Merge "lock: Add named lock capability"

include/asterisk/_private.h

@@ -39,6 +39,7 @@ int ast_dns_system_resolver_init(void); /*!< Provided by dns_system_resolver.c *
 void threadstorage_init(void);		/*!< Provided by threadstorage.c */
 int ast_device_state_engine_init(void);	/*!< Provided by devicestate.c */
 int astobj2_init(void);			/*!< Provided by astobj2.c */
+int ast_named_locks_init(void);		/*!< Provided by named_locks.c */
 int ast_file_init(void);		/*!< Provided by file.c */
 int ast_features_init(void);            /*!< Provided by features.c */
 void ast_autoservice_init(void);	/*!< Provided by autoservice.c */

include/asterisk/named_locks.h

@@ -0,0 +1,105 @@
+/*
+ * 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 Locks
+ *
+ * \author George Joseph <george.joseph@fairview5.com>
+ */
+
+#ifndef INCLUDE_ASTERISK_NAMED_LOCKS_H_
+#define INCLUDE_ASTERISK_NAMED_LOCKS_H_
+
+#include "asterisk/astobj2.h"
+
+/*!
+ * \defgroup named_locks Named mutex and read-write locks
+ * @{
+ * \page NamedLocks Named mutex and read-write locks
+ * \since 13.9.0
+ *
+ * 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 name.  Now an aor named "1000" can be locked and
+ * any other thread attempting to lock the aor named "1000" will wait regardless of whether
+ * the underlying ao2 object is the same or not.
+ *
+ * To use a named lock:
+ * 	Call ast_named_lock_get with the appropriate keyspace and key.
+ * 	Use the standard ao2 lock/unlock functions as needed.
+ * 	Call ast_named_lock_put when you're finished with it.
+ */
+
+/*!
+ * \brief Which type of lock to request.
+ */
+enum ast_named_lock_type {
+	/*! Request a named mutex. */
+	AST_NAMED_LOCK_TYPE_MUTEX = AO2_ALLOC_OPT_LOCK_MUTEX,
+	/*! Request a named read/write lock. */
+	AST_NAMED_LOCK_TYPE_RWLOCK = AO2_ALLOC_OPT_LOCK_RWLOCK,
+};
+
+struct ast_named_lock;
+
+struct ast_named_lock *__ast_named_lock_get(const char *filename, int lineno, const char *func,
+	enum ast_named_lock_type lock_type, const char *keyspace, const char *key);
+
+int __ast_named_lock_put(const char *filename, int lineno, const char *func,
+	struct ast_named_lock *lock);
+
+/*!
+ * \brief Geta named lock handle
+ * \since 13.9.0
+ *
+ * \param lock_type One of ast_named_lock_type
+ * \param keyspace
+ * \param key
+ * \retval A pointer to an ast_named_lock structure
+ * \retval NULL on error
+ *
+ * \note
+ * keyspace and key can be anything.  For sorcery objects, keyspace could be the object type
+ * and key could be the object id.
+ */
+#define ast_named_lock_get(lock_type, keyspace, key) \
+	__ast_named_lock_get(__FILE__, __LINE__, __PRETTY_FUNCTION__, lock_type, \
+		keyspace, key)
+
+/*!
+ * \brief Put a named lock handle away
+ * \since 13.9.0
+ *
+ * \param lock The pointer to the ast_named_lock structure returned by ast_named_lock_get
+ * \retval 0 Success
+ * \retval -1 Failure
+ */
+#define ast_named_lock_put(lock) \
+	__ast_named_lock_put(__FILE__, __LINE__, __PRETTY_FUNCTION__, lock)
+
+/*!
+ * @}
+ */
+
+#endif /* INCLUDE_ASTERISK_NAMED_LOCKS_H_ */

main/asterisk.c

@@ -4339,6 +4339,11 @@ static void asterisk_daemon(int isroot, const char *runuser, const char *rungrou
 		exit(1);
 	}
 
+	if (ast_named_locks_init()) {
+		printf("Failed: ast_named_locks_init\n%s", term_quit());
+		exit(1);
+	}
+
 	if (ast_opt_console) {
 		if (el_hist == NULL || el == NULL)
 			ast_el_initialize();

main/named_locks.c

@@ -0,0 +1,142 @@
+/*
+ * 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 Locks
+ *
+ * \author George Joseph <george.joseph@fairview5.com>
+ */
+
+#include "asterisk.h"
+
+ASTERISK_REGISTER_FILE()
+
+#include "asterisk/_private.h"
+#include "asterisk/astobj2.h"
+#include "asterisk/named_locks.h"
+#include "asterisk/utils.h"
+
+struct ao2_container *named_locks;
+#define NAMED_LOCKS_BUCKETS 101
+
+struct ast_named_lock {
+	char key[0];
+};
+
+static int named_locks_hash(const void *obj, const int flags)
+{
+	const struct ast_named_lock *lock = obj;
+
+	switch (flags & OBJ_SEARCH_MASK) {
+	case OBJ_SEARCH_KEY:
+		return ast_str_hash(obj);
+	case OBJ_SEARCH_OBJECT:
+		return ast_str_hash(lock->key);
+	default:
+		/* Hash can only work on something with a full key. */
+		ast_assert(0);
+		return 0;
+	}
+}
+
+static int named_locks_cmp(void *obj_left, void *obj_right, int flags)
+{
+	const struct ast_named_lock *object_left = obj_left;
+	const struct ast_named_lock *object_right = obj_right;
+	const char *right_key = obj_right;
+	int cmp;
+
+	switch (flags & OBJ_SEARCH_MASK) {
+	case OBJ_SEARCH_OBJECT:
+		right_key = object_right->key;
+		/* Fall through */
+	case OBJ_SEARCH_KEY:
+		cmp = strcmp(object_left->key, right_key);
+		break;
+	case OBJ_SEARCH_PARTIAL_KEY:
+		cmp = strncmp(object_left->key, right_key, strlen(right_key));
+		break;
+	default:
+		cmp = 0;
+		break;
+	}
+
+	return cmp ? 0 : CMP_MATCH;
+}
+
+static void named_locks_shutdown(void)
+{
+	ao2_cleanup(named_locks);
+}
+
+int ast_named_locks_init(void)
+{
+	named_locks = ao2_container_alloc_hash(0, 0, NAMED_LOCKS_BUCKETS, named_locks_hash, NULL,
+		named_locks_cmp);
+	if (!named_locks) {
+		return -1;
+	}
+
+	ast_register_cleanup(named_locks_shutdown);
+
+	return 0;
+}
+
+struct ast_named_lock *__ast_named_lock_get(const char *filename, int lineno, const char *func,
+	enum ast_named_lock_type lock_type, const char *keyspace, const char *key)
+{
+	struct ast_named_lock *lock = NULL;
+	int concat_key_buff_len = strlen(keyspace) + strlen(key) + 2;
+	char *concat_key = ast_alloca(concat_key_buff_len);
+
+	sprintf(concat_key, "%s-%s", keyspace, key); /* Safe */
+
+	ao2_lock(named_locks);
+	lock = ao2_find(named_locks, concat_key, OBJ_SEARCH_KEY | OBJ_NOLOCK);
+	if (lock) {
+		ao2_unlock(named_locks);
+		ast_assert((ao2_options_get(lock) & AO2_ALLOC_OPT_LOCK_MASK) == lock_type);
+		return lock;
+	}
+
+	lock = ao2_alloc_options(sizeof(*lock) + concat_key_buff_len, NULL, lock_type);
+	if (lock) {
+		strcpy(lock->key, concat_key); /* Safe */
+		ao2_link_flags(named_locks, lock, OBJ_NOLOCK);
+	}
+	ao2_unlock(named_locks);
+
+	return lock;
+}
+
+int __ast_named_lock_put(const char *filename, int lineno, const char *func,
+	struct ast_named_lock *lock)
+{
+	if (!lock) {
+		return -1;
+	}
+
+	ao2_lock(named_locks);
+	if (ao2_ref(lock, -1) == 2) {
+		ao2_unlink_flags(named_locks, lock, OBJ_NOLOCK);
+	}
+	ao2_unlock(named_locks);
+
+	return 0;
+}

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");