buserror on osx.4

[Franklin Kingma]

On Dec 21, 2006, at 9:59 AM, Igor Sysoev wrote:

> On Thu, 21 Dec 2006, Igor Sysoev wrote:
>
>>> (gdb) disassemble ___compare_and_swap32
>>> Dump of assembler code for function ___compare_and_swap32:
>>> 0xffff8080 <___compare_and_swap32+0>:   lwarx   r7,0,r5
>>> 0xffff8084 <___compare_and_swap32+4>:   cmplw   r7,r3
>>> 0xffff8088 <___compare_and_swap32+8>:   bne-    0xffff809c  
>>> <___compare_and_swap32+28>
>>> 0xffff808c <___compare_and_swap32+12>:  stwcx.  r4,0,r5
>>> 0xffff8090 <___compare_and_swap32+16>:  bne-    0xffff8080  
>>> <___compare_and_swap32>
>>> 0xffff8094 <___compare_and_swap32+20>:  li      r3,1
>>> 0xffff8098 <___compare_and_swap32+24>:  blr
>>> 0xffff809c <___compare_and_swap32+28>:  li      r3,0
>>> 0xffff80a0 <___compare_and_swap32+32>:  blr
>>> 0xffff80a4 <___compare_and_swap32+36>:  .long 0x0
>>> 0xffff80a8 <___compare_and_swap32+40>:  .long 0x0
>>> 0xffff80ac <___compare_and_swap32+44>:  .long 0x0
>>> 0xffff80b0 <___compare_and_swap32+48>:  .long 0x0
>>> 0xffff80b4 <___compare_and_swap32+52>:  .long 0x0
>>> 0xffff80b8 <___compare_and_swap32+56>:  .long 0x0
>>> 0xffff80bc <___compare_and_swap32+60>:  .long 0x0
>>> End of assembler dump.
>>
>> OK, then I will do atomic operation using MacOSX builtin
>> OSAtomicCompareAndSwap32Barrier()
>
> Just to be sure that OSAtomicCompareAndSwap32() does not cycle forever
> (as it may if lwarx/stwcx pair does not work) on your Mac compile
> this program:
>
> -----------
> #include <libkern/OSAtomic.h>
>
> static  int32_t  test;
>
> int main()
> {
>     int  rc;
>
>     rc = OSAtomicCompareAndSwap32(0, 1, &test);
>
>     printf("rc: %d, test: %d\n", rc, test);
> }
> -----------
>
> using
>
> cc -o q q.c
>
> and run, it should show:
>
> rc: 1, test: 1

pluks:~ franklin$ cc -o q q.c
q.c: In function 'main':
q.c:11: warning: incompatible implicit declaration of built-in  
function 'printf'
pluks:~ franklin$ ./q
rc: 1, test: 1