十个线程写作打印4个文件的C代码实现

打印要求：

建立10个线程，编号为0~9，分别打印4个文件A.txt，B.txt，C.txt，D.txt
每个文件要求打印100行内容，以/r/n作为行分隔符。
其中，A.txt的内容如下：
Thread 1 print
Thread 2 print
Thread 3 print
Thread 4 print
Thread 5 print
Thread 6 print
Thread 7 print
Thread 8 print
Thread 9 print
Thread 0 print
Thread 1 print
Thread 2 print
Thread 3 print
...
Thread 0 print

B.txt的内容如下：
Thread 0 print
Thread 9 print
Thread 8 print
Thread 7 print
Thread 6 print
Thread 5 print
Thread 4 print
Thread 3 print
Thread 2 print
Thread 1 print
Thread 0 print
Thread 9 print
Thread 8 print
...
Thread 1 print

C.txt的内容如下：
Thread 1 print
Thread 3 print
Thread 5 print
Thread 7 print
Thread 9 print
Thread 1 print
Thread 3 print
...
Thread 9 print

D.txt的内容如下：
Thread 2 print
Thread 4 print
Thread 6 print
Thread 8 print
Thread 0 print
Thread 2 print
Thread 4 print
...
Thread 0 print

 

代码实现

编写过程中，遇到的主要问题是信号丢失问题。

后来用了定时锁定，过了时间后自动解除阻塞，程序继续运行。

可以避免线程之间下入死锁的局面。

#include <stdio.h>#include <pthread.h>#include <time.h>#include <sys/timeb.h>#defineMAX_LINE_NUM 10000pthread_t thread[10];pthread_mutex_tthread_mutex[10];pthread_cond_t condition[10];intprint_queue[10][4];pthread_mutex_t file_a_mutex;pthread_mutex_t file_b_mutex;pthread_mutex_t file_c_mutex;pthread_mutex_t file_d_mutex;int file_a_thread_no;int file_b_thread_no;int file_c_thread_no;int file_d_thread_no;int print_a_times = 0;int print_b_times = 0;int print_c_times = 0;int print_d_times = 0;FILE *file_a_writer;FILE *file_b_writer;FILE *file_c_writer;FILE *file_d_writer;void *print_file(void *p_t_index){int thread_index = *(int *)p_t_index;int file_a_over= 0;int file_b_over= 0;int file_c_over= 0;int file_d_over= 0;int block_ret_status;struct timespec block_end_time;printf("Thread [%d] create/n", thread_index);while(1){printf("Thread [%d] wait for lock/n", thread_index);pthread_mutex_lock(&thread_mutex[thread_index]);block_end_time.tv_sec = time(NULL) + 1;block_end_time.tv_nsec = 0;printf("Thread [%d] wait for condition/n", thread_index);block_ret_status = pthread_cond_timedwait(&condition[thread_index], &thread_mutex[thread_index], &block_end_time);if(block_ret_status == 0){printf("Thread [%d] get condition/n", thread_index);}else{printf("Thread [%d] wait for condition timeout/n", thread_index);}/*****************************print A.txt*****************************************///printf("Thread [%d] try lock,A/n", thread_index);if(0 == pthread_mutex_trylock(&file_a_mutex)){//printf("Thread [%d] get lock,print no[%d],A/n", thread_index, file_a_thread_no);if(MAX_LINE_NUM <= print_a_times){file_a_over = 1;}else{if(thread_index == file_a_thread_no){fprintf(file_a_writer, "Thread [%d] print A/r/n", thread_index);fflush(file_a_writer);file_a_thread_no = (file_a_thread_no + 1) % 10;//printf("Thread [%d] print A,signal thead[%d]/r/n", thread_index, file_a_thread_no);print_a_times++;}}}//sleep(1);printf("Signal thread[%d],A/r/n", file_a_thread_no);pthread_cond_signal(&condition[file_a_thread_no]);pthread_mutex_unlock(&file_a_mutex);/*****************************print B.txt*****************************************///printf("Thread [%d] try lock,B/n", thread_index);if(0 == pthread_mutex_trylock(&file_b_mutex)){//printf("Thread [%d] get lock,print no[%d],A/n", thread_index, file_b_thread_no);if(MAX_LINE_NUM <= print_b_times){file_b_over = 1;}else{if(thread_index == file_b_thread_no){fprintf(file_b_writer, "Thread [%d] print B/r/n", thread_index);fflush(file_b_writer);file_b_thread_no = (file_b_thread_no + 10 - 1) % 10;//printf("Thread [%d] print B,signal thead[%d]/r/n", thread_index, file_b_thread_no);print_b_times++;}}}//sleep(1);printf("Signal thread[%d],B/r/n", file_b_thread_no);pthread_cond_signal(&condition[file_b_thread_no]);pthread_mutex_unlock(&file_b_mutex);/*****************************print C.txt*****************************************///printf("Thread [%d] try lock,C/n", thread_index);if(0 == pthread_mutex_trylock(&file_c_mutex)){//printf("Thread [%d] get lock,print no[%d],C/n", thread_index, file_c_thread_no);if(MAX_LINE_NUM <= print_c_times){file_c_over = 1;}else{if(thread_index == file_c_thread_no){fprintf(file_c_writer, "Thread [%d] print C/r/n", thread_index);fflush(file_c_writer);file_c_thread_no = (file_c_thread_no + 2) % 10;//printf("Thread [%d] print C,signal thead[%d]/r/n", thread_index, file_c_thread_no);print_c_times++;}}}//sleep(1);printf("Signal thread[%d],C/r/n", file_c_thread_no);pthread_cond_signal(&condition[file_c_thread_no]);pthread_mutex_unlock(&file_c_mutex);/*****************************print D.txt*****************************************///printf("Thread [%d] try lock,D/n", thread_index);if(0 == pthread_mutex_trylock(&file_d_mutex)){//printf("Thread [%d] get lock,print no[%d],D/n", thread_index, file_d_thread_no);if(MAX_LINE_NUM <= print_d_times){file_d_over = 1;}else{if(thread_index == file_d_thread_no){fprintf(file_d_writer, "Thread [%d] print D/r/n", thread_index);fflush(file_d_writer);file_d_thread_no = (file_d_thread_no + 2) % 10;//printf("Thread [%d] print D,signal thead[%d]/r/n", thread_index, file_d_thread_no);print_d_times++;}}}//sleep(1);printf("Signal thread[%d],D/r/n", file_d_thread_no);pthread_cond_signal(&condition[file_d_thread_no]);pthread_mutex_unlock(&file_d_mutex);printf("Thread [%d] unlock/n", thread_index);pthread_mutex_unlock(&thread_mutex[thread_index]);if(file_a_over && file_b_over && file_c_over && file_d_over){int index = 0;for(;index < 10;index++){pthread_cond_signal(&condition[index]);}printf("Thread [%d] exit/n", thread_index);pthread_exit(NULL);} }}int main(){int thread_index = 0;structtimebbegin_time_p;structtm*begin_time_m;structtimebend_time_p;structtm*end_time_m;file_a_writer = fopen("A.txt", "ab+");file_b_writer = fopen("B.txt", "ab+");file_c_writer = fopen("C.txt", "ab+");file_d_writer = fopen("D.txt", "ab+");ftime(&begin_time_p);begin_time_m = localtime(&(begin_time_p.time));pthread_mutex_init(&file_a_mutex, NULL);pthread_mutex_init(&file_b_mutex, NULL);pthread_mutex_init(&file_c_mutex, NULL);pthread_mutex_init(&file_d_mutex, NULL);file_a_thread_no = 1;file_b_thread_no = 0;file_c_thread_no = 1;file_d_thread_no = 2;for(thread_index = 0; thread_index < 10; thread_index++){ pthread_attr_t tattr;int thread_init_res = 0;pthread_attr_setschedpolicy(&tattr, SCHED_RR);thread_init_res = pthread_create(&thread[thread_index], &tattr, print_file, (void *)&thread_index);pthread_cond_init(&condition[thread_index], NULL);pthread_mutex_init(&thread_mutex[thread_index], NULL);}printf("before thread condition signal!/n");pthread_cond_signal(&condition[0]);pthread_cond_signal(&condition[1]);pthread_cond_signal(&condition[1]);pthread_cond_signal(&condition[2]);for(thread_index = 0; thread_index < 10; thread_index++){ pthread_join(thread[thread_index], NULL);}ftime(&end_time_p);end_time_m = localtime(&(end_time_p.time));printf("Time Cost[%4d-%2d-%2d %2d:%2d:%2d:%2d]/n", end_time_m->tm_year - begin_time_m->tm_year,end_time_m->tm_mon - begin_time_m->tm_mon,end_time_m->tm_mday - begin_time_m->tm_mday, end_time_m->tm_hour - begin_time_m->tm_hour,end_time_m->tm_min - begin_time_m->tm_min,end_time_m->tm_sec - begin_time_m->tm_sec);getchar();return 0;}