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
22 #include <dpl/single_instance.h>
23 #include <dpl/log/log.h>
27 #include <dpl/assert.h>
31 namespace // anonumous
33 const char *LOCK_PREFIX_PATH = "/tmp/dpl_single_instance_";
35 SingleInstance::SingleInstance()
41 SingleInstance::~SingleInstance()
43 Assert(!m_locked && "Single instance must be released before exit!");
46 bool SingleInstance::TryLock(const std::string &lockName)
48 LogPedantic("Locking single instance: " << lockName);
52 lock.l_type = F_WRLCK;
53 lock.l_whence = SEEK_SET;
58 m_fdLock = TEMP_FAILURE_RETRY(open((std::string(LOCK_PREFIX_PATH) + lockName).c_str(), O_WRONLY | O_CREAT, 0666));
61 ThrowMsg(Exception::LockError, "Cannot open single instance lock file!");
64 int result = TEMP_FAILURE_RETRY(fcntl(m_fdLock, F_SETLK, &lock));
66 // Was the instance successfuly locked ?
69 LogPedantic("Instance locked: " << lockName);
78 if (errno == EACCES || errno == EAGAIN)
80 LogPedantic("Instance is already running: " << lockName);
85 ThrowMsg(Exception::LockError, "Cannot lock single instance lock file!");
88 void SingleInstance::Release()
93 LogPedantic("Unlocking single instance");
98 lock.l_type = F_UNLCK;
99 lock.l_whence = SEEK_SET;
103 int result = TEMP_FAILURE_RETRY(fcntl(m_fdLock, F_SETLK, &lock));
105 // Was the instance successfuly unlocked ?
107 ThrowMsg(Exception::LockError, "Cannot unlock single instance lock file!");
110 if (TEMP_FAILURE_RETRY(close(m_fdLock)) == -1)
111 ThrowMsg(Exception::LockError, "Cannot close single instance lock file!");
117 LogPedantic("Instance unlocked");