2 * Copyright (c) 2011 Samsung Electronics Co., Ltd All Rights Reserved
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 * @file single_instance.cpp
18 * @author Przemyslaw Dobrowolski (p.dobrowolsk@samsung.com)
20 * @brief This file is the implementation file of single instance
23 #include <dpl/single_instance.h>
24 #include <dpl/log/log.h>
28 #include <dpl/assert.h>
32 namespace // anonumous
34 const char *LOCK_PREFIX_PATH = "/tmp/dpl_single_instance_";
36 SingleInstance::SingleInstance()
42 SingleInstance::~SingleInstance()
44 Assert(!m_locked && "Single instance must be released before exit!");
47 bool SingleInstance::TryLock(const std::string &lockName)
49 LogPedantic("Locking single instance: " << lockName);
53 lock.l_type = F_WRLCK;
54 lock.l_whence = SEEK_SET;
59 m_fdLock = TEMP_FAILURE_RETRY(open((std::string(LOCK_PREFIX_PATH) + lockName).c_str(), O_WRONLY | O_CREAT, 0666));
62 ThrowMsg(Exception::LockError, "Cannot open single instance lock file!");
65 int result = TEMP_FAILURE_RETRY(fcntl(m_fdLock, F_SETLK, &lock));
67 // Was the instance successfuly locked ?
70 LogPedantic("Instance locked: " << lockName);
79 if (errno == EACCES || errno == EAGAIN)
81 LogPedantic("Instance is already running: " << lockName);
86 ThrowMsg(Exception::LockError, "Cannot lock single instance lock file!");
89 void SingleInstance::Release()
94 LogPedantic("Unlocking single instance");
99 lock.l_type = F_UNLCK;
100 lock.l_whence = SEEK_SET;
104 int result = TEMP_FAILURE_RETRY(fcntl(m_fdLock, F_SETLK, &lock));
106 // Was the instance successfuly unlocked ?
108 ThrowMsg(Exception::LockError, "Cannot unlock single instance lock file!");
111 if (TEMP_FAILURE_RETRY(close(m_fdLock)) == -1)
112 ThrowMsg(Exception::LockError, "Cannot close single instance lock file!");
118 LogPedantic("Instance unlocked");