/*!
\internal
*/
bool QSystemSemaphorePrivate::modifySemaphore(int count)
{
if (-1 == handle())
return false;
struct sembuf operation;
operation.sem_num = 0;
operation.sem_op = count;
operation.sem_flg = SEM_UNDO;
int res;
EINTR_LOOP(res, semop(semaphore, &operation, 1));
if (-1 == res) {
// If the semaphore was removed be nice and create it and then modifySemaphore again
if (errno == EINVAL || errno == EIDRM) {
semaphore = -1;
cleanHandle();
handle();
return modifySemaphore(count);
}
setErrorString(QLatin1String("QSystemSemaphore::modifySemaphore"));
#if defined QSYSTEMSEMAPHORE_DEBUG
qDebug() << QLatin1String("QSystemSemaphore::modify failed") << count << semctl(semaphore, 0, GETVAL) << errno << EIDRM << EINVAL;
#endif
return false;
}
clearError();
return true;
}
/*!
\internal
*/
bool QSystemSemaphorePrivate::modifySemaphore(int count)
{
#ifndef QT_POSIX_IPC
if (-1 == handle())
return false;
struct sembuf operation;
operation.sem_num = 0;
operation.sem_op = count;
operation.sem_flg = SEM_UNDO;
register int res;
EINTR_LOOP(res, semop(semaphore, &operation, 1));
if (-1 == res) {
// If the semaphore was removed be nice and create it and then modifySemaphore again
if (errno == EINVAL || errno == EIDRM) {
semaphore = -1;
cleanHandle();
handle();
return modifySemaphore(count);
}
setErrorString(QLatin1String("QSystemSemaphore::modifySemaphore"));
#ifdef QSYSTEMSEMAPHORE_DEBUG
qDebug() << QLatin1String("QSystemSemaphore::modify failed") << count << semctl(semaphore, 0, GETVAL) << errno << EIDRM << EINVAL;
#endif
return false;
}
#else
if (!handle())
return false;
if (count > 0) {
int cnt = count;
do {
if (sem_post(semaphore) == -1) {
setErrorString(QLatin1String("QSystemSemaphore::modifySemaphore (sem_post)"));
#ifdef QSYSTEMSEMAPHORE_DEBUG
qDebug() << QLatin1String("QSystemSemaphore::modify sem_post failed") << count << errno;
#endif
// rollback changes to preserve the SysV semaphore behavior
for ( ; cnt < count; ++cnt) {
register int res;
EINTR_LOOP(res, sem_wait(semaphore));
}
return false;
}
--cnt;
} while (cnt > 0);
} else {
register int res;
EINTR_LOOP(res, sem_wait(semaphore));
if (res == -1) {
// If the semaphore was removed be nice and create it and then modifySemaphore again
if (errno == EINVAL || errno == EIDRM) {
semaphore = SEM_FAILED;
return modifySemaphore(count);
}
setErrorString(QLatin1String("QSystemSemaphore::modifySemaphore (sem_wait)"));
#ifdef QSYSTEMSEMAPHORE_DEBUG
qDebug() << QLatin1String("QSystemSemaphore::modify sem_wait failed") << count << errno;
#endif
return false;
}
}
#endif // QT_POSIX_IPC
return true;
}
