<?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;
+
+require_once 'include/dba.php';
/**
* @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 = [];
- 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_host = Config::get('system', 'memcache_host', '127.0.0.1');
+ $memcache_port = Config::get('system', 'memcache_port', 11211);
- $memcache = new Memcache;
+ $memcache = new Memcache;
- if (!$memcache->connect($memcache_host, $memcache_port)) {
- return false;
- }
+ if (!$memcache->connect($memcache_host, $memcache_port)) {
+ return false;
+ }
- return $memcache;
- }
+ 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, $fn_name);
+ }
+
+ return ftok($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($lock)) {
// When the process id isn't used anymore, we can safely claim the lock for us.
// Or we do want to lock something that was already locked by us.
- if (!posix_kill($pid, 0) OR ($pid == getmypid())) {
+ if (!posix_kill($pid, 0) || ($pid == getmypid())) {
$lock = false;
}
}
$memcache->set($cachekey, getmypid(), MEMCACHE_COMPRESSED, 300);
$got_lock = true;
}
- if (!$got_lock) {
- usleep($wait_sec * 1000000);
+
+ dba::unlock();
+
+ if (!$got_lock && ($timeout > 0)) {
+ usleep(rand(10000, 200000));
}
- } while (!$got_lock AND ((time(true) - $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));
+ $lock = dba::selectFirst('locks', ['locked', 'pid'], ['name' => $fn_name]);
- if (dbm::is_result($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($lock['pid'], 0)) {
}
}
if (!$lock['locked']) {
- dba::update('locks', array('locked' => true, 'pid' => getmypid()), array('name' => $fn_name));
+ dba::update('locks', ['locked' => true, 'pid' => getmypid()], ['name' => $fn_name]);
$got_lock = true;
}
- } elseif (!dbm::is_result($lock)) {
- dba::insert('locks', array('name' => $fn_name, 'locked' => true, 'pid' => getmypid()));
+ } elseif (!DBM::is_result($lock)) {
+ dba::insert('locks', ['name' => $fn_name, 'locked' => true, 'pid' => getmypid()]);
$got_lock = true;
}
dba::unlock();
- if (!$got_lock) {
- 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;
}
* @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);
return;
}
- dba::update('locks', array('locked' => false, 'pid' => 0), array('name' => $fn_name, 'pid' => getmypid()));
+ dba::update('locks', ['locked' => false, 'pid' => 0], ['name' => $fn_name, 'pid' => getmypid()]);
return;
}
/**
* @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;
}
- dba::update('locks', array('locked' => false, 'pid' => 0), array('pid' => getmypid()));
+ dba::update('locks', ['locked' => false, 'pid' => 0], ['pid' => getmypid()]);
return;
}
}
projects / friendica.git / blobdiff