linux c/c++ 后台开发常用组件之:高性能阻塞队列

阻塞队列是后台开发中多线程异步架构的基本数据结构，像python, java 都提供线程安全的阻塞队列，c++ 可能需要自己实现一个模板。

从性能考虑，自己没有使用STL的queue作为基本数据结构，而是使用循环数组作为基本数据结构，性能应该比queue高，省去了动态内存分配和回收。

确点就是，队列大小不可动态扩展，当时实际开发中，可以通过压力测试和内存的限制，配置合适的队列大小来满足应用需求。

/********************************************function: thread safe blocking queue.author: liuyidate: 2014.11.13version: 2.0********************************************/#ifndef BLOCK_QUEUE_H#define BLOCK_QUEUE_H#include <iostream>#include <stdlib.h>#include <pthread.h>#include <sys/time.h>using namespace std;template<class T>class block_queue{public:block_queue(int max_size = 1000){if(max_size <= 0){exit(-1);}m_max_size = max_size;m_array = new T[max_size];m_size = 0;m_front = -1;m_back = -1;m_mutex = new pthread_mutex_t;m_cond = new pthread_cond_t;pthread_mutex_init(m_mutex, NULL);pthread_cond_init(m_cond, NULL);}void clear(){pthread_mutex_lock(m_mutex);m_size = 0;m_front = -1;m_back = -1;pthread_mutex_unlock(m_mutex);}~block_queue(){pthread_mutex_lock(m_mutex);if(m_array != NULL)delete  m_array;pthread_mutex_unlock(m_mutex);pthread_mutex_destroy(m_mutex);pthread_cond_destroy(m_cond);delete m_mutex;delete m_cond;}bool full()const{pthread_mutex_lock(m_mutex);if(m_size >= m_max_size){pthread_mutex_unlock(m_mutex);return true;}pthread_mutex_unlock(m_mutex);return false;}bool empty()const{pthread_mutex_lock(m_mutex);if(0 == m_size){pthread_mutex_unlock(m_mutex);return true;}pthread_mutex_unlock(m_mutex);return false;}bool front(T& value)const{pthread_mutex_lock(m_mutex);if(0 == m_size){pthread_mutex_unlock(m_mutex);return false;}value = m_array[m_front];pthread_mutex_unlock(m_mutex);return true;}bool back(T& value)const{pthread_mutex_lock(m_mutex);if(0 == m_size){pthread_mutex_unlock(m_mutex);return false;}value = m_array[m_back];pthread_mutex_unlock(m_mutex);return true;}int size()const{int tmp = 0;pthread_mutex_lock(m_mutex);tmp = m_size;pthread_mutex_unlock(m_mutex);return tmp;}int max_size()const{int tmp = 0;pthread_mutex_lock(m_mutex);tmp = m_max_size;pthread_mutex_unlock(m_mutex);return tmp;}bool push(const T& item){pthread_mutex_lock(m_mutex);if(m_size >= m_max_size){pthread_cond_broadcast(m_cond);pthread_mutex_unlock(m_mutex);return false;}m_back = (m_back + 1) % m_max_size;m_array[m_back] = item;m_size++;pthread_cond_broadcast(m_cond);pthread_mutex_unlock(m_mutex);return true;}bool pop(T& item){pthread_mutex_lock(m_mutex);while(m_size <= 0){if(0 != pthread_cond_wait(m_cond, m_mutex)){pthread_mutex_unlock(m_mutex);return false;}}m_front = (m_front + 1) % m_max_size;item = m_array[m_front];m_size--;pthread_mutex_unlock(m_mutex);return true;}bool pop(T& item, int ms_timeout){struct timespec t = {0,0};struct timeval now = {0,0};gettimeofday(&now, NULL);pthread_mutex_lock(m_mutex);if(m_size <= 0){t.tv_sec = now.tv_sec + ms_timeout/1000;t.tv_nsec = (ms_timeout % 1000)*1000;if(0 != pthread_cond_timedwait(m_cond, m_mutex, &t)){pthread_mutex_unlock(m_mutex);return false;}}if(m_size <= 0){pthread_mutex_unlock(m_mutex);return false;}m_front = (m_front + 1) % m_max_size;item = m_array[m_front];m_size--;pthread_mutex_unlock(m_mutex);return true;}private:pthread_mutex_t *m_mutex;pthread_cond_t *m_cond;T *m_array;int m_size;int m_max_size;int m_front;int m_back;};#endif

//测试程序

#include<iostream>#include"block_queue.h"using namespace std;block_queue<int> g_queue(100);void *p(void *args){sleep(1);int data = 0;for(int i = 0; i < 100; i++){g_queue.push(data++);}return NULL;}void *c(void* args){while(true){int t = 0;if(!g_queue.pop(t,1000)){cout<<"timeout"<<endl;continue;}else{cout<<t<<endl;}g_queue.pop(t);cout<<"block="<<t<<endl;}return NULL;}int main(){pthread_t id;pthread_create(&id, NULL, p, NULL);//pthread_create(&id, NULL, p, NULL);//pthread_create(&id, NULL, c, NULL);pthread_create(&id, NULL, c, NULL);for(;;)sleep(1);return 0;}