零散知识.
1.线程id--- 进程id的类型是pid_t, 线程id的类型是pthread_t;
比较两个线程id：
#include <pthread.h>
int pthread_equal ( pthread_t tid1, pthread_t tid2 );
获得自身的线程id：
pthread_t pthread_self(void)
2.线程创建
int pthread_create( pthread_t *restrict tidp, const pthread_attr_t *restrict attr,
void *(*start_rtn)(void *), void *restrict arg );
接下来是打印线程id的例子：
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <pthread.h>
pthread_t ntid;
void printids(const char *s){
pid_t pid;
pthread_t tid;
pid = getpid();
tid = pthread_self();
printf("%s pid %u tid %u (0x%x)n",s, (unsigned int)pid,
(unsigned int)tid, (unsigned int) tid);
}
void *thr_fn(void *arg){
printids("new thread: ");
return ((void*)0);
}
int main(){
int err = 0;
err = pthread_create(&ntid, NULL, thr_fn, NULL);
//err = pthread_create(&ntid, NULL, thr_fn, NULL);
if(err!=0){
printf("%sn", strerror(err) );
}
printids("main thread:");
sleep(1);
exit(0);
}
使用ubuntu,eclipse编译,提示找不到pthread_create. 头文件是定义了,但是没有连接线程库. 需要设置eclipse. 选择工程--属性--c、c build--settings---gcc c linker---libraries, 添加库 pthread. 再次编译运行.ok.
main thread: pid 2164 tid 3079145152 (0xb78806c0)
new thread: pid 2164 tid 3079142256 (0xb787fb70)
3、线程终止
void *thr_fn1(void *arg){
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printf("thread 1 returningn");
return ((void* )1);
}
void *thr_fn2(void *arg){
printf("thread 2 exitingn");
pthread_exit((void *)1);
}
int main(){
int err;
pthread_t tid1, tid2;
void *tret;
err = pthread_create(&tid1, NULL, thr_fn1, NULL);
if( err != 0){
printf("can''t create thread 1:%sn", strerror(err));
}
err = pthread_create(&tid2, NULL, thr_fn2, NULL);
if( err!=0){
printf("can''t create thread 2:%sn", strerror(err));
}
err = pthread_join(tid1, &tret);
if(err!=0){
printf("can''t join with thread 1:%sn", strerror(err));
}
printf(" thread 1 exit code %dn", (int)tret);
err = pthread_join(tid2, &tret);
if(err!=0){
printf("can''t join eith thread 2:%sn", strerror(err));
}
printf("thread 2 exit code %dn", (int)tret);
exit(0);
}
本文出自 “今年我们二十三四” 博客,请务必保留此出处http://no001.blog.51cto.com/1142339/541779
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