Revert r255444.

It doesn't build on Windows and broke the Windows LLD and LLDB bots:
http://lab.llvm.org:8011/builders/lld-x86_64-win7/builds/27693/steps/build_Lld/logs/stdio
http://lab.llvm.org:8011/builders/lldb-x86-windows-msvc/builds/13468/steps/build/logs/stdio

llvm-svn: 255446

1 files changed, 0 insertions, 143 deletions

diff --git a/llvm/lib/Support/ThreadPool.cpp b/llvm/lib/Support/ThreadPool.cpp
deleted file mode 100644
index 40f1da9ef3f..00000000000
--- a/llvm/lib/Support/ThreadPool.cpp
+++ /dev/null
@@ -1,143 +0,0 @@
-//==-- 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