I am trying to create a event driven multiple threads UDP/DTLS server. The design is based on the following concepts
- Have a UDP socket where the Clients connects on
- Use Epoll to ask for events on the UDP listen socket.
The UDP socket acts as a TCP listen socket and creates child fds that connect to the specific client. For this I have implemented a UDPAccept method for my object which has the pseudo code as shown below
UDPAccept(int fd,struct sockaddr * addr, socklen_t * addr_len,void *sockBuf,size_t *read) { //sanity checks int childfd = -1; int error = 1; socklen_t localLen,peerLen; int family; struct sockaddr_in local4,peer4; struct sockaddr temp; size_t maxLen = 65535; getsockname(fd,(struct sockaddr *)&temp,&localLen); family = temp.sa_family; do { childfd = socket(family,SOCK_DGRAM,0); //error handling //handle IPV6 local4 = (sockaddr_in *)temp; error = recvfrom( fd, sockBuf, maxLen,0,(struct sockaddr *)&peer4, &peerLen); error = bind(childfd,(struct sockaddr *)&local4,sizeof local4); error = connect(childfd,(struct sockaddr *)&peerV4,peerLen); //handle error }while(0); if(addr != NULL && addr_len != NULL) { *addr_len = peerLen; addr = &peerV4; *read = error; } // error handling and cleanup return childfd; }Add the child socket to Epoll table.
epoll_ctl(efd,EPOLL_CTL_ADD,newFd,&event);Poll for events on the child and listen socket
currentSize = epoll_wait(efd,events,MAX_SOCKET_FD,timeout); //handle errors for(i = 0; i < currentSize;i++) { if(events[i].data.fd == listenUDP) //call UDPAccept // update local tables else //handle child fd events }Have multiple threads to the same thing, synchronize using locks during accept
Now my question is will epoll stop giving me POLLIN events on the listening socket because I have created a new UDP child connected socket to the client or will I have to handle it myself
