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Annotation of Gnu-Mach/linux/src/include/asm-i386/atomic.h, revision 1.1.1.1

1.1       root        1: #ifndef __ARCH_I386_ATOMIC__
                      2: #define __ARCH_I386_ATOMIC__
                      3: 
                      4: /*
                      5:  * Atomic operations that C can't guarantee us.  Useful for
                      6:  * resource counting etc..
                      7:  */
                      8: 
                      9: #ifdef __SMP__
                     10: #define LOCK "lock ; "
                     11: #else
                     12: #define LOCK ""
                     13: #endif
                     14: 
                     15: /*
                     16:  * Make sure gcc doesn't try to be clever and move things around
                     17:  * on us. We need to use _exactly_ the address the user gave us,
                     18:  * not some alias that contains the same information.
                     19:  */
                     20: #define __atomic_fool_gcc(x) (*(struct { int a[100]; } *)x)
                     21: 
                     22: typedef int atomic_t;
                     23: 
                     24: static __inline__ void atomic_add(atomic_t i, atomic_t *v)
                     25: {
                     26:        __asm__ __volatile__(
                     27:                LOCK "addl %1,%0"
                     28:                :"=m" (__atomic_fool_gcc(v))
                     29:                :"ir" (i), "m" (__atomic_fool_gcc(v)));
                     30: }
                     31: 
                     32: static __inline__ void atomic_sub(atomic_t i, atomic_t *v)
                     33: {
                     34:        __asm__ __volatile__(
                     35:                LOCK "subl %1,%0"
                     36:                :"=m" (__atomic_fool_gcc(v))
                     37:                :"ir" (i), "m" (__atomic_fool_gcc(v)));
                     38: }
                     39: 
                     40: static __inline__ void atomic_inc(atomic_t *v)
                     41: {
                     42:        __asm__ __volatile__(
                     43:                LOCK "incl %0"
                     44:                :"=m" (__atomic_fool_gcc(v))
                     45:                :"m" (__atomic_fool_gcc(v)));
                     46: }
                     47: 
                     48: static __inline__ void atomic_dec(atomic_t *v)
                     49: {
                     50:        __asm__ __volatile__(
                     51:                LOCK "decl %0"
                     52:                :"=m" (__atomic_fool_gcc(v))
                     53:                :"m" (__atomic_fool_gcc(v)));
                     54: }
                     55: 
                     56: static __inline__ int atomic_dec_and_test(atomic_t *v)
                     57: {
                     58:        unsigned char c;
                     59: 
                     60:        __asm__ __volatile__(
                     61:                LOCK "decl %0; sete %1"
                     62:                :"=m" (__atomic_fool_gcc(v)), "=qm" (c)
                     63:                :"m" (__atomic_fool_gcc(v)));
                     64:        return c != 0;
                     65: }
                     66: 
                     67: #endif

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