Issue 1480: Atomic fences don't have synchronizes with relation

1480. Atomic fences don't have synchronizes with relation

Section: 32.5.11 [atomics.fences] Status: C++11 Submitter: BSI Opened: 2010-08-25 Last modified: 2016-01-28

Priority: Not Prioritized

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Discussion:

Addresses GB-137

Thread fence not only establish synchronizes with relationships, there are semantics of fences that are expressed not in terms of synchronizes with relationships (for example see 32.5.4 [atomics.order] p.5). These semantics also need to apply to the use of atomic_signal_fence in a restricted way.

[Batavia: Concurrency group discussed issue, and is OK with the proposed resolution.]

[2011-02-26 Reflector discussion]

Moved to Tentatively Ready after 5 votes.

Proposed resolution:

Change 32.5.11 [atomics.fences] p. 6 as indicated:

void atomic_signal_fence(memory_order);  
6 Effects: equivalent to atomic_thread_fence(order), except that ~~synchronizes with relationships~~the resulting ordering constraints are established only between a thread and a signal handler executed in the same thread.