#include "EventLoopThreadPool.h"
#include "EventLoopThread.h"

#include <memory>

EventLoopThreadPool::EventLoopThreadPool(EventLoop* baseLoop, const std::string& nameArg)
  :baseLoop_(baseLoop)
   ,name_(nameArg)
   ,started_(false)
   ,numThreads_(0)
   ,next_(0){

}

EventLoopThreadPool::~EventLoopThreadPool(){
  //不需要析构loop，loop是个栈变量
}

void EventLoopThreadPool::start(const ThreadInitCallback& cb){
  started_ = true;

  for(int i=0; i<numThreads_; ++i){
    char buf[name_.size() + 32];
    snprintf(buf, sizeof buf, "%s%d", name_.c_str(), i);
    EventLoopThread* t = new EventLoopThread(cb, buf);
    threads_.push_back(std::unique_ptr<EventLoopThread>(t));
    loops_.push_back(t->startLoop()); //底层创建线程，绑定一个新的EventLoop，并返回该loop的地址
    
  }
  
  //没进for循环，那么说明整个服务端只有一个线程，就只运行着baseLoop
  if(numThreads_ == 0 && cb){
    cb(baseLoop_);
  }
}
    
//如果工作在多线程中，baseLoop_中默认以轮询的方式分配Channel给subLoop
EventLoop* EventLoopThreadPool::getNextLoop(){
  EventLoop* loop = baseLoop_;
  
  if(!loops_.empty()){ //通过轮询方式获取下一个处理事件的loop
    loop = loops_[next_];
    ++next_;
    if(next_ >= loops_.size()){
      next_ = 0;
    }
  }

  return loop;
}

std::vector<EventLoop*> EventLoopThreadPool::getAllLoops(){
  if(loops_.empty()){
    return std::vector<EventLoop*>(1, baseLoop_);
  }
  else{
    return loops_;
  }
}