基于无锁队列和c++11的高性能线程池

基于无锁队列和c++11的高性能线程池
线程使用c++11库
和线程池之间的消息通讯使用一个简单的无锁消息队列
适用于linux平台，gcc 4.6以上

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代码片段(6)[全屏查看所有代码]

1. [代码]lckfree.h

// lckfree.h

// Implementation of lock free queue using CAS operations

// for simple multi-threading use cases like:

// 1. multiple worker to process incoming messages

// 2. async processing using a thread pool

// 3. simple tcp server deal with async requests

// Author: typhoon_1986@163.com

// Refrence: http://coolshell.cn/articles/8239.html

#ifndef __LCKFREE_H__

#define __LCKFREE_H__

#include <string>

using namespace std;

namespace bfd {

struct LinkNode {

string data;

LinkNode* next;

};

typedef struct LinkNode LinkNode;

class LckFreeQueue {

public:

LckFreeQueue();

~LckFreeQueue();

int push(const string &msg);

string pop(); // non-block pop method

// string bpop(); // block pop method

bool empty();

private:

LinkNode * head_;

LinkNode * tail_;

bool empty_;

unsigned int length_;

};

} // namespace bfd

#endif

2. [代码]lckfree.cpp

#include <lckfree.h>

namespace bfd {

LckFreeQueue::LckFreeQueue(): head_(NULL), tail_(NULL), empty_(true), length_(0) {

head_ = new LinkNode;

head_->next = NULL;

tail_ = head_;

}

LckFreeQueue::~LckFreeQueue() {

LinkNode *p = head_;

if (p) {

LinkNode *q = p->next;

delete p;

p = q;

}

int LckFreeQueue::push(const string &msg) {

LinkNode * q = new LinkNode;

q->data = msg;

q->next = NULL;

LinkNode * p = tail_;

LinkNode * oldp = p;

do {

while (p->next != NULL)

p = p->next;

} while( __sync_bool_compare_and_swap(&(p->next), NULL, q) != true); //如果没有把结点链在尾上，再试

__sync_bool_compare_and_swap(&tail_, oldp, q); //置尾结点

return 0;

}

string LckFreeQueue::pop() {

LinkNode * p;

do{

p = head_;

if (p->next == NULL){

return "";

}

} while( __sync_bool_compare_and_swap(&head_, p, p->next) != true );

return p->next->data;

}

bool LckFreeQueue::empty() {

return empty_;

}

3. [代码]workthreadpool.h

// workthreadpool.h

// 一个用于将消息分发给多个进程，并使用多个进程处理的库，工作进程并不返回数据

#ifndef __WORK_THREAD_POOL__

#define __WORK_THREAD_POOL__

#include <stdio.h>

#include <thread>

#include <queue>

#include <string>

#include <vector>

#include "lckfree.h"

using namespace std;

namespace bfd {

class WorkThreadPool {

public:

WorkThreadPool(int size);

virtual ~WorkThreadPool();

// 需要子类继承并实现的函数，每个线程实际执行的内容

virtual void Init() {};

virtual void Finish() {};

virtual void Handle(const string &msg)=0;

// 将消息放入处理队列, 消息只支持string类型

int SendMessage(const string &msg);

int Start();

int Stop();

private:

void Worker();

int size_;

LckFreeQueue msg_queue_; // 线程池的协作基于这个无锁队列

vector<thread> thread_pool_;

};

} // namespace

#endif

4. [代码]workthreadpool.cpp

#include "workthreadpool.h"

#include <sstream>

#include <unistd.h>

namespace bfd {

WorkThreadPool::WorkThreadPool(int size) {

if (size <= 0) { // 最小也需要有1个线程

size_ = 1;

} else {

size_ = size;

}

WorkThreadPool::~WorkThreadPool() {

}

int WorkThreadPool::SendMessage(const string &msg) {

msg_queue_.push(msg);

return 0;

}

void WorkThreadPool::Worker() {

unsigned int msg_count = 0;

while (1) {

string msg = msg_queue_.pop();

if (msg.empty()) {

printf("no msg got, sleep for 0.1 sec\n");

usleep(100000); // 0.1 sec

continue;

}

if (msg == "__exit__") {

stringstream ss;

ss << "exit worker: " << std::this_thread::get_id() << ", processed: " << msg_count << "..";

printf("%s\n", ss.str().c_str());

return;

}

Handle(msg);

msg_count++;

if (msg_count % 1000 == 0) {

printf("every 1000 msg count\n");

}

int WorkThreadPool::Start() {

for (int i=0; i < size_; i++) {

thread_pool_.push_back( thread(&WorkThreadPool::Worker, this) );

}

return 0;

}

int WorkThreadPool::Stop() {

for (int i=0; i < size_; i++) {

SendMessage("__exit__");

}

for (int i=0; i < size_; i++) {

thread_pool_[i].join();

}

return 0;

}

5. [代码]main.cpp

#include "workthreadpool.h"

#include <sstream>

#include <math.h>

class MyThreadPool : public bfd::WorkThreadPool {

public:

MyThreadPool(int size) : bfd::WorkThreadPool(size) {

}

void Handle(const string &msg) {

stringstream ss;

ss << "worker (" << std::this_thread::get_id() << ") got msg: " << msg;

printf("%s\n", ss.str().c_str());

for (int i=0; i<=999999; i++) {

double result = sqrt(sqrt(i) / 93.234);

}

};

int main() {

printf("start running ....\n");

MyThreadPool pool(5);

pool.Start();

for (int i=0; i<100; i++) {

pool.SendMessage("msg info ----------");

}

pool.Stop();

return 0;

}

6. [代码]Makefile

LIB_SRC_FILES = src/workthreadpool.cpp src/lckfree.cpp

TEST_SRC_FILES = src/main.cpp

INCLUDE_DIR = src

STD_FLAG = -std=c++0x

all: main.o libs

g++ $(STD_FLAG) -o test_workthreadpool main.o libworkthreadpool.so -lpthread

main.o: $(TEST_SRC_FILES)

g++ $(STD_FLAG) -c $(TEST_SRC_FILES) -I$(INCLUDE_DIR)

libs: $(LIB_SRC_FILES)

g++ $(STD_FLAG) -o libworkthreadpool.so -fPIC -O2 -shared -Wl,--no-as-needed -Isrc $(LIB_SRC_FILES) -lpthread

.PHONY : clean

clean :

rm -f test_workthreadpool main.o libworkthreadpool.so