lock: Add named lock capability

Locking some objects like sorcery objects can be tricky because the underlying
ao2 object may not be the same for all callers.  For instance, two threads that
call ast_sorcery_retrieve_by_id on the same aor name might actually get 2
different ao2 objects if the underlying wizard had to rehydrate the aor from a
database. Locking one ao2 object doesn't have any effect on the other even if
those objects had locks in the first place.

Named locks allow access control by keyspace and key strings.  Now an "aor"
named "1000" can be locked and any other thread attempting to lock "aor" "1000"
will wait regardless of whether the underlying ao2 object is the same or not.
Mutex and rwlocks are supported.

This capability will initially be used to lock an aor when multiple threads may
be attempting to prune expired contacts from it.

Change-Id: If258c0b7f92b02d07243ce70e535821a1ea7fb45

1 files changed, 151 insertions, 0 deletions

diff --git a/tests/test_named_lock.c b/tests/test_named_lock.c
new file mode 100644
index 000000000..9e383088e
--- /dev/null
+++ b/tests/test_named_lock.c
@@ -0,0 +1,151 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2016, Fairview 5 Engineering, LLC
+ *
+ * George Joseph <george.joseph@fairview5.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*!
+ * \file
+ * \brief Named Lock unit tests
+ *
+ * \author George Joseph <george.joseph@fairview5.com>
+ *
+ */
+
+/*** MODULEINFO
+	<depend>TEST_FRAMEWORK</depend>
+	<support_level>core</support_level>
+ ***/
+
+#include "asterisk.h"
+#include <signal.h>
+
+#include "asterisk/test.h"
+#include "asterisk/utils.h"
+#include "asterisk/module.h"
+#include "asterisk/lock.h"
+#include "asterisk/named_locks.h"
+
+static void *lock_thread(void *data)
+{
+	struct ast_named_lock *lock = ast_named_lock_get(AST_NAMED_LOCK_TYPE_MUTEX, "lock_test", data);
+
+	if (!lock) {
+		return NULL;
+	}
+
+	ao2_lock(lock);
+	usleep(3000000);
+	ao2_unlock(lock);
+
+	ast_named_lock_put(lock);
+
+	return NULL;
+}
+
+AST_TEST_DEFINE(named_lock_test)
+{
+	enum ast_test_result_state res = AST_TEST_FAIL;
+	struct ast_named_lock *lock1 = NULL;
+	struct ast_named_lock *lock2 = NULL;
+	pthread_t thread1;
+	pthread_t thread2;
+	struct timeval start_time;
+	int64_t duration;
+
+	switch(cmd) {
+	case TEST_INIT:
+		info->name = "named_lock_test";
+		info->category = "/main/lock/";
+		info->summary = "Named Lock test";
+		info->description =
+			"Tests that named locks operate as expected";
+		return AST_TEST_NOT_RUN;
+	case TEST_EXECUTE:
+		break;
+	}
+
+	ast_test_status_update(test, "This test should take about 3 seconds\n");
+
+	/* 2 locks/threads to make sure they're independent */
+	ast_pthread_create(&thread1, NULL, lock_thread, "lock_1");
+	ast_pthread_create(&thread2, NULL, lock_thread, "lock_2");
+
+	lock1 = ast_named_lock_get(AST_NAMED_LOCK_TYPE_MUTEX, "lock_test", "lock_1");
+	ast_test_validate_cleanup(test, lock1 != NULL, res, fail);
+
+	lock2 = ast_named_lock_get(AST_NAMED_LOCK_TYPE_MUTEX, "lock_test", "lock_2");
+	ast_test_validate_cleanup(test, lock2 != NULL, res, fail);
+
+	usleep(1000000);
+
+	/* These should both fail */
+	if (!ao2_trylock(lock1)) {
+		ast_test_status_update(test, "ao2_trylock on lock1 succeeded when it should have failed\n");
+		ao2_unlock(lock1);
+		goto fail;
+	}
+
+	if (!ao2_trylock(lock2)) {
+		ast_test_status_update(test, "ao2_trylock on lock2 succeeded when it should have failed\n");
+		ao2_unlock(lock2);
+		goto fail;
+	}
+
+	start_time = ast_tvnow();
+
+	/* These should both succeed eventually */
+	if (ao2_lock(lock1)) {
+		ast_test_status_update(test, "ao2_lock on lock1 failed\n");
+		goto fail;
+	}
+	ao2_unlock(lock1);
+
+	if (ao2_lock(lock2)) {
+		ast_test_status_update(test, "ao2_lock on lock2 failed\n");
+		goto fail;
+	}
+	ao2_unlock(lock2);
+
+	duration = ast_tvdiff_ms(ast_tvnow(), start_time);
+	ast_test_validate_cleanup(test, duration > 1500 && duration < 3500, res, fail);
+
+	res = AST_TEST_PASS;
+
+fail:
+
+	ast_named_lock_put(lock1);
+	ast_named_lock_put(lock2);
+
+	pthread_join(thread1, NULL);
+	pthread_join(thread2, NULL);
+
+	return res;
+}
+
+
+static int unload_module(void)
+{
+	AST_TEST_UNREGISTER(named_lock_test);
+	return 0;
+}
+
+static int load_module(void)
+{
+	AST_TEST_REGISTER(named_lock_test);
+	return AST_MODULE_LOAD_SUCCESS;
+}
+
+AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Named Lock test module");