Stage Scheduling Policies
- exclusive stage: at most one operation of a stage is executing at a
time. No synchronization between operations is needed. Similar to a
monitor.
- partitioned stage: invocations used a key to avoid sharing data
between operations.
- shared stage: multiple operations with sharing---need synchronization.
When a stage is activated on a processor, it executes all of its
outstanding operations.
Stages do not have to be scheduled as cohorts, but authors argue it is
natural to combine programming model with scheduling policy.
Figure 5 shows three partitioned stages