atomicvar.h

版本6.0.1
定義原子操作
使用pthread庫定義如下

/* Implementation using pthread mutex. */

#define atomicIncr(var,count) do { \
    pthread_mutex_lock(&var ## _mutex); \
    var += (count); \
    pthread_mutex_unlock(&var ## _mutex); \
} while(0)
#define atomicGetIncr(var,oldvalue_var,count) do { \
    pthread_mutex_lock(&var ## _mutex); \
    oldvalue_var = var; \
    var += (count); \
    pthread_mutex_unlock(&var ## _mutex); \
} while(0)
#define atomicDecr(var,count) do { \
    pthread_mutex_lock(&var ## _mutex); \
    var -= (count); \
    pthread_mutex_unlock(&var ## _mutex); \
} while(0)
#define atomicGet(var,dstvar) do { \
    pthread_mutex_lock(&var ## _mutex); \
    dstvar = var; \
    pthread_mutex_unlock(&var ## _mutex); \
} while(0)
#define atomicSet(var,value) do { \
    pthread_mutex_lock(&var ## _mutex); \
    var = value; \
    pthread_mutex_unlock(&var ## _mutex); \
} while(0)

使用上需要存在var名稱+_mutex後綴的mutex類型的鎖，示例如下：

 long myvar;
 pthread_mutex_t myvar_mutex;
 atomicSet(myvar,12345);
 
 long oldvalue;
 atomicGetIncr(myvar,oldvalue,1);
 doSomethingWith(oldvalue);