This paper was approved at the June ISO C++ meeting.

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Document number: N4063

Date: 2014-06-20

On Parallel Invocations of Functions in Parallelism TS

by Artur Laksberg

Excerpt:

At the Issaquah meeting in February 2014, Hans Boehm raised the following issue regarding N3850 (Working Draft, Technical Specification for C++ Extensions for Parallelism):

It seems to me that the execution policies need to be a bit more precise about which calls to parameter functions they can make. Something needs to specify that sort may make parallel invocations to swap, but only if the arguments for concurrent calls don’t overlap. I didn’t quickly find such text. In general, “non-racing” calls can be made concurrently, but “racing” ones cannot.

Upon further discussion, it was decided that the resolution of this issue warrants a separate paper that can be presented for discussion in SG1 during the Rapperswil meeting.

...

This paper supersedes N3993. The discussion in Rapperswil illuminated the need for additional changes to describe the difference between read-only and mutating functons. ...