| // Copyright 2010-2015, Google Inc. |
| // All rights reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #ifndef MOZC_BASE_PROCESS_MUTEX_H_ |
| #define MOZC_BASE_PROCESS_MUTEX_H_ |
| |
| #include <string> |
| |
| #ifdef OS_WIN |
| #include "base/scoped_handle.h" |
| #endif // OS_WIN |
| |
| #include "base/port.h" |
| |
| // Process-wide named mutex class: |
| // Make a simple process-wide named mutex using file locking. |
| // Useful to prevent a process from being instantiated twice or more. |
| // |
| // Example: |
| // ProcessMutex foo("foo"); |
| // if (!foo.Lock()) { |
| // process foo is already running |
| // exit(-1); |
| // } |
| // |
| // foo.Lock(); |
| // /* process named "foo" is never instatiated inside this block */ |
| // foo.Unlock(); |
| |
| namespace mozc { |
| |
| class ProcessMutex { |
| public: |
| explicit ProcessMutex(const char *name); |
| ~ProcessMutex(); |
| |
| // return false if the process is already locked |
| bool Lock(); |
| |
| // Lock the mutex file and write some message to this file |
| bool LockAndWrite(const string &message); |
| |
| // always return true at this moment. |
| bool UnLock(); |
| |
| // return lock filename |
| // filename: <user_profile>/.lock.<name> |
| const string &lock_filename() const { |
| return filename_; |
| } |
| |
| void set_lock_filename(const string &filename) { |
| filename_ = filename; |
| } |
| |
| bool locked() const { |
| return locked_; |
| } |
| |
| private: |
| #ifdef OS_WIN |
| ScopedHandle handle_; |
| #endif |
| |
| // TODO(yukawa): Remove this flag as it can always be determined by other |
| // internal state. |
| bool locked_; |
| string filename_; |
| |
| DISALLOW_COPY_AND_ASSIGN(ProcessMutex); |
| }; |
| |
| } // namespace mozc |
| |
| #endif // MOZC_BASE_PROCESS_MUTEX_H_ |