[PATCH 0/5] Add systemd socket launching support.

[Matthew Leach <matthew@mattleach.net>]

Systemd has the ability to create a socket, launch a daemon upon
connection to that socket and hand over the socket to the new process
to handle.  In Emacs' case, we can delay the start of the Emacs daemon
until emacsclient is called upon a socket.

These patches can be tested by creating minimal systemd setup.  First,
create two systemd unit files:

emacs.socket
============
[Socket]
ListenStream=/home/foobar/test.socket

[Install]
WantedBy=sockets.target

emacs.service
=============
[Service]
Type=forking
ExecStart=/path/to/emacs --daemon

Once these files have been created, execute:

# systemctl daemon-reload
# systemctl start enacs.socket

The socket will now be created, and when a connection is made, the
Emacs daemon will be started:

# emacsclient -s /home/foobar/test.socket -t

Feedback & comments welcome!

Thanks,
Matt

Matthew Leach (5):
  Check for libsystemd when building Emacs.
  Read the number of sockets passed by systemd.
  Permit systemd-allocated socket file-descriptors to be used.
  Allow the systed socket fd to be retrieved.
  When set, use the systemd socket descriptor.

 configure.ac    | 13 +++++++++++++
 lisp/server.el  |  5 ++++-
 src/Makefile.in |  6 +++++-
 src/emacs.c     | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 src/process.c   | 28 +++++++++++++++++++++-------
 5 files changed, 90 insertions(+), 9 deletions(-)

-- 
2.7.4