目录
条件变量函数
等待条件满足
阻塞队列
升级版
信号量
POSIX信号量
环形队列
条件变量函数
等待条件满足
int pthread_cond_wait(pthread_cond_t *restrict cond,pthread_mutex_t *restrict mutex); 参数： cond：要在这个条件变量上等待 mutex：互斥量，后面详细解释 pthread_cond_wait：第二个参数必须是正在使用的互斥锁
a.pthread_cond_wait：该函数调用时，会以原子性的方式将锁释放，并将自己挂起
b.pthread_cond_wait：该函数被唤醒返回的时候，会自动从新获取锁
阻塞队列
blockqueue.hpp
#pragma once
#include<iostream>
#include<string>
#include<queue>
#include<unistd.h>
#include<pthread.h>using namespace std;
static const int gmaxcap=5;
template<class T>
class BlockQueue
{
public:BlockQueue(const int& maxcap=gmaxcap):_maxcap(maxcap){pthread_mutex_init(&_mutex,nullptr);pthread_cond_init(&_pcond,nullptr);pthread_cond_init(&_ccond,nullptr);}void push(const T& in){pthread_mutex_lock(&_mutex);while (is_full())pthread_cond_wait(&_pcond,&_mutex);//生产条件不满足_q.push(in);//阻塞队列中一定有数据pthread_cond_signal(&_ccond);pthread_mutex_unlock(&_mutex);}void pop(T* out){pthread_mutex_lock(&_mutex);while(is_empty)pthread_cond_wait(&_ccond,&_mutex);*out=_q.front();_q.pop();//队列中一定有一个空位置pthread_cond_signal(&_pcond);pthread_mutex_unlock(&_mutex);}~BlockQueue(){pthread_mutex_destroy(&_mutex);pthread_cond_destroy(&_pcond);pthread_cond_destroy(&_ccond);}
private:bool is_empty(){return _q.empty();}bool is_full(){return _q.size()==_maxcap;}
private:queue<T> _q;int _maxcap;pthread_mutex_t _mutex;pthread_cond_t _pcond;//生产者对应的条件变量pthread_cond_t _ccond;
};task.hpp
#pragma once
#include<iostream>
#include<cstdio>
#include<string>
#include<functional>using namespace std;
class Task
{using func_t=function<int(int,int,char)>;
public:Task(){}Task(int x,int y,char op,func_t func):_x(x),_y(y),_op(op),_callback(func){}string operator()(){int result=_callback(_x,_y,_op);char buffer[1024];snprintf(buffer,sizeof buffer,"%d %c %d = %d ",_x,_op,_y,result);return buffer;}string toTaskString(){char buffer[1024];snprintf(buffer,sizeof buffer,"%d %c %d = ? ",_x,_op,_y);return buffer;}
private:int _x;int _y;char _op;func_t _callback;
};升级版
blockqueue.hpp
#pragma once
#include<iostream>
#include<string>
#include<queue>
#include<unistd.h>
#include<pthread.h>using namespace std;
static const int gmaxcap=5;
template<class T>
class BlockQueue
{
public:BlockQueue(const int& maxcap=gmaxcap):_maxcap(maxcap){pthread_mutex_init(&_mutex,nullptr);pthread_cond_init(&_pcond,nullptr);pthread_cond_init(&_ccond,nullptr);}void push(const T& in){pthread_mutex_lock(&_mutex);while (is_full())pthread_cond_wait(&_pcond,&_mutex);//生产条件不满足_q.push(in);//阻塞队列中一定有数据pthread_cond_signal(&_ccond);pthread_mutex_unlock(&_mutex);}void pop(T* out){pthread_mutex_lock(&_mutex);while(is_empty)pthread_cond_wait(&_ccond,&_mutex);*out=_q.front();_q.pop();//队列中一定有一个空位置pthread_cond_signal(&_pcond);pthread_mutex_unlock(&_mutex);}~BlockQueue(){pthread_mutex_destroy(&_mutex);pthread_cond_destroy(&_pcond);pthread_cond_destroy(&_ccond);}
private:bool is_empty(){return _q.empty();}bool is_full(){return _q.size()==_maxcap;}
private:queue<T> _q;int _maxcap;pthread_mutex_t _mutex;pthread_cond_t _pcond;//生产者对应的条件变量pthread_cond_t _ccond;
};task.hpp
#pragma once
#include<iostream>
#include<cstdio>
#include<string>
#include<functional>using namespace std;
class CalTask
{using func_t=function<int(int,int,char)>;
public:CalTask(){}CalTask(int x,int y,char op,func_t func):_x(x),_y(y),_op(op),_callback(func){}string operator()(){int result=_callback(_x,_y,_op);char buffer[1024];snprintf(buffer,sizeof buffer,"%d %c %d = %d ",_x,_op,_y,result);return buffer;}string toTaskString(){char buffer[1024];snprintf(buffer,sizeof buffer,"%d %c %d = ? ",_x,_op,_y);return buffer;}
private:int _x;int _y;char _op;func_t _callback;
};
const string oper="+-*/%";
int mymath(int x,int y,char op)
{int result=0;switch (op){case '+':result=x+y;break;case '-':result=x-y;break;case '*':result=x*y;break;case '/':{if(y==0){cerr<<"div zero error!"<<endl;result=-1;} else result=x/y;}break;case '%':{if(y==0){cerr<<"div zero error!"<<endl;result=-1;} else result=x%y;}break;default:break;}return result;
}
class SaveTask
{typedef function<void(const string&)> func_t;
public:SaveTask(){}SaveTask(const string& message,func_t func):_message(message),_func(func){}void operator()(){_func(_message);}
private:string _message;func_t _func;
};
void Save(const string& message)
{const string target="./log.txt";FILE* fp=fopen(target.c_str(),"a+");if(!fp){cerr<<"fopen error"<<endl;return;}fputs(message.c_str(),fp);fputs("\n",fp);fclose(fp);
}MainCp.cc
#include"BlockQueue.hpp"
#include"task.hpp"
#include<sys/types.h>
#include<unistd.h>
#include<ctime>//
//
template<class C,class S>
class BlockQueues
{public:BlockQueue<C>* c_bq;BlockQueue<S>* s_bq;
};
void* consumer(void* bqs_)
{BlockQueue<CalTask>* bq=(static_cast<BlockQueues<CalTask,SaveTask>* >(bqs_))->c_bq;BlockQueue<SaveTask>* save_bq=(static_cast<BlockQueues<CalTask,SaveTask>* >(bqs_))->s_bq;while(true){/* consumer */// int data;// bq->pop(&data);CalTask t;bq->pop(&t);string result=t();cout<<"消费数据: "<<result<<endl;SaveTask save(result,Save);save_bq->push(save);cout<<"推送保存任务完成..."<<endl;sleep(1);}return nullptr;
}
void* producter(void* bqs_)
{BlockQueue<CalTask>* bq=(static_cast<BlockQueues<CalTask,SaveTask>* >(bqs_))->c_bq;while (true){//producerint x=rand()%10+1;int y=rand()%5;int operCode=rand()%oper.size();CalTask t(x,y,oper[operCode],mymath);bq->push(t);cout<<"生产任务: "<<t.toTaskString()<<endl;// sleep(1);}return nullptr;
}
void* saver(void* bqs_)
{BlockQueue<SaveTask>* save_bq=(static_cast<BlockQueues<CalTask,SaveTask>* >(bqs_))->s_bq;while (true){SaveTask t;save_bq->pop(&t);t();cout << "推送保存任务完成..." << endl;}return nullptr;
}
int main()
{srand((unsigned long)time(nullptr));BlockQueues<CalTask,SaveTask> bqs;bqs.c_bq=new BlockQueue<CalTask>();bqs.s_bq=new BlockQueue<SaveTask>();pthread_t c,p,s;pthread_create(&c,nullptr,consumer,&bqs);pthread_create(&p,nullptr,producter,&bqs);pthread_create(&s,nullptr,saver,&bqs);pthread_join(c,nullptr);pthread_join(p,nullptr);pthread_join(s,nullptr);delete bqs.c_bq;delete bqs.s_bq;return 0;
}./MainCp
生产任务: 9 * 0 = ?
生产任务: 9 - 4 = ?
生产任务: 8 - 0 = ?
生产任务: 3 - 4 = ?
生产任务: 6 + 1 = ?
消费数据: 9 * 0 = 0
推送保存任务完成...
生产任务: 2 - 2 = ?
推送保存任务完成...
消费数据: 9 - 4 = 5
推送保存任务完成...
生产任务: 9 - 0 = ?
推送保存任务完成...
消费数据: 8 - 0 = 8
推送保存任务完成...
生产任务: 6 * 3 = ?
推送保存任务完成...
消费数据: 3 - 4 = -1
推送保存任务完成...
生产任务: 4 * 4 = ?
推送保存任务完成...
消费数据: 6 + 1 = 7
推送保存任务完成...
生产任务: 5 % 4 = ?
推送保存任务完成...
^C
zhangsan@ubuntu:~/practice-using-ubuntu/20241005/blockqueue$ cat log.txt
9 * 0 = 0
9 - 4 = 5
8 - 0 = 8
3 - 4 = -1
6 + 1 = 7
信号量
a.信号量的本质就是计数器
b.只有拥有信号量，在未来就一定能拥有临界资源的一部分
申请信号量的本质就是：对临界资源中特点小块资源的预定机制
sem-- 申请资源 P 必须保证操作的原子性
sem++ 释放资源 V 必须保证操作的原子性
POSIX信号量
环形队列
RingQueue.hpp
#pragma once#include<iostream>
#include<cassert>
#include<vector>
#include<ctime>
#include<cstdlib>
#include<semaphore.h>
#include<unistd.h>
#include<pthread.h>static const int gcap=5;template<class T>
class RingQueue
{
private:void P(sem_t& sem){int n=sem_wait(&sem);assert(n==0);}void V(sem_t& sem){int n=sem_post(&sem);assert(n==0);}
public:RingQueue(const int& cap=gcap):_queue(cap),_cap(cap){int n=sem_init(&_spaceSem,0,_cap);assert(n==0);n=sem_init(&_dataSem,0,0);assert(n==0);_productorStep=_consumerStep=0;pthread_mutex_init(&_pmutex,nullptr);pthread_mutex_init(&_cmutex,nullptr);}void Push(const T& in){P(_spaceSem);//productorpthread_mutex_lock(&_pmutex);_queue[_productorStep++]=in;_productorStep%=_cap;pthread_mutex_unlock(&_pmutex);//更高效V(_dataSem);}void Pop(T* out){pthread_mutex_lock(&_cmutex);P(_dataSem);*out=_queue[_consumerStep++];_consumerStep%=_cap;V(_spaceSem);pthread_mutex_unlock(&_cmutex);}~RingQueue(){sem_destroy(&_spaceSem);sem_destroy(&_dataSem);pthread_mutex_destroy(&_pmutex);pthread_mutex_destroy(&_cmutex);}
private:vector<T> _queue;int _cap;sem_t _spaceSem;//生产者->空间资源sem_t _dataSem;int _productorStep;int _consumerStep;pthread_mutex_t _pmutex;pthread_mutex_t _cmutex;
};task.hpp
#pragma once
#include<iostream>
#include<cstdio>
#include<string>
#include<functional>using namespace std;
class Task
{using func_t=function<int(int,int,char)>;
public:Task(){}Task(int x,int y,char op,func_t func):_x(x),_y(y),_op(op),_callback(func){}string operator()(){int result=_callback(_x,_y,_op);char buffer[1024];snprintf(buffer,sizeof buffer,"%d %c %d = %d ",_x,_op,_y,result);return buffer;}string toTaskString(){char buffer[1024];snprintf(buffer,sizeof buffer,"%d %c %d = ? ",_x,_op,_y);return buffer;}
private:int _x;int _y;char _op;func_t _callback;
};
const string oper="+-*/%";
int mymath(int x,int y,char op)
{int result=0;switch (op){case '+':result=x+y;break;case '-':result=x-y;break;case '*':result=x*y;break;case '/':{if(y==0){cerr<<"div zero error!"<<endl;result=-1;} else result=x/y;}break;case '%':{if(y==0){cerr<<"div zero error!"<<endl;result=-1;} else result=x%y;}break;default:break;}return result;
}
main.cc
#include"RingQueue.hpp"
#include"task.hpp"using namespace std;void* ProductorRoutine(void* rq)
{RingQueue<Task>* ringqueue=static_cast<RingQueue<Task>* >(rq);while (true){/* code */int x=rand()%100;int y=rand()%50;char op=oper[rand()%oper.size()];Task t(x,y,op,mymath);ringqueue->Push(t);cout<<"生产者派发了一个任务: "<<t.toTaskString()<<endl;sleep(1);}
}
void* ConsumerRoutine(void* rq)
{RingQueue<Task>* ringqueue=static_cast<RingQueue<Task>* >(rq);while (true){/* code */Task t;ringqueue->Pop(&t);string result=t();cout<<"消费者消费了一个任务"<<result<<endl;}}
int main()
{srand((unsigned int)time(nullptr));RingQueue<Task>* rq=new RingQueue<Task>();pthread_t p,c;pthread_create(&p,nullptr,ProductorRoutine,rq);pthread_create(&c,nullptr,ConsumerRoutine,rq);pthread_join(p,nullptr);pthread_join(c,nullptr);delete rq;return 0;
}