November 14, 2010 Compiler optimization breaks multi-threaded code | ||||
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There is one question on SO which seems like a serious problem for atomic ops. http://stackoverflow.com/questions/4165149/compiler-optimization-breaks- multi-threaded-code in short: shared uint cnt; void atomicInc ( ) { uint o; while ( !cas( &cnt, o, o + 1 ) ) o = cnt; } is compile with dmd -O to something like: shared uint cnt; void atomicInc ( ) { while ( !cas( &cnt, cnt, cnt + 1 ) ) { } } see the web page for details. |
November 14, 2010 Re: Compiler optimization breaks multi-threaded code | ||||
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Posted in reply to Michal Minich | On Sunday 14 November 2010 01:04:46 Michal Minich wrote: > There is one question on SO which seems like a serious problem for atomic ops. > > http://stackoverflow.com/questions/4165149/compiler-optimization-breaks- multi-threaded-code > > in short: > > shared uint cnt; > void atomicInc ( ) { uint o; while ( !cas( &cnt, o, o + 1 ) ) o = cnt; } > > is compile with dmd -O to something like: > > shared uint cnt; > void atomicInc ( ) { while ( !cas( &cnt, cnt, cnt + 1 ) ) { } } > > see the web page for details. Please repost this to the D list and/or create bug report: http://d.puremagic.com/issues/enter_bug.cgi?product=D The Bugs list is not for posting to. It's for the bug tracker to send updates to. You sign up for it if you want to receive those updates, not to post information on bugs. - Jonathan M Davis |
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