目前我正在使用 epoll 实现一个多线程网络客户端应用程序。我的模型很简单：
获取client_fd & 向远程服务器写入请求
设置 fd 非阻塞并将其添加到 epfd(EPOLLIN|EPOLLET|EPOLLONESHOT) 以等待响应
从 fd 获取 EPOLLIN，读取整个响应并释放资源
我遇到的问题是，有时我会在同一个 fd 上获得多个 EPOLLIN（通过使用 EPOLLIN|EPOLLET|EPOLLONESHOT）。由于我在第一个 EPOLLIN evt 中释放了所有资源（包括 client_fd），第二个 evt 使我的程序崩溃。
任何建议都非常感谢:)
这是代码片段：
//multi-thread wait on the sem, since there should be only one thread
//at epoll_wait at the same time(L-F model)
sem_wait(wait_sem);
int nfds = epoll_wait(epoll_fd,evts,max_evt_cnt,wait_time_out);
//leader got the fds to proceed
for(int i =0; i < nfds; ++i){
io_request* req = (io_request*)evts[i].data.ptr;
int sockfd = req->fd;
if(evts[i].events & EPOLLIN){
ev.data.fd=sockfd;
if(0!=epoll_ctl(epoll_fd,EPOLL_CTL_DEL,sockfd,&ev)){
switch(errno){
case EBADF:
//multiple EPOLLIN cause EPOLL_CTL_DEL fail
WARNING("delete fd failed for EBADF");
break;
default:
WARNING("delete fd failed for %d", errno);
}
}
else{
//currently walk around by just ignore the error fd
crt_idx.push_back(i);
}
}
}
if(crt_idx.size() != nfds)//just warning when the case happen
WARNING("crt_idx.size():%u != nfds:%d there has been some error!!", crt_idx.size(), nfds);
//current leader waked up next leader, and become a follower
sem_post(wait_sem);
for(int i = 0; i < crt_idx.size(); ++i)
{
io_request* req = (io_request*)evts[crt_idx[i]].data.ptr;
...do business logic...
...release the resources & release the client_fd
}