[ruby-core:59429] [ruby-trunk - Feature #9330][Open] [PATCH 0/3] avoid redundant fcntl/fstat syscalls for cloexec sockets

Issue #9330 has been reported by normalperson (Eric Wong).

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Feature #9330: [PATCH 0/3] avoid redundant fcntl/fstat syscalls for cloexec sockets
https://bugs.ruby-lang.org/issues/9330

Author: normalperson (Eric Wong)
Status: Open
Priority: Low
Assignee: 
Category: ext
Target version: next minor


commit 52525b673669019dc3c03474e613937fd3587187
Author: Eric Wong <[e-mail]>
Date:   Tue Dec 31 02:09:27 2013 +0000

    socket: avoid redundant fcntl calls for FD passing
    
    If MSG_CMSG_CLOEXEC works on the first recvmsg syscall, we should
    assume it always works and avoid checking it with every single FD
    received.
    
    While we're at it, it is pointless to set FD_CLOEXEC immediately
    before we close it in discard_cmsg; so only update the max FD (the
    FD is likely to be recycled, so we should update even if we close
    it).
    
    Note: I think it's safe to assume any system with MSG_CMSG_CLOEXEC
    will have implemented SOCK_CLOEXEC; too, so we reuse use
    rsock_detect_cloexec instead of defining a new function wrapped
    by #ifdef MSG_CMSG_CLOEXEC.

commit aa9ed17a5f10cf53f72dc5ab1f4ff8d8b5e4dd84
Author: Eric Wong <[e-mail]>
Date:   Tue Dec 31 01:36:27 2013 +0000

    socket: avoid redundant calls to rb_update_max_fd
    
    rsock_init_sock already calls rb_update_max_fd, so do not
    waste time making redundant fstat() and atomic CAS instructions.

commit b1694d7bac55bd9f537426624fe599c46b10dee6
Author: Eric Wong <[e-mail]>
Date:   Mon Dec 30 23:58:32 2013 +0000

    socket: avoid redundant fcntl(fd, F_GETFD) with SOCK_CLOEXEC
    
    If socket or socketpair succeeds with SOCK_CLOEXEC once, we should
    expect it to succeed for all subsequent invocations of each of those
    syscalls.  This reduces the number of syscalls made and makes strace
    output cleaner.
    
    While we're at it, swap some remaining rb_fd_fix_cloexec calls for
    rb_maygvl_fd_fix_cloexec, as the former calls rb_update_max_fd
    redundantly.  A future commit will reduce rb_update_max_fd calls
    further.


The following changes since commit d6c7ab9ffeff31fb5a49776ab74a61b478344107:

  * 2013-12-31 (2013-12-30 19:48:05 +0000)

are available in the git repository at:

  git://bogomips.org/ruby.git socket_cloexec_once

for you to fetch changes up to 52525b673669019dc3c03474e613937fd3587187:

  socket: avoid redundant fcntl calls for FD passing (2013-12-31 02:17:53 +0000)

----------------------------------------------------------------
Eric Wong (3):
      socket: avoid redundant fcntl(fd, F_GETFD) with SOCK_CLOEXEC
      socket: avoid redundant calls to rb_update_max_fd
      socket: avoid redundant fcntl calls for FD passing

 ext/socket/ancdata.c    |  9 +++++++--
 ext/socket/init.c       | 49 ++++++++++++++++++++++++++++++++++++++-----------
 ext/socket/rubysocket.h |  2 ++
 ext/socket/socket.c     | 31 ++++++++++++++++++++++---------
 ext/socket/unixsocket.c | 10 ++++++++--
 5 files changed, 77 insertions(+), 24 deletions(-)



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