代码初始化

addons/crontab/library/SimpleFork/Lock/Semaphore.php

@@ -0,0 +1,163 @@
+<?php
+/**
+ * Created by PhpStorm.
+ * User: Jenner
+ * Date: 2015/8/12
+ * Time: 20:52
+ */
+
+namespace Jenner\SimpleFork\Lock;
+
+
+/**
+ * sem lock
+ *
+ * @package Jenner\SimpleFork\Lock
+ */
+class Semaphore implements LockInterface
+{
+    /**
+     * @var
+     */
+    private $lock_id;
+    /**
+     * @var bool
+     */
+    private $locked = false;
+
+    /**
+     * init a lock
+     *
+     * @param $key
+     * @param $count
+     * @throws \RuntimeException
+     */
+    private function __construct($key, $count = 1)
+    {
+        if (($this->lock_id = sem_get($this->_stringToSemKey($key), $count)) === false) {
+            throw new \RuntimeException("Cannot create semaphore for key: {$key}");
+        }
+    }
+
+    /**
+     * Semaphore requires a numeric value as the key
+     *
+     * @param $identifier
+     * @return int
+     */
+    protected function _stringToSemKey($identifier)
+    {
+        $md5 = md5($identifier);
+        $key = 0;
+        for ($i = 0; $i < 32; $i++) {
+            $key += ord($md5{$i}) * $i;
+        }
+        return $key;
+    }
+
+    /**
+     * create a lock instance
+     *
+     * @param $key
+     * @return Semaphore
+     */
+    public static function create($key)
+    {
+        return new Semaphore($key);
+    }
+
+    /**
+     * release lock
+     *
+     * @throws \RuntimeException
+     */
+    public function __destruct()
+    {
+        if ($this->isLocked()) {
+            $this->release();
+        }
+    }
+
+    /**
+     * is locked
+     *
+     * @return bool
+     */
+    public function isLocked()
+    {
+        return $this->locked === true ? true : false;
+    }
+
+    /**
+     * release lock
+     *
+     * @return bool
+     * @throws \RuntimeException
+     */
+    public function release()
+    {
+        if (!$this->locked) {
+            throw new \RuntimeException("release a non lock");
+        }
+
+        if (!sem_release($this->lock_id)) {
+            return false;
+        }
+        $this->locked = false;
+
+        return true;
+    }
+
+    /**
+     * get a lock
+     *
+     * @param bool $blocking
+     * @return bool
+     */
+    public function acquire($blocking = true)
+    {
+        if ($this->locked) {
+            throw new \RuntimeException('already lock by yourself');
+        }
+
+        if ($blocking === false) {
+            if (version_compare(PHP_VERSION, '5.6.0') < 0) {
+                throw new \RuntimeException('php version is at least 5.6.0 for param blocking');
+            }
+            if (!sem_acquire($this->lock_id, true)) {
+                return false;
+            }
+            $this->locked = true;
+
+            return true;
+        }
+
+        if (!sem_acquire($this->lock_id)) {
+            return false;
+        }
+        $this->locked = true;
+
+        return true;
+    }
+
+    /**
+     * remove the semaphore resource
+     *
+     * @return bool
+     */
+    public function remove()
+    {
+        if ($this->locked) {
+            throw new \RuntimeException('can not remove a locked semaphore resource');
+        }
+        if (!is_resource($this->lock_id)) {
+            throw new \RuntimeException('can not remove a empty semaphore resource');
+        }
+
+        if (!sem_release($this->lock_id)) {
+            return false;
+        }
+
+        return true;
+    }
+}