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Re: Memory not updating in thread as expected

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Test <test@.nil.invalid.com> writes:

Let's label the line numbers:

t1: str1=alloc(50);
t2: str1[0]=50;
t3: while (str1[0]==50)
    {
t4:   sleep(1);
    }
t5: tr1[0]=2; // signal main program that I'm out of teh loop and about to finish
t6: return;
 } 
> // str2 has the address of str1 in the thread, ie. (long)str1==(long)str2
m1: str2[0]=0;  // signal thread that it should exit the loop
m2: printf("%d\n",(int)str2[0]);   // "0" is shown
m3: // {int i11;for (i11=0;i11<8;i11++) printf("[%.2X]",str2[i11]);printf("\n");}
m4: while (str2[0]==0)
    { // waiting for the thread to signal it's about to finish 
m5:    printf("%d\n",(int)str2[0]);   // "50" is shown WTF??
m6:    sleep(1);
>    }
m7: printf("Done %d\n",(int)str2[0]);   // "50" is shown WTF??

Your code can easily execute in the order
t1 m1 m2 m3 m4 t2 m5

(even in the absence of issues with volatile keywords or optimization)

>
> When the main program loop started str2[0] was zero but suddenly changed to 50.
> The thread is not changing it within its loop.
> What gives? It works if I uncomment the line "{int i11;for (i1..." and get:
> 0
> [00][00][00][00][00][00][00][00]
> ..on the screen

-- 
"Erwin, have you seen the cat?" -- Mrs. Shrödinger

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Memory not updating in thread as expected Test <test@.nil.invalid.com> - 2017-02-13 12:46 +0200
  Re: Memory not updating in thread as expected m.labanowicz@gmail.com - 2017-02-13 05:18 -0800
    Re: Memory not updating in thread as expected Test <test@.nil.invalid.com> - 2017-02-13 16:25 +0200
      Re: Memory not updating in thread as expected m.labanowicz@gmail.com - 2017-02-13 10:30 -0800
        Re: Memory not updating in thread as expected Jerry Stuckle <jstucklex@attglobal.net> - 2017-02-13 14:30 -0500
  Re: Memory not updating in thread as expected m.labanowicz@gmail.com - 2017-02-13 05:46 -0800
    Re: Memory not updating in thread as expected Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-13 14:30 +0000
      Re: Memory not updating in thread as expected "Chris M. Thomasson" <invalid@invalid.invalid> - 2017-02-13 15:13 -0800
    Re: Memory not updating in thread as expected Test <test@.nil.invalid.com> - 2017-02-13 16:36 +0200
      Re: Memory not updating in thread as expected David Brown <david.brown@hesbynett.no> - 2017-02-13 23:15 +0100
        Re: Memory not updating in thread as expected James Kuyper <jameskuyper@verizon.net> - 2017-02-13 22:04 -0500
          Re: Memory not updating in thread as expected David Brown <david.brown@hesbynett.no> - 2017-02-14 09:44 +0100
            Re: Memory not updating in thread as expected Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-14 11:07 +0000
              Re: Memory not updating in thread as expected David Brown <david.brown@hesbynett.no> - 2017-02-14 12:46 +0100
                Re: Memory not updating in thread as expected Robert Wessel <robertwessel2@yahoo.com> - 2017-02-16 05:12 -0600
                Re: Memory not updating in thread as expected David Brown <david.brown@hesbynett.no> - 2017-02-16 12:44 +0100
              Re: Memory not updating in thread as expected Alain Ketterlin <alain@universite-de-strasbourg.fr.invalid> - 2017-02-14 15:53 +0100
                Re: Memory not updating in thread as expected Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-14 15:36 +0000
                Re: Memory not updating in thread as expected Alain Ketterlin <alain@universite-de-strasbourg.fr.invalid> - 2017-02-14 17:58 +0100
                Re: Memory not updating in thread as expected Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-14 17:26 +0000
          Re: Memory not updating in thread as expected Alain Ketterlin <alain@universite-de-strasbourg.fr.invalid> - 2017-02-14 10:43 +0100
            Re: Memory not updating in thread as expected Robert Wessel <robertwessel2@yahoo.com> - 2017-02-14 03:52 -0600
              Re: Memory not updating in thread as expected Alain Ketterlin <alain@universite-de-strasbourg.fr.invalid> - 2017-02-14 11:36 +0100
              Re: Memory not updating in thread as expected supercat@casperkitty.com - 2017-02-14 05:31 -0800
  Re: Memory not updating in thread as expected Ken Brody <kenbrody@spamcop.net> - 2017-02-13 12:44 -0500
  Re: Memory not updating in thread as expected Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-02-13 10:58 -0700
  Re: Memory not updating in thread as expected "Chris M. Thomasson" <invalid@invalid.invalid> - 2017-02-14 15:13 -0800
    Re: Memory not updating in thread as expected "Chris M. Thomasson" <invalid@invalid.invalid> - 2017-02-14 16:37 -0800

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