// Copyright 2023 The Dawn & Tint Authors
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#include <gtest/gtest.h>

#include <atomic>
#include <chrono>
#include <memory>
#include <thread>
#include <utility>

#include "dawn/native/AsyncTask.h"
#include "mocks/DawnMockTest.h"

namespace dawn::native {
namespace {

using ::testing::Test;

class DeviceAsyncTaskTests : public DawnMockTest {};

// Test that a long async task's execution won't extend to after the device is dropped.
// Device dropping should wait for that task to finish.
TEST_F(DeviceAsyncTaskTests, LongAsyncTaskFinishesBeforeDeviceIsDropped) {
    std::atomic_bool done(false);

    // Simulate that an async task would take a long time to finish.
    AsyncTaskFunction task([&done] {
        std::this_thread::sleep_for(std::chrono::milliseconds(1000));
        done = true;
    });

    mDeviceMock->GetAsyncTaskManager()->PostTask<AsyncTask>(std::move(task));
    DropDevice();
    // Dropping the device should force the async task to finish.
    EXPECT_TRUE(done.load());
}

// Test that error scope resolution is blocked on AsyncTask completion.
TEST_F(DeviceAsyncTaskTests, ErrorScopeBlockedOnAsyncTask) {
    device.PushErrorScope(wgpu::ErrorFilter::Validation);

    // Set up a task that won't complete until the mutex is unlocked
    std::mutex mutex;
    std::unique_lock lock(mutex);
    auto task = mDeviceMock->GetAsyncTaskManager()->PostTask<ErrorGeneratingAsyncTask>(
        [&mutex]() -> MaybeError {
            std::scoped_lock<std::mutex> taskLock(mutex);
            return {};
        });

    // Register the error generating task with the device so it's associated with the current error
    // scopes
    mDeviceMock->HandleErrorGeneratingAsyncTask(task);

    // Set up a simple callback which sets `callbackTriggered`
    std::atomic_bool callbackTriggered = false;
    device.PopErrorScope(wgpu::CallbackMode::AllowProcessEvents,
                         [&callbackTriggered](wgpu::PopErrorScopeStatus, wgpu::ErrorType,
                                              wgpu::StringView) { callbackTriggered = true; });

    // Expect that the callback is not called yet since the AsyncTask has not completed.
    ProcessEvents();
    EXPECT_FALSE(callbackTriggered);

    // Complete the async task and expect that the future resolves and callback is triggered
    lock.unlock();
    task->Wait();
    ProcessEvents();
    EXPECT_TRUE(callbackTriggered);
}

}  // anonymous namespace
}  // namespace dawn::native