+++ /dev/null
-//===-- llvm/Support/ThreadPool.h - A ThreadPool implementation -*- C++ -*-===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file defines a crude C++11 based thread pool.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_SUPPORT_THREAD_POOL_H
-#define LLVM_SUPPORT_THREAD_POOL_H
-
-#include "llvm/Support/thread.h"
-
-#include <condition_variable>
-#include <functional>
-#include <future>
-#include <memory>
-#include <mutex>
-#include <queue>
-#include <utility>
-
-namespace llvm {
-
-/// A ThreadPool for asynchronous parallel execution on a defined number of
-/// threads.
-///
-/// The pool keeps a vector of threads alive, waiting on a condition variable
-/// for some work to become available.
-class ThreadPool {
-public:
- using TaskTy = std::function<void()>;
-
- /// Construct a pool with the number of core available on the system (or
- /// whatever the value returned by std::thread::hardware_concurrency() is).
- ThreadPool();
-
- /// Construct a pool of \p ThreadCount threads
- ThreadPool(unsigned ThreadCount);
-
- /// Blocking destructor: the pool will wait for all the threads to complete.
- ~ThreadPool();
-
- /// Asynchronous submission of a task to the pool. The returned future can be
- /// used to wait for the task to finish and is *non-blocking* on destruction.
- template <typename Function, typename... Args>
- inline std::shared_future<void> async(Function &&F, Args &&... ArgList) {
- auto Task =
- std::bind(std::forward<Function>(F), std::forward<Args...>(ArgList...));
- return asyncImpl(Task);
- }
-
- /// Asynchronous submission of a task to the pool. The returned future can be
- /// used to wait for the task to finish and is *non-blocking* on destruction.
- template <typename Function>
- inline std::shared_future<void> async(Function &&F) {
- return asyncImpl(F);
- }
-
- /// Blocking wait for all the threads to complete and the queue to be empty.
- /// It is an error to try to add new tasks while blocking on this call.
- void wait();
-
-private:
- /// Asynchronous submission of a task to the pool. The returned future can be
- /// used to wait for the task to finish and is *non-blocking* on destruction.
- std::shared_future<void> asyncImpl(TaskTy f);
-
- /// Threads in flight
- std::vector<llvm::thread> Threads;
-
- /// Tasks waiting for execution in the pool.
- std::queue<std::packaged_task<void()>> Tasks;
-
- /// Locking and signaling for accessing the Tasks queue.
- std::mutex QueueLock;
- std::condition_variable QueueCondition;
-
- /// Locking and signaling for job completion
- std::mutex CompletionLock;
- std::condition_variable CompletionCondition;
-
- /// Keep track of the number of thread actually busy
- std::atomic<unsigned> ActiveThreads;
-
- /// Signal for the destruction of the pool, asking thread to exit.
- bool EnableFlag;
-};
-}
-
-#endif // LLVM_SUPPORT_THREAD_POOL_H
#else // !LLVM_ENABLE_THREADS
-#include <utility>
-
namespace llvm {
struct thread {
StringRef.cpp
SystemUtils.cpp
TargetParser.cpp
- ThreadPool.cpp
Timer.cpp
ToolOutputFile.cpp
Triple.cpp
+++ /dev/null
-//==-- llvm/Support/ThreadPool.cpp - A ThreadPool implementation -*- C++ -*-==//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements a crude C++11 based thread pool.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Support/ThreadPool.h"
-
-#include "llvm/Config/llvm-config.h"
-#include "llvm/Support/raw_ostream.h"
-
-using namespace llvm;
-
-#if LLVM_ENABLE_THREADS
-
-// Default to std::thread::hardware_concurrency
-ThreadPool::ThreadPool() : ThreadPool(std::thread::hardware_concurrency()) {}
-
-ThreadPool::ThreadPool(unsigned ThreadCount)
- : ActiveThreads(0), EnableFlag(true) {
- // Create ThreadCount threads that will loop forever, wait on QueueCondition
- // for tasks to be queued or the Pool to be destroyed.
- Threads.reserve(ThreadCount);
- for (unsigned ThreadID = 0; ThreadID < ThreadCount; ++ThreadID) {
- Threads.emplace_back([&] {
- while (true) {
- std::packaged_task<void()> Task;
- {
- std::unique_lock<std::mutex> LockGuard(QueueLock);
- // Wait for tasks to be pushed in the queue
- QueueCondition.wait(LockGuard,
- [&] { return !EnableFlag || !Tasks.empty(); });
- // Exit condition
- if (!EnableFlag && Tasks.empty())
- return;
- // Yeah, we have a task, grab it and release the lock on the queue
-
- // We first need to signal that we are active before popping the queue
- // in order for wait() to properly detect that even if the queue is
- // empty, there is still a task in flight.
- {
- ++ActiveThreads;
- std::unique_lock<std::mutex> LockGuard(CompletionLock);
- }
- Task = std::move(Tasks.front());
- Tasks.pop();
- }
- // Run the task we just grabbed
- Task();
-
- {
- // Adjust `ActiveThreads`, in case someone waits on ThreadPool::wait()
- std::unique_lock<std::mutex> LockGuard(CompletionLock);
- --ActiveThreads;
- }
-
- // Notify task completion, in case someone waits on ThreadPool::wait()
- CompletionCondition.notify_all();
- }
- });
- }
-}
-
-void ThreadPool::wait() {
- // Wait for all threads to complete and the queue to be empty
- std::unique_lock<std::mutex> LockGuard(CompletionLock);
- CompletionCondition.wait(LockGuard,
- [&] { return Tasks.empty() && !ActiveThreads; });
-}
-
-std::shared_future<void> ThreadPool::asyncImpl(TaskTy Task) {
- /// Wrap the Task in a packaged_task to return a future object.
- std::packaged_task<void()> PackagedTask(std::move(Task));
- std::future<void> Future = PackagedTask.get_future();
- {
- // Lock the queue and push the new task
- std::unique_lock<std::mutex> LockGuard(QueueLock);
-
- // Don't allow enqueueing after disabling the pool
- assert(EnableFlag && "Queuing a thread during ThreadPool destruction");
-
- Tasks.push(std::move(PackagedTask));
- }
- QueueCondition.notify_one();
- return Future.share();
-}
-
-// The destructor joins all threads, waiting for completion.
-ThreadPool::~ThreadPool() {
- {
- std::unique_lock<std::mutex> LockGuard(QueueLock);
- EnableFlag = false;
- }
- QueueCondition.notify_all();
- for (auto &Worker : Threads)
- Worker.join();
-}
-
-#else // LLVM_ENABLE_THREADS Disabled
-
-ThreadPool::ThreadPool() : ThreadPool(0) {}
-
-// No threads are launched, issue a warning if ThreadCount is not 0
-ThreadPool::ThreadPool(unsigned ThreadCount)
- : ActiveThreads(0), EnableFlag(true) {
- if (ThreadCount) {
- errs() << "Warning: request a ThreadPool with " << ThreadCount
- << " threads, but LLVM_ENABLE_THREADS has been turned off\n";
- }
-}
-
-void ThreadPool::wait() {
- // Sequential implementation running the tasks
- while (!Tasks.empty()) {
- auto Task = std::move(Tasks.front());
- Tasks.pop();
- Task();
- }
-}
-
-std::shared_future<void> ThreadPool::asyncImpl(TaskTy Task) {
- // Get a Future with launch::deferred execution using std::async
- auto Future = std::async(std::launch::deferred, std::move(Task)).share();
- // Wrap the future so that both ThreadPool::wait() can operate and the
- // returned future can be sync'ed on.
- std::packaged_task<void()> PackagedTask([Future]() { Future.get(); });
- Tasks.push(std::move(PackagedTask));
- return Future;
-}
-
-ThreadPool::~ThreadPool() {
- EnableFlag = false;
- wait();
-}
-
-#endif
SwapByteOrderTest.cpp
TargetRegistry.cpp
ThreadLocalTest.cpp
- ThreadPool.cpp
TimeValueTest.cpp
TrailingObjectsTest.cpp
UnicodeTest.cpp
+++ /dev/null
-//========- unittests/Support/ThreadPools.cpp - ThreadPools.h tests --========//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Support/ThreadPool.h"
-
-#include "llvm/ADT/STLExtras.h"
-
-#include "gtest/gtest.h"
-
-using namespace llvm;
-using namespace std::chrono;
-
-/// Try best to make this thread not progress faster than the main thread
-static void yield() {
-#ifdef LLVM_ENABLE_THREADS
- std::this_thread::yield();
-#endif
- std::this_thread::sleep_for(milliseconds(200));
-#ifdef LLVM_ENABLE_THREADS
- std::this_thread::yield();
-#endif
-}
-
-TEST(ThreadPoolTest, AsyncBarrier) {
- // test that async & barrier work together properly.
-
- std::atomic_int checked_in{0};
-
- ThreadPool Pool;
- for (size_t i = 0; i < 5; ++i) {
- Pool.async([&checked_in, i] {
- yield();
- ++checked_in;
- });
- }
- ASSERT_EQ(0, checked_in);
- Pool.wait();
- ASSERT_EQ(5, checked_in);
-}
-
-TEST(ThreadPoolTest, Async) {
- ThreadPool Pool;
- std::atomic_int i{0};
- // sleep here just to ensure that the not-equal is correct.
- Pool.async([&i] {
- yield();
- ++i;
- });
- Pool.async([&i] { ++i; });
- ASSERT_NE(2, i.load());
- Pool.wait();
- ASSERT_EQ(2, i.load());
-}
-
-TEST(ThreadPoolTest, GetFuture) {
- ThreadPool Pool;
- std::atomic_int i{0};
- // sleep here just to ensure that the not-equal is correct.
- Pool.async([&i] {
- yield();
- ++i;
- });
- // Force the future using get()
- Pool.async([&i] { ++i; }).get();
- ASSERT_NE(2, i.load());
- Pool.wait();
- ASSERT_EQ(2, i.load());
-}
-
-TEST(ThreadPoolTest, PoolDestruction) {
- // Test that we are waiting on destruction
- std::atomic_int checked_in{0};
-
- {
- ThreadPool Pool;
- for (size_t i = 0; i < 5; ++i) {
- Pool.async([&checked_in, i] {
- yield();
- ++checked_in;
- });
- }
- ASSERT_EQ(0, checked_in);
- }
- ASSERT_EQ(5, checked_in);
-}
projects / oota-llvm.git / commitdiff