Revert "Add a C++11 ThreadPool implementation in LLVM"

This reverts commit r255589. Breaks g++

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255591 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 0 insertions, 115 deletions

diff --git a/include/llvm/Support/ThreadPool.h b/include/llvm/Support/ThreadPool.h
deleted file mode 100644
index 8a90c85865a..00000000000
--- a/include/llvm/Support/ThreadPool.h
+++ /dev/null
@@ -1,113 +0,0 @@
-//===-- 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:
-#ifndef _MSC_VER
-  using VoidTy = void;
-#else
-  // MSVC 2013 has a bug and can't use std::packaged_task<void()>;
-  // We force it to use bool(bool) instead.
-  using VoidTy = bool;
-#endif
-  using TaskTy = std::function<VoidTy(VoidTy)>;
-  using PackagedTaskTy = std::packaged_task<VoidTy(VoidTy)>;
-
-  /// 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<VoidTy> async(Function &&F, Args &&... ArgList) {
-    auto Task =
-        std::bind(std::forward<Function>(F), std::forward<Args...>(ArgList...));
-#ifndef _MSC_VER
-    return asyncImpl(std::move(Task));
-#else
-    return asyncImpl([Task] (VoidTy) -> VoidTy { Task(); return VoidTy(); });
-#endif
-  }
-
-  /// 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<VoidTy> async(Function &&F) {
-#ifndef _MSC_VER
-    return asyncImpl(std::forward<Function>(F));
-#else
-    return asyncImpl([F] (VoidTy) -> VoidTy { F(); return VoidTy(); });
-#endif
-  }
-
-  /// 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<VoidTy> asyncImpl(TaskTy F);
-
-  /// Threads in flight
-  std::vector<llvm::thread> Threads;
-
-  /// Tasks waiting for execution in the pool.
-  std::queue<PackagedTaskTy> 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;
-
-#if LLVM_ENABLE_THREADS // avoids warning for unused variable
-  /// Signal for the destruction of the pool, asking thread to exit.
-  bool EnableFlag;
-#endif
-};
-}
-
-#endif // LLVM_SUPPORT_THREAD_POOL_H
diff --git a/include/llvm/Support/thread.h b/include/llvm/Support/thread.h
index 2d130418a57..2d1f1b3a3ec 100644
--- a/include/llvm/Support/thread.h
+++ b/include/llvm/Support/thread.h
@@ -43,8 +43,6 @@ typedef std::thread thread;
 
 #else // !LLVM_ENABLE_THREADS
 
-#include <utility>
-
 namespace llvm {
 
 struct thread {