#include "Thread.h"
#include "CurrentThread.h"

#include <semaphore.h>

//std::atomic_int Thread::numCreated_ = 0; 这样的写法报错
std::atomic_int Thread::numCreated_(0);

Thread::Thread(ThreadFunc func, const std::string& name)
  :started_(false)
   ,joined_(false)
   ,tid_(0)
   ,func_(std::move(func))
   ,name_(name)
{
  setDefaultName();
}

Thread::~Thread(){
  if(started_ && !joined_){
    thread_->detach(); //thread类提供的设置分离线程的方法
  }
}

void Thread::start(){ //一个Thread对象，记录的就是一个新线程的详细信息
  started_ = true;
  sem_t sem;
  sem_init(&sem,false,0);
  //开启线程
  thread_ = std::shared_ptr<std::thread>(new std::thread([&](){
      //获取线程的tid值
      tid_ = CurrentThread::tid();
      sem_post(&sem);
      func_(); //开启一个新线程，专门执行该线程函数
  }));

  //这里必须等待获取上面新创建的线程的tid值
  sem_wait(&sem);
}

void Thread::join(){
  joined_ = true;
  thread_->join();
}

void Thread::setDefaultName(){
  int num = ++numCreated_;
  if(name_.empty()){
    char buf[32] = {0};
    snprintf(buf,sizeof buf,"Thread%d",num);
    name_ = buf;
  }
}