Standard C Library Functions                       atomiccas(3C)



NAME
     atomiccas, atomiccas8,  atomiccasuchar,  atomiccas16,
     atomiccasushort,      atomiccas32,      atomiccasuint,
     atomiccasulong,  atomiccas64,  atomiccasptr  -  atomic
     compare and swap operations

SYNOPSIS
     #include 

     uint8t atomiccas8(volatile uint8t *target, uint8t cmp,
          uint8t newval);


     uchart atomiccasuchar(volatile uchart *target, uchart cmp,
          uchart newval);


     uint16t atomiccas16(volatile uint16t *target, uint16t cmp,
          uint16t newval);


     ushortt atomiccasushort(volatile ushortt *target, ushortt cmp,
          ushortt newval);


     uint32t atomiccas32(volatile uint32t *target, uint32t cmp,
          uint32t newval);


     uintt atomiccasuint(volatile uintt *target, uintt cmp,
          uintt newval);


     ulongt atomiccasulong(volatile ulongt *target, ulongt cmp,
          ulongt newval);


     uint64t atomiccas64(volatile uint64t *target, uint64t cmp,
          uint64t newval);


     void *atomiccasptr(volatile void *target, void *cmp,
          void *newval);


DESCRIPTION
     These functions enable a compare and swap operation to occur
     atomically. The value stored in target is compared with cmp.
     If these values are equal, the value  stored  in  target  is
     replaced  with  newval.  The  old  value stored in target is
     returned by the function  whether  or  not  the  replacement
     occurred.



SunOS 5.11          Last change: 13 May 2005                    1






Standard C Library Functions                       atomiccas(3C)



RETURN VALUES
     These functions return the old of *target.

ERORS
     No errors are defined.

ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Interface Stability          Stable                      
    
     MT-Level                     MT-Safe                     
    


SEE ALSO
     atomicadd(3C),       atomicand(3C),       atomicbits(3C),
     atomicdec(3C),        atomicinc(3C),        atomicor(3C),
     atomicswap(3C),       membarops(3C),        attributes(5),
     atomicops(9F)





























SunOS 5.11          Last change: 13 May 2005                    2