和菜鸟一起深入学习国嵌实验之线程编程
1、 线程创建
代码：
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <math.h>
#include <pthread.h>
struct member
{
int a;
char *s;
};
void *create(void *arg)
{
struct member *temp;
temp = (struct member *)arg;
printf("member->a : %d\n", temp->a);
printf("member->s : %s\n", temp->s);
return (void*)0;
}
int main(int argc, char *argv[])
{
int error;
pthread_t tidp;
struct member *b;
b= (struct member *)malloc(sizeof(struct member));
b->a = 4;
b->s = "eastmoon";
error = pthread_create(&tidp, NULL, create, (void*)b);
if(error)
{
printf("pthread is not create...\n");
return -1;
}
sleep(1);
printf("pthread is created...\n");
return 0;
}
Makefile:
CC = gcc
CURTDIR = $(shell pwd)
TARGET = mythread
%.o:%.c
$(CC)-c $(EXTRAFLAGS) $< -o $@
%.o:%.S
$(CC)-c $(EXTRAFLAGS) $< -o $@
.PHONY: all clean
$(TARGET): $(TARGET).o
$(CC) -o $@ $^ -lpthread
clean:
rm-rf $(TARGET) $(TARGET).o
运行结果：
eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.1$ make gcc -c mythread.c -o mythread.o gcc -o mythread mythread.o -lpthread eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.1$ ls Makefile mypipe.txt mythread mythread.c mythread.o eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.1$ ./mythread member->a : 4 member->s : eastmoon pthread is created...
2、 线程等待
代码：
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <math.h>
#include <pthread.h>
void *create(void *arg)
{
int i;
for(i = 0; i < 3; i++)
{
sleep(2);
printf("This in the thread :%d\n", i);
}
return NULL;
}
int main(int argc, char *argv[])
{
pthread_t pth;
int i, ret;
ret = pthread_create(&pth, NULL, create, NULL);
if(ret)
{
printf("pthread is not create...\n");
return -1;
}
pthread_join(pth, NULL);
printf("thread was exit\n");
for(i = 0; i < 3; i++)
{
sleep(1);
printf("This in the main: %d\n", i);
}
return 0;
}
Makefile：
CC = gcc
CURTDIR = $(shell pwd)
TARGET = mythread_join
%.o:%.c
$(CC)-c $(EXTRAFLAGS) $< -o $@
%.o:%.S
$(CC)-c $(EXTRAFLAGS) $< -o $@
.PHONY: all clean
$(TARGET): $(TARGET).o
$(CC) -o $@ $^ -lpthread
clean:
rm-rf $(TARGET) $(TARGET).o
运行结果：
eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.2$make gcc -c mythread_join.c -o mythread_join.o gcc -o mythread_join mythread_join.o -lpthread eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.2$ls Makefile mythread_join mythread_join.c mythread_join.o eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.2$./mythread_join This in the thread :0 This in the thread :1 This in the thread :2 thread was exit This in the main: 0 This in the main: 1 This in the main: 2
总结：运行程序后，在没有调用thread_join之前线程和进程是同时运行的，调用了thread_join之后进程阻塞直到线程退出。
3、 线程退出保护设计
代码:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <math.h>
#include <pthread.h>
void *clean(void *arg)
{
printf("cleanup: %s\n", (char *)arg);
return (void *)0;
}
void *thr_fn1(void *arg)
{
printf("thread 1 start \n");
pthread_cleanup_push((void *)clean, "thread 1 first handler");
pthread_cleanup_push((void *)clean, "thread 1 secondhandler");
printf("thread 1 push complete\n");
if(arg)
{
return (void*)1;
}
pthread_cleanup_pop(0);
pthread_cleanup_pop(0);
return (void *)1;
}
void *thr_fn2(void *arg)
{
printf("thread 2 start \n");
pthread_cleanup_push((void *)clean, "thread 2 first handler");
pthread_cleanup_push((void *)clean, "thread 2 secondhandler");
printf("thread 2 push complete\n");
if(arg)
{
pthread_exit((void *)2);
}
pthread_cleanup_pop(0);
pthread_cleanup_pop(0);
pthread_exit((void *)2);
}
int main(int argc, char *argv[])
{
pthread_t tid1, tid2;
int i, ret;
void *tret;
ret = pthread_create(&tid1, NULL, thr_fn1, (void *)1);
if(ret)
{
printf("pthread 1 is not create...\n");
return -1;
}
ret = pthread_create(&tid2, NULL, thr_fn2, (void *)1);
if(ret)
{
printf("pthread 2 is not create...\n");
return -1;
}
ret = pthread_join(tid1, &tret);
if(ret)
{
printf("pthread 1 join error......\n");
return -1;
}
printf("thread 1 exit code %d\n", (int)tret);
ret = pthread_join(tid2, &tret);
if(ret)
{
printf("pthread 2 join error......\n");
return -1;
}
printf("thread 2 exit code %d\n", (int)tret);
return 0;
}
Makefile：
CC = gcc
CURTDIR = $(shell pwd)
TARGET = mythread_clean
%.o:%.c
$(CC)-c $(EXTRAFLAGS) $< -o $@
%.o:%.S
$(CC)-c $(EXTRAFLAGS) $< -o $@
.PHONY: all clean
$(TARGET): $(TARGET).o
$(CC) -o $@ $^ -lpthread
clean:
rm-rf $(TARGET) $(TARGET).o
运行结果：
eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.3$make
gcc -c mythread_clean.c -o mythread_clean.o
gcc -o mythread_clean mythread_clean.o -lpthread
eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.3$ls
Makefile mythread_clean mythread_clean.c mythread_clean.o
eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.3$./mythread_clean
thread 2 start
thread 2 push complete
cleanup: thread 2 second handler
cleanup: thread 2 first handler
thread 1 start
thread 1 push complete
thread 1 exit code 1
thread 2 exit code 2
总结：由运行结果可知，线程1是return退出的，所以不运行线程清理函数，而线程2是pthread_exit退出的，所以执行了线程清理函数。
