[Support] Base RWMutex on std::shared_timed_mutex (C++14)

This should have the same semantics. We use std::shared_mutex instead on
MSVC and C++17, std::shared_timed_mutex is less efficient than our
custom implementation on Windows, std::shared_mutex should be faster.

llvm-svn: 369018

1 files changed, 0 insertions, 124 deletions

diff --git a/llvm/lib/Support/RWMutex.cpp b/llvm/lib/Support/RWMutex.cpp
deleted file mode 100644
index 7ce856b716c..00000000000
--- a/llvm/lib/Support/RWMutex.cpp
+++ /dev/null
@@ -1,124 +0,0 @@
-//===- RWMutex.cpp - Reader/Writer Mutual Exclusion Lock --------*- C++ -*-===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the llvm::sys::RWMutex class.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Support/Allocator.h"
-#include "llvm/Support/RWMutex.h"
-#include "llvm/Config/config.h"
-
-//===----------------------------------------------------------------------===//
-//=== WARNING: Implementation here must contain only TRULY operating system
-//===          independent code.
-//===----------------------------------------------------------------------===//
-
-#if !defined(LLVM_ENABLE_THREADS) || LLVM_ENABLE_THREADS == 0
-// Define all methods as no-ops if threading is explicitly disabled
-
-using namespace llvm;
-using namespace sys;
-
-RWMutexImpl::RWMutexImpl() = default;
-RWMutexImpl::~RWMutexImpl() = default;
-
-bool RWMutexImpl::reader_acquire() { return true; }
-bool RWMutexImpl::reader_release() { return true; }
-bool RWMutexImpl::writer_acquire() { return true; }
-bool RWMutexImpl::writer_release() { return true; }
-
-#else
-
-#if defined(HAVE_PTHREAD_H) && defined(HAVE_PTHREAD_RWLOCK_INIT)
-
-#include <cassert>
-#include <cstdlib>
-#include <pthread.h>
-
-using namespace llvm;
-using namespace sys;
-
-// Construct a RWMutex using pthread calls
-RWMutexImpl::RWMutexImpl()
-{
-  // Declare the pthread_rwlock data structures
-  pthread_rwlock_t* rwlock =
-    static_cast<pthread_rwlock_t*>(safe_malloc(sizeof(pthread_rwlock_t)));
-
-#ifdef __APPLE__
-  // Workaround a bug/mis-feature in Darwin's pthread_rwlock_init.
-  bzero(rwlock, sizeof(pthread_rwlock_t));
-#endif
-
-  // Initialize the rwlock
-  int errorcode = pthread_rwlock_init(rwlock, nullptr);
-  (void)errorcode;
-  assert(errorcode == 0);
-
-  // Assign the data member
-  data_ = rwlock;
-}
-
-// Destruct a RWMutex
-RWMutexImpl::~RWMutexImpl()
-{
-  pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
-  assert(rwlock != nullptr);
-  pthread_rwlock_destroy(rwlock);
-  free(rwlock);
-}
-
-bool
-RWMutexImpl::reader_acquire()
-{
-  pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
-  assert(rwlock != nullptr);
-
-  int errorcode = pthread_rwlock_rdlock(rwlock);
-  return errorcode == 0;
-}
-
-bool
-RWMutexImpl::reader_release()
-{
-  pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
-  assert(rwlock != nullptr);
-
-  int errorcode = pthread_rwlock_unlock(rwlock);
-  return errorcode == 0;
-}
-
-bool
-RWMutexImpl::writer_acquire()
-{
-  pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
-  assert(rwlock != nullptr);
-
-  int errorcode = pthread_rwlock_wrlock(rwlock);
-  return errorcode == 0;
-}
-
-bool
-RWMutexImpl::writer_release()
-{
-  pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
-  assert(rwlock != nullptr);
-
-  int errorcode = pthread_rwlock_unlock(rwlock);
-  return errorcode == 0;
-}
-
-#elif defined(LLVM_ON_UNIX)
-#include "Unix/RWMutex.inc"
-#elif defined( _WIN32)
-#include "Windows/RWMutex.inc"
-#else
-#warning Neither LLVM_ON_UNIX nor _WIN32 was set in Support/Mutex.cpp
-#endif
-#endif