Unable to simulate distributed functions

[m-morelli]

Background

Distributed functions modeling is a fundamental concept in modeling and simulation of distributed systems. In a Simulink model, functionality is represented by Simulink subsystems. Task blocks running onto different execution nodes (Kernels) must be able to drive the activation and termination of subsystems, regardless of how they are interconnected.

Problem Description

The current version of tres_bundle cannot simulate models where, in a path, source and sink subsystems are executed by a task on a node and the other blocks in the path are executed by a task in another node.

Consider a simple model with two Kernel blocks, each one executing one task. Tasks execute 3 functions connected in a series. Task1_1 (1st task onto the 1st kernel, red) executes the source (first) and sink (last) functions (red); Task1_2 (1st task onto the 2nd kernel, blue) executes the function in the middle between the two (blue).

At the beginning of the simulation, Simulink raises the following error:

Discussion

The above error occurs because of function-call dependency. The red subsystems Latch11 and Segment21 are driven by the same fcn-call source, leaving the middle blocks (blue) alone outside, making it impossible to execute them between the called red subsystems.