When to use throw/catch events and send/receive tasks

The following table is a quick guide to which kind of inter-process communication mechanism you should use in various circumstances:

	Throw/catch message events	Throw/catch signal events	Send/receive tasks
Ability to attach a boundary event to catch errors	No	No	Yes
Asynchronous	Either	Yes	Yes
Invoked process becomes a ...	Child	Child	Peer
The process you want to invoke starts with a ...	Catch message event or receive task that creates an instance	Catch signal event	Receive task
You know who the receiver is at design time	Yes	No	Yes
You want to send the 'message' to ... receivers	One	Any number	One
Failure of called process propagates to calling process*	No	No	Yes

Note

Propagation of failures will be covered in Chapter 4, Handling Exceptions.