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//
// NamedMutex_UNIX.cpp
//
// Library: Foundation
// Package: Processes
// Module: NamedMutex
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#include "Poco/NamedMutex_UNIX.h"
#include "Poco/Format.h"
#include "Poco/Exception.h"
#include <fcntl.h>
#include <sys/stat.h>
#include <errno.h>
#if defined(sun) || defined(__APPLE__) || defined(__osf__) || defined(_AIX)
#include <semaphore.h>
#else
#include <unistd.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#endif
namespace Poco {
#if (POCO_OS == POCO_OS_LINUX) || (POCO_OS == POCO_OS_ANDROID) || (POCO_OS == POCO_OS_CYGWIN) || (POCO_OS == POCO_OS_FREE_BSD)
union semun
{
int val;
struct semid_ds* buf;
unsigned short int* array;
struct seminfo* __buf;
};
#elif (POCO_OS == POCO_OS_HPUX)
union semun
{
int val;
struct semid_ds* buf;
ushort* array;
};
#endif
NamedMutexImpl::NamedMutexImpl(const std::string& name):
_name(name)
{
std::string fileName = getFileName();
#if defined(sun) || defined(__APPLE__) || defined(__osf__) || defined(__QNX__) || defined(_AIX)
_sem = sem_open(fileName.c_str(), O_CREAT, S_IRWXU | S_IRWXG | S_IRWXO, 1);
if ((long) _sem == (long) SEM_FAILED)
throw SystemException(Poco::format("cannot create named mutex %s (sem_open() failed, errno=%d)", fileName, errno), _name);
#else
int fd = open(fileName.c_str(), O_RDONLY | O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
if (fd != -1)
close(fd);
else
throw SystemException(Poco::format("cannot create named mutex %s (lockfile)", fileName), _name);
key_t key = ftok(fileName.c_str(), 'p');
if (key == -1)
throw SystemException(Poco::format("cannot create named mutex %s (ftok() failed, errno=%d)", fileName, errno), _name);
_semid = semget(key, 1, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH | IPC_CREAT | IPC_EXCL);
if (_semid >= 0)
{
union semun arg;
arg.val = 1;
semctl(_semid, 0, SETVAL, arg);
_owned = true;
return;
}
else if (errno == EEXIST)
{
_semid = semget(key, 1, 0);
_owned = false;
if (_semid >= 0) return;
}
throw SystemException(Poco::format("cannot create named mutex %s (semget() failed, errno=%d)", fileName, errno), _name);
#endif // defined(sun) || defined(__APPLE__) || defined(__osf__) || defined(__QNX__) || defined(_AIX)
}
NamedMutexImpl::~NamedMutexImpl()
{
#if defined(sun) || defined(__APPLE__) || defined(__osf__) || defined(__QNX__) || defined(_AIX)
sem_close(_sem);
#else
if (_owned) semctl(_semid, 0, IPC_RMID, 0);
#endif
}
void NamedMutexImpl::lockImpl()
{
#if defined(sun) || defined(__APPLE__) || defined(__osf__) || defined(__QNX__) || defined(_AIX)
int err;
do
{
err = sem_wait(_sem);
}
while (err && errno == EINTR);
if (err) throw SystemException("cannot lock named mutex", _name);
#else
struct sembuf op;
op.sem_num = 0;
op.sem_op = -1;
op.sem_flg = SEM_UNDO;
int err;
do
{
err = semop(_semid, &op, 1);
}
while (err && errno == EINTR);
if (err) throw SystemException("cannot lock named mutex", _name);
#endif
}
bool NamedMutexImpl::tryLockImpl()
{
#if defined(sun) || defined(__APPLE__) || defined(__osf__) || defined(__QNX__) || defined(_AIX)
return sem_trywait(_sem) == 0;
#else
struct sembuf op;
op.sem_num = 0;
op.sem_op = -1;
op.sem_flg = SEM_UNDO | IPC_NOWAIT;
return semop(_semid, &op, 1) == 0;
#endif
}
void NamedMutexImpl::unlockImpl()
{
#if defined(sun) || defined(__APPLE__) || defined(__osf__) || defined(__QNX__) || defined(_AIX)
if (sem_post(_sem) != 0)
throw SystemException("cannot unlock named mutex", _name);
#else
struct sembuf op;
op.sem_num = 0;
op.sem_op = 1;
op.sem_flg = SEM_UNDO;
if (semop(_semid, &op, 1) != 0)
throw SystemException("cannot unlock named mutex", _name);
#endif
}
std::string NamedMutexImpl::getFileName()
{
#if defined(sun) || defined(__APPLE__) || defined(__QNX__)
std::string fn = "/";
#else
std::string fn = "/tmp/";
#endif
fn.append(_name);
fn.append(".mutex");
return fn;
}
} // namespace Poco
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