Working with cainiao to learn the thread programming of the National embedded experiment

1. Thread Creation

Code:

#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

Running result:

eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.1$ makegcc -c  mythread.c -o mythread.ogcc  -o mythread mythread.o -lpthreadeastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.1$ lsMakefile  mypipe.txt  mythread  mythread.c  mythread.oeastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.1$ ./mythread member->a : 4member->s : eastmoonpthread is created...

2. Thread waiting

Code:

#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). o

 

Running result:

eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.2$makegcc -c mythread_join.c -o mythread_join.ogcc -o mythread_join mythread_join.o -lpthread eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.2$lsMakefile mythread_join mythread_join.c  mythread_join.o eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.2$./mythread_joinThis in the thread :0This in the thread :1This in the thread :2thread was exitThis in the main: 0This in the main: 1This in the main: 2

Conclusion: after running the program, the thread and process run simultaneously before thread_join is called. After thread_join is called, the process is blocked until the thread exits.

3. Thread exit Protection Design

Code:

#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  

Running result:

eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.3$makegcc -c mythread_clean.c -o mythread_clean.ogcc -o mythread_clean mythread_clean.o -lpthread eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.3$lsMakefile mythread_clean mythread_clean.c  mythread_clean.o eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.3$./mythread_cleanthread 2 startthread 2 push completecleanup: thread 2 second handlercleanup: thread 2 first handlerthread 1 startthread 1 push completethread 1 exit code 1thread 2 exit code 2 

Conclusion: According to the running results, thread 1 exits with return, so it does not run the thread cleanup function, and thread 2 exits with pthread_exit. Therefore, the thread cleanup function is executed.