tree 2983de710f4e0fc0e7ddac95ac670ac9697a2a13
parent dcad31aeb442369a6fb52f4dc7d4f781bc56006c
author Bill Fenner <fenner@gmail.com> 1406036968 -0700
committer Bill Fenner <fenner@gmail.com> 1406036968 -0700

When enlarging a large_fd_set, use FD_ZERO if possible

The most common case of creating a large_fd_set on UNIX
is to create it with size zero, and then immediately enlarge
it to size FD_SETSIZE.  Instead of looping and calling
FD_CLR(), we can optimize this common case with the OS's
FD_ZERO.