src/gallium/include/pipe/p_atomic.h

   1 /**
   2  * Many similar implementations exist. See for example libwsbm
   3  * or the linux kernel include/atomic.h
   4  *
   5  * No copyright claimed on this file.
   6  *
   7  */
   8
   9 #ifndef P_ATOMIC_H
  10 #define P_ATOMIC_H
  11
  12 #include "p_defines.h"
  13 #include <stdint.h>
  14
  15 #ifdef __cplusplus
  16 extern "C" {
  17 #endif
  18
  19 #if (defined(PIPE_CC_GCC))
  20 struct pipe_atomic {
  21    int32_t count;
  22 };
  23
  24 #define p_atomic_set(_v, _i) ((_v)->count = (_i))
  25 #define p_atomic_read(_v) ((_v)->count)
  26
  27
  28 static INLINE boolean
  29 p_atomic_dec_zero(struct pipe_atomic *v)
  30 {
  31 #ifdef __i386__
  32    unsigned char c;
  33
  34    __asm__ __volatile__("lock; decl %0; sete %1":"+m"(v->count), "=qm"(c)
  35                         ::"memory");
  36
  37    return c != 0;
  38 #else  /* __i386__*/
  39    return (__sync_sub_and_fetch(&v->count, 1) == 0);
  40 #endif /* __i386__*/
  41 }
  42
  43 static INLINE void
  44 p_atomic_inc(struct pipe_atomic *v)
  45 {
  46 #ifdef __i386__
  47    __asm__ __volatile__("lock; incl %0":"+m"(v->count));
  48 #else /* __i386__*/
  49    (void) __sync_add_and_fetch(&v->count, 1);
  50 #endif /* __i386__*/
  51 }
  52
  53 static INLINE void
  54 p_atomic_dec(struct pipe_atomic *v)
  55 {
  56 #ifdef __i386__
  57    __asm__ __volatile__("lock; decl %0":"+m"(v->count));
  58 #else /* __i386__*/
  59    (void) __sync_sub_and_fetch(&v->count, 1);
  60 #endif /* __i386__*/
  61 }
  62
  63 static INLINE int32_t
  64 p_atomic_cmpxchg(struct pipe_atomic *v, int32_t old, int32_t new)
  65 {
  66    return __sync_val_compare_and_swap(&v->count, old, new);
  67 }
  68
  69 #else /* (defined(PIPE_CC_GCC)) */
  70
  71 #include "pipe/p_thread.h"
  72
  73 /**
  74  * This implementation should really not be used.
  75  * Add an assembly port instead. It may abort and
  76  * doesn't destroy used mutexes.
  77  */
  78
  79 struct pipe_atomic {
  80    pipe_mutex mutex;
  81    int32_t count;
  82 };
  83
  84 static INLINE void
  85 p_atomic_set(struct pipe_atomic *v, int32_t i)
  86 {
  87    int ret;
  88    ret = pipe_mutex_init(v->mutex);
  89    if (ret)
  90       abort();
  91    pipe_mutex_lock(v->mutex);
  92    v->count = i;
  93    pipe_mutex_unlock(v->mutex);
  94 }
  95
  96 static INLINE int32_t
  97 p_atomic_read(struct pipe_atomic *v)
  98 {
  99    int32_t ret;
 100
 101    pipe_mutex_lock(v->mutex);
 102    ret = v->count;
 103    pipe_mutex_unlock(v->mutex);
 104    return ret;
 105 }
 106
 107 static INLINE void
 108 p_atomic_inc(struct pipe_atomic *v)
 109 {
 110    pipe_mutex_lock(v->mutex);
 111    ++v->count;
 112    pipe_mutex_unlock(v->mutex);
 113 }
 114
 115 static INLINE void
 116 p_atomic_dec(struct pipe_atomic *v)
 117 {
 118    pipe_mutex_lock(v->mutex);
 119    --v->count;
 120    pipe_mutex_unlock(v->mutex);
 121 }
 122
 123 static INLINE boolean
 124 p_atomic_dec_zero(struct pipe_atomic *v)
 125 {
 126    boolean ret;
 127
 128    pipe_mutex_lock(v->mutex);
 129    ret = (--v->count == 0);
 130    pipe_mutex_unlock(v->mutex);
 131    return ret;
 132 }
 133
 134 static INLINE int32_t
 135 p_atomic_cmpxchg(struct pipe_atomic *v, int32_t old, int32_t new)
 136 {
 137    int32_t ret;
 138
 139    pipe_mutex_lock(v->mutex);
 140    ret = v->count;
 141    if (ret == old)
 142       v->count = new;
 143    pipe_mutex_unlock(v->mutex);
 144
 145    return ret;
 146 }
 147
 148 #endif /* (defined(PIPE_CC_GCC)) */
 149
 150 #ifdef __cplusplus
 151 }
 152 #endif
 153
 154 #endif /* P_ATOMIC_H */