3.6 Event Method Invocations

Event method invocations vary significantly from entry method invocations in Charm++, and various forms should be used depending on where the event method is being invoked. In addition, event messages sent to an event method should be allocated specifically for an event invocation, and cannot be recycled or deleted.

There are three ways to send events within a POSE module. The first and most commonly used way involves specifying and offset in simulation time from the current time. The syntax follows:

 
aMsg = new eventMsg;
POSE_invoke(myEventMethod(aMsg), mySim, hdl, 0);

Here, we've created an eventMsg and sent it to myEventMethod, an event entry point on mySim. mySim was created at handle hdl, and we want the event to take place now, i.e. at the current simulation time, so the offset is zero.

The second way to send an event is reserved for use by non-poser objects within the module. It should not be used by posers. This version allows you to specify an absolute simulation time at which the event happens (as opposed to an offset to the current time). Since non-poser objects are not a part of the simulation, they do not have a current time, or OVT, by which to specify an offset. The syntax is nearly identical to that above, only the last parameter is an absolute time.

 
aMsg = new eventMsg;
POSE_invoke_at(myEventMethod(aMsg), mySim, hdl, 56);

Posers should not use this approach because of the risk of specifying an absolute time that is earlier than the current time on the object sending the event.

Using this method, event methods can be injected into the system from outside any module, but this is not recommended.

The third approach is useful when an object send events to itself. It is simply a slightly shorter syntax for the same thing as POSE_invoke:

 
aMsg = new eventMsg;
POSE_local_invoke(myEventMethod(aMsg), offset);