Add some typehints and comments to see how it all works

Author: Willem Stuursma

.gitignore

@@ -1,2 +1,3 @@
+/.idea/
 /composer.lock
 /vendor/

classes/mutex/PHPRedisMutex.php

@@ -20,7 +20,6 @@
  */
 class PHPRedisMutex extends RedisMutex
 {
-    
     /**
      * Sets the connected Redis APIs.
      *
@@ -43,7 +42,9 @@ public function __construct(array $redisAPIs, $name, $timeout = 3)
      */
     protected function add($redis, $key, $value, $expire)
     {
+        /** @var Redis $redis */
         try {
+            //  Will set the key, if it doesn't exist, with a ttl of $expire seconds
             return $redis->set($key, $value, ["nx", "ex" => $expire]);
         } catch (RedisException $e) {
             $message = sprintf(
@@ -60,6 +61,7 @@ protected function add($redis, $key, $value, $expire)
      */
     protected function evalScript($redis, $script, $numkeys, array $arguments)
     {
+        /** @var Redis $redis */
         try {
             return $redis->eval($script, $arguments, $numkeys);
         } catch (RedisException $e) {
@@ -70,12 +72,13 @@ protected function evalScript($redis, $script, $numkeys, array $arguments)
             throw new LockReleaseException($message, 0, $e);
         }
     }
-    
+
     /**
      * @internal
      */
     protected function getRedisIdentifier($redis)
     {
+        /** @var Redis $redis */
         return sprintf("redis://%s:%d?database=%s", $redis->getHost(), $redis->getPort(), $redis->getDBNum());
     }
 }

classes/mutex/RedisMutex.php

@@ -135,6 +135,10 @@ protected function release($key)
          * token, which results in releasing the wrong key.
          */
 
+        /*
+         * All Redis commands must be analyzed before execution to determine which keys the command will operate on. In
+         * order for this to be true for EVAL, keys must be passed explicitly.
+         */
         $script = '
             if redis.call("get",KEYS[1]) == ARGV[1] then
                 return redis.call("del",KEYS[1])

composer.json

@@ -11,6 +11,11 @@
             "email": "[email protected]",
             "homepage": "http://markus.malkusch.de",
             "role": "Developer"
+        },
+        {
+            "name": "Willem Stuursma-Ruwen",
+            "email": "[email protected]",
+            "role": "Developer"
         }
     ],
     "autoload": {