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#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; }