如何在Linux下实现你的线程池(Step By Step，Pthread)

200行C代码就可以实现线程池？开玩笑吧？不，告诉你，我是认真的，200行C代码真的可以实现一个简单可用的线程池！！！

首先，你应该知道 PThread 吧，如果不知道，那你怎么穿越到我这个页面的，你应该先去看看维基，或者这个，这个，什么，你想在Windows系统下使用 pthread，那你应该去这个页面看看啦，亲！咱们先看实现代码吧，木有注释，木有例子 ^0^，下次再给例子，请留意了，今天就到这里吧～～～

 

/* * ============================================================================= * *       Filename:  tiny-threadpool.h * *    Description:  tiny threadpool implementation in c. * *        Created:  09/28/2012 07:37:30 PM * *         Author:  Fu Haiping (forhappy), [e-mail] *        Company:  ICT ( Institute Of Computing Technology, CAS ) * * ============================================================================= */#ifndef TINY_THREADPOOL_H#define TINY_THREADPOOL_H#include <pthread.h>typedef struct _tthreadpool_s tthreadpool_t;typedef struct _tthread_s tthread_t;typedef struct _tjob_s tjob_t;struct _tthreadpool_s {    tthread_t *threads;    tjob_t *jobs;    int num_jobs;    int num_threads;    pthread_mutex_t jobs_mutex;    pthread_mutex_t num_jobs_mutex;    pthread_cond_t jobs_not_empty_cond;    pthread_cond_t jobs_not_full_cond;};struct _tthread_s {    pthread_t thread_id;    tthreadpool_t *pool;    tthread_t *prev;    tthread_t *next;    int killed;};struct _tjob_s {    void (*job_function)(tjob_t *job);    void *user_data;    tjob_t *prev;    tjob_t *next;};extern inttthreadpool_init(tthreadpool_t *pool, int numWorkers);extern voidtthreadpool_shutdown(tthreadpool_t *pool);extern voidtthreadpool_add_job(tthreadpool_t *pool, tjob_t *job);extern voidtthreadpool_add_job_ex(tthreadpool_t *pool, tjob_t *job);extern voidtthreadpool_wait(tthreadpool_t *pool);#endif // TINY_THREADPOOL_H

/* * ============================================================================= * *       Filename:  tiny-threadpool.c * *    Description:  tiny threadpool implementation in c. * *        Created:  09/28/2012 07:37:20 PM * *         Author:  Fu Haiping (forhappy), [e-mail] *        Company:  ICT ( Institute Of Computing Technology, CAS ) * * ============================================================================= */#include <assert.h>#include <stdio.h>#include <stdlib.h>#include <string.h>#include "tiny-threadpool.h"#define ADD_THREAD(item, list) {     item->prev = NULL;     item->next = list;     list = item; }#define REMOVE_JOB(item, list) {     if (item->prev != NULL) item->prev->next = item->next;     if (item->next != NULL) item->next->prev = item->prev;     if (list == item) list = item->next;     item->prev = item->next = NULL; }static void *thread_function(void *ptr) {    tthread_t *thread = (tthread_t *)ptr;    tjob_t *job;    while (1) {        pthread_mutex_lock(&thread->pool->num_jobs_mutex);        pthread_mutex_lock(&thread->pool->jobs_mutex);        while (thread->pool->jobs == NULL) {            pthread_cond_wait(&thread->pool->jobs_not_empty_cond, &thread->pool->jobs_mutex);        }        job = thread->pool->jobs;        if (job != NULL) {            REMOVE_JOB(job, thread->pool->jobs);            thread->pool->num_jobs--;            pthread_cond_signal(&thread->pool->jobs_not_full_cond);        }        pthread_mutex_unlock(&thread->pool->jobs_mutex);        pthread_mutex_unlock(&thread->pool->num_jobs_mutex);        if (thread->killed) break;        if (job == NULL) continue;        job->job_function(job);    }    free(thread);    pthread_exit(NULL);}int tthreadpool_init(tthreadpool_t *pool, int num_threads) {    int i = 0;    tthread_t *thread;    pthread_cond_t blank_cond = PTHREAD_COND_INITIALIZER;    pthread_mutex_t blank_mutex = PTHREAD_MUTEX_INITIALIZER;    if (num_threads < 1) num_threads = 1;    memset(pool, 0, sizeof(*pool));    memcpy(&pool->jobs_mutex, &blank_mutex, sizeof(pool->jobs_mutex));    memcpy(&pool->num_jobs_mutex, &blank_mutex, sizeof(pool->num_jobs_mutex));    memcpy(&pool->jobs_not_empty_cond, &blank_cond, sizeof(pool->jobs_not_empty_cond));    memcpy(&pool->jobs_not_full_cond, &blank_cond, sizeof(pool->jobs_not_full_cond));    pool->num_threads = num_threads;    pool->num_jobs = 0;    for (i = 0; i < num_threads; i++) {        if ((thread = malloc(sizeof(tthread_t))) == NULL) {            fprintf(stderr, "Failed to allocate threads");            return -1;        }        memset(thread, 0, sizeof(tthread_t));        thread->pool = pool;        if (pthread_create(&thread->thread_id, NULL, thread_function, (void *)thread)) {            fprintf(stderr, "Failed to start all threads");            free(thread);            return -1;        }        ADD_THREAD(thread, thread->pool->threads);    }    return 0;}void tthreadpool_shutdown(tthreadpool_t *pool) {    tthread_t *thread = NULL;    for (thread = pool->threads; thread != NULL; thread = thread->next) {        thread->killed = 1;    }    pthread_mutex_lock(&pool->jobs_mutex);    pool->threads = NULL;    pool->jobs = NULL;    pthread_cond_broadcast(&pool->jobs_not_empty_cond);    pthread_mutex_unlock(&pool->jobs_mutex);}void tthreadpool_add_job(tthreadpool_t *pool, tjob_t *job) {    pthread_mutex_lock(&pool->jobs_mutex);    ADD_THREAD(job, pool->jobs);    pthread_cond_signal(&pool->jobs_not_empty_cond);    pthread_mutex_unlock(&pool->jobs_mutex);}void tthreadpool_add_job_ex(tthreadpool_t *pool, tjob_t *job) {    pthread_mutex_lock(&pool->jobs_mutex);    while(pool->num_jobs == 2 * pool->num_threads) {        pthread_cond_wait(&pool->jobs_not_full_cond, &pool->jobs_mutex);    }        ADD_THREAD(job, pool->jobs);    pool->num_jobs++;    pthread_cond_signal(&pool->jobs_not_empty_cond);    pthread_mutex_unlock(&pool->jobs_mutex);}void tthreadpool_wait(tthreadpool_t *pool) {    tthread_t *thread = NULL;    for (thread = pool->threads; thread != NULL; thread = thread->next) {        pthread_join(thread->thread_id, NULL);    }}