#include
#include
#include
#include
#include
#if 0 //预定义
char * str_accumulate(char *s)
{
static char accu[1024]={0};
strcat(accu,s);
return accu;
}
#endif
static pthread_key_t str_key; //顶一个键值
static pthread_once_t str_alloc_key_once = PTHREAD_ONCE_INIT; //用于解决键冲突
static void str_alloc_key(); //按键分配函数
static void str_alloc_destroy_accu(void *accu); //撤销按键分配函数
//处理函数
char * str_accumulate(const char *s)
{
char *accu;
pthread_once(&str_alloc_key_once,str_alloc_key); //解决按键冲突
accu = (char *)pthread_getspecific(str_key); //获取线程的私有数据地址
if(accu == NULL)
{
accu = malloc(1024); //分配1024的空间
if(accu == NULL) //如果accu为NULL则直接返回NULL
{
return NULL;
}
accu[0] = 0;
pthread_setspecific(str_key,(void *)accu); //将accu存放的数据作为键值关联
printf("Thread %lx : allocating buffer at %p\n",pthread_self(),accu); //打印输出
}
strcat (accu,s); //将accu和s字符串连接到一起
return accu;
}
//这是一个键值分派函数
static void str_alloc_key()
{
pthread_key_create(&str_key,str_alloc_destroy_accu); //创建键值
printf("Thread %lx : allocated key %d\n",pthread_self(), str_key);
}
//这是撤销键值的函数
static void str_alloc_destroy_accu(void *accu)
{
printf("Thread %lx : freeing buffer at %p\n",pthread_self(),accu);
free(accu); //释放空间
}
//线程处理函数
void *threaddeal(void *arg)
{
//该函数的主要工作是将arg的字符串和“Result of和thread连接到一起”
char *str;
str = str_accumulate("Result of ");
str = str_accumulate((char *)arg);
str = str_accumulate(" thread");
printf("Thread %lx: \"%s\" \n",pthread_self(),str);
return NULL;
}
//主函数
int main(int argc, char *argv[])
{
char *str;
pthread_t th2,th3;
str = str_accumulate("Result of ");
pthread_create(&th2,NULL,threaddeal,(void *)"first");
pthread_create(&th3,NULL,threaddeal,(void *)"second"); //建立两个线程
str = str_accumulate("initial thread");
printf("Thread %lx :\"%s\"\n",pthread_self(),str);
pthread_join(th2,NULL);
pthread_join(th3,NULL); //阻塞线程1和线程2
return 0;
}
文章标题:[Linux线程]使用线程的私有数据
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