db2/mutex/x86.gcc

   1 /*
   2  * @(#)x86.gcc  10.3 (Sleepycat) 8/27/97
   3  *
   4  * For gcc/x86, 0 is clear, 1 is set.
   5  */
   6 #define TSL_SET(tsl) ({                                                 \
   7         register tsl_t *__l = (tsl);                                    \
   8         int __r;                                                        \
   9         asm volatile("movl $1,%%eax; lock; xchgb %1,%%al; xorl $1,%%eax"\
  10             : "=&a" (__r), "=m" (*__l)                                  \
  11             : "1" (*__l)                                                \
  12             );                                                          \
  13         __r & 1;                                                        \
  14 })
  15
  16 #define TSL_UNSET(tsl)  (*(tsl) = 0)
  17 #define TSL_INIT(tsl)   TSL_UNSET(tsl)