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Fig. 11 XACC code with shadow clause
Fig. 12 XACC Code with barrier_device construct
line 11, the reflect directive updates the shadow areas of the distributed array a
on the device memory.
2.5.5 barrier_device Construct
The barrier_device construct specifies an explicit barrier among devices at
the point which the construct appears.
The barrier_device construct blocks accelerator devices until all ongoing
asynchronous operations on them are completed regardless of the host operations.
Example
Figure 12 is an example of the barrier_devices construct. In lines 1–
2, the devices directives define device sets d and e. In lines 4–5, the first
barrier_device construct performs a barrier operation for all devices, and the
second one performs a barrier operation for devices in the device set e.