Implemented some experimental event loops with nextTick() support.

* ExtEventLoop - based on the ext-event PHP extension * StreamSelectNextTickLoop - based on stream_select
reactphp · nrk · Dec 5, 2013 · Nov 13, 2013 · Nov 13, 2013 · Nov 13, 2013
commit db41311c7d380a003d3f421d7033555347791c9d
diff --git a/src/React/EventLoop/AbstractNextTickLoop.php b/src/React/EventLoop/AbstractNextTickLoop.php
@@ -0,0 +1,180 @@
+<?php
+
+namespace React\EventLoop;
+
+use React\EventLoop\Timer\Timer;
+use React\EventLoop\Timer\TimerInterface;
+use SplQueue;
+
+/**
+ * Common functionality for event loops that implement NextTickLoopInterface.
+ */
+abstract class AbstractNextTickLoop implements NextTickLoopInterface
+{
+    private $nextTickQueue;
+    private $explicitlyStopped;
+
+    public function __construct()
+    {
+        $this->nextTickQueue = new SplQueue;
+        $this->explicitlyStopped = false;
+    }
+
+    /**
+     * Enqueue a callback to be invoked once after the given interval.
+     *
+     * The execution order of timers scheduled to execute at the same time is
+     * not guaranteed.
+     *
+     * @param numeric  $interval The number of seconds to wait before execution.
+     * @param callable $callback The callback to invoke.
+     *
+     * @return TimerInterface
+     */
+    public function addTimer($interval, $callback)
+    {
+        $timer = new Timer($this, $interval, $callback, false);
+
+        $this->scheduleTimer($timer);
+
+        return $timer;
+    }
+
+    /**
+     * Enqueue a callback to be invoked repeatedly after the given interval.
+     *
+     * The execution order of timers scheduled to execute at the same time is
+     * not guaranteed.
+     *
+     * @param numeric  $interval The number of seconds to wait before execution.
+     * @param callable $callback The callback to invoke.
+     *
+     * @return TimerInterface
+     */
+    public function addPeriodicTimer($interval, $callback)
+    {
+        $timer = new Timer($this, $interval, $callback, true);
+
+        $this->scheduleTimer($timer);
+
+        return $timer;
+    }
+
+    /**
+     * Schedule a callback to be invoked on the next tick of the event loop.
+     *
+     * Callbacks are guaranteed to be executed in the order they are enqueued,
+     * before any timer or stream events.
+     *
+     * @param callable $listner The callback to invoke.
+     */
+    public function nextTick(callable $listener)
+    {
+        $this->nextTickQueue->enqueue($listener);
+    }
+
+    /**
+     * Perform a single iteration of the event loop.
+     */
+    public function tick()
+    {
+        $this->tickLogic(false);
+    }
+
+    /**
+     * Run the event loop until there are no more tasks to perform.
+     */
+    public function run()
+    {
+        $this->explicitlyStopped = false;
+
+        while ($this->isRunning()) {
+            $this->tickLogic(true);
+        }
+    }
+
+    /**
+     * Instruct a running event loop to stop.
+     */
+    public function stop()
+    {
+        $this->explicitlyStopped = true;
+    }
+
+    /**
+     * Invoke all callbacks in the next-tick queue.
+     */
+    protected function flushNextTickQueue()
+    {
+        while ($this->nextTickQueue->count()) {
+            call_user_func(
+                $this->nextTickQueue->dequeue(),
+                $this
+            );
+        }
+    }
+
+    /**
+     * Check if there is any pending work to do.
+     *
+     * @return boolean
+     */
+    protected function isRunning()
+    {
+        // The loop has been explicitly stopped and should exit ...
+        if ($this->explicitlyStopped) {
+            return false;
+
+        // The next tick queue has items on it ...
+        } elseif ($this->nextTickQueue->count() > 0) {
+            return true;
+        }
+
+        return !$this->isEmpty();
+    }
+
+    /**
+     * Perform the low-level tick logic.
+     */
+    protected function tickLogic($blocking)
+    {
+        $this->flushNextTickQueue();
+
+        $this->flushEvents(
+            $blocking && 0 === $this->nextTickQueue->count()
+        );
+    }
+
+    /**
+     * Get a key that can be used to identify a stream resource.
+     *
+     * @param string $stream
+     *
+     * @return integer|string
+     */
+    protected function streamKey($stream)
+    {
+        return (int) $stream;
+    }
+
+    /**
+     * Schedule a timer for execution.
+     *
+     * @param TimerInterface $timer
+     */
+    abstract protected function scheduleTimer(TimerInterface $timer);
+
+    /**
+     * Flush any timer and IO events.
+     *
+     * @param boolean $blocking True if loop should block waiting for next event.
+     */
+    abstract protected function flushEvents($blocking);
+
+    /**
+     * Check if the loop has any pending timers or streams.
+     *
+     * @return boolean
+     */
+    abstract protected function isEmpty();
+}