Quelle Mutex.cpp Sprache: C

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "threading/Mutex.h"

using namespace js;

#ifdef DEBUG

MOZ_THREAD_LOCAL(js::Mutex*) js::Mutex::HeldMutexStack;

/* static */
bool js::Mutex::Init() { return HeldMutexStack.init(); }

void js::Mutex::lock() {
  preLockChecks();
  impl_.lock();
  postLockChecks();
}

bool js::Mutex::tryLock() {
  preLockChecks();
  if (!impl_.tryLock()) {
    return false;
  }

  postLockChecks();
  return true;
}

void js::Mutex::preLockChecks() const {
  Mutex* prev = HeldMutexStack.get();
  if (prev) {
    if (id_.order <= prev->id_.order) {
      fprintf(stderr,
              "Attempt to acquire mutex %s with order %u while holding %s with "
              "order %u\n",
              id_.name, id_.order, prev->id_.name, prev->id_.order);
      MOZ_CRASH("Mutex ordering violation");
    }
  }
}

void js::Mutex::postLockChecks() {
  MOZ_ASSERT(!owningThread_);
  owningThread_ = ThreadId::ThisThreadId();

  MOZ_ASSERT(prev_ == nullptr);
  prev_ = HeldMutexStack.get();
  HeldMutexStack.set(this);
}

void js::Mutex::unlock() {
  preUnlockChecks();
  impl_.unlock();
}

void js::Mutex::preUnlockChecks() {
  Mutex* stack = HeldMutexStack.get();
  MOZ_ASSERT(stack == this);
  HeldMutexStack.set(prev_);
  prev_ = nullptr;

  MOZ_ASSERT(ThreadId::ThisThreadId() == owningThread_);
  owningThread_ = ThreadId();
}

void js::Mutex::assertOwnedByCurrentThread() const {
  // This check is only thread-safe if it succeeds.
  MOZ_ASSERT(ThreadId::ThisThreadId() == owningThread_);

  MOZ_ASSERT(isOwnedByCurrentThread());
}

bool js::Mutex::isOwnedByCurrentThread() const {
  // Check whether the mutex is on the thread-local mutex stack.
  for (Mutex* mutex = HeldMutexStack.get(); mutex; mutex = mutex->prev_) {
    if (mutex == this) {
      return true;
    }
  }

  return false;
}

#endif

quality96%

¤ Dauer der Verarbeitung: 0.14 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.