linux线程学习初步02

杀死线程的函数

int pthread_cancel(pthread_t thread);
参数介绍：需要输入的tid
返回值：识别返回 errno成功返回 0
被杀死的线程，退出状态值为一个
#define PTHREAD_CANCELED((void *)-1)

代码案例：

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>void* thr(void *arg) {while(1) {printf("I am a common thread\n");sleep(1);}return 100;
}int main() {pthread_t ptid;pthread_create(&ptid, NULL, thr, NULL);sleep(5);void *ret;pthread_cancel(ptid);int num = pthread_join(ptid, &ret);printf("num = %d, ret = %d\n",num , (int)ret);return 0;
}
``2. 线程分离函数```cppint pthread_detach(pthread_t thread);

使用了线程分离函数，该线程不用再被
pthread_join函数回收资源

代码案例：

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>
#include <string.h>void* thr(void *arg) {printf("I am a common thread  1\n");sleep(3);printf("I am a common thread  1-\n");return (void *)100;
}int main() {pthread_t ptid;pthread_create(&ptid, NULL, thr, NULL);pthread_detach(ptid);sleep(4);int ret = pthread_join(ptid, NULL);printf("ret = %d error is %s\n",ret, strerror(ret));return 0;
}

比较两个线程id是否相等

int pthread_equal(pthread_t t1, pthread_t t2);

线程id在进程内部是唯一的，但是在整个操作系统中不是唯一的

线程属性设置

初始化线程属性
int pthread_attr_init(pthread_attr_t *attr);销毁线程属性
int pthread_attr_destroy(pthread_attr_t *attr);

设置线程分离

int pthread_attr_setdetachstate(pthread_attr_t *attr, int detachstate);
参数介绍：attr:init初始化的属性detachstate：PTHREAD_CREATE_DETACHEDThreads that are created using attr will be created in a detached state.PTHREAD_CREATE_JOINABLEThreads that are created using attr will be created in a joinable state.int pthread_attr_getdetachstate(const pthread_attr_t *attr, int *detachstate);

发现，设置成为线程分离后，主线程如果先执行完了，子线程没有机会执行
代码案例：

nclude <unistd.h>
#include <pthread.h>
#include <string.h>void* thr(void *arg) {sleep(2);printf("I am a common thread  1\n");return (void *)100;
}int main() {pthread_attr_t attr;pthread_attr_init(&attr);pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);pthread_t ptid;pthread_create(&ptid, &attr, thr, NULL);printf("I am a main thread\n");pthread_attr_destroy(&attr);pthread_exit(NULL);// 如果不加这句话，自线程没有机会打印
}