Select()

 
int fdServer;
fd_set bvfdRead;

FD_ZERO(&bvfdRead);
FD_SET(fdServer, &bvfdRead);   /* socket for the server */
FD_SET(fdIn, &bvfdRead);	   /* fd for stdin */
while (select (fdServer+1, &bvfdRead, 0, 0, 0) > 0) {
    if (FD_ISSET(fdServer, &bvfdRead)) {
        cch = read (fdServer, sb, cchMax);
	...
    ...

Problems:

• must pass entire bitmap on each request

• all information must be passed back

• does not work with asynchronous I/O