• Michal Minich (11/11) Nov 14 2010 There is one question on SO which seems like a serious problem for atomi...
• Jonathan M Davis (7/24) Nov 14 2010 Please repost this to the D list and/or create bug report:

Michal Minich <michal.minich gmail.com> writes:

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.

Jonathan M Davis <jmdavisProg gmx.com> writes:

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

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- Jonathan M Davis