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Re: [Cross post: prog+asm+c]thread problem: one write, many read

Cross-posted to 3 groups.

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"io_x" <a@b.c.invalid> ha scritto nel messaggio
news:4f83ef7f$0$1378$4fafbaef@reader2.news.tin.it...
>>> there is one buffer, only one thread write,
>>> many threads read that buffer
>>>
>>> what is the best solution for this problem for the x86 cpu?
>>> How do you useful express that using the C language? :) i'm not ot
>>>
>>> i think it is this: [because i believe it is possible many
>>> threads can read one peace of memory in the same time...]
> unsigned32bits   v=0, mem=0;
>
> thread write:
/* atomic++mem means:
 1) if mem has the lockWrite counter!=0 wait()
 2) if the lockWrite counter == 0
     increment lockWrire counter for mem
       increment mem 1
     decrement lockWrire counter for mem
 3) if thread read it when lockWrite counter !=0
    that thread read the before [or the pass?] value
    of mem
 4) if mem==-1  inc mem is seg fault
 */
 atomic++mem;
 wait(&v, 0);
 write(buffer, len)
 atomic--mem;


 threads read:
 /*waitLockWrite(&mem)
    wait until mem is 0, in the same time mem is 0
             lock it only for write <=>
             increment the lock_write counter for mem
  is this operation possible?
  unlockWrite(&mem);
      decrement the lock_write counter
 */
 waitLockWrite(&mem); atomic++v; unlockWrite(&mem);
 read(buffer, len)
                atomic--v;

> where are deadLock and how to find them?
> Do you know the right primitive for get threads go ok?
>
> thank you

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[Cross post: prog+asm+c]thread problem: one write, many read "io_x" <a@b.c.invalid> - 2012-04-10 08:24 +0200
  Re: [Cross post: prog+asm+c]thread problem: one write, many read "io_x" <a@b.c.invalid> - 2012-04-10 08:42 +0200
    Re: [Cross post: prog+asm+c]thread problem: one write, many read "io_x" <a@b.c.invalid> - 2012-04-10 10:34 +0200
      Re: [Cross post: prog+asm+c]thread problem: one write, many read "io_x" <a@b.c.invalid> - 2012-04-10 11:26 +0200
        Re: [Cross post: prog+asm+c]thread problem: one write, many read "io_x" <a@b.c.invalid> - 2012-04-10 12:56 +0200
          Re: [Cross post: prog+asm+c]thread problem: one write, many read "io_x" <a@b.c.invalid> - 2012-04-14 07:20 +0200
            Re: [Cross post: prog+asm+c]thread problem: one write, many read "io_x" <a@b.c.invalid> - 2012-04-15 08:04 +0200
  Re: [Cross post: prog+asm+c]thread problem: one write, many read "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2012-04-10 10:01 +0200
  Re: thread problem: one write, many read "christian.bau" <christian.bau@cbau.wanadoo.co.uk> - 2012-04-13 17:13 -0700
    Re: thread problem: one write, many read "io_x" <a@b.c.invalid> - 2012-04-14 10:56 +0200

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