C ++ thread security blocking queue, thread blocking queue

C ++ thread security blocking queue, thread blocking queue

Blocking queue is the basic data structure of multi-thread asynchronous architecture in background development. For python and java, thread-safe blocking queues are provided. c ++ may need to implement a template by itself.

In terms of performance, I did not use the STL queue as the basic data structure, but used the cyclic array as the basic data structure. The performance should be higher than the queue, saving the need for dynamic memory allocation and recovery.

It is determined that the queue size cannot be dynamically expanded. At that time, in actual development, the appropriate queue size can be configured through stress testing.

/********************************************function: thread safe blocking queue.author: liuyidate: 2014.11.13version: 2.0********************************************/#ifndef BLOCK_QUEUE_H#define BLOCK_QUEUE_H#include <iostream>#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);}~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;}}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

// Test the program

#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;}