diff --git a/src/Core/Cache/MemcachedCacheDriver.php b/src/Core/Cache/MemcachedCacheDriver.php
index 9c860711f8..dda36ba19c 100644
--- a/src/Core/Cache/MemcachedCacheDriver.php
+++ b/src/Core/Cache/MemcachedCacheDriver.php
@@ -16,7 +16,7 @@ class MemcachedCacheDriver extends BaseObject implements IMemoryCacheDriver
 	use TraitCompareDelete;
 
 	/**
-	 * @var Memcached
+	 * @var \Memcached
 	 */
 	private $memcached;
 
diff --git a/src/Core/Cache/RedisCacheDriver.php b/src/Core/Cache/RedisCacheDriver.php
index 25c18aa6b6..735418b2d2 100644
--- a/src/Core/Cache/RedisCacheDriver.php
+++ b/src/Core/Cache/RedisCacheDriver.php
@@ -14,7 +14,7 @@ use Friendica\Core\Cache;
 class RedisCacheDriver extends BaseObject implements IMemoryCacheDriver
 {
 	/**
-	 * @var Redis
+	 * @var \Redis
 	 */
 	private $redis;
 
diff --git a/src/Core/Lock.php b/src/Core/Lock.php
index 47a1f9b4fe..9892f1f4e4 100644
--- a/src/Core/Lock.php
+++ b/src/Core/Lock.php
@@ -1,7 +1,5 @@
 <?php
-/**
- * @file src/Util/Lock.php
- */
+
 namespace Friendica\Core;
 
 /**
@@ -115,20 +113,20 @@ class Lock
 	 *
 	 * @return boolean Was the lock successful?
 	 */
-	public static function acquireLock($key, $timeout = 120)
+	public static function acquire($key, $timeout = 120)
 	{
-		return self::getDriver()->acquire($key, $timeout);
+		return self::getDriver()->acquireLock($key, $timeout);
 	}
 
 	/**
 	 * @brief Releases a lock if it was set by us
 	 *
 	 * @param string $key Name of the lock
-	 * @return mixed
+	 * @return void
 	 */
-	public static function releaseLock($key)
+	public static function release($key)
 	{
-		return self::getDriver()->release($key);
+		self::getDriver()->releaseLock($key);
 	}
 
 	/**
diff --git a/src/Core/Lock/AbstractLockDriver.php b/src/Core/Lock/AbstractLockDriver.php
index 53597d45fc..033d6f356e 100644
--- a/src/Core/Lock/AbstractLockDriver.php
+++ b/src/Core/Lock/AbstractLockDriver.php
@@ -52,7 +52,7 @@ abstract class AbstractLockDriver extends BaseObject implements ILockDriver
 	 */
 	public function releaseAll() {
 		foreach ($this->acquiredLocks as $acquiredLock => $hasLock) {
-			$this->release($acquiredLock);
+			$this->releaseLock($acquiredLock);
 		}
 	}
 }
diff --git a/src/Core/Lock/CacheLockDriver.php b/src/Core/Lock/CacheLockDriver.php
index 57627acecf..2dd6f3fad9 100644
--- a/src/Core/Lock/CacheLockDriver.php
+++ b/src/Core/Lock/CacheLockDriver.php
@@ -24,7 +24,7 @@ class CacheLockDriver extends AbstractLockDriver
 	/**
 	 * (@inheritdoc)
 	 */
-	public function acquire($key, $timeout = 120)
+	public function acquireLock($key, $timeout = 120)
 	{
 		$got_lock = false;
 		$start = time();
@@ -60,7 +60,7 @@ class CacheLockDriver extends AbstractLockDriver
 	/**
 	 * (@inheritdoc)
 	 */
-	public function release($key)
+	public function releaseLock($key)
 	{
 		$cachekey = self::getCacheKey($key);
 
diff --git a/src/Core/Lock/DatabaseLockDriver.php b/src/Core/Lock/DatabaseLockDriver.php
index 8f8e174214..6f4b942a4d 100644
--- a/src/Core/Lock/DatabaseLockDriver.php
+++ b/src/Core/Lock/DatabaseLockDriver.php
@@ -14,7 +14,7 @@ class DatabaseLockDriver extends AbstractLockDriver
 	/**
 	 * (@inheritdoc)
 	 */
-	public function acquire($key, $timeout = 120)
+	public function acquireLock($key, $timeout = 120)
 	{
 		$got_lock = false;
 		$start = time();
@@ -55,7 +55,7 @@ class DatabaseLockDriver extends AbstractLockDriver
 	/**
 	 * (@inheritdoc)
 	 */
-	public function release($key)
+	public function releaseLock($key)
 	{
 		dba::delete('locks', ['name' => $key, 'pid' => getmypid()]);
 
diff --git a/src/Core/Lock/ILockDriver.php b/src/Core/Lock/ILockDriver.php
index af8a1d56ae..cd54cc03c3 100644
--- a/src/Core/Lock/ILockDriver.php
+++ b/src/Core/Lock/ILockDriver.php
@@ -26,7 +26,7 @@ interface ILockDriver
 	 *
 	 * @return boolean Was the lock successful?
 	 */
-	public function acquire($key, $timeout = 120);
+	public function acquireLock($key, $timeout = 120);
 
 	/**
 	 * Releases a lock if it was set by us
@@ -35,7 +35,7 @@ interface ILockDriver
 	 *
 	 * @return void
 	 */
-	public function release($key);
+	public function releaseLock($key);
 
 	/**
 	 * Releases all lock that were set by us
diff --git a/src/Core/Lock/SemaphoreLockDriver.php b/src/Core/Lock/SemaphoreLockDriver.php
index 250a75fbfe..d032d46cc6 100644
--- a/src/Core/Lock/SemaphoreLockDriver.php
+++ b/src/Core/Lock/SemaphoreLockDriver.php
@@ -20,7 +20,7 @@ class SemaphoreLockDriver extends AbstractLockDriver
 	{
 		$temp = get_temppath();
 
-		$file = $temp.'/'.$key.'.sem';
+		$file = $temp . '/' . $key . '.sem';
 
 		if (!file_exists($file)) {
 			file_put_contents($file, $key);
@@ -33,7 +33,7 @@ class SemaphoreLockDriver extends AbstractLockDriver
 	 *
 	 * (@inheritdoc)
 	 */
-	public function acquire($key, $timeout = 120)
+	public function acquireLock($key, $timeout = 120)
 	{
 		self::$semaphore[$key] = sem_get(self::semaphoreKey($key));
 		if (self::$semaphore[$key]) {
@@ -49,7 +49,7 @@ class SemaphoreLockDriver extends AbstractLockDriver
 	/**
 	 * (@inheritdoc)
 	 */
-	public function release($key)
+	public function releaseLock($key)
 	{
 		if (empty(self::$semaphore[$key])) {
 			return false;
@@ -66,6 +66,6 @@ class SemaphoreLockDriver extends AbstractLockDriver
 	 */
 	public function isLocked($key)
 	{
-		return @sem_get(self::$semaphore[$key]) !== false;
+		return isset(self::$semaphore[$key]);
 	}
 }
diff --git a/src/Core/Worker.php b/src/Core/Worker.php
index cbf2ae8bd9..c4c91bbf8b 100644
--- a/src/Core/Worker.php
+++ b/src/Core/Worker.php
@@ -4,15 +4,11 @@
  */
 namespace Friendica\Core;
 
-use Friendica\Core\Addon;
-use Friendica\Core\Config;
-use Friendica\Core\System;
-use Friendica\Core\Lock;
+use dba;
 use Friendica\Database\DBM;
 use Friendica\Model\Process;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Network;
-use dba;
 
 require_once 'include/dba.php';
 
@@ -108,16 +104,16 @@ class Worker
 				}
 
 				// If possible we will fetch new jobs for this worker
-				if (!$refetched && Lock::acquireLock('worker_process', 0)) {
+				if (!$refetched && Lock::acquire('worker_process', 0)) {
 					$stamp = (float)microtime(true);
 					$refetched = self::findWorkerProcesses($passing_slow);
 					self::$db_duration += (microtime(true) - $stamp);
-					Lock::releaseLock('worker_process');
+					Lock::release('worker_process');
 				}
 			}
 
 			// To avoid the quitting of multiple workers only one worker at a time will execute the check
-			if (Lock::acquireLock('worker', 0)) {
+			if (Lock::acquire('worker', 0)) {
 				$stamp = (float)microtime(true);
 				// Count active workers and compare them with a maximum value that depends on the load
 				if (self::tooMuchWorkers()) {
@@ -130,7 +126,7 @@ class Worker
 					logger('Memory limit reached, quitting.', LOGGER_DEBUG);
 					return;
 				}
-				Lock::releaseLock('worker');
+				Lock::release('worker');
 				self::$db_duration += (microtime(true) - $stamp);
 			}
 
@@ -883,7 +879,7 @@ class Worker
 		dba::close($r);
 
 		$stamp = (float)microtime(true);
-		if (!Lock::acquireLock('worker_process')) {
+		if (!Lock::acquire('worker_process')) {
 			return false;
 		}
 		self::$lock_duration = (microtime(true) - $stamp);
@@ -892,7 +888,7 @@ class Worker
 		$found = self::findWorkerProcesses($passing_slow);
 		self::$db_duration += (microtime(true) - $stamp);
 
-		Lock::releaseLock('worker_process');
+		Lock::release('worker_process');
 
 		if ($found) {
 			$r = dba::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
@@ -1097,13 +1093,13 @@ class Worker
 		}
 
 		// If there is a lock then we don't have to check for too much worker
-		if (!Lock::acquireLock('worker', 0)) {
+		if (!Lock::acquire('worker', 0)) {
 			return true;
 		}
 
 		// If there are already enough workers running, don't fork another one
 		$quit = self::tooMuchWorkers();
-		Lock::releaseLock('worker');
+		Lock::release('worker');
 
 		if ($quit) {
 			return true;
diff --git a/src/Model/Item.php b/src/Model/Item.php
index ac53bb0220..d31d7c1323 100644
--- a/src/Model/Item.php
+++ b/src/Model/Item.php
@@ -6,26 +6,22 @@
 
 namespace Friendica\Model;
 
+use dba;
 use Friendica\BaseObject;
 use Friendica\Content\Text;
 use Friendica\Core\Addon;
 use Friendica\Core\Config;
 use Friendica\Core\L10n;
+use Friendica\Core\Lock;
 use Friendica\Core\PConfig;
 use Friendica\Core\System;
 use Friendica\Core\Worker;
 use Friendica\Database\DBM;
-use Friendica\Model\Contact;
-use Friendica\Model\Conversation;
-use Friendica\Model\Group;
-use Friendica\Model\Term;
 use Friendica\Object\Image;
 use Friendica\Protocol\Diaspora;
 use Friendica\Protocol\OStatus;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\XML;
-use Friendica\Util\Lock;
-use dba;
 use Text_LanguageDetect;
 
 require_once 'boot.php';
@@ -1595,7 +1591,7 @@ class Item extends BaseObject
 		}
 
 		// To avoid timing problems, we are using locks.
-		$locked = Lock::set('item_insert_content');
+		$locked = Lock::acquire('item_insert_content');
 		if (!$locked) {
 			logger("Couldn't acquire lock for URI " . $item['uri'] . " - proceeding anyway.");
 		}
@@ -1615,7 +1611,7 @@ class Item extends BaseObject
 			logger('Could not insert content for URI ' . $item['uri'] . ' - trying asynchronously');
 		}
 		if ($locked) {
-			Lock::remove('item_insert_content');
+			Lock::release('item_insert_content');
 		}
 	}
 
diff --git a/src/Protocol/OStatus.php b/src/Protocol/OStatus.php
index d94f44814f..dadc19dcca 100644
--- a/src/Protocol/OStatus.php
+++ b/src/Protocol/OStatus.php
@@ -4,6 +4,9 @@
  */
 namespace Friendica\Protocol;
 
+use dba;
+use DOMDocument;
+use DOMXPath;
 use Friendica\Content\Text\BBCode;
 use Friendica\Content\Text\HTML;
 use Friendica\Core\Cache;
@@ -22,9 +25,6 @@ use Friendica\Object\Image;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Network;
 use Friendica\Util\XML;
-use dba;
-use DOMDocument;
-use DOMXPath;
 
 require_once 'include/dba.php';
 require_once 'include/items.php';
@@ -513,9 +513,9 @@ class OStatus
 							logger("Item with uri ".$item["uri"]." is from a blocked contact.", LOGGER_DEBUG);
 						} else {
 							// We are having duplicated entries. Hopefully this solves it.
-							if (Lock::acquireLock('ostatus_process_item_insert')) {
+							if (Lock::acquire('ostatus_process_item_insert')) {
 								$ret = Item::insert($item);
-								Lock::releaseLock('ostatus_process_item_insert');
+								Lock::release('ostatus_process_item_insert');
 								logger("Item with uri ".$item["uri"]." for user ".$importer["uid"].' stored. Return value: '.$ret);
 							} else {
 								$ret = Item::insert($item);
diff --git a/tests/src/Core/Lock/CacheLockDriverTest.php b/tests/src/Core/Lock/CacheLockDriverTest.php
index b39000e119..a089059725 100644
--- a/tests/src/Core/Lock/CacheLockDriverTest.php
+++ b/tests/src/Core/Lock/CacheLockDriverTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Friendica\Test\Core\Lock;
+namespace Friendica\Test\src\Core\Lock;
 
 
 use Friendica\Core\Cache\ArrayCache;
diff --git a/tests/src/Core/Lock/DatabaseLockDriverTest.php b/tests/src/Core/Lock/DatabaseLockDriverTest.php
index c6ded6e3d7..a80ff4c37c 100644
--- a/tests/src/Core/Lock/DatabaseLockDriverTest.php
+++ b/tests/src/Core/Lock/DatabaseLockDriverTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Friendica\Test\Core\Lock;
+namespace Friendica\Test\src\Core\Lock;
 
 use dba;
 use Friendica\Core\Lock\DatabaseLockDriver;
diff --git a/tests/src/Core/Lock/LockTest.php b/tests/src/Core/Lock/LockTest.php
index d6a450c86b..c8c0c32ae2 100644
--- a/tests/src/Core/Lock/LockTest.php
+++ b/tests/src/Core/Lock/LockTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Friendica\Test\Core\Lock;
+namespace Friendica\Test\src\Core\Lock;
 
 use Friendica\App;
 use Friendica\Core\Config;
@@ -34,43 +34,43 @@ abstract class LockTest extends TestCase
 	}
 
 	public function testLock() {
-		$this->instance->acquire('foo', 1);
+		$this->instance->acquireLock('foo', 1);
 		$this->assertTrue($this->instance->isLocked('foo'));
 		$this->assertFalse($this->instance->isLocked('bar'));
 	}
 
 	public function testDoubleLock() {
-		$this->instance->acquire('foo', 1);
+		$this->instance->acquireLock('foo', 1);
 		$this->assertTrue($this->instance->isLocked('foo'));
 		// We already locked it
-		$this->assertTrue($this->instance->acquire('foo', 1));
+		$this->assertTrue($this->instance->acquireLock('foo', 1));
 	}
 
 	public function testReleaseLock() {
-		$this->instance->acquire('foo', 1);
+		$this->instance->acquireLock('foo', 1);
 		$this->assertTrue($this->instance->isLocked('foo'));
-		$this->instance->release('foo');
+		$this->instance->releaseLock('foo');
 		$this->assertFalse($this->instance->isLocked('foo'));
 	}
 
 	public function testReleaseAll() {
-		$this->instance->acquire('foo', 1);
-		$this->instance->acquire('bar', 1);
-		$this->instance->acquire('#/$%§', 1);
+		$this->instance->acquireLock('foo', 1);
+		$this->instance->acquireLock('bar', 1);
+		$this->instance->acquireLock('nice', 1);
 
 		$this->instance->releaseAll();
 
 		$this->assertFalse($this->instance->isLocked('foo'));
 		$this->assertFalse($this->instance->isLocked('bar'));
-		$this->assertFalse($this->instance->isLocked('#/$%§'));
+		$this->assertFalse($this->instance->isLocked('nice'));
 	}
 
 	public function testReleaseAfterUnlock() {
-		$this->instance->acquire('foo', 1);
-		$this->instance->acquire('bar', 1);
-		$this->instance->acquire('#/$%§', 1);
+		$this->instance->acquireLock('foo', 1);
+		$this->instance->acquireLock('bar', 1);
+		$this->instance->acquireLock('nice', 1);
 
-		$this->instance->release('foo');
+		$this->instance->releaseLock('foo');
 
 		$this->instance->releaseAll();
 
diff --git a/tests/src/Core/Lock/SemaphoreLockDriverTest.php b/tests/src/Core/Lock/SemaphoreLockDriverTest.php
index 0fcf789e61..56c96458f2 100644
--- a/tests/src/Core/Lock/SemaphoreLockDriverTest.php
+++ b/tests/src/Core/Lock/SemaphoreLockDriverTest.php
@@ -1,14 +1,26 @@
 <?php
 
-namespace Friendica\Test\Core\Lock;
+namespace Friendica\Test\src\Core\Lock;
 
 
 use Friendica\Core\Lock\SemaphoreLockDriver;
 
 class SemaphoreLockDriverTest extends LockTest
 {
+	/**
+	 * @var \Friendica\Core\Lock\SemaphoreLockDriver
+	 */
+	private $semaphoreLockDriver;
+
 	protected function getInstance()
 	{
-		return new SemaphoreLockDriver();
+		$this->semaphoreLockDriver = new SemaphoreLockDriver();
+		return $this->semaphoreLockDriver;
+	}
+
+	public function tearDown()
+	{
+		$this->semaphoreLockDriver->releaseAll();
+		parent::tearDown();
 	}
 }
\ No newline at end of file