev) Add ap_stat_check() to httpd.h
  * 20211221.31 (2.5.1-dev) Add ap_*_timingsafe() to httpd.h
- * 20211221.32 (2.5.1-dev) Add optional hooks for MPM to accept UDP conns.
+ * 20211221.32 (2.5.1-dev) Add the optional functions ap_mpm_note_extra_
+ *                         connection_added() and ap_mpm_note_extra_
+ *                         connection_removed() to mpm_common.h
  */
 
 #define MODULE_MAGIC_COOKIE 0x41503235UL /* "AP25" */

include/mpm_common.h

@@ -571,6 +571,12 @@ void mpm_common_pre_config(apr_pool_t *pconf);
  * Call ap_mpm_note_extra_connection_added() when such a connection starts,
  * and ap_mpm_note_extra_connection_removed() when it ends. These functions
  * may be NULL if the active MPM does not implement them.
+ *
+ * A module using them is expected to notice that the child is stopping (e.g.
+ * with the child_stopping hook) and to end the connections it noted in a
+ * timely manner, gracefully or not.  The MPM waits for them no longer than
+ * max(Timeout, GracefulShutdownTimeout), then logs a warning and exits
+ * anyway, possibly cutting those connections short.
  */
 APR_DECLARE_OPTIONAL_FN(void, ap_mpm_note_extra_connection_added, (void));
 APR_DECLARE_OPTIONAL_FN(void, ap_mpm_note_extra_connection_removed, (void));

server/mpm/prefork/prefork.c

@@ -90,7 +90,7 @@
 
 /* config globals */
 
-static apr_uint32_t connection_count = 0;   /* Number of open connections */
+static apr_uint32_t extra_connection_count = 0; /* Number of open connections that the MPM does not own */
 static int ap_daemons_to_start=0;
 static int ap_daemons_min_free=0;
 static int ap_daemons_max_free=0;
@@ -219,9 +219,19 @@ static void prefork_note_child_started(int slot, pid_t pid)
     ap_run_child_status(ap_server_conf, pid, gen, slot, MPM_CHILD_STARTED);
 }
 
+static void ap_mpm_note_extra_connection_added(void)
+{
+    apr_atomic_inc32(&extra_connection_count);
+}
+
+static void ap_mpm_note_extra_connection_removed(void)
+{
+    apr_atomic_dec32(&extra_connection_count);
+}
+
 static void wait_for_extra_connections(void)
 {
-    apr_uint32_t count = apr_atomic_read32(&connection_count);
+    apr_uint32_t count = apr_atomic_read32(&extra_connection_count);
     apr_time_t graceful, timeout, deadline;
 
     if (count == 0) {
@@ -234,7 +244,7 @@ static void wait_for_extra_connections(void)
 
     do {
         apr_sleep(apr_time_from_msec(100));
-        count = apr_atomic_read32(&connection_count);
+        count = apr_atomic_read32(&extra_connection_count);
     } while (count > 0 && apr_time_now() < deadline);
 
     if (count > 0) {
@@ -413,16 +423,6 @@ static void just_die(int sig)
 /* volatile because it's updated from a signal handler */
 static int volatile die_now = 0;
 
-static void ap_mpm_note_extra_connection_added(void)
-{
-    apr_atomic_inc32(&connection_count);
-}
-
-static void ap_mpm_note_extra_connection_removed(void)
-{
-    apr_atomic_dec32(&connection_count);
-}
-
 static void stop_listening(int sig)
 {
     retained->mpm->mpm_state = AP_MPMQ_STOPPING;

server/mpm/winnt/child.c

@@ -131,11 +131,10 @@ static apr_thread_mutex_t  *ctxpool_lock;
 static winnt_conn_ctx_t *ctxpool_head = NULL;
 static apr_uint32_t num_completion_contexts = 0;
 static apr_uint32_t max_num_completion_contexts = 0;
-static apr_uint32_t extra_connection_count = 0;
+static apr_uint32_t extra_connection_count = 0; /* Number of open connections that the MPM does not own */
 static HANDLE ThreadDispatchIOCP = NULL;
 static HANDLE ctxpool_wait_event = NULL;
 
-/* Connections a module accepted itself, which the worker threads do not serve. */
 void ap_mpm_note_extra_connection_added(void)
 {
     apr_atomic_inc32(&extra_connection_count);
@@ -149,16 +148,15 @@ void ap_mpm_note_extra_connection_removed(void)
 static void wait_for_extra_connections(void)
 {
     apr_uint32_t count = apr_atomic_read32(&extra_connection_count);
-    apr_time_t graceful, timeout;
-    int time_remains;
+    apr_time_t graceful, timeout, time_remains;
 
     if (count == 0) {
         return;
     }
 
     graceful = apr_time_from_sec(ap_graceful_shutdown_timeout);
     timeout = (graceful > ap_server_conf->timeout) ? graceful : ap_server_conf->timeout;
-    time_remains = (int)(timeout / APR_TIME_C(1000));
+    time_remains = timeout / APR_TIME_C(1000);
 
     do {
         Sleep(100);

server/mpm/worker/worker.c

@@ -118,7 +118,7 @@
  * Actual definitions of config globals
  */
 
-static apr_uint32_t connection_count = 0;   /* Number of open connections */
+static apr_uint32_t extra_connection_count = 0; /* Number of open connections that the MPM does not own */
 static int threads_per_child = 0;     /* Worker threads per child */
 static int ap_daemons_to_start = 0;
 static int min_spare_threads = 0;
@@ -515,17 +515,17 @@ static void check_infinite_requests(void)
 
 static void ap_mpm_note_extra_connection_added(void)
 {
-    apr_atomic_inc32(&connection_count);
+    apr_atomic_inc32(&extra_connection_count);
 }
 
 static void ap_mpm_note_extra_connection_removed(void)
 {
-    apr_atomic_dec32(&connection_count);
+    apr_atomic_dec32(&extra_connection_count);
 }
 
 static void wait_for_extra_connections(void)
 {
-    apr_uint32_t count = apr_atomic_read32(&connection_count);
+    apr_uint32_t count = apr_atomic_read32(&extra_connection_count);
     apr_time_t graceful, timeout, deadline;
 
     if (count == 0) {
@@ -538,7 +538,7 @@ static void wait_for_extra_connections(void)
 
     do {
         apr_sleep(apr_time_from_msec(100));
-        count = apr_atomic_read32(&connection_count);
+        count = apr_atomic_read32(&extra_connection_count);
     } while (count > 0 && apr_time_now() < deadline);
 
     if (count > 0) {