Introduce WorkerBackingThread

third_party/WebKit/Source/modules/compositorworker/CompositorWorkerThreadTest.cpp

Index: third_party/WebKit/Source/modules/compositorworker/CompositorWorkerThreadTest.cpp
diff --git a/third_party/WebKit/Source/modules/compositorworker/CompositorWorkerThreadTest.cpp b/third_party/WebKit/Source/modules/compositorworker/CompositorWorkerThreadTest.cpp
index 2154ae7f54d597edf8f2a6120b3a773ccd3dca00..7e997a9f7493e7e54c25a146281641ccbbc5407d 100644
--- a/third_party/WebKit/Source/modules/compositorworker/CompositorWorkerThreadTest.cpp
+++ b/third_party/WebKit/Source/modules/compositorworker/CompositorWorkerThreadTest.cpp
@@ -8,6 +8,7 @@
 #include "bindings/core/v8/V8GCController.h"
 #include "core/inspector/ConsoleMessage.h"
 #include "core/testing/DummyPageHolder.h"
+#include "core/workers/WorkerBackingThread.h"
 #include "core/workers/WorkerLoaderProxy.h"
 #include "core/workers/WorkerObjectProxy.h"
 #include "core/workers/WorkerThreadStartupData.h"
@@ -23,45 +24,6 @@
 namespace blink {
 namespace {
 
-class TestCompositorWorkerThread : public CompositorWorkerThread {
-public:
-    TestCompositorWorkerThread(WorkerLoaderProxyProvider* loaderProxyProvider, WorkerObjectProxy& objectProxy, double timeOrigin, WaitableEvent* startEvent)
-        : CompositorWorkerThread(WorkerLoaderProxy::create(loaderProxyProvider), objectProxy, timeOrigin)
-        , m_startEvent(startEvent)
-    {
-    }
-
-    ~TestCompositorWorkerThread() override {}
-
-    void setCallbackAfterV8Termination(PassOwnPtr<Function<void()>> callback)
-    {
-        m_v8TerminationCallback = callback;
-    }
-
-private:
-    // WorkerThread:
-    void didStartWorkerThread() override
-    {
-        m_startEvent->signal();
-    }
-    void terminateV8Execution() override
-    {
-        CompositorWorkerThread::terminateV8Execution();
-        if (m_v8TerminationCallback)
-            (*m_v8TerminationCallback)();
-    }
-
-    void willDestroyIsolate() override
-    {
-        v8::Isolate::GetCurrent()->RequestGarbageCollectionForTesting(v8::Isolate::kFullGarbageCollection);
-        Heap::collectAllGarbage();
-        CompositorWorkerThread::willDestroyIsolate();
-    }
-
-    WaitableEvent* m_startEvent;
-    OwnPtr<Function<void()>> m_v8TerminationCallback;
-};
-
 // A null WorkerObjectProxy, supplied when creating CompositorWorkerThreads.
 class TestCompositorWorkerObjectProxy : public WorkerObjectProxy {
 public:
@@ -119,6 +81,7 @@ class CompositorWorkerThreadTest : public ::testing::Test {
 public:
     void SetUp() override
     {
+        CompositorWorkerThread::resetSharedBackingThreadForTest();
         m_page = DummyPageHolder::create();
         m_objectProxy = TestCompositorWorkerObjectProxy::create(&m_page->document());
         m_securityOrigin = SecurityOrigin::create(KURL(ParsedURLString, "http://fake.url/"));
@@ -126,15 +89,15 @@ public:
 
     void TearDown() override
     {
-        ASSERT(!hasThread());
-        ASSERT(!hasIsolate());
         m_page.clear();
+        CompositorWorkerThread::resetSharedBackingThreadForTest();
     }
 
-    PassRefPtr<TestCompositorWorkerThread> createCompositorWorker(WaitableEvent* startEvent)
+    PassRefPtr<CompositorWorkerThread> createCompositorWorker()
     {
-        TestCompositorWorkerThread* workerThread = new TestCompositorWorkerThread(nullptr, *m_objectProxy, 0, startEvent);
+        RefPtr<CompositorWorkerThread> workerThread = CompositorWorkerThread::create(nullptr, *m_objectProxy, 0);
         OwnPtrWillBeRawPtr<WorkerClients> clients = nullptr;
+        workerThread->workerBackingThread().setInitializationEventForTest();
         workerThread->start(WorkerThreadStartupData::create(
             KURL(ParsedURLString, "http://fake.url/"),
             "fake user agent",
@@ -145,12 +108,8 @@ public:
             m_securityOrigin.get(),
             clients.release(),
             V8CacheOptionsDefault));
-        return adoptRef(workerThread);
-    }
 
-    void createWorkerAdapter(RefPtr<CompositorWorkerThread>* workerThread, WaitableEvent* creationEvent)
-    {
-        *workerThread = createCompositorWorker(creationEvent);
+        return workerThread;
     }
 
     // Attempts to run some simple script for |worker|.
@@ -162,20 +121,19 @@ public:
         waitEvent->wait();
     }
 
-    void waitForWaitableEventAfterIteratingCurrentLoop(WaitableEvent* waitEvent)
-    {
-        testing::runPendingTasks();
-        waitEvent->wait();
-    }
-
-    bool hasThread() const
+    bool hasCurrentIsolateInWorkerThread(WorkerBackingThread* thread)
     {
-        return CompositorWorkerThread::hasThreadForTest();
+        WaitableEvent event;
+        bool hasIsolate = false;
+        thread->backingThread().platformThread().taskRunner()->postTask(BLINK_FROM_HERE, threadSafeBind(&hasCurrentIsolate, AllowCrossThreadAccess(&event), AllowCrossThreadAccess(&hasIsolate)));
+        event.wait();
+        return hasIsolate;
     }
 
-    bool hasIsolate() const
+    void waitForWaitableEventAfterIteratingCurrentLoop(WaitableEvent* waitEvent)
     {
-        return CompositorWorkerThread::hasIsolateForTest();
+        testing::runPendingTasks();
+        waitEvent->wait();
     }
 
 private:
@@ -187,6 +145,12 @@ private:
         waitEvent->signal();
     }
 
+    static void hasCurrentIsolate(WaitableEvent* event, bool* hasIsolate)
+    {
+        *hasIsolate = !!v8::Isolate::GetCurrent();
+        event->signal();
+    }
+
     OwnPtr<DummyPageHolder> m_page;
     RefPtr<SecurityOrigin> m_securityOrigin;
     OwnPtr<WorkerObjectProxy> m_objectProxy;
@@ -195,9 +159,8 @@ private:
 
 TEST_F(CompositorWorkerThreadTest, Basic)
 {
-    OwnPtr<WaitableEvent> creationEvent = adoptPtr(new WaitableEvent());
-    RefPtr<CompositorWorkerThread> compositorWorker = createCompositorWorker(creationEvent.get());
-    waitForWaitableEventAfterIteratingCurrentLoop(creationEvent.get());
+    RefPtr<CompositorWorkerThread> compositorWorker = createCompositorWorker();
+    waitForWaitableEventAfterIteratingCurrentLoop(compositorWorker->workerBackingThread().initializationEventForTest());

[kinuko, 2016/02/29 09:32:54]

Would it be possible to just replace this with posting a task & waiting for the
task to finish? I don't really remember if we needed to specifically wait for
the initialize() in these tests...

[yhirano, 2016/02/29 23:47:32]

Done.

     checkWorkerCanExecuteScript(compositorWorker.get());
     compositorWorker->terminateAndWait();
 }
@@ -206,25 +169,22 @@ TEST_F(CompositorWorkerThreadTest, Basic)
 TEST_F(CompositorWorkerThreadTest, CreateSecondAndTerminateFirst)
 {
     // Create the first worker and wait until it is initialized.
-    OwnPtr<WaitableEvent> firstCreationEvent = adoptPtr(new WaitableEvent());
-    RefPtr<CompositorWorkerThread> firstWorker = createCompositorWorker(firstCreationEvent.get());
-    WebThreadSupportingGC* firstThread = CompositorWorkerThread::sharedBackingThread();
+    RefPtr<CompositorWorkerThread> firstWorker = createCompositorWorker();
+    WebThreadSupportingGC* firstThread = &firstWorker->backingThread();
     ASSERT(firstThread);
-    waitForWaitableEventAfterIteratingCurrentLoop(firstCreationEvent.get());
+    waitForWaitableEventAfterIteratingCurrentLoop(firstWorker->workerBackingThread().initializationEventForTest());
     v8::Isolate* firstIsolate = firstWorker->isolate();
     ASSERT(firstIsolate);
 
     // Create the second worker and immediately destroy the first worker.
-    OwnPtr<WaitableEvent> secondCreationEvent = adoptPtr(new WaitableEvent());
-    RefPtr<CompositorWorkerThread> secondWorker = createCompositorWorker(secondCreationEvent.get());
+    RefPtr<CompositorWorkerThread> secondWorker = createCompositorWorker();
     firstWorker->terminateAndWait();
 
     // Wait until the second worker is initialized. Verify that the second worker is using the same
     // thread and Isolate as the first worker.
-    WebThreadSupportingGC* secondThread = CompositorWorkerThread::sharedBackingThread();
+    WebThreadSupportingGC* secondThread = &secondWorker->backingThread();
     ASSERT(secondThread);
-    waitForWaitableEventAfterIteratingCurrentLoop(secondCreationEvent.get());
-    EXPECT_EQ(firstThread, secondThread);
+    ASSERT_EQ(firstThread, secondThread);
 
     v8::Isolate* secondIsolate = secondWorker->isolate();
     ASSERT(secondIsolate);
@@ -246,25 +206,32 @@ static void checkCurrentIsolate(v8::Isolate* isolate, WaitableEvent* event)
 TEST_F(CompositorWorkerThreadTest, TerminateFirstAndCreateSecond)
 {
     // Create the first worker, wait until it is initialized, and terminate it.
-    OwnPtr<WaitableEvent> creationEvent = adoptPtr(new WaitableEvent());
-    RefPtr<CompositorWorkerThread> compositorWorker = createCompositorWorker(creationEvent.get());
-    WebThreadSupportingGC* firstThread = CompositorWorkerThread::sharedBackingThread();
-    waitForWaitableEventAfterIteratingCurrentLoop(creationEvent.get());
-    ASSERT(compositorWorker->isolate());
+    RefPtr<CompositorWorkerThread> compositorWorker = createCompositorWorker();
+    RefPtr<WorkerBackingThread> workerBackingThread = &compositorWorker->workerBackingThread();
+    WebThreadSupportingGC* firstThread = &compositorWorker->backingThread();
+    waitForWaitableEventAfterIteratingCurrentLoop(compositorWorker->workerBackingThread().initializationEventForTest());
+    v8::Isolate* firstIsolate = compositorWorker->isolate();
+    ASSERT(firstIsolate);
+
+    EXPECT_TRUE(hasCurrentIsolateInWorkerThread(workerBackingThread.get()));
     compositorWorker->terminateAndWait();
 
-    // Create the second worker. Verify that the second worker lives in a different WebThread since the first
-    // thread will have been destroyed after destroying the first worker.
-    creationEvent = adoptPtr(new WaitableEvent());
-    compositorWorker = createCompositorWorker(creationEvent.get());
-    WebThreadSupportingGC* secondThread = CompositorWorkerThread::sharedBackingThread();
-    EXPECT_NE(firstThread, secondThread);
-    waitForWaitableEventAfterIteratingCurrentLoop(creationEvent.get());
+    // The backing thread is still alive but its isolate is detached.
+    // TODO(yhirano): Enable this check if / when returning null from
+    // v8::Isolate::GetCurrent() is allowed.
+    // EXPECT_FALSE(hasCurrentIsolateInWorkerThread(workerBackingThread.get()));
+
+    // Create the second worker. The backing thread is same.
+    compositorWorker = createCompositorWorker();
+    WebThreadSupportingGC* secondThread = &compositorWorker->backingThread();
+    EXPECT_EQ(firstThread, secondThread);
+    waitForWaitableEventAfterIteratingCurrentLoop(compositorWorker->workerBackingThread().initializationEventForTest());
 
     // Jump over to the worker's thread to verify that the Isolate is set up correctly and execute script.
     OwnPtr<WaitableEvent> checkEvent = adoptPtr(new WaitableEvent());
     secondThread->platformThread().taskRunner()->postTask(BLINK_FROM_HERE, threadSafeBind(&checkCurrentIsolate, AllowCrossThreadAccess(compositorWorker->isolate()), AllowCrossThreadAccess(checkEvent.get())));
     waitForWaitableEventAfterIteratingCurrentLoop(checkEvent.get());
+    EXPECT_TRUE(hasCurrentIsolateInWorkerThread(workerBackingThread.get()));
     checkWorkerCanExecuteScript(compositorWorker.get());
 
     compositorWorker->terminateAndWait();
@@ -273,21 +240,22 @@ TEST_F(CompositorWorkerThreadTest, TerminateFirstAndCreateSecond)
 // Tests that v8::Isolate and WebThread are correctly set-up if a worker is created while another is terminating.
 TEST_F(CompositorWorkerThreadTest, CreatingSecondDuringTerminationOfFirst)
 {
-    OwnPtr<WaitableEvent> firstCreationEvent = adoptPtr(new WaitableEvent());
-    RefPtr<TestCompositorWorkerThread> firstWorker = createCompositorWorker(firstCreationEvent.get());
-    waitForWaitableEventAfterIteratingCurrentLoop(firstCreationEvent.get());
+    RefPtr<CompositorWorkerThread> firstWorker = createCompositorWorker();
+    waitForWaitableEventAfterIteratingCurrentLoop(firstWorker->workerBackingThread().initializationEventForTest());
     v8::Isolate* firstIsolate = firstWorker->isolate();
     ASSERT(firstIsolate);
 
-    // Request termination of the first worker, and set-up to make sure the second worker is created right as
-    // the first worker terminates its isolate.
-    OwnPtr<WaitableEvent> secondCreationEvent = adoptPtr(new WaitableEvent());
-    RefPtr<CompositorWorkerThread> secondWorker;
-    firstWorker->setCallbackAfterV8Termination(bind(&CompositorWorkerThreadTest::createWorkerAdapter, this, &secondWorker, secondCreationEvent.get()));
-    firstWorker->terminateAndWait();
+    // Request termination of the first worker and create the second worker
+    // as soon as possible.
+    EXPECT_EQ(1u, firstWorker->workerBackingThread().workerScriptCount());
+    firstWorker->terminate();
+    // We don't wait for its termination.
+    // Note: We rely on the assumption that the termination steps don't run
+    // on the worker thread so quickly. This could be a source of flakiness.
+
+    RefPtr<CompositorWorkerThread> secondWorker = createCompositorWorker();
     ASSERT(secondWorker);
 
-    waitForWaitableEventAfterIteratingCurrentLoop(secondCreationEvent.get());
     v8::Isolate* secondIsolate = secondWorker->isolate();
     ASSERT(secondIsolate);
     EXPECT_EQ(firstIsolate, secondIsolate);