diff --git a/src/Threading/Internal/Mutex.php b/src/Threading/Internal/Mutex.php
index 29650d4..b4c69f8 100644
--- a/src/Threading/Internal/Mutex.php
+++ b/src/Threading/Internal/Mutex.php
@@ -27,7 +27,7 @@ class Mutex extends \Threaded
             return ($this->lock ? $this->lock = false : true);
         };
 
-        while ($this->lock && $this->synchronized($tsl)) {
+        while (!$this->lock || $this->synchronized($tsl)) {
             yield Coroutine\sleep(self::LATENCY_TIMEOUT);
         }
 
diff --git a/src/Threading/Internal/Semaphore.php b/src/Threading/Internal/Semaphore.php
index 52a6817..ce7b155 100644
--- a/src/Threading/Internal/Semaphore.php
+++ b/src/Threading/Internal/Semaphore.php
@@ -13,21 +13,11 @@ class Semaphore extends \Threaded
 {
     const LATENCY_TIMEOUT = 0.01; // 10 ms
 
-    /**
-     * @var int
-     */
-    private $nextId = 0;
-
     /**
      * @var int The number of available locks.
      */
     private $locks;
 
-    /**
-     * @var array A queue of lock requests.
-     */
-    private $waitQueue = [];
-
     /**
      * Creates a new semaphore with a given number of locks.
      *
@@ -72,7 +62,7 @@ class Semaphore extends \Threaded
             return true;
         };
 
-        while ($this->locks > 0 && $this->synchronized($tsl)) {
+        while ($this->locks < 1 || $this->synchronized($tsl)) {
             yield Coroutine\sleep(self::LATENCY_TIMEOUT);
         }