X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=src%2FUtil%2FLock.php;h=9c449844597c56620bb90106ce67bd19fe4772c8;hb=7099a54b3d209bd5eb04613010ac3484563f0c45;hp=af15e106d56545a4c976976e609382bc85de93d8;hpb=f4652d6e5026abe7d7b352d2307622bd567aa433;p=friendica.git

diff --git a/src/Util/Lock.php b/src/Util/Lock.php
index af15e106d5..9c44984459 100644
--- a/src/Util/Lock.php
+++ b/src/Util/Lock.php
@@ -1,66 +1,101 @@
 <?php
-
+/**
+ * @file src/Util/Lock.php
+ */
 namespace Friendica\Util;
 
 /**
  * @file src/Util/Lock.php
  * @brief Functions for preventing parallel execution of functions
- *
  */
 
 use Friendica\Core\Config;
+use Friendica\Database\DBM;
 use Memcache;
 use dba;
-use dbm;
 
 /**
  * @brief This class contain Functions for preventing parallel execution of functions
  */
-class Lock {
-       /**
-         * @brief Check for memcache and open a connection if configured
-         *
-         * @return object|boolean The memcache object - or "false" if not successful
-         */
-        public static function memcache() {
-                if (!function_exists('memcache_connect')) {
-                        return false;
-                }
+class Lock
+{
+	private static $semaphore = array();
 
-                if (!Config::get('system', 'memcache')) {
-                        return false;
-                }
+	/**
+	 * @brief Check for memcache and open a connection if configured
+	 *
+	 * @return object|boolean The memcache object - or "false" if not successful
+	 */
+	private static function connectMemcache()
+	{
+		if (!function_exists('memcache_connect')) {
+			return false;
+		}
 
-                $memcache_host = Config::get('system', 'memcache_host', '127.0.0.1');
-                $memcache_port = Config::get('system', 'memcache_port', 11211);
+		if (!Config::get('system', 'memcache')) {
+			return false;
+		}
 
-                $memcache = new Memcache;
+		$memcache_host = Config::get('system', 'memcache_host', '127.0.0.1');
+		$memcache_port = Config::get('system', 'memcache_port', 11211);
 
-                if (!$memcache->connect($memcache_host, $memcache_port)) {
-                        return false;
-                }
+		$memcache = new Memcache;
 
-                return $memcache;
-        }
+		if (!$memcache->connect($memcache_host, $memcache_port)) {
+			return false;
+		}
+
+		return $memcache;
+	}
 
 	/**
-	 * @brief Sets a lock for a given name
+	 * @brief Creates a semaphore key
 	 *
 	 * @param string $fn_name Name of the lock
+	 *
+	 * @return ressource the semaphore key
+	 */
+	private static function semaphoreKey($fn_name)
+	{
+		$temp = get_temppath();
+
+		$file = $temp.'/'.$fn_name.'.sem';
+
+		if (!file_exists($file)) {
+			file_put_contents($file, $function);
+		}
+
+		return ftok($file, 'f');
+	}
+
+	/**
+	 * @brief Sets a lock for a given name
+	 *
+	 * @param string  $fn_name Name of the lock
 	 * @param integer $timeout Seconds until we give up
 	 *
 	 * @return boolean Was the lock successful?
 	 */
-	public static function set($fn_name, $timeout = 120) {
+	public static function set($fn_name, $timeout = 120)
+	{
 		$got_lock = false;
 		$start = time();
 
-		$memcache = self::memcache();
+		// The second parameter for "sem_acquire" doesn't exist before 5.6.1
+		if (function_exists('sem_get') && version_compare(PHP_VERSION, '5.6.1', '>=')) {
+			self::$semaphore[$fn_name] = sem_get(self::semaphoreKey($fn_name));
+			if (self::$semaphore[$fn_name]) {
+				return sem_acquire(self::$semaphore[$fn_name], ($timeout == 0));
+			}
+		}
+
+		$memcache = self::connectMemcache();
 		if (is_object($memcache)) {
-			$wait_sec = 0.2;
 			$cachekey = get_app()->get_hostname().";lock:".$fn_name;
 
 			do {
+				// We only lock to be sure that nothing happens at exactly the same time
+				dba::lock('locks');
 				$lock = $memcache->get($cachekey);
 
 				if (!is_bool($lock)) {
@@ -68,7 +103,7 @@ class Lock {
 
 					// When the process id isn't used anymore, we can safely claim the lock for us.
 					// Or we do want to lock something that was already locked by us.
-					if (!posix_kill($pid, 0) OR ($pid == getmypid())) {
+					if (!posix_kill($pid, 0) || ($pid == getmypid())) {
 						$lock = false;
 					}
 				}
@@ -76,21 +111,22 @@ class Lock {
 					$memcache->set($cachekey, getmypid(), MEMCACHE_COMPRESSED, 300);
 					$got_lock = true;
 				}
-				if (!$got_lock AND ($timeout > 0)) {
-					usleep($wait_sec * 1000000);
+
+				dba::unlock();
+
+				if (!$got_lock && ($timeout > 0)) {
+					usleep(rand(10000, 200000));
 				}
-			} while (!$got_lock AND ((time() - $start) < $timeout));
+			} while (!$got_lock && ((time() - $start) < $timeout));
 
 			return $got_lock;
 		}
 
-		$wait_sec = 2;
-
 		do {
 			dba::lock('locks');
 			$lock = dba::select('locks', array('locked', 'pid'), array('name' => $fn_name), array('limit' => 1));
 
-			if (dbm::is_result($lock)) {
+			if (DBM::is_result($lock)) {
 				if ($lock['locked']) {
 					// When the process id isn't used anymore, we can safely claim the lock for us.
 					if (!posix_kill($lock['pid'], 0)) {
@@ -105,17 +141,17 @@ class Lock {
 					dba::update('locks', array('locked' => true, 'pid' => getmypid()), array('name' => $fn_name));
 					$got_lock = true;
 				}
-			} elseif (!dbm::is_result($lock)) {
+			} elseif (!DBM::is_result($lock)) {
 				dba::insert('locks', array('name' => $fn_name, 'locked' => true, 'pid' => getmypid()));
 				$got_lock = true;
 			}
 
 			dba::unlock();
 
-			if (!$got_lock AND ($timeout > 0)) {
-				sleep($wait_sec);
+			if (!$got_lock && ($timeout > 0)) {
+				usleep(rand(100000, 2000000));
 			}
-		} while (!$got_lock AND ((time() - $start) < $timeout));
+		} while (!$got_lock && ((time() - $start) < $timeout));
 
 		return $got_lock;
 	}
@@ -124,9 +160,21 @@ class Lock {
 	 * @brief Removes a lock if it was set by us
 	 *
 	 * @param string $fn_name Name of the lock
+	 * @return mixed
 	 */
-	public static function remove($fn_name) {
-		$memcache = self::memcache();
+	public static function remove($fn_name)
+	{
+		if (function_exists('sem_get') && version_compare(PHP_VERSION, '5.6.1', '>=')) {
+			if (empty(self::$semaphore[$fn_name])) {
+				return false;
+			} else {
+				$success = @sem_release(self::$semaphore[$fn_name]);
+				unset(self::$semaphore[$fn_name]);
+				return $success;
+			}
+		}
+
+		$memcache = self::connectMemcache();
 		if (is_object($memcache)) {
 			$cachekey = get_app()->get_hostname().";lock:".$fn_name;
 			$lock = $memcache->get($cachekey);
@@ -145,9 +193,11 @@ class Lock {
 
 	/**
 	 * @brief Removes all lock that were set by us
+	 * @return void
 	 */
-	public static function removeAll() {
-		$memcache = self::memcache();
+	public static function removeAll()
+	{
+		$memcache = self::connectMemcache();
 		if (is_object($memcache)) {
 			// We cannot delete all cache entries, but this doesn't matter with memcache
 			return;