Move webrtc/{base => rtc_base}

webrtc/base/criticalsection.cc

-/*
- *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- */
-
-#include "webrtc/base/criticalsection.h"
-
-#include "webrtc/base/checks.h"
-#include "webrtc/base/platform_thread.h"
-
-// TODO(tommi): Split this file up to per-platform implementation files.
-
-namespace rtc {
-
-CriticalSection::CriticalSection() {
-#if defined(WEBRTC_WIN)
-  InitializeCriticalSection(&crit_);
-#else
-#if defined(WEBRTC_MAC) && !USE_NATIVE_MUTEX_ON_MAC
-  lock_queue_ = 0;
-  owning_thread_ = 0;
-  recursion_ = 0;
-  semaphore_ = dispatch_semaphore_create(0);
-#else
-  pthread_mutexattr_t mutex_attribute;
-  pthread_mutexattr_init(&mutex_attribute);
-  pthread_mutexattr_settype(&mutex_attribute, PTHREAD_MUTEX_RECURSIVE);
-  pthread_mutex_init(&mutex_, &mutex_attribute);
-  pthread_mutexattr_destroy(&mutex_attribute);
-#endif
-  CS_DEBUG_CODE(thread_ = 0);
-  CS_DEBUG_CODE(recursion_count_ = 0);
-#endif
-}
-
-CriticalSection::~CriticalSection() {
-#if defined(WEBRTC_WIN)
-  DeleteCriticalSection(&crit_);
-#else
-#if defined(WEBRTC_MAC) && !USE_NATIVE_MUTEX_ON_MAC
-  dispatch_release(semaphore_);
-#else
-  pthread_mutex_destroy(&mutex_);
-#endif
-#endif
-}
-
-void CriticalSection::Enter() const EXCLUSIVE_LOCK_FUNCTION() {
-#if defined(WEBRTC_WIN)
-  EnterCriticalSection(&crit_);
-#else
-#if defined(WEBRTC_MAC) && !USE_NATIVE_MUTEX_ON_MAC
-  int spin = 3000;
-  PlatformThreadRef self = CurrentThreadRef();
-  bool have_lock = false;
-  do {
-    // Instead of calling TryEnter() in this loop, we do two interlocked
-    // operations, first a read-only one in order to avoid affecting the lock
-    // cache-line while spinning, in case another thread is using the lock.
-    if (!IsThreadRefEqual(owning_thread_, self)) {
-      if (AtomicOps::AcquireLoad(&lock_queue_) == 0) {
-        if (AtomicOps::CompareAndSwap(&lock_queue_, 0, 1) == 0) {
-          have_lock = true;
-          break;
-        }
-      }
-    } else {
-      AtomicOps::Increment(&lock_queue_);
-      have_lock = true;
-      break;
-    }
-
-    sched_yield();
-  } while (--spin);
-
-  if (!have_lock && AtomicOps::Increment(&lock_queue_) > 1) {
-    // Owning thread cannot be the current thread since TryEnter() would
-    // have succeeded.
-    RTC_DCHECK(!IsThreadRefEqual(owning_thread_, self));
-    // Wait for the lock to become available.
-    dispatch_semaphore_wait(semaphore_, DISPATCH_TIME_FOREVER);
-    RTC_DCHECK(owning_thread_ == 0);
-    RTC_DCHECK(!recursion_);
-  }
-
-  owning_thread_ = self;
-  ++recursion_;
-
-#else
-  pthread_mutex_lock(&mutex_);
-#endif
-
-#if CS_DEBUG_CHECKS
-  if (!recursion_count_) {
-    RTC_DCHECK(!thread_);
-    thread_ = CurrentThreadRef();
-  } else {
-    RTC_DCHECK(CurrentThreadIsOwner());
-  }
-  ++recursion_count_;
-#endif
-#endif
-}
-
-bool CriticalSection::TryEnter() const EXCLUSIVE_TRYLOCK_FUNCTION(true) {
-#if defined(WEBRTC_WIN)
-  return TryEnterCriticalSection(&crit_) != FALSE;
-#else
-#if defined(WEBRTC_MAC) && !USE_NATIVE_MUTEX_ON_MAC
-  if (!IsThreadRefEqual(owning_thread_, CurrentThreadRef())) {
-    if (AtomicOps::CompareAndSwap(&lock_queue_, 0, 1) != 0)
-      return false;
-    owning_thread_ = CurrentThreadRef();
-    RTC_DCHECK(!recursion_);
-  } else {
-    AtomicOps::Increment(&lock_queue_);
-  }
-  ++recursion_;
-#else
-  if (pthread_mutex_trylock(&mutex_) != 0)
-    return false;
-#endif
-#if CS_DEBUG_CHECKS
-  if (!recursion_count_) {
-    RTC_DCHECK(!thread_);
-    thread_ = CurrentThreadRef();
-  } else {
-    RTC_DCHECK(CurrentThreadIsOwner());
-  }
-  ++recursion_count_;
-#endif
-  return true;
-#endif
-}
-void CriticalSection::Leave() const UNLOCK_FUNCTION() {
-  RTC_DCHECK(CurrentThreadIsOwner());
-#if defined(WEBRTC_WIN)
-  LeaveCriticalSection(&crit_);
-#else
-#if CS_DEBUG_CHECKS
-  --recursion_count_;
-  RTC_DCHECK(recursion_count_ >= 0);
-  if (!recursion_count_)
-    thread_ = 0;
-#endif
-#if defined(WEBRTC_MAC) && !USE_NATIVE_MUTEX_ON_MAC
-  RTC_DCHECK(IsThreadRefEqual(owning_thread_, CurrentThreadRef()));
-  RTC_DCHECK_GE(recursion_, 0);
-  --recursion_;
-  if (!recursion_)
-    owning_thread_ = 0;
-
-  if (AtomicOps::Decrement(&lock_queue_) > 0 && !recursion_)
-    dispatch_semaphore_signal(semaphore_);
-#else
-  pthread_mutex_unlock(&mutex_);
-#endif
-#endif
-}
-
-bool CriticalSection::CurrentThreadIsOwner() const {
-#if defined(WEBRTC_WIN)
-  // OwningThread has type HANDLE but actually contains the Thread ID:
-  // http://stackoverflow.com/questions/12675301/why-is-the-owningthread-member-of-critical-section-of-type-handle-when-it-is-de
-  // Converting through size_t avoids the VS 2015 warning C4312: conversion from
-  // 'type1' to 'type2' of greater size
-  return crit_.OwningThread ==
-         reinterpret_cast<HANDLE>(static_cast<size_t>(GetCurrentThreadId()));
-#else
-#if CS_DEBUG_CHECKS
-  return IsThreadRefEqual(thread_, CurrentThreadRef());
-#else
-  return true;
-#endif  // CS_DEBUG_CHECKS
-#endif
-}
-
-CritScope::CritScope(const CriticalSection* cs) : cs_(cs) { cs_->Enter(); }
-CritScope::~CritScope() { cs_->Leave(); }
-
-TryCritScope::TryCritScope(const CriticalSection* cs)
-    : cs_(cs), locked_(cs->TryEnter()) {
-  CS_DEBUG_CODE(lock_was_called_ = false);
-}
-
-TryCritScope::~TryCritScope() {
-  CS_DEBUG_CODE(RTC_DCHECK(lock_was_called_));
-  if (locked_)
-    cs_->Leave();
-}
-
-bool TryCritScope::locked() const {
-  CS_DEBUG_CODE(lock_was_called_ = true);
-  return locked_;
-}
-
-void GlobalLockPod::Lock() {
-#if !defined(WEBRTC_WIN) && (!defined(WEBRTC_MAC) || USE_NATIVE_MUTEX_ON_MAC)
-  const struct timespec ts_null = {0};
-#endif
-
-  while (AtomicOps::CompareAndSwap(&lock_acquired, 0, 1)) {
-#if defined(WEBRTC_WIN)
-    ::Sleep(0);
-#elif defined(WEBRTC_MAC) && !USE_NATIVE_MUTEX_ON_MAC
-    sched_yield();
-#else
-    nanosleep(&ts_null, nullptr);
-#endif
-  }
-}
-
-void GlobalLockPod::Unlock() {
-  int old_value = AtomicOps::CompareAndSwap(&lock_acquired, 1, 0);
-  RTC_DCHECK_EQ(1, old_value) << "Unlock called without calling Lock first";
-}
-
-GlobalLock::GlobalLock() {
-  lock_acquired = 0;
-}
-
-GlobalLockScope::GlobalLockScope(GlobalLockPod* lock)
-    : lock_(lock) {
-  lock_->Lock();
-}
-
-GlobalLockScope::~GlobalLockScope() {
-  lock_->Unlock();
-}
-
-}  // namespace rtc