C++線程池的簡略完成辦法。本站提示廣大學習愛好者:(C++線程池的簡略完成辦法)文章只能為提供參考,不一定能成為您想要的結果。以下是C++線程池的簡略完成辦法正文
本文以實例情勢較為具體的講述了C++線程池的簡略完成辦法。分享給年夜家供年夜家參考之用。詳細辦法以下:
1、幾個根本的線程函數:
1.線程把持函數:
int pthread_create(pthread_t *tidp, const pthread_attr_t *attr, (void*)(*start_rtn)(void *), void *arg); //創立 void pthread_exit(void *retval); //終止本身 int pthread_cancel(pthread_t tid); //終止其他.發送終止旌旗燈號後目的線程紛歧定終止,要挪用join函數期待 int pthread_join(pthread_t tid, void **retval); //壅塞並期待其他線程
2.屬性:
int pthread_attr_init(pthread_attr_t *attr); //初始化屬性 int pthread_attr_setdetachstate(pthread_attr_t *attr, int detachstate); //設置分別狀況 int pthread_attr_destroy(pthread_attr_t *attr); //燒毀屬性
3.同步函數
互斥鎖
int pthread_mutex_init(pthread_mutex_t *restrict mutex, const pthread_mutexattr_t *restrict attr); //初始化鎖 int pthread_mutex_destroy(pthread_mutex_t *mutex); //燒毀鎖 int pthread_mutex_lock(pthread_mutex_t *mutex); //加鎖 int pthread_mutex_trylock(pthread_mutex_t *mutex); //測驗考試加鎖,下面lock的非壅塞版本 int pthread_mutex_unlock(pthread_mutex_t *mutex); //解鎖
4.前提變量
int pthread_cond_init(pthread_cond_t *cv, const pthread_condattr_t *cattr); //初始化 int pthread_cond_destroy(pthread_cond_t *cond); //燒毀 int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex); //期待前提 int pthread_cond_signal(pthread_cond_t *cond); //告訴,叫醒第一個挪用pthread_cond_wait()而進入眠眠的線程
5.對象函數
int pthread_equal(pthread_t t1, pthread_t t2); //比擬線程ID int pthread_detach(pthread_t tid); //分別線程 pthread_t pthread_self(void); //本身ID
上述代碼中,線程的cancel和join,和最初的對象函數,這些函數的參數都為構造體變量,其他的函數參數都是構造體變量指針;咀嚼一下,參數為指針的,由於都須要轉變構造體的內容,而參數為通俗變量的,則只須要讀內容便可。
2、線程池代碼:
#include <stdio.h> #include <stdlib.h> #include <pthread.h> //linux情況中多線程的頭文件,非C說話尺度庫,編譯時最初要加 -lpthread 挪用靜態鏈接庫 //任務鏈表的構造 typedef struct worker { void *(*process)(void *arg); //任務函數 void *arg; //函數的參數 struct worker *next; }CThread_worker; //線程池的構造 typedef struct { pthread_mutex_t queue_lock; //互斥鎖 pthread_cond_t queue_ready; //前提變量/旌旗燈號量 CThread_worker *queue_head; //指向任務鏈表的頭結點,臨界區 int cur_queue_size; //記載鏈表中任務的數目,臨界區 int max_thread_num; //最年夜線程數 pthread_t *threadid; //線程ID int shutdown; //開關 }CThread_pool; static CThread_pool *pool = NULL; //一個線程池變量 int pool_add_worker(void *(*process)(void *arg), void *arg); //擔任向任務鏈表中添加任務 void *thread_routine(void *arg); //線程例程 //線程池初始化 void pool_init(int max_thread_num) { int i = 0; pool = (CThread_pool *) malloc (sizeof(CThread_pool)); //創立線程池 pthread_mutex_init(&(pool->queue_lock), NULL); //互斥鎖初始化,參數為鎖的地址 pthread_cond_init( &(pool->queue_ready), NULL); //前提變量初始化,參數為變量地址 pool->queue_head = NULL; pool->cur_queue_size = 0; pool->max_thread_num = max_thread_num; pool->threadid = (pthread_t *) malloc(max_thread_num * sizeof(pthread_t)); for (i = 0; i < max_thread_num; i++) { pthread_create(&(pool->threadid[i]), NULL, thread_routine, NULL); //創立線程, 參數為線程ID變量地址、屬性、例程、參數 } pool->shutdown = 0; } //例程,挪用詳細的任務函數 void *thread_routine(void *arg) { printf("starting thread 0x%x\n", (int)pthread_self()); while(1) { pthread_mutex_lock(&(pool->queue_lock)); //從任務鏈表中取任務,要先加互斥鎖,參數為鎖地址 while(pool->cur_queue_size == 0 && !pool->shutdown) { //鏈表為空 printf("thread 0x%x is waiting\n", (int)pthread_self()); pthread_cond_wait(&(pool->queue_ready), &(pool->queue_lock)); //期待資本,旌旗燈號量用於告訴。會釋放第二個參數的鎖,以供添加;函數前往時從新加鎖。 } if(pool->shutdown) { pthread_mutex_unlock(&(pool->queue_lock)); //停止開關開啟,釋放鎖並加入線程 printf("thread 0x%x will exit\n", (int)pthread_self()); pthread_exit(NULL); //參數為void * } printf("thread 0x%x is starting to work\n", (int)pthread_self()); --pool->cur_queue_size; CThread_worker *worker = pool->queue_head; pool->queue_head = worker->next; pthread_mutex_unlock (&(pool->queue_lock)); //獲得一個任務後釋放鎖 (*(worker->process))(worker->arg); //唱工作 free(worker); worker = NULL; } pthread_exit(NULL); } //燒毀線程池 int pool_destroy() { if(pool->shutdown) //檢測停止開關能否開啟,若開啟,則一切線程會主動加入 return -1; pool->shutdown = 1; pthread_cond_broadcast( &(pool->queue_ready) ); //播送,叫醒一切線程,預備加入 int i; for(i = 0; i < pool->max_thread_num; ++i) pthread_join(pool->threadid[i], NULL); //主線程期待一切線程加入,只要join第一個參數不是指針,第二個參數類型是void **,吸收exit的前往值,須要強迫轉換 free(pool->threadid); CThread_worker *head = NULL; while(pool->queue_head != NULL) { //釋放未履行的任務鏈表殘剩結點 head = pool->queue_head; pool->queue_head = pool->queue_head->next; free(head); } pthread_mutex_destroy(&(pool->queue_lock)); //燒毀鎖和前提變量 pthread_cond_destroy(&(pool->queue_ready)); free(pool); pool=NULL; return 0; } void *myprocess(void *arg) { printf("threadid is 0x%x, working on task %d\n", (int)pthread_self(), *(int*)arg); sleep (1); return NULL; } //添加任務 int pool_add_worker(void *(*process)(void *arg), void *arg) { CThread_worker *newworker = (CThread_worker *) malloc(sizeof(CThread_worker)); newworker->process = process; //詳細的任務函數 newworker->arg = arg; newworker->next = NULL; pthread_mutex_lock( &(pool->queue_lock) ); //加鎖 CThread_worker *member = pool->queue_head; //拔出鏈表尾部 if( member != NULL ) { while( member->next != NULL ) member = member->next; member->next = newworker; } else { pool->queue_head = newworker; } ++pool->cur_queue_size; pthread_mutex_unlock( &(pool->queue_lock) ); //解鎖 pthread_cond_signal( &(pool->queue_ready) ); //告訴一個期待的線程 return 0; } int main(int argc, char **argv) { pool_init(3); //主線程創立線程池,3個線程 int *workingnum = (int *) malloc(sizeof(int) * 10); int i; for(i = 0; i < 10; ++i) { workingnum[i] = i; pool_add_worker(myprocess, &workingnum[i]); //主線程擔任添加任務,10個任務 } sleep (5); pool_destroy(); //燒毀線程池 free (workingnum); return 0; }
願望本文所述對年夜家的C++法式設計有所贊助。