static int nbglGetExclusiveSceneAccess(scene_t* scene)
{
int pid = (int) getpid();
int oldPID = OPA_cas_int(&scene->attachedLock, 0, pid);
if (oldPID != 0)
{
if (mwProcessIsAlive(oldPID))
{
mw_printf("Could not get exclusive access to simulation shared segment "
"(Owned by process %d)\n",
oldPID);
return 1;
}
else
{
mw_printf("Simulation shared segment owned by dead process %d, stealing it\n",
oldPID);
/* Process is dead, steal the lock */
nbglReleaseSceneLocks(scene);
return 0;
}
}
else
{
OPA_store_int(&scene->attachedPID, 0);
return 0;
}
}
void lock() {
do {
if (OPA_cas_int(&flag, 1, 0)) break;
} while (lockint);
}