Worker: Attempt to gracefully terminate WorkerThread as much as possible

third_party/WebKit/Source/core/workers/WorkerThreadTest.cpp

Index: third_party/WebKit/Source/core/workers/WorkerThreadTest.cpp
diff --git a/third_party/WebKit/Source/core/workers/WorkerThreadTest.cpp b/third_party/WebKit/Source/core/workers/WorkerThreadTest.cpp
index 8fb299c9d7693bf4a41fbf1664d1646ac85b57d8..499c37396dccd8e9d36ab391309b5f402585aa76 100644
--- a/third_party/WebKit/Source/core/workers/WorkerThreadTest.cpp
+++ b/third_party/WebKit/Source/core/workers/WorkerThreadTest.cpp
@@ -5,19 +5,16 @@
 #include "core/workers/WorkerThread.h"
 
 #include "core/workers/WorkerThreadTestHelper.h"
-#include "public/platform/WebScheduler.h"
+#include "platform/testing/UnitTestHelpers.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using testing::_;
 using testing::AtMost;
-using testing::Invoke;
-using testing::Return;
-using testing::Mock;
 
 namespace blink {
 
-class WorkerThreadTest : public testing::Test {
+class WorkerThreadTest : public ::testing::Test {
 public:
     void SetUp() override
     {
@@ -36,21 +33,33 @@ public:
 
     void start()
     {
-        startWithSourceCode("//fake source code");
+        m_workerThread->startWithSourceCode(m_securityOrigin.get(), "//fake source code");
     }
 
-    void startWithSourceCode(const String& source)
+    void startWithSourceCodeNotToFinish()
     {
-        m_workerThread->startWithSourceCode(m_securityOrigin.get(), source);
+        // Use a JavaScript source code that makes an infinite loop so that we
+        // can catch some kind of issues as a timeout.
+        m_workerThread->startWithSourceCode(m_securityOrigin.get(), "while(true) {}");
     }
 
-    void waitForInit()
+    void waitForShutdown()
     {
-        m_workerThread->waitForInit();
+        m_workerThread->m_shutdownEvent->wait();
+    }
+
+    void setForceTerminationDelayInMs(long long forceTerminationDelayInMs)
+    {
+        m_workerThread->setForceTerminationDelayInMsForTesting(forceTerminationDelayInMs);
+    }
+
+    bool isForceTerminationTaskScheduled()
+    {
+        return m_workerThread->m_scheduledForceTerminationTask.get();
     }
 
 protected:
-    void expectWorkerLifetimeReportingCalls()
+    void expectReportingCalls()
     {
         EXPECT_CALL(*m_mockWorkerReportingProxy, workerGlobalScopeStarted(_)).Times(1);
         EXPECT_CALL(*m_mockWorkerReportingProxy, didEvaluateWorkerScript(true)).Times(1);
@@ -58,51 +67,188 @@ protected:
         EXPECT_CALL(*m_mockWorkerReportingProxy, willDestroyWorkerGlobalScope()).Times(1);
     }
 
+    void expectReportingCallsForWorkerPossiblyTerminatedBeforeStarting()
+    {
+        EXPECT_CALL(*m_mockWorkerReportingProxy, workerGlobalScopeStarted(_)).Times(AtMost(1));
+        EXPECT_CALL(*m_mockWorkerReportingProxy, didEvaluateWorkerScript(_)).Times(AtMost(1));
+        EXPECT_CALL(*m_mockWorkerReportingProxy, workerThreadTerminated()).Times(AtMost(1));
+        EXPECT_CALL(*m_mockWorkerReportingProxy, willDestroyWorkerGlobalScope()).Times(AtMost(1));
+    }
+
+    void expectReportingCallsForWorkerForciblyTerminated()
+    {
+        EXPECT_CALL(*m_mockWorkerReportingProxy, workerGlobalScopeStarted(_)).Times(1);
+        EXPECT_CALL(*m_mockWorkerReportingProxy, didEvaluateWorkerScript(false)).Times(1);
+        EXPECT_CALL(*m_mockWorkerReportingProxy, workerThreadTerminated()).Times(1);
+        EXPECT_CALL(*m_mockWorkerReportingProxy, willDestroyWorkerGlobalScope()).Times(1);
+    }
+
     RefPtr<SecurityOrigin> m_securityOrigin;
     OwnPtr<MockWorkerLoaderProxyProvider> m_mockWorkerLoaderProxyProvider;
     OwnPtr<MockWorkerReportingProxy> m_mockWorkerReportingProxy;
     OwnPtr<WorkerThreadForTest> m_workerThread;
 };
 
-TEST_F(WorkerThreadTest, StartAndStop)
+TEST_F(WorkerThreadTest, StartAndTerminate_AsyncTerminate)
 {
-    expectWorkerLifetimeReportingCalls();
+    expectReportingCalls();
     start();
-    waitForInit();
+    m_workerThread->waitForInit();
+
+    // The worker thread is not being blocked, so the worker thread should be
+    // gracefully shut down.
+    m_workerThread->terminate();
+    EXPECT_TRUE(isForceTerminationTaskScheduled());
+    waitForShutdown();
+    EXPECT_EQ(WorkerThread::ExitCode::GracefullyTerminated, m_workerThread->exitCode());
+}
+
+TEST_F(WorkerThreadTest, StartAndTerminate_SyncTerminate)
+{
+    expectReportingCalls();
+    start();
+    m_workerThread->waitForInit();
     m_workerThread->terminateAndWait();
+    EXPECT_EQ(WorkerThread::ExitCode::SyncForciblyTerminated, m_workerThread->exitCode());
+}
+
+TEST_F(WorkerThreadTest, StartAndTerminateImmediately_AsyncTerminate)
+{
+    expectReportingCallsForWorkerPossiblyTerminatedBeforeStarting();
+    start();
+
+    // There are two possible cases depending on timing:
+    // (1) If the thread hasn't been initialized on the worker thread yet,
+    // terminate() should not attempt to shut down the thread.
+    // (2) If the thread has already been initialized on the worker thread,
+    // terminate() should gracefully shut down the thread.
+    m_workerThread->terminate();
+    waitForShutdown();
+    WorkerThread::ExitCode exitCode = m_workerThread->exitCode();
+    EXPECT_TRUE(WorkerThread::ExitCode::TerminatedBeforeStarting == exitCode || WorkerThread::ExitCode::GracefullyTerminated == exitCode);
 }
 
-TEST_F(WorkerThreadTest, StartAndStopImmediately)
+TEST_F(WorkerThreadTest, StartAndTerminateImmediately_SyncTerminate)
 {
-    EXPECT_CALL(*m_mockWorkerReportingProxy, workerGlobalScopeStarted(_))
-        .Times(AtMost(1));
-    EXPECT_CALL(*m_mockWorkerReportingProxy, didEvaluateWorkerScript(_))
-        .Times(AtMost(1));
-    EXPECT_CALL(*m_mockWorkerReportingProxy, workerThreadTerminated())
-        .Times(AtMost(1));
-    EXPECT_CALL(*m_mockWorkerReportingProxy, willDestroyWorkerGlobalScope())
-        .Times(AtMost(1));
+    expectReportingCallsForWorkerPossiblyTerminatedBeforeStarting();
     start();
+
+    // There are two possible cases depending on timing:
+    // (1) If the thread hasn't been initialized on the worker thread yet,
+    // terminateAndWait() should not attempt to shut down the thread.
+    // (2) If the thread has already been initialized on the worker thread,
+    // terminateAndWait() should synchronously forcibly terminates the isolate.
+    m_workerThread->terminateAndWait();
+    WorkerThread::ExitCode exitCode = m_workerThread->exitCode();
+    EXPECT_TRUE(WorkerThread::ExitCode::TerminatedBeforeStarting == exitCode || WorkerThread::ExitCode::SyncForciblyTerminated == exitCode);
+}
+
+TEST_F(WorkerThreadTest, TerminateBeforeStart_AsyncTerminate)
+{
+    m_workerThread->terminate();
+    EXPECT_EQ(WorkerThread::ExitCode::TerminatedBeforeStarting, m_workerThread->exitCode());
+    EXPECT_FALSE(isForceTerminationTaskScheduled());
+
+    // Sync termination requests after the thread is terminated should not block
+    // the main thread.
+    m_workerThread->terminateAndWait();
+    m_workerThread->terminateAndWaitForAllWorkers();

[yhirano, 2016/05/31 04:48:07]

[optional] I prefer calling static member functions explicitly (in this case,
WorkerThread::terminateAndWaitForAllWorkers)

[nhiroki, 2016/05/31 06:08:56]

Done.

+}
+
+TEST_F(WorkerThreadTest, TerminateBeforeStart_SyncTerminate)
+{
+    // Terminating the worker thread that hasn't started yet does not block the
+    // main thread.
+    m_workerThread->terminateAndWait();
+    EXPECT_EQ(WorkerThread::ExitCode::TerminatedBeforeStarting, m_workerThread->exitCode());
+
+    // Async termination request after the thread is terminated should not
+    // schedule a delayed task.
+    m_workerThread->terminate();
+    EXPECT_FALSE(isForceTerminationTaskScheduled());
+
+    // Sync termination requests after the thread is terminated should not block
+    // the main thread.
     m_workerThread->terminateAndWait();
+    m_workerThread->terminateAndWaitForAllWorkers();
 }
 
-TEST_F(WorkerThreadTest, StartAndStopOnScriptLoaded)
+TEST_F(WorkerThreadTest, StartAndTerminateOnScriptLoaded_SyncForciblyTerminate)
 {
-    // Use a JavaScript source code that makes an infinite loop so that we can
-    // catch some kind of issues as a timeout.
-    const String source("while(true) {}");
-
-    EXPECT_CALL(*m_mockWorkerReportingProxy, workerGlobalScopeStarted(_))
-        .Times(AtMost(1));
-    EXPECT_CALL(*m_mockWorkerReportingProxy, didEvaluateWorkerScript(_))
-        .Times(AtMost(1));
-    EXPECT_CALL(*m_mockWorkerReportingProxy, workerThreadTerminated())
-        .Times(AtMost(1));
-    EXPECT_CALL(*m_mockWorkerReportingProxy, willDestroyWorkerGlobalScope())
-        .Times(AtMost(1));
-    startWithSourceCode(source);
+    expectReportingCallsForWorkerForciblyTerminated();
+    startWithSourceCodeNotToFinish();
     m_workerThread->waitUntilScriptLoaded();
+
+    // terminateAndWait() synchronously terminates the isolate.
     m_workerThread->terminateAndWait();
+    EXPECT_EQ(WorkerThread::ExitCode::SyncForciblyTerminated, m_workerThread->exitCode());
+}
+
+TEST_F(WorkerThreadTest, StartAndTerminateOnScriptLoaded_AsyncForciblyTerminate)
+{
+    const long long kForceTerminationDelayInMs = 10;
+    setForceTerminationDelayInMs(kForceTerminationDelayInMs);
+
+    expectReportingCallsForWorkerForciblyTerminated();
+    startWithSourceCodeNotToFinish();
+    m_workerThread->waitUntilScriptLoaded();
+
+    // terminate() schedules a force termination task.
+    m_workerThread->terminate();
+    EXPECT_TRUE(isForceTerminationTaskScheduled());
+    EXPECT_EQ(WorkerThread::ExitCode::NotTerminated, m_workerThread->exitCode());
+
+    // Wait until the force termination task runs.
+    testing::runDelayedTasks(kForceTerminationDelayInMs);
+    waitForShutdown();
+    EXPECT_EQ(WorkerThread::ExitCode::AsyncForciblyTerminated, m_workerThread->exitCode());
 }
 
+TEST_F(WorkerThreadTest, StartAndTerminateOnScriptLoaded_AsyncForciblyTerminate_MultipleTimes)
+{
+    const long long kForceTerminationDelayInMs = 10;
+    setForceTerminationDelayInMs(kForceTerminationDelayInMs);
+
+    expectReportingCallsForWorkerForciblyTerminated();
+    startWithSourceCodeNotToFinish();
+    m_workerThread->waitUntilScriptLoaded();
+
+    // terminate() schedules a force termination task.
+    m_workerThread->terminate();
+    EXPECT_TRUE(isForceTerminationTaskScheduled());
+    EXPECT_EQ(WorkerThread::ExitCode::NotTerminated, m_workerThread->exitCode());
+
+    // Multiple terminate() calls should not take effect.
+    m_workerThread->terminate();
+    m_workerThread->terminate();
+    EXPECT_EQ(WorkerThread::ExitCode::NotTerminated, m_workerThread->exitCode());
+
+    // Wait until the force termination task runs.
+    testing::runDelayedTasks(kForceTerminationDelayInMs);
+    waitForShutdown();
+    EXPECT_EQ(WorkerThread::ExitCode::AsyncForciblyTerminated, m_workerThread->exitCode());
+}
+
+TEST_F(WorkerThreadTest, StartAndTerminateOnScriptLoaded_SyncForciblyTerminateAfterTerminationTaskIsScheduled)
+{
+    const long long kForceTerminationDelayInMs = 10;
+    setForceTerminationDelayInMs(kForceTerminationDelayInMs);
+
+    expectReportingCallsForWorkerForciblyTerminated();
+    startWithSourceCodeNotToFinish();
+    m_workerThread->waitUntilScriptLoaded();
+
+    // terminate() schedules a force termination task.
+    m_workerThread->terminate();
+    EXPECT_TRUE(isForceTerminationTaskScheduled());
+    EXPECT_EQ(WorkerThread::ExitCode::NotTerminated, m_workerThread->exitCode());
+
+    // terminateAndWait() should overtake the scheduled force termination task.
+    m_workerThread->terminateAndWait();
+    EXPECT_FALSE(isForceTerminationTaskScheduled());
+    EXPECT_EQ(WorkerThread::ExitCode::SyncForciblyTerminated, m_workerThread->exitCode());
+}
+
+// TODO(nhiroki): Add tests for terminateAndWaitForAllWorkers.
+
 } // namespace blink