Fix EventLoopScheduler issue (#186)

* Corrects EventLoopScheduler issue. Fixes #184

* Give test a little more breathing room.

Author: mbonneau

src/Scheduler/EventLoopScheduler.php

@@ -42,9 +42,27 @@ function ($ms, $callable) use ($timerCallableOrLoop) {
         });
     }
 
+    private function scheduleStartup()
+    {
+        if ($this->insideInvoke) {
+            return;
+        }
+        $this->currentTimer->dispose();
+        $this->nextTimer    = $this->getClock();
+        $this->currentTimer = call_user_func($this->delayCallback, 0, [$this, 'start']);
+    }
+
     public function scheduleAbsoluteWithState($state, int $dueTime, callable $action): DisposableInterface
     {
-        $disp = parent::scheduleAbsoluteWithState($state, $dueTime, $action);
+        $disp = new CompositeDisposable([
+            parent::scheduleAbsoluteWithState($state, $dueTime, $action),
+            new CallbackDisposable(function () use ($dueTime) {
+                if ($dueTime > $this->nextTimer) {
+                    return;
+                }
+                $this->scheduleStartup();
+            })
+        ]);
 
         if ($this->insideInvoke) {
             return $disp;
@@ -54,20 +72,9 @@ public function scheduleAbsoluteWithState($state, int $dueTime, callable $action
             return $disp;
         }
 
-        $this->nextTimer = $this->getClock();
-
-        $this->currentTimer->dispose();
-        $this->currentTimer = call_user_func($this->delayCallback, 0, [$this, 'start']);
+        $this->scheduleStartup();
 
-        return new CompositeDisposable([
-            $disp,
-            new CallbackDisposable(function () {
-                if (!$this->insideInvoke) {
-                    $this->currentTimer->dispose();
-                    $this->currentTimer = call_user_func($this->delayCallback, 0, [$this, 'start']);
-                }
-            })
-        ]);
+        return $disp;
     }
 
     public function start()

test/Rx/Scheduler/EventLoopSchedulerTest.php

@@ -152,22 +152,20 @@ public function testScheduledItemsFromOutsideOfSchedulerDontCreateExtraTimers()
             });
         });
 
-        $scheduler->schedule(function () {}, 20);
+        $scheduler->schedule(function () {}, 40);
 
-        $scheduler->schedule(function () {}, 15)->dispose();
-        $scheduler->schedule(function () {}, 14)->dispose();
-        $scheduler->schedule(function () {}, 13)->dispose();
-        $scheduler->schedule(function () {}, 12)->dispose();
+        $scheduler->schedule(function () {}, 35)->dispose();
+        $scheduler->schedule(function () {}, 34)->dispose();
 
-        $scheduler->schedule(function () {}, 10);
+        $scheduler->schedule(function () {}, 20);
 
         $loop->run();
 
-        $this->assertEquals($timersCreated, 3);
-        $this->assertEquals($timersExecuted, 3);
+        $this->assertLessThanOrEqual(3, $timersCreated);
+        $this->assertLessThanOrEqual(3, $timersExecuted);
     }
 
-    public function testMultipleSchedulersFromOutsideInSameTickDontCreateExtraTimers()
+    public function testMultipleSchedulesFromOutsideInSameTickDontCreateExtraTimers()
     {
         $timersCreated   = 0;
         $timersExecuted = 0;
@@ -190,13 +188,13 @@ public function testMultipleSchedulersFromOutsideInSameTickDontCreateExtraTimers
             $scheduler->schedule(function () {}, 25)->dispose();
             $scheduler->schedule(function () {}, 24)->dispose();
             $scheduler->schedule(function () {}, 23)->dispose();
-            $scheduler->schedule(function () {}, 22)->dispose();
+            $scheduler->schedule(function () {}, 25)->dispose();
         });
 
         $loop->run();
 
-        $this->assertEquals($timersCreated, 3);
-        $this->assertEquals($timersExecuted, 3);
+        $this->assertEquals(3, $timersCreated);
+        $this->assertEquals(3, $timersExecuted);
     }
 
     public function testThatStuffScheduledWayInTheFutureDoesntKeepTheLoopRunningIfDisposed()
@@ -244,4 +242,23 @@ public function testThatDisposalOfSingleScheduledItemOutsideOfInvokeCancelsTimer
 
         $this->assertLessThan(2, $endTime - $startTime);
     }
+
+    public function testScheduledItemPastNextScheduledItemKillsItOwnTimerIfItBecomesTheNextOneAndIsDisposed()
+    {
+        $loop      = Factory::create();
+        $scheduler = new EventLoopScheduler($loop);
+
+        $startTime = microtime(true);
+
+        $scheduler->schedule(function () {}, 30);
+        $disp  = $scheduler->schedule(function () {}, 3000);
+        $loop->addTimer(0.050, function () use ($disp) {
+            $disp->dispose();
+        });
+
+        $loop->run();
+        $endTime = microtime(true);
+
+        $this->assertLessThan(2, $endTime - $startTime);
+    }
 }