本文实例讲述了c++线程池实现方法。分享给大家供大家参考。具体分析如下：
下面这个线程池是我在工作中用到过的，原理还是建立一个任务队列，让多个线程互斥的在队列中取出任务，然后执行，显然，队列是要加锁的
环境：ubuntu linux
文件名：locker.h
#ifndef LOCKER_H_
#define LOCKER_H_
#include "pthread.h"
class locker
{
public:
locker();
virtual ~locker();
bool lock();
void unlock();
private:
pthread_mutex_t m_mutex;
};
#endif /* LOCKER_H_ */
文件名：locker.cpp
#include "locker.h"
locker::locker()
{
pthread_mutex_init(&m_mutex, 0);
}
locker::~locker()
{
pthread_mutex_destroy(&m_mutex);
}
bool locker::lock()
{
if(0 == pthread_mutex_lock(&m_mutex))
return true;
return false;
}
void locker::unlock()
{
pthread_mutex_unlock(&m_mutex);
}
文件名：task_list.h
#ifndef TASK_LIST_H_
#define TASK_LIST_H_
#include "list"
#include "locker.h"
#include "netinet/in.h"
#include "semaphore.h"
using namespace std;
typedef void* (*THREAD_FUNC)(void*);
// 线程池中运行的任务，对于下行任务，sin中包含目的地址信息
// parm0指向发出数据的对象，parm1指向数据，parm2为数据的长度
typedef struct
{
THREAD_FUNC func;
void* parm0;
void* parm1;
void* parm2;
} task_info;
typedef list<task_info*> TASK_LIST;
typedef list<task_info*>::iterator PTASK_LIST;
class task_list
{
public:
task_list();
virtual ~task_list();
void append_task(task_info* tsk);
task_info* fetch_task();
private:
TASK_LIST m_tasklist;
locker m_lk;
sem_t m_sem;
};
#endif /* TASK_LIST_H_ */
文件名：task_list.cpp
#include "task_list.h"
task_list::task_list()
{
// Init Semaphore
sem_init(&m_sem, 0, 0);
m_tasklist.clear();
}
task_list::~task_list()
{
while(!m_tasklist.empty())
{
task_info* tr = m_tasklist.front();
m_tasklist.pop_front();
if(tr)
delete tr;
}
// Destroy Semaphore
sem_destroy(&m_sem);
}
void task_list::append_task(task_info* tsk)
{
// Lock before Modify the list
m_lk.lock();
m_tasklist.push_back(tsk);
m_lk.unlock();
// Increase the Semaphore
sem_post(&m_sem);
}
task_info* task_list::fetch_task()
{
task_info* tr = NULL;
sem_wait(&m_sem);
m_lk.lock();
tr = m_tasklist.front();
m_tasklist.pop_front();
m_lk.unlock();
return tr;
}
文件名：thread_pool.h
#ifndef THREAD_POOL_H_
#define THREAD_POOL_H_
#include "task_list.h"
#include "pthread.h"
#define DEFAULT_THREAD_COUNT 4
#define MAXIMUM_THREAD_COUNT 1000
class thread_pool
{
public:
thread_pool();
virtual ~thread_pool();
int create_threads(int n = DEFAULT_THREAD_COUNT);
void delete_threads();
void set_tasklist(task_list* plist);
void del_tasklist();
protected:
static void* thread_func(void* parm);
task_info* get_task();
private:
int m_thread_cnt;
pthread_t m_pids[MAXIMUM_THREAD_COUNT];
task_list* m_tasklist;
};
#endif /* THREAD_POOL_H_ */
文件名:thread_pool.cpp
#include "thread_pool.h"
thread_pool::thread_pool()
{
m_thread_cnt = 0;
m_tasklist = NULL;
}
thread_pool::~thread_pool()
{
delete_threads();
}
task_info* thread_pool::get_task()
{
task_info* tr;
if (m_tasklist)
{
tr = m_tasklist->fetch_task();
return tr;
}
return NULL;
}
void* thread_pool::thread_func(void* parm)
{
thread_pool *ptp = static_cast<thread_pool*> (parm);
task_info *task;
while (true)
{
task = ptp->get_task();
if (task)
{
(*task->func)(task);
//delete task; //func负责释放task_info
}
}
return NULL;
}
int thread_pool::create_threads(int n)
{
if (n > MAXIMUM_THREAD_COUNT)
n = MAXIMUM_THREAD_COUNT;
delete_threads();
for (int i = 0; i < n; i++)
{
int ret = pthread_create(&m_pids[i], NULL, thread_func, (void*) this);
if (ret != 0)
break;
m_thread_cnt++;
}
return m_thread_cnt;
}
void thread_pool::delete_threads()
{
for (int i = 0; i < m_thread_cnt; i++)
{
void* retval;
pthread_cancel(m_pids[i]);
pthread_join(m_pids[i], &retval);
}
m_thread_cnt = 0;
}
void thread_pool::set_tasklist(task_list* plist)
{
m_tasklist = plist;
}
void thread_pool::del_tasklist()
{
m_tasklist = NULL;
}
文件名：test.cpp
#include "unistd.h"
#include "stdio.h"
#include "stdlib.h"
#include "task_list.h"
#include "thread_pool.h"
void* fun(void *parm)
{
task_info* ptk = (task_info*)parm;
pid_t tid = pthread_self();
int count = (int)ptk->parm0;
printf("count=%d, tid=%d\n", count, tid);
return NULL;
}
int main()
{
int count = 0;
thread_pool tp;
task_list tl;
tp.create_threads(4 - 1);
tp.set_tasklist(&tl);
while (1)
{
task_info* pti = NULL;
pti = (task_info *) malloc(sizeof(task_info));
pti->func = fun;
pti->parm0 = (void *)count;
tl.append_task(pti);
count++;
sleep(2);
}
// printf("hello,world\n");
return 0;
}
编译运行，我是用ecplise建立的automake工程，所以只要修改一下Makefile.am就可以编译成功了
文件名:Makefile.am
bin_PROGRAMS=test
test_SOURCES=test.cpp locker.h locker.cpp \
task_list.h task_list.cpp \
thread_pool.h thread_pool.cpp
test_LDADD=-lpthread
执行结果：
count=0, tid=-1219888272 count=1, tid=-1219888272 count=2, tid=-1228280976 count=3, tid=-1236673680 count=4, tid=-1219888272 count=5, tid=-1228280976 count=6, tid=-1236673680 count=7, tid=-1219888272 count=8, tid=-1228280976 count=9, tid=-1236673680
希望本文所述对大家的C++程序设计有所帮助。
