pthread线程编程常用API

<pre name="code" class="cpp"><p>自己写共享控制</p><p>#include <stdio.h></p>#include <unistd.h>#include <stdlib.h>#include <pthread.h>//基本的共享变量交互void *thread_function(void *arg);int run_now = 1;char message[] = "Hello World";int main() {    int res;    pthread_t a_thread;    void *thread_result;    int print_count1 = 0;    res = pthread_create(&a_thread, NULL, thread_function, (void *)message);    if (res != 0) {        perror("Thread creation failed");        exit(EXIT_FAILURE);    }    while(print_count1++ < 20) {        if (run_now == 1) {            printf("1");            run_now = 2;        }        else {            sleep(1);        }    }    printf("\nWaiting for thread to finish...\n");    res = pthread_join(a_thread, &thread_result);    if (res != 0) {        perror("Thread join failed");        exit(EXIT_FAILURE);    }    printf("Thread joined\n");    exit(EXIT_SUCCESS);}void *thread_function(void *arg) {    int print_count2 = 0;    while(print_count2++ < 20) {        if (run_now == 2) {            printf("2");            run_now = 1;        }        else {            sleep(1);        }    }    sleep(3);}

信号量的使用

<pre name="code" class="cpp">#include <stdio.h>#include <unistd.h>#include <stdlib.h>#include <string.h>#include <pthread.h>#include <semaphore.h>void *thread_function(void *arg);sem_t bin_sem;#define WORK_SIZE 1024char work_area[WORK_SIZE];int main() {    int res;    pthread_t a_thread;    void *thread_result;    res = sem_init(&bin_sem, 0, 0);    if (res != 0) {        perror("Semaphore initialization failed");        exit(EXIT_FAILURE);    }    res = pthread_create(&a_thread, NULL, thread_function, NULL);    if (res != 0) {        perror("Thread creation failed");        exit(EXIT_FAILURE);    }    printf("Input some text. Enter 'end' to finish\n");    while(strncmp("end", work_area, 3) != 0) {        fgets(work_area, WORK_SIZE, stdin);        sem_post(&bin_sem);    }    printf("\nWaiting for thread to finish...\n");    res = pthread_join(a_thread, &thread_result);    if (res != 0) {        perror("Thread join failed");        exit(EXIT_FAILURE);    }    printf("Thread joined\n");    sem_destroy(&bin_sem);    exit(EXIT_SUCCESS);}void *thread_function(void *arg) {    sem_wait(&bin_sem);    while(strncmp("end", work_area, 3) != 0) {        printf("You input %d characters\n", strlen(work_area) -1);        sem_wait(&bin_sem);    }    pthread_exit(NULL);}

互斥量的使用

<pre name="code" class="cpp">#include <stdio.h>#include <unistd.h>#include <stdlib.h>#include <string.h>#include <pthread.h>#include <semaphore.h>void *thread_function(void *arg);pthread_mutex_t work_mutex; /* protects both work_area and time_to_exit */#define WORK_SIZE 1024char work_area[WORK_SIZE];int time_to_exit = 0;int main() {    int res;    pthread_t a_thread;    void *thread_result;    res = pthread_mutex_init(&work_mutex, NULL);    if (res != 0) {        perror("Mutex initialization failed");        exit(EXIT_FAILURE);    }    res = pthread_create(&a_thread, NULL, thread_function, NULL);    if (res != 0) {        perror("Thread creation failed");        exit(EXIT_FAILURE);    }    pthread_mutex_lock(&work_mutex);    printf("Input some text. Enter 'end' to finish\n");    while(!time_to_exit) {        fgets(work_area, WORK_SIZE, stdin);        pthread_mutex_unlock(&work_mutex);        while(1) {            pthread_mutex_lock(&work_mutex);            if (work_area[0] != '\0') {                pthread_mutex_unlock(&work_mutex);                sleep(1);            }            else {                break;            }        }    }    pthread_mutex_unlock(&work_mutex);    printf("\nWaiting for thread to finish...\n");    res = pthread_join(a_thread, &thread_result);    if (res != 0) {        perror("Thread join failed");        exit(EXIT_FAILURE);    }    printf("Thread joined\n");    pthread_mutex_destroy(&work_mutex);    exit(EXIT_SUCCESS);}void *thread_function(void *arg) {    sleep(1);    pthread_mutex_lock(&work_mutex);    while(strncmp("end", work_area, 3) != 0) {        printf("You input %d characters\n", strlen(work_area) -1);        work_area[0] = '\0';        pthread_mutex_unlock(&work_mutex);        sleep(1);        pthread_mutex_lock(&work_mutex);        while (work_area[0] == '\0' ) {            pthread_mutex_unlock(&work_mutex);            sleep(1);            pthread_mutex_lock(&work_mutex);        }    }    time_to_exit = 1;    work_area[0] = '\0';    pthread_mutex_unlock(&work_mutex);    pthread_exit(0);}

条件变量的使用

#include <pthread.h>  #include <stdio.h>  #include <stdlib.h>  pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;/*初始化互斥锁*/  pthread_cond_t cond = PTHREAD_COND_INITIALIZER;/*初始化条件变量*/  void *thread1(void *);  void *thread2(void *);  int i=1;  int main(void)  {      pthread_t t_a;      pthread_t t_b;      pthread_create(&t_a,NULL,thread1,(void *)NULL);/*创建进程t_a*/      pthread_create(&t_b,NULL,thread2,(void *)NULL); /*创建进程t_b*/      pthread_join(t_a, NULL);/*等待进程t_a结束*/      pthread_join(t_b, NULL);/*等待进程t_b结束*/      pthread_mutex_destroy(&mutex);      pthread_cond_destroy(&cond);      exit(0);  }  void *thread1(void *junk)  {      for(i=1;i<=6;i++)      {          pthread_mutex_lock(&mutex);/*锁住互斥量*/          printf("thread1: lock %d/n", __LINE__);          if(i%3==0){              printf("thread1:signal 1  %d/n", __LINE__);              pthread_cond_signal(&cond);/*条件改变，发送信号，通知t_b进程*/              printf("thread1:signal 2  %d/n", __LINE__);              sleep(1);          }          pthread_mutex_unlock(&mutex);/*解锁互斥量*/          printf("thread1: unlock %d/n/n", __LINE__);          sleep(1);      }  }  void *thread2(void *junk)  {      while(i<6)      {          pthread_mutex_lock(&mutex);          printf("thread2: lock %d/n", __LINE__);          if(i%3!=0){              printf("thread2: wait 1  %d/n", __LINE__);              pthread_cond_wait(&cond,&mutex);/*解锁mutex，并等待cond改变*/              printf("thread2: wait 2  %d/n", __LINE__);          }          pthread_mutex_unlock(&mutex);          printf("thread2: unlock %d/n/n", __LINE__);          sleep(1);      }  }  

线程属性的设置

<pre name="code" class="cpp">#include <stdio.h>#include <unistd.h>#include <stdlib.h>#include <pthread.h>void *thread_function(void *arg);char message[] = "Hello World";int thread_finished = 0;int main() {    int res;    pthread_t a_thread;    void *thread_result;    pthread_attr_t thread_attr;    res = pthread_attr_init(&thread_attr);    if (res != 0) {        perror("Attribute creation failed");        exit(EXIT_FAILURE);    }    res = pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED);    if (res != 0) {        perror("Setting detached attribute failed");        exit(EXIT_FAILURE);    }    res = pthread_create(&a_thread, &thread_attr, thread_function, (void *)message);    if (res != 0) {        perror("Thread creation failed");        exit(EXIT_FAILURE);    }    //       while(!thread_finished) {        printf("Waiting for thread to say it's finished...\n");        sleep(1);    }     (void)pthread_attr_destroy(&thread_attr);    printf("Other thread finished, bye!\n");    exit(EXIT_SUCCESS);}void *thread_function(void *arg) {    printf("thread_function is running. Argument was %s\n", (char *)arg);    sleep(4);    printf("Second thread setting finished flag, and exiting now\n");    thread_finished = 1;    pthread_exit(NULL);}

多线程的管理

<pre name="code" class="cpp">#include <stdio.h>#include <unistd.h>#include <stdlib.h>#include <pthread.h>#define NUM_THREADS 6 //创建6个线程void *thread_function(void *arg);int main() {    int res;    pthread_t a_thread[NUM_THREADS];    void *thread_result;    int lots_of_threads;    for(lots_of_threads = 0; lots_of_threads < NUM_THREADS; lots_of_threads++) {        res = pthread_create(&(a_thread[lots_of_threads]), NULL, thread_function, (void *)&lots_of_threads);        if (res != 0) {            perror("Thread creation failed");            exit(EXIT_FAILURE);        }        sleep(1);    }    printf("Waiting for threads to finish...\n");    for(lots_of_threads = NUM_THREADS - 1; lots_of_threads >= 0; lots_of_threads--) { //从后往前join        res = pthread_join(a_thread[lots_of_threads], &thread_result);        if (res == 0) {            printf("Picked up a thread\n");        }        else {            perror("pthread_join failed");        }    }    printf("All done\n");    exit(EXIT_SUCCESS);}void *thread_function(void *arg) {    int my_number = *(int *)arg;    int rand_num;    printf("thread_function is running. Argument was %d\n", my_number);    rand_num=1+(int)(9.0*rand()/(RAND_MAX+1.0)); //1到10之间    //printf("RAND_MAX:%d\n", RAND_MAX);    sleep(rand_num);    printf("Bye from %d\n", my_number);    pthread_exit(NULL);}

线程的局部存储

<pre name="code" class="cpp">#include <stdio.h>#include <pthread.h>//#include <malloc.h>#include <stdlib.h>static pthread_key_t thread_log_key;void write_to_thread_log( char const * message ){        FILE * thread_log = ( FILE * )pthread_getspecific( thread_log_key );        fprintf( thread_log, "%s/n", message );}void close_thread_log( void * thread_log ){        fclose( ( FILE * )thread_log );}void * thread_function( void * args ){        char thread_log_filename[ 20 ];        FILE* thread_log;        sprintf( thread_log_filename, "thread%d.log", ( int )pthread_self() );        thread_log = fopen( thread_log_filename, "w" );        pthread_setspecific( thread_log_key, thread_log );        write_to_thread_log( "Thread starting." );        return NULL;}int main(){        int i;        pthread_t threads[5];        pthread_key_create( &thread_log_key, close_thread_log );        for ( i = 0; i < 5; ++i )        {                pthread_create( &(threads[i]), NULL, thread_function, NULL );        }        for ( i = 0; i < 5; ++i )        {                pthread_join( threads[i], NULL );        }        //注意close_thread_log将会在各个线程结束的时候执行，和delete无关。        pthread_key_delete(thread_log_key);        return 0;}