libmuscle.endpoint module

class libmuscle.endpoint.Endpoint(kernel: Reference, index: List[int], port: Identifier, slot: List[int])

Bases: object

Place that a message is sent from and to.

In the model description, we have kernels with ports connected by conduits. However, these kernels may be replicated, in which case there are many instances of them at run time. Thus, at run time there also need to be many conduit instances to connect the many kernel instances.

A conduit always connects a port on a kernel to another port on another kernel. A conduit instance connects an endpoint to another endpoint. An endpoint has the name of a kernel, its index, the name of a port on that kernel, and a slot. The kernel and port name of a sender or receiver of a conduit instance come from the corresponding conduit.

When a kernel is instantiated multiple times, the instances each have a unique index, which is a list of integers, to distinguish them from each other. Since a conduit instance connects kernel instances, each side will have an index to supply to the endpoint. The slot is an optional integer, like the index, and is passed when sending or receiving a message, and gives additional information on where to send the message.

For example, assume a single kernel named abc with port p1 which is connected to a port p2 on kernel def by a conduit, and of kernel def there are 10 instances. A message sent by abc on p1 to the fourth instance of def port p2 is sent from an endpoint with kernel abc, index [], port p1 and slot 3, and received on an endpoint with kernel def, index [3], port p2 and slot None.

Conduit instances are never actually created in the code, but Endpoints are.

instance() → Reference

Get a Reference to the instance this endpoint is on.

ref() → Reference

Express as Reference.

This yields a valid Reference of the form kernel[index].port[slot], with index and port omitted if they are zero-length.

Returns:

A Reference to this Endpoint.