/*!
\internal
Setup unix_key
*/
key_t QSystemLockPrivate::handle()
{
if (key.isEmpty())
return -1;
// ftok requires that an actual file exists somewhere
// If we have already made at some point in the past,
// double check that it is still there.
if (-1 != unix_key) {
int aNewunix_key = ftok(QFile::encodeName(fileName).constData(), 'Q');
if (aNewunix_key != unix_key) {
cleanHandle();
} else {
return unix_key;
}
}
// Create the file needed for ftok
#if defined(Q_OS_SYMBIAN)
int built = createUnixKeyFile(fileName);
#else
int built = QSharedMemoryPrivate::createUnixKeyFile(fileName);
#endif
if (-1 == built)
return -1;
createdFile = (1 == built);
// Get the unix key for the created file
unix_key = ftok(QFile::encodeName(fileName).constData(), 'Q');
if (-1 == unix_key) {
setErrorString(QLatin1String("QSystemLock::handle ftok"));
return -1;
}
// Get semaphore
semaphore = semget(unix_key, 1, 0666 | IPC_CREAT | IPC_EXCL);
if (-1 == semaphore) {
if (errno == EEXIST)
semaphore = semget(unix_key, 1, 0666 | IPC_CREAT);
if (-1 == semaphore) {
setErrorString(QLatin1String("QSystemLock::handle semget"));
cleanHandle();
return -1;
}
} else {
// Created semaphore, initialize value.
createdSemaphore = true;
qt_semun init_op;
init_op.val = MAX_LOCKS;
if (-1 == semctl(semaphore, 0, SETVAL, init_op)) {
setErrorString(QLatin1String("QSystemLock::handle semctl"));
cleanHandle();
return -1;
}
}
return unix_key;
}
bool QSharedMemoryPrivate::create(int size)
{
// build file if needed
bool createdFile = false;
int built = createUnixKeyFile(makePlatformSafeKey(key));
if (built == -1) {
errorString = QSharedMemory::tr("%1: unable to make key").arg(QLatin1String("QSharedMemory::handle:"));
error = QSharedMemory::KeyError;
return false;
}
if (built == 1) {
createdFile = true;
}
// get handle
if (!handle()) {
if (createdFile)
QFile::remove(makePlatformSafeKey(key));
return false;
}
// create
if (-1 == shmget(unix_key, size, 0666 | IPC_CREAT | IPC_EXCL)) {
QString function = QLatin1String("QSharedMemory::create");
switch (errno) {
case EINVAL:
errorString = QSharedMemory::tr("%1: system-imposed size restrictions").arg(QLatin1String("QSharedMemory::handle"));
error = QSharedMemory::InvalidSize;
break;
default:
setErrorString(function);
}
if (createdFile && error != QSharedMemory::AlreadyExists)
QFile::remove(makePlatformSafeKey(key));
return false;
}
return true;
}