Epsilon and EM-4
Epsilon and EM-4 execute instructions from a thread consecutively.
The circular pipeline of fine-grain dataflow is retained.
However, the matching unit has to be enhanced with a mechanism that, after firing the first instruction of a thread, delays matching of further tokens in favor of consecutive issuing of all instructions of the started thread.
Example: strongly connected arc model (EM-4):
- each arc of the dataflow graph is classified as either a normal arc or a strongly connected arc
- The set of nodes that are connected by strongly connected arcs is called strongly connected block.
- such a block is fired if its source nodes are enabled
- the instructions in the block executed successively
Problem: implementation of an efficient synchronization mechanism