| /* |
| * Copyright (C) 2015 Apple Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' |
| * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
| * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS |
| * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF |
| * THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "config.h" |
| #include <condition_variable> |
| #include <mutex> |
| #include <thread> |
| #include <wtf/DataLog.h> |
| #include <wtf/HashSet.h> |
| #include <wtf/ListDump.h> |
| #include <wtf/ParkingLot.h> |
| #include <wtf/Threading.h> |
| #include <wtf/ThreadingPrimitives.h> |
| |
| using namespace WTF; |
| |
| namespace TestWebKitAPI { |
| |
| namespace { |
| |
| struct SingleLatchTest { |
| void initialize(unsigned numThreads) |
| { |
| // This implements a fair (FIFO) semaphore, and it starts out unavailable. |
| semaphore.store(0); |
| |
| for (unsigned i = numThreads; i--;) { |
| threads.append( |
| Thread::create( |
| "Parking Test Thread", |
| [&] () { |
| down(); |
| |
| std::lock_guard<std::mutex> locker(lock); |
| awake.add(Thread::current()); |
| lastAwoken = &Thread::current(); |
| condition.notify_one(); |
| })); |
| } |
| } |
| |
| void unparkOne(unsigned singleUnparkIndex) |
| { |
| EXPECT_TRUE(nullptr == lastAwoken); |
| |
| unsigned numWaitingOnAddress = 0; |
| Vector<RefPtr<Thread>, 8> queue; |
| ParkingLot::forEach( |
| [&] (Thread& thread, const void* address) { |
| if (address != &semaphore) |
| return; |
| |
| queue.append(&thread); |
| |
| numWaitingOnAddress++; |
| }); |
| |
| EXPECT_LE(numWaitingOnAddress, threads.size() - singleUnparkIndex); |
| |
| up(); |
| |
| { |
| std::unique_lock<std::mutex> locker(lock); |
| while (awake.size() < singleUnparkIndex + 1) |
| condition.wait(locker); |
| EXPECT_TRUE(nullptr != lastAwoken); |
| if (!queue.isEmpty() && queue[0] != lastAwoken) { |
| dataLog("Woke up wrong thread: queue = ", listDump(queue), ", last awoken = ", lastAwoken, "\n"); |
| EXPECT_EQ(queue[0], lastAwoken); |
| } |
| lastAwoken = nullptr; |
| } |
| } |
| |
| void finish(unsigned numSingleUnparks) |
| { |
| unsigned numWaitingOnAddress = 0; |
| ParkingLot::forEach( |
| [&] (Thread&, const void* address) { |
| if (address != &semaphore) |
| return; |
| |
| numWaitingOnAddress++; |
| }); |
| |
| EXPECT_LE(numWaitingOnAddress, threads.size() - numSingleUnparks); |
| |
| semaphore.store(threads.size() - numSingleUnparks); |
| ParkingLot::unparkAll(&semaphore); |
| |
| numWaitingOnAddress = 0; |
| ParkingLot::forEach( |
| [&] (Thread&, const void* address) { |
| if (address != &semaphore) |
| return; |
| |
| numWaitingOnAddress++; |
| }); |
| |
| EXPECT_EQ(0u, numWaitingOnAddress); |
| |
| { |
| std::unique_lock<std::mutex> locker(lock); |
| while (awake.size() < threads.size()) |
| condition.wait(locker); |
| } |
| |
| for (auto& thread : threads) |
| thread->waitForCompletion(); |
| } |
| |
| // Semaphore operations. |
| void down() |
| { |
| for (;;) { |
| int oldSemaphoreValue = semaphore.load(); |
| int newSemaphoreValue = oldSemaphoreValue - 1; |
| if (!semaphore.compareExchangeWeak(oldSemaphoreValue, newSemaphoreValue)) |
| continue; |
| |
| if (oldSemaphoreValue > 0) { |
| // We acquired the semaphore. Done. |
| return; |
| } |
| |
| // We need to wait. |
| if (ParkingLot::compareAndPark(&semaphore, newSemaphoreValue).wasUnparked) { |
| // We did wait, and then got woken up. This means that someone who up'd the semaphore |
| // passed ownership onto us. |
| return; |
| } |
| |
| // We never parked, because the semaphore value changed. Undo our decrement and try again. |
| for (;;) { |
| int oldSemaphoreValue = semaphore.load(); |
| if (semaphore.compareExchangeWeak(oldSemaphoreValue, oldSemaphoreValue + 1)) |
| break; |
| } |
| } |
| } |
| void up() |
| { |
| int oldSemaphoreValue; |
| for (;;) { |
| oldSemaphoreValue = semaphore.load(); |
| if (semaphore.compareExchangeWeak(oldSemaphoreValue, oldSemaphoreValue + 1)) |
| break; |
| } |
| |
| // Check if anyone was waiting on the semaphore. If they were, then pass ownership to them. |
| if (oldSemaphoreValue < 0) |
| ParkingLot::unparkOne(&semaphore); |
| } |
| |
| Atomic<int> semaphore; |
| std::mutex lock; |
| std::condition_variable condition; |
| HashSet<Ref<Thread>> awake; |
| Vector<Ref<Thread>> threads; |
| RefPtr<Thread> lastAwoken; |
| }; |
| |
| void runParkingTest(unsigned numLatches, unsigned delay, unsigned numThreads, unsigned numSingleUnparks) |
| { |
| std::unique_ptr<SingleLatchTest[]> tests = std::make_unique<SingleLatchTest[]>(numLatches); |
| |
| for (unsigned latchIndex = numLatches; latchIndex--;) |
| tests[latchIndex].initialize(numThreads); |
| |
| for (unsigned unparkIndex = 0; unparkIndex < numSingleUnparks; ++unparkIndex) { |
| std::this_thread::sleep_for(std::chrono::microseconds(delay)); |
| for (unsigned latchIndex = numLatches; latchIndex--;) |
| tests[latchIndex].unparkOne(unparkIndex); |
| } |
| |
| for (unsigned latchIndex = numLatches; latchIndex--;) |
| tests[latchIndex].finish(numSingleUnparks); |
| } |
| |
| void repeatParkingTest(unsigned numRepeats, unsigned numLatches, unsigned delay, unsigned numThreads, unsigned numSingleUnparks) |
| { |
| while (numRepeats--) |
| runParkingTest(numLatches, delay, numThreads, numSingleUnparks); |
| } |
| |
| } // anonymous namespace |
| |
| TEST(WTF_ParkingLot, UnparkAllOneFast) |
| { |
| repeatParkingTest(10000, 1, 0, 1, 0); |
| } |
| |
| TEST(WTF_ParkingLot, UnparkAllHundredFast) |
| { |
| repeatParkingTest(100, 1, 0, 100, 0); |
| } |
| |
| TEST(WTF_ParkingLot, UnparkOneOneFast) |
| { |
| repeatParkingTest(1000, 1, 0, 1, 1); |
| } |
| |
| TEST(WTF_ParkingLot, UnparkOneHundredFast) |
| { |
| repeatParkingTest(20, 1, 0, 100, 100); |
| } |
| |
| TEST(WTF_ParkingLot, UnparkOneFiftyThenFiftyAllFast) |
| { |
| repeatParkingTest(50, 1, 0, 100, 50); |
| } |
| |
| TEST(WTF_ParkingLot, UnparkAllOne) |
| { |
| repeatParkingTest(100, 1, 10000, 1, 0); |
| } |
| |
| TEST(WTF_ParkingLot, UnparkAllHundred) |
| { |
| repeatParkingTest(100, 1, 10000, 100, 0); |
| } |
| |
| TEST(WTF_ParkingLot, UnparkOneOne) |
| { |
| repeatParkingTest(10, 1, 10000, 1, 1); |
| } |
| |
| TEST(WTF_ParkingLot, UnparkOneFifty) |
| { |
| repeatParkingTest(1, 1, 10000, 50, 50); |
| } |
| |
| TEST(WTF_ParkingLot, UnparkOneFiftyThenFiftyAll) |
| { |
| repeatParkingTest(2, 1, 10000, 100, 50); |
| } |
| |
| TEST(WTF_ParkingLot, HundredUnparkAllOneFast) |
| { |
| repeatParkingTest(100, 100, 0, 1, 0); |
| } |
| |
| TEST(WTF_ParkingLot, HundredUnparkAllOne) |
| { |
| repeatParkingTest(1, 100, 10000, 1, 0); |
| } |
| |
| } // namespace TestWebKitAPI |
| |