inline MachineThreads& wasmThreads()
{
    static LazyNeverDestroyed<MachineThreads> threads;
    static std::once_flag once;
    std::call_once(once, [] {
        threads.construct();
    });

    return threads;
}
Exemplo n.º 2
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FunctionOverrides& FunctionOverrides::overrides()
{
    static LazyNeverDestroyed<FunctionOverrides> overrides;
    static std::once_flag initializeListFlag;
    std::call_once(initializeListFlag, [] {
        const char* overridesFileName = Options::functionOverrides();
        overrides.construct(overridesFileName);
    });
    return overrides;
}
const Extensions3DCache& Extensions3DCache::singleton()
{
    static std::once_flag onceFlag;
    static LazyNeverDestroyed<Extensions3DCache> extensions3DCache;
    std::call_once(onceFlag, []{
        extensions3DCache.construct();
    });

    return extensions3DCache;
}
FunctionWhitelist& FunctionWhitelist::ensureGlobalWhitelist()
{
    static LazyNeverDestroyed<FunctionWhitelist> functionWhitelist;
    static std::once_flag initializeWhitelistFlag;
    std::call_once(initializeWhitelistFlag, [] {
        const char* functionWhitelistFile = Options::dfgWhitelist();
        functionWhitelist.construct(functionWhitelistFile);
    });
    return functionWhitelist;
}
DefaultSharedWorkerRepository& DefaultSharedWorkerRepository::instance()
{
    static std::once_flag onceFlag;
    static LazyNeverDestroyed<DefaultSharedWorkerRepository> instance;
    std::call_once(onceFlag, []{
        instance.construct();
    });

    return instance;
}
NetworkStateNotifier& networkStateNotifier()
{
    static std::once_flag onceFlag;
    static LazyNeverDestroyed<NetworkStateNotifier> networkStateNotifier;

    std::call_once(onceFlag, []{
        networkStateNotifier.construct();
    });

    return networkStateNotifier;
}
// FIXME: move all guid-related functions to a DatabaseVersionTracker class.
static std::mutex& guidMutex()
{
    static std::once_flag onceFlag;
    static LazyNeverDestroyed<std::mutex> mutex;

    std::call_once(onceFlag, []{
        mutex.construct();
    });

    return mutex;
}
Exemplo n.º 8
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// Because of driver bugs, exiting the program when there are active pbuffers
// can crash the X server (this has been observed with the official Nvidia drivers).
// We need to ensure that we clean everything up on exit. There are several reasons
// that GraphicsContext3Ds will still be alive at exit, including user error (memory
// leaks) and the page cache. In any case, we don't want the X server to crash.
static HashSet<GLContextGLX*>& activeContexts()
{
    static std::once_flag onceFlag;
    static LazyNeverDestroyed<HashSet<GLContextGLX*>> contexts;
    std::call_once(onceFlag, [] {
        contexts.construct();
        std::atexit([] {
            for (auto* context : activeContexts())
                context->clear();
        });
    });
    return contexts;
}
Exemplo n.º 9
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void WorkQueue::concurrentApply(size_t iterations, WTF::Function<void (size_t index)>&& function)
{
    if (!iterations)
        return;

    if (iterations == 1) {
        function(0);
        return;
    }

    class ThreadPool {
    public:
        ThreadPool()
        {
            // We don't need a thread for the current core.
            unsigned threadCount = numberOfProcessorCores() - 1;

            m_workers.reserveInitialCapacity(threadCount);
            for (unsigned i = 0; i < threadCount; ++i) {
                m_workers.append(Thread::create("ThreadPool Worker", [this] {
                    threadBody();
                }));
            }
        }

        size_t workerCount() const { return m_workers.size(); }

        void dispatch(const WTF::Function<void ()>* function)
        {
            LockHolder holder(m_lock);

            m_queue.append(function);
            m_condition.notifyOne();
        }

    private:
        NO_RETURN void threadBody()
        {
            while (true) {
                const WTF::Function<void ()>* function;

                {
                    LockHolder holder(m_lock);

                    m_condition.wait(m_lock, [this] {
                        return !m_queue.isEmpty();
                    });

                    function = m_queue.takeFirst();
                }

                (*function)();
            }
        }

        Lock m_lock;
        Condition m_condition;
        Deque<const WTF::Function<void ()>*> m_queue;

        Vector<Ref<Thread>> m_workers;
    };

    static LazyNeverDestroyed<ThreadPool> threadPool;
    static std::once_flag onceFlag;
    std::call_once(onceFlag, [] {
        threadPool.construct();
    });

    // Cap the worker count to the number of iterations (excluding this thread)
    const size_t workerCount = std::min(iterations - 1, threadPool->workerCount());

    std::atomic<size_t> currentIndex(0);
    std::atomic<size_t> activeThreads(workerCount + 1);

    Condition condition;
    Lock lock;

    WTF::Function<void ()> applier = [&, function = WTFMove(function)] {
        size_t index;

        // Call the function for as long as there are iterations left.
        while ((index = currentIndex++) < iterations)
            function(index);

        // If there are no active threads left, signal the caller.
        if (!--activeThreads) {
            LockHolder holder(lock);
            condition.notifyOne();
        }
    };

    for (size_t i = 0; i < workerCount; ++i)
        threadPool->dispatch(&applier);
    applier();

    LockHolder holder(lock);
    condition.wait(lock, [&] { return !activeThreads; });
}