Tools/TestWebKitAPI/Tests/WTF/SuspendableWorkQueueTests.cpp

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#include "config.h"

#include "Helpers/Test.h"
#include "Helpers/Utilities.h"
#include <wtf/Lock.h>
#include <wtf/RunLoop.h>
#include <wtf/SuspendableWorkQueue.h>

namespace TestWebKitAPI {

TEST(WTF_SuspendableWorkQueue, Suspend)
{
    Lock lock;
    const int taskCount = 100;
    int scheduledTaskCount = 0;
    int completedTaskCount = 0;
    int lastCompletedTaskCount = 0;
    bool suspended = false;
    // Main thread only.
    bool suspendCompletionHandlerCalled = false;
    bool allTasksAreCompleted = false;

    auto queue = SuspendableWorkQueue::create("com.apple.WebKit.Test.simple"_s);
    // Schedule first batch of tasks.
    for (; scheduledTaskCount < taskCount / 2; ++scheduledTaskCount) {
        queue->dispatch([&]() mutable {
            Locker locker { lock };
            ++completedTaskCount;
        });
    }

    queue->suspend([&] {
        Locker locker { lock };
        suspended = true;
    }, [&] {
        suspendCompletionHandlerCalled = true;
    });

    // Schedule second batch of tasks after suspension.
    for (; scheduledTaskCount < taskCount; ++scheduledTaskCount) {
        queue->dispatch([&]() mutable {
            Locker locker { lock };
            suspended = false;
            ++completedTaskCount;

            if (completedTaskCount == taskCount) {
                RunLoop::mainSingleton().dispatch([&]() {
                    allTasksAreCompleted = true;
                });
            }
        });
    }

    // Ensure not all tasks are completed.
    Util::run(&suspendCompletionHandlerCalled);
    {
        Locker locker { lock };
        EXPECT_LT(completedTaskCount, taskCount);
        EXPECT_TRUE(suspended);
        lastCompletedTaskCount = completedTaskCount;
    }

    // Ensure no more task is processed.
    Util::runFor(100_ms);
    {
        Locker locker { lock };
        EXPECT_EQ(lastCompletedTaskCount, completedTaskCount);
    }

    queue->resume();
    Util::run(&allTasksAreCompleted);
    Locker locker { lock };
    EXPECT_EQ(completedTaskCount, taskCount);
    EXPECT_FALSE(suspended);
}

TEST(WTF_SuspendableWorkQueue, SuspendTwice)
{
    Lock lock;
    bool suspendCompletionHandlerCalled = false;
    int suspendCount = 0;
    auto queue = SuspendableWorkQueue::create("com.apple.WebKit.Test.simple"_s);
    queue->suspend([&]() {
        Locker locker { lock };
        ++suspendCount;
    }, [&] {
        suspendCompletionHandlerCalled = true;
    });
    Util::run(&suspendCompletionHandlerCalled);
    {
        Locker locker { lock };
        EXPECT_EQ(1, suspendCount);
    }
    
    suspendCompletionHandlerCalled = false;
    queue->suspend([&]() {
        Locker locker { lock };
        ++suspendCount;
    }, [&] {
        suspendCompletionHandlerCalled = true;
    });
    Util::run(&suspendCompletionHandlerCalled);
    Locker locker { lock };
    EXPECT_EQ(1, suspendCount);
}

} // namesapce TestWebKitAPI