QLockFile::LockError QLockFilePrivate::tryLock_sys()
{
// Assemble data, to write in a single call to write
// (otherwise we'd have to check every write call)
// Use operator% from the fast builder to avoid multiple memory allocations.
QByteArray fileData = QByteArray::number(QCoreApplication::applicationPid()) + '\n'
+ qAppName().toUtf8() + '\n'
+ localHostName().toUtf8() + '\n';
const QByteArray lockFileName = QFile::encodeName(fileName);
const int fd = qt_safe_open(lockFileName.constData(), O_WRONLY | O_CREAT | O_EXCL, 0644);
if (fd < 0) {
switch (errno) {
case EEXIST:
return QLockFile::LockFailedError;
case EACCES:
case EROFS:
return QLockFile::PermissionError;
default:
return QLockFile::UnknownError;
}
}
// Ensure nobody else can delete the file while we have it
if (!setNativeLocks(fd))
qWarning() << "setNativeLocks failed:" << strerror(errno);
// We hold the lock, continue.
fileHandle = fd;
QLockFile::LockError error = QLockFile::NoError;
if (qt_write_loop(fd, fileData.constData(), fileData.size()) < fileData.size())
error = QLockFile::UnknownError; // partition full
return error;
}
bool QLockFilePrivate::removeStaleLock()
{
const QByteArray lockFileName = QFile::encodeName(fileName);
const int fd = qt_safe_open(lockFileName.constData(), O_WRONLY, 0644);
if (fd < 0) // gone already?
return false;
bool success = setNativeLocks(fd) && (::unlink(lockFileName) == 0);
close(fd);
return success;
}
QLockFile::LockError QLockFilePrivate::tryLock_sys()
{
// Assemble data, to write in a single call to write
// (otherwise we'd have to check every write call)
// Use operator% from the fast builder to avoid multiple memory allocations.
QByteArray fileData = QByteArray::number(QCoreApplication::applicationPid()) % '\n'
% QCoreApplication::applicationName().toUtf8() % '\n'
% localHostName() % '\n';
const QByteArray lockFileName = QFile::encodeName(fileName);
const int fd = qt_safe_open(lockFileName.constData(), O_WRONLY | O_CREAT | O_EXCL, 0644);
if (fd < 0) {
switch (errno) {
case EEXIST:
return QLockFile::LockFailedError;
case EACCES:
case EROFS:
return QLockFile::PermissionError;
default:
return QLockFile::UnknownError;
}
}
// Ensure nobody else can delete the file while we have it
if (!setNativeLocks(fileName, fd)) {
const int errnoSaved = errno;
qWarning() << "setNativeLocks failed:" << qt_error_string(errnoSaved);
}
if (qt_write_loop(fd, fileData.constData(), fileData.size()) < fileData.size()) {
close(fd);
if (!QFile::remove(fileName))
qWarning("QLockFile: Could not remove our own lock file %s.", qPrintable(fileName));
return QLockFile::UnknownError; // partition full
}
// We hold the lock, continue.
fileHandle = fd;
// Sync to disk if possible. Ignore errors (e.g. not supported).
#if defined(_POSIX_SYNCHRONIZED_IO) && _POSIX_SYNCHRONIZED_IO > 0
fdatasync(fileHandle);
#else
fsync(fileHandle);
#endif
return QLockFile::NoError;
}
