/** Report that the manager state has changed. This is called by the manager. */
public void managerStateChanged(Manager manager) {
Manager.State newState = manager.getState();
if (newState != _previousState) {
report(manager.getState().getDescription());
_previousState = newState;
}
}
/**
* Put a token on the queue contained in this receiver. If the queue is full, then suspend the
* calling thread (blocking write) and inform the director of the same. Resume the process on
* detecting room in the queue. If a termination is requested, then initiate the termination of
* the calling process by throwing a TerminateProcessException. On detecting a room in the queue,
* put a token in the queue. Check whether any process is blocked on a read from this receiver. If
* a process is indeed blocked, then unblock the process, and inform the director of the same.
*
* @param token The token to be put in the receiver, or null to not put anything.
* @exception NoRoomException If during initialization, capacity cannot be increased enough to
* accommodate initial tokens.
*/
public void put(Token token) throws NoRoomException {
IOPort port = getContainer();
if (port == null || token == null) {
return; // Nothing to do.
}
Workspace workspace = port.workspace();
while (!_terminate) {
int depth = 0;
try {
// NOTE: Avoid acquiring read access on the workspace
// while holding the lock on the director because if
// some other process is trying to acquire write access,
// the request for read access will be deferred.
Nameable container = getContainer().getContainer();
Manager manager = ((Actor) container).getManager();
// NOTE: This used to synchronize on this, but since it calls
// director methods that are synchronized on the director,
// this can cause deadlock.
synchronized (_director) {
// Need to check this again after acquiring the lock.
// Otherwise, could end up calling wait() below _after_
// notification has occurred.
if (_terminate) {
break;
}
// If we are in the initialization phase, then we may have
// to increase the queue capacity before proceeding. This
// may be needed to support PublisherPorts that produce
// initial tokens (or, I suppose, any actor that produces
// initial tokens during initialize()?).
if (!super.hasRoom()) {
if (container instanceof Actor) {
if (manager.getState().equals(Manager.INITIALIZING)) {
try {
_queue.setCapacity(_queue.getCapacity() + 1);
} catch (IllegalActionException e) {
throw new NoRoomException(
getContainer(),
"Failed to increase queue capacity enough to accommodate initial tokens");
}
}
}
}
// Try to write.
if (super.hasRoom()) {
super.put(token);
// If any thread is blocked on a get(), then it will become
// unblocked. Notify the director now so that there isn't a
// spurious deadlock detection.
if (_readPending != null) {
_director.threadUnblocked(_readPending, this, PNDirector.READ_BLOCKED);
_readPending = null;
}
// Normally, the _writePending reference will have
// been cleared by the read that unblocked this write.
// However, it might be that the director increased the
// buffer size, which would also have the affect of unblocking
// this write. Hence, we clear it here if it is set.
if (_writePending != null) {
_director.threadUnblocked(_writePending, this, PNDirector.WRITE_BLOCKED);
_writePending = null;
}
break;
}
// Wait to try again.
_writePending = Thread.currentThread();
_director.threadBlocked(_writePending, this, PNDirector.WRITE_BLOCKED);
// NOTE: We cannot use workspace.wait(Object) here without
// introducing a race condition, because we have to release
// the lock on the _director before calling workspace.wait(_director).
depth = workspace.releaseReadPermission();
_director.wait();
} // release lock on _director before reacquiring read permissions.
} catch (InterruptedException e) {
_terminate = true;
} finally {
if (depth > 0) {
workspace.reacquireReadPermission(depth);
}
}
}
if (_terminate) {
throw new TerminateProcessException("Process terminated.");
}
}
/**
* Report in debugging statements that the manager state has changed. This method is called if the
* referenced model is executed in another thread and the manager changes state.
*
* @param manager The manager controlling the execution.
* @see Manager#getState()
*/
public void managerStateChanged(Manager manager) {
if (_debugging) {
_debug("Referenced model manager state: " + manager.getState());
}
}
