4 ms·

Yeah but fds are guaranteed to be opened lowest available on first, so thats ok, you cant get fd=1026 without having 1026 open. The Linux syscall does not have

• geocar 5y ago
  > Yeah but fds are guaranteed to be opened lowest available on first, so thats ok, you cant get fd=1026 without having 1026 open. This is exactly correct. > The Linux syscall does not have a fixed FD_SETSIZE so glibc could increase the size. The application writer can define FD_SETSIZE before including <sys/socket.h> and set it to whatever they want on BSD (including OSX). glibc could* adopt this trick, but my feeling is you probably don't want to stack-allocate this stuff anyway. Dealing with a large number of very-active connections concurrently efficiently requires more effort than just this though.
• dasyatidprime 5y ago
  To be more precise on one bit, you can't get fd=1026 without having had at least 1027 open at some point in the past. You can subsequently close a bunch of them in the middle. A compatibility hack for some applications reliant on badly-done select() might be to set RLIMIT_NOFILE to FD_SETSIZE.
  • geocar 5y ago
    > To be more precise on one bit, you can't get fd=1026 without having had at least 1027 open at some point in the past. Of course you can. dup2(0,1026)
    • dasyatidprime 5y ago
      Hah! Yes, okay. I should have said “… by opening”.
• deleted 5y ago
  [deleted]