[Asterisk-code-review] res sorcery memory cache.c: Shutdown in a less crash potenti... (asterisk[master])

[Richard Mudgett]

Richard Mudgett has uploaded a new change for review.

  https://gerrit.asterisk.org/1358

Change subject: res_sorcery_memory_cache.c: Shutdown in a less crash potential order.
......................................................................

res_sorcery_memory_cache.c: Shutdown in a less crash potential order.

Basically you should shutdown in the opposite order of how you setup since
later setup pieces likely depend on earlier setup pieces.  e.g.,
Registering your external API with the rest of the system should be the
last thing setup and the first thing unregistered during shutdown.

Change-Id: I5715765b723100c8d3c2642e9e72cc7ad5ad115e
---
M res/res_sorcery_memory_cache.c
1 file changed, 29 insertions(+), 24 deletions(-)


  git pull ssh://gerrit.asterisk.org:29418/asterisk refs/changes/58/1358/1

diff --git a/res/res_sorcery_memory_cache.c b/res/res_sorcery_memory_cache.c
index 0a33ae4..53fa3b9 100644
--- a/res/res_sorcery_memory_cache.c
+++ b/res/res_sorcery_memory_cache.c
@@ -2482,22 +2482,6 @@
 
 static int unload_module(void)
 {
-	if (sched) {
-		ast_sched_context_destroy(sched);
-		sched = NULL;
-	}
-
-	ao2_cleanup(caches);
-
-	ast_sorcery_wizard_unregister(&memory_cache_object_wizard);
-
-	ast_cli_unregister_multiple(cli_memory_cache, ARRAY_LEN(cli_memory_cache));
-
-	ast_manager_unregister("SorceryMemoryCacheExpireObject");
-	ast_manager_unregister("SorceryMemoryCacheExpire");
-	ast_manager_unregister("SorceryMemoryCacheStaleObject");
-	ast_manager_unregister("SorceryMemoryCacheStale");
-
 	AST_TEST_UNREGISTER(open_with_valid_options);
 	AST_TEST_UNREGISTER(open_with_invalid_options);
 	AST_TEST_UNREGISTER(create_and_retrieve);
@@ -2507,12 +2491,41 @@
 	AST_TEST_UNREGISTER(expiration);
 	AST_TEST_UNREGISTER(stale);
 
+	ast_manager_unregister("SorceryMemoryCacheExpireObject");
+	ast_manager_unregister("SorceryMemoryCacheExpire");
+	ast_manager_unregister("SorceryMemoryCacheStaleObject");
+	ast_manager_unregister("SorceryMemoryCacheStale");
+
+	ast_cli_unregister_multiple(cli_memory_cache, ARRAY_LEN(cli_memory_cache));
+
+	ast_sorcery_wizard_unregister(&memory_cache_object_wizard);
+
+	/*
+	 * XXX There is the potential to leak memory if there are pending
+	 * next-cache-expiration and stale-cache-update tasks in the scheduler.
+	 */
+	if (sched) {
+		ast_sched_context_destroy(sched);
+		sched = NULL;
+	}
+
+	ao2_cleanup(caches);
+	caches = NULL;
+
 	return 0;
 }
 
 static int load_module(void)
 {
 	int res;
+
+	caches = ao2_container_alloc(CACHES_CONTAINER_BUCKET_SIZE, sorcery_memory_cache_hash,
+		sorcery_memory_cache_cmp);
+	if (!caches) {
+		ast_log(LOG_ERROR, "Failed to create container for configured caches\n");
+		unload_module();
+		return AST_MODULE_LOAD_DECLINE;
+	}
 
 	sched = ast_sched_context_create();
 	if (!sched) {
@@ -2523,14 +2536,6 @@
 
 	if (ast_sched_start_thread(sched)) {
 		ast_log(LOG_ERROR, "Failed to create scheduler thread for cache management\n");
-		unload_module();
-		return AST_MODULE_LOAD_DECLINE;
-	}
-
-	caches = ao2_container_alloc(CACHES_CONTAINER_BUCKET_SIZE, sorcery_memory_cache_hash,
-		sorcery_memory_cache_cmp);
-	if (!caches) {
-		ast_log(LOG_ERROR, "Failed to create container for configured caches\n");
 		unload_module();
 		return AST_MODULE_LOAD_DECLINE;
 	}

-- 
To view, visit https://gerrit.asterisk.org/1358
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Gerrit-MessageType: newchange
Gerrit-Change-Id: I5715765b723100c8d3c2642e9e72cc7ad5ad115e
Gerrit-PatchSet: 1
Gerrit-Project: asterisk
Gerrit-Branch: master
Gerrit-Owner: Richard Mudgett <rmudgett at digium.com>