blob: 69a2c7a136b6e04a0f8095bb61704220caf653b4 [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <pthread.h>
namespace base {
class FilePath;
namespace rlz_lib {
// Creating a recursive cross-process mutex on Windows is one line. On POSIX,
// there's no primitive for that, so this lock is emulated by an in-process
// mutex to get the recursive part, followed by a cross-process lock for the
// cross-process part.
// This is a struct so that it doesn't need a static initializer.
struct RecursiveCrossProcessLock {
// Tries to acquire a recursive cross-process lock. Note that this _always_
// acquires the in-process lock (if it wasn't already acquired). The parent
// directory of |lock_file| must exist.
bool TryGetCrossProcessLock(const base::FilePath& lock_filename);
// Releases the lock. Should always be called, even if
// TryGetCrossProcessLock() returned |false|.
void ReleaseLock();
pthread_mutex_t recursive_lock_;
pthread_t locking_thread_;
int file_lock_;
// On Mac, PTHREAD_RECURSIVE_MUTEX_INITIALIZER doesn't exist before 10.7 and
// is buggy on 10.7 (,
// so emulate recursive locking with a normal non-recursive mutex.
} // namespace rlz_lib