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Groups > comp.programming.threads > #960
| From | "aminer" <aminer@videotron.ca> |
|---|---|
| Newsgroups | comp.programming.threads, comp.programming |
| Subject | Re: About lockfree_mpmc - |
| Date | 2012-07-22 18:51 -0500 |
| Organization | A noiseless patient Spider |
| Message-ID | <jui06e$1pa$1@dont-email.me> (permalink) |
| References | <juhuo3$q5s$1@dont-email.me> <juhv62$sda$1@dont-email.me> |
Cross-posted to 2 groups.
Hello, I have inserted an mfence between line [1] and [2] in lockfree_mpmc and i have updated all my programs that uses lockfree_mpmc, and you can download all the source codes of my programs from: http://pages.videotron.com/aminer/ Sincerely, Amine Moulay Ramdane. "aminer" <aminer@videotron.ca> wrote in message news:juhv62$sda$1@dont-email.me... > > I wrote: >> So as you have noticed the processor can then reorder the loads on line >> [2] with the older >> store on line [1] and this will cause a problem, so i think i have to >> insert a load between >> line [1] and line [2]. > > > Even if i insert a load beween line [1] and [2] this will not work , > i have to insert an mfence between line [1] and [2]. > > > What do you think ? > > > Sincerely, > Amine Moulay Ramdane. > > > > > > > "aminer" <aminer@videotron.ca> wrote in message > news:juhuo3$q5s$1@dont-email.me... >> >> Hello all, >> >> I think i have discovered a problem with lockfree_mpmc: >> >> You will find the source code of lockfree_mpmc at: >> >> http://pages.videotron.com/aminer/ >> >> >> So please follow with me: >> >> If you take a look at the lockfree_mpmc , here is the source code >> of the push() method: >> >> --- >> >> function TLockfree_MPMC.push(tm : tNodeQueue):boolean; >> var lasttail,newtemp:long; >> i,j:integer; >> begin >> >> if getlength >= fsize >> then >> begin >> result:=false; >> exit; >> end; >> result:=true; >> >> newTemp:=LockedIncLong(temp); >> >> [1] lastTail:=newTemp-1; >> [2] setObject(lastTail,tm); >> >> repeat >> >> if CAS(tail,lasttail,newtemp) >> then >> begin >> exit; >> end; >> sleep(0); >> until false; >> >> end; >> >> --- >> >> As you know in the x86 architecture Loads may be reordered with older >> stores >> to different locations. >> >> So in line [2] there is a load of tail and lasttail to the registers of >> the processor >> before calling setobject() and just before on line [1] there is a store >> to lasttail. >> >> So as you have noticed the processor can then reorder the loads on line >> [2] with the older >> store on line [1] and this will cause a problem, so i think i have to >> insert a load between >> line [1] and line [2]. >> >> >> What do you think ? >> >> >> >> Sincerely, >> Amine Moulay Ramdane. >> >> > >
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About lockfree_mpmc - "aminer" <aminer@videotron.ca> - 2012-07-22 18:27 -0500
Re: About lockfree_mpmc - "aminer" <aminer@videotron.ca> - 2012-07-22 18:34 -0500
Re: About lockfree_mpmc - "aminer" <aminer@videotron.ca> - 2012-07-22 18:51 -0500
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