简单实现Linux C下的线程池.
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;
}
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.