简单实现LinuxC下的线程池.

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What I write, what I lose.

之前有点时间, 重新熟悉Linux的进程间通讯的东西.

于是想起之前项目中自己写啦个很简单的线程池.

这次想重新写下.

主要目的是用进程间或者线程间通信的阻塞/取消阻塞方法实现对线程池线程的等待作业和开始作业.

算是对这些代码的一种实践.

以上.

===================================================================

我对一个简单线程池的一些理解.

1.创建大量的线程.

2.工作线程的执行体功能为:

　　while(1)

　　{

　　　　//按照一定条件(A)阻塞.

　　　　//按照任务的参数设置开始执行任务.　

　　}

3.控制线程的功能为.

　　{

　　　　//接受新任务的参数, 一般为回调函数+参数. (为保持兼容, 我设置的格式为 (void*)(*thread_task)(void*) + void* . 跟线程创建保持形式兼容.)

　　　　//按照一定规则查找空闲的线程.

　　　　//将接受的新任务参数赋给这条线程数据体.

　　　　//解除这条线程的阻塞条件.

　　}

===================================================================

common-thread-pool.c 线程池主要实现+一个简单的测试代码.

　　　　　　　　　　　　接口没有拿出来.

thread-control.h　　　提供线程池线程的等待作业和开始作业接口.

thread-control-xxxxx.c thread-control.h的接口实现. 可以使用多种方式.

common-thread-pool.c

View Code

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <pthread.h>
#include <assert.h>
#include <sys/types.h>

#define DBGPRINTF_DEBUG printf
#define DBGPRINTF_ERROR printf

#define ASSERT  assert



#include "thread-control.h"

typedef void*(*thread_task_func)(void* arg);

/*线程执行任务的数据.*/
struct _thread_task_t
{
int taskid;                     /*任务id.*/
    thread_task_func task_func;     /*任务函数及参数*/
void* task_arg;
};
typedef struct _thread_task_t thread_task_t;

/*线程状态.*/
typedef enum
{
    ethread_status_unknown = 0,
    ethread_status_idle ,
    ethread_status_running ,
    ethread_status_terminel ,
    ethread_status_cannotuse ,
}thread_status_e;

/*线程数据.*/
struct _thread_data_t
{
int thread_id;
    pthread_t pid;
    thread_status_e status;

    thread_task_t thread_task;
    THREAD_CONTROL thread_control;
};
typedef struct _thread_data_t thread_data_t;

/*线程池数据.*/
struct _thread_pool_t
{
    thread_data_t* thread_data_set;
int num_thread;
int taskid_base;

    pthread_mutex_t thread_pool_lock;
};
typedef struct _thread_pool_t thread_pool_t;

thread_pool_t g_thread_pool;

/*设置线程状态.*/
int thread_pool_setthreadstatus(thread_data_t* thread_data, thread_status_e status)
{
    thread_pool_t* thread_pool = &g_thread_pool;
    pthread_mutex_lock(&(thread_pool->thread_pool_lock));

    thread_data->status = status;

    pthread_mutex_unlock(&(thread_pool->thread_pool_lock));

return 0;
}


/*线程池线程函数体.*/
void* thread_pool_func(void* arg)
{
    sleep(1);   //Wait pthread_t count.

    thread_data_t* thread_data = (thread_data_t*)arg;
    DBGPRINTF_DEBUG("Thread start run. Thread_id = %d, pid = 0x%x . \n", 
            thread_data->thread_id, (unsigned int)thread_data->pid); 

/*
     Continue to wait the task, then based on new task_func and task_arg to perform this task.
*/
while(1)
    {
        thread_control_wait(thread_data->thread_control);

//Need to lock? Yes.
        thread_pool_setthreadstatus(thread_data, ethread_status_running);
        DBGPRINTF_DEBUG("Task start. taskid = %d .\n", thread_data->thread_task.taskid);

        thread_data->thread_task.task_func(thread_data->thread_task.task_arg);

        DBGPRINTF_DEBUG("Task end. taskid = %d .\n", thread_data->thread_task.taskid);
//Need to lock?Yes.
        thread_pool_setthreadstatus(thread_data, ethread_status_idle);
    }

    DBGPRINTF_DEBUG("Thread end run. Thread_id = %d, pid = 0x%x . \n", 
            thread_data->thread_id, (unsigned int)thread_data->pid); 
}


int thread_task_init(thread_task_t* thread_task)
{

    thread_task->taskid             = -1;
    thread_task->task_func          = NULL;
    thread_task->task_arg           = NULL;

return 0;
}


int thread_data_init(thread_data_t* thread_data)
{
    thread_data->thread_id = -1;
    thread_data->pid = 0x0;
    thread_data->status = ethread_status_unknown ,

    thread_task_init(&(thread_data->thread_task));
    thread_control_init(&(thread_data->thread_control));

return 0;
}


int thread_pool_create(int num_thread)
{
    ASSERT(num_thread > 0 && num_thread <= 10*1024);
    thread_pool_t* thread_pool = &g_thread_pool;

int i = 0;
    thread_pool->thread_data_set = (thread_data_t*)malloc(sizeof(thread_data_t) * num_thread);
    ASSERT(thread_pool->thread_data_set != NULL);
    thread_pool->num_thread = num_thread;
    thread_pool->taskid_base = -1;
    pthread_mutex_init(&(thread_pool->thread_pool_lock), NULL);

for(i=0; i<num_thread; i++)
    {
        thread_data_t* thread_data = thread_pool->thread_data_set+i;
        thread_data_init(thread_data);
        thread_data->thread_id = i;
        thread_data->status = ethread_status_idle;

/* pthread_create set to detached. */
        pthread_attr_t attr;
        pthread_attr_init(&attr);
        pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
int ret = pthread_create(&(thread_data->pid), &attr, thread_pool_func, thread_data);
if(ret != 0)
        {
            DBGPRINTF_DEBUG("pthread_create error[%d].\n", i);
break;
        }
    }

    sleep(2);

return 0;
}




void* test_func(void* arg)
{
int t_sleep = (int)arg;
    DBGPRINTF_DEBUG("Test func. Sleep %d .\n", t_sleep);
/*
    int a[2048*1024] = {0};
    int i = 0;
    for(i=0; i<2028*1024; i++)
    {
        a[i] = i*i;
    }
    DBGPRINTF_DEBUG("a[0]=%d. \n", a[0]);
*/
    sleep(t_sleep);

    DBGPRINTF_DEBUG("Test func finished. \n");

return NULL;
}


/*查询可接收任务的线程.*/
int thread_pool_queryfree(thread_data_t** thread_data_found)
{
    *thread_data_found = NULL;
    thread_pool_t* thread_pool = &g_thread_pool;
    pthread_mutex_lock(&(thread_pool->thread_pool_lock));

int i = 0;
for(i=0; i<thread_pool->num_thread; i++)
    {
        thread_data_t* thread_data = thread_pool->thread_data_set+i;
if(thread_data->status == ethread_status_idle)
        {
            *thread_data_found = thread_data;
break;
        }
    }

    pthread_mutex_unlock(&(thread_pool->thread_pool_lock));

return 0;
}

/*分配taskid.*/
int thread_pool_gettaskid(int* taskid)
{
    thread_pool_t* thread_pool = &g_thread_pool;
    pthread_mutex_lock(&(thread_pool->thread_pool_lock));

    thread_pool->taskid_base ++;
    *taskid = thread_pool->taskid_base;

    pthread_mutex_unlock(&(thread_pool->thread_pool_lock));

return 0;
}

/*向线程池增加任务.*/
int thread_pool_addtask(thread_task_func task_func, void* arg)
{
/* Find a free thread. */
    thread_data_t* thread_data_found = NULL;
    thread_pool_queryfree(&thread_data_found);

if(thread_data_found != NULL)
    {
        DBGPRINTF_DEBUG("Thread [%d] perferm this task.\n", thread_data_found->thread_id);

/* Set task data. */
        thread_data_found->thread_task.task_func    = task_func;       
        thread_data_found->thread_task.task_arg     = arg;       
        thread_pool_gettaskid(&(thread_data_found->thread_task.taskid));

/* Start the task. */
        thread_pool_setthreadstatus(thread_data_found, ethread_status_running);
        thread_control_start(thread_data_found->thread_control);
        DBGPRINTF_DEBUG("Thread [%d] Add task[%d] finished.\n", 
                thread_data_found->thread_id, thread_data_found->thread_task.taskid);
    }
else
    {
        DBGPRINTF_ERROR("Thread pool full. Task not added.\n");
    }

return 0;
}




int main()
{
    thread_pool_create(10);
//thread_pool_create(10);
    thread_pool_addtask(test_func, (void*)(1<<0));
    thread_pool_addtask(test_func, (void*)(1<<1));
    thread_pool_addtask(test_func, (void*)(1<<2));
    thread_pool_addtask(test_func, (void*)(1<<3));
    thread_pool_addtask(test_func, (void*)(1<<4));
    thread_pool_addtask(test_func, (void*)(1<<5));
    thread_pool_addtask(test_func, (void*)(1<<6));
    thread_pool_addtask(test_func, (void*)(1<<7));

    sleep(6);
    thread_pool_addtask(test_func, (void*)(1<<0));
    thread_pool_addtask(test_func, (void*)(1<<1));
    thread_pool_addtask(test_func, (void*)(1<<2));
    thread_pool_addtask(test_func, (void*)(1<<3));
    thread_pool_addtask(test_func, (void*)(1<<4));
    thread_pool_addtask(test_func, (void*)(1<<5));
    thread_pool_addtask(test_func, (void*)(1<<6));
    thread_pool_addtask(test_func, (void*)(1<<7));

    sleep(100000);

return 0;
}

thread-control.h

View Code

#define THREAD_CONTROL  void*





int thread_control_init(THREAD_CONTROL* thread_control);
int thread_control_deinit(THREAD_CONTROL* thread_control);
int thread_control_wait(THREAD_CONTROL thread_control);
int thread_control_start(THREAD_CONTROL thread_control);

thread-control.h的接口实现. 可以使用多种方式.

只要进程间通信/线程间通信中存在阻塞等待/解除阻塞等待的都可以拿来作实验.

比如:条件变量.
thread-control-condition.c

View Code

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <pthread.h>
#include <assert.h>
#include <sys/types.h>

#define DBGPRINTF_DEBUG printf
#define DBGPRINTF_ERROR printf

#define ASSERT  assert



#include "thread-control.h"

struct _thread_control_cond_t
{
    pthread_mutex_t lock;
    pthread_cond_t condition;
};
typedef struct _thread_control_cond_t thread_control_cond_t;






int thread_control_init(THREAD_CONTROL* thread_control)
{
    *thread_control = NULL;

    thread_control_cond_t* cond = (thread_control_cond_t*)malloc(sizeof(thread_control_cond_t)); 
    assert(cond != NULL);

    pthread_mutex_init(&(cond->lock), NULL);
    pthread_cond_init(&(cond->condition), NULL);

    *thread_control = cond;

return 0;
}


int thread_control_deinit(THREAD_CONTROL* thread_control)
{

    thread_control_cond_t* cond = (thread_control_cond_t*)(*thread_control); 

    pthread_mutex_destroy(&(cond->lock));
    pthread_cond_destroy(&(cond->condition));

    free(cond);
    *thread_control = NULL;

return 0;
}


int thread_control_wait(THREAD_CONTROL thread_control)
{
    thread_control_cond_t* cond = (thread_control_cond_t*)(thread_control); 

//Wait pthread condition.
    pthread_mutex_lock(&(cond->lock));
    pthread_cond_wait(&(cond->condition), &(cond->lock));
    pthread_mutex_unlock(&(cond->lock));

return 0;
}


int thread_control_start(THREAD_CONTROL thread_control)
{
    thread_control_cond_t* cond = (thread_control_cond_t*)(thread_control); 

//start pthread condition.
    pthread_mutex_lock(&(cond->lock));
    pthread_cond_signal(&(cond->condition));
    pthread_mutex_unlock(&(cond->lock));

return 0;
}

比如:有名管道.

thread-control-fifopipe.c

View Code

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <pthread.h>
#include <assert.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>

#define DBGPRINTF_DEBUG printf
#define DBGPRINTF_ERROR printf

#define ASSERT  assert



#include "thread-control.h"

static int path_index = 0;
#define LEN_CMD_PATH    10
struct _fifopipe_control_t
{
char fifopipe_cmd_path[LEN_CMD_PATH];
};
typedef struct _fifopipe_control_t fifopipe_control_t;


int thread_control_init(THREAD_CONTROL* thread_control)
{
    *thread_control = NULL;

    fifopipe_control_t* fifopipe_control = (fifopipe_control_t*)malloc(sizeof(fifopipe_control_t));
    assert(fifopipe_control != NULL);

    path_index ++;
    snprintf(fifopipe_control->fifopipe_cmd_path, LEN_CMD_PATH, "./xxx%d", path_index);

int ret = mkfifo(fifopipe_control->fifopipe_cmd_path, 0666/*(O_CREAT | O_RDWR)*/);
    assert(ret == 0);


    *thread_control = fifopipe_control;

return 0;
}


int thread_control_deinit(THREAD_CONTROL* thread_control)
{
    fifopipe_control_t* fifopipe_control = (fifopipe_control_t*)(*thread_control);


    free(fifopipe_control);
    *thread_control = NULL;

return 0;
}


int thread_control_wait(THREAD_CONTROL thread_control)
{
    fifopipe_control_t* fifopipe_control = (fifopipe_control_t*)(thread_control);

int fd = open(fifopipe_control->fifopipe_cmd_path, O_RDONLY, 0);
    assert(fd>0);

char tmp = 0;
    read(fd, &tmp, 1);

return 0;
}


int thread_control_start(THREAD_CONTROL thread_control)
{
    fifopipe_control_t* fifopipe_control = (fifopipe_control_t*)(thread_control);

int fd = open(fifopipe_control->fifopipe_cmd_path, O_WRONLY, 0);
    assert(fd>0);

char tmp = 0;
    write(fd, &tmp, 1);

return 0;
}