简单实现LINUX C下的线程池.

本篇文章由导学宝转自：http://www.cnblogs.com/freezee/archive/2012/02/29/2373958.html

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

int i = ;
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=; 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 != )
{
DBGPRINTF_DEBUG("pthread_create error[%d].\n", i);
break;
}
}

sleep(2);

return ;
}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 = ;
for(i=; 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 ;
}/*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 ;
}/*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 ;
}int main()
{
thread_pool_create(10);
//thread_pool_create(10);     thread_pool_addtask(test_func, (void*)(1<<));
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<<));
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 ;
}

复制代码

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);

复制代码

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 ;
}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 ;
}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 ;
}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 ;
}

复制代码

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 = ;#define LEN_CMD_PATH    10struct _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 == );

*thread_control = fifopipe_control;

return ;
}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 ;
}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, );
assert(fd>);

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

return ;
}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, );
assert(fd>);

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

return ;
}

复制代码

比如:管道, 消息队列, socket, while(condition?){sleep}等等.

以上代码中, 注释的比较少.

差不多.其实我都有点不知道自己在写什么.