[GIT] Experimental threaded udev

[Alan Jenkins <alan-jenkins@tuffmail.co.uk>]

Now available for your delight and/or horror.

<http://github.com/sourcejedi/udev/commits/threading-v0.3>

For now, I'm still treating this as a patch series.  That is, I may
publish future versions with a rewritten history.  I'll preserve the old
branches though.

It turns out the MADV_DONTFORK hack I was so proud of is
implementation-dependant, i.e. a dirty hack.  However, I'm confident
that glibc can and should be modified to do it for all programs.  And it
is so worth it.  On my test machine, threading alone goes from 2s
boot-time coldplug to 1.3-ish.  MADV_DONTFORK takes it down to 0.7-ish. 
The hack is contained in the last patch, "when forking a program, only
copy the stack of the _current_ thread".

Thanks for your time and encouragement
Alan



      udevd: don't use alarm() for timeouts
      Build udevd with pthreads
      Protect selinux context against concurrent modification
      Add close-on-exec wrappers for open(), fopen(), pipe() and socket()
      Convert udevd and libudev to use close-on-exec wrapper functions
      Add abstraction layer for udev event tasks
      Run udev event tasks in threads
      udevd: when forking a program, only copy the stack of the
_current_ thread

 configure.ac                       |   15 ++
 extras/ata_id/Makefile.am          |    3 +-
 extras/cdrom_id/Makefile.am        |    3 +-
 extras/collect/Makefile.am         |    3 +-
 extras/edd_id/Makefile.am          |    3 +-
 extras/floppy/Makefile.am          |    1 +
 extras/fstab_import/Makefile.am    |    3 +-
 extras/scsi_id/Makefile.am         |    3 +-
 extras/usb_id/Makefile.am          |    3 +-
 m4/acx_pthread.m4                  |  280 ++++++++++++++++++++++++++++++
 udev/Makefile.am                   |    8 +
 udev/lib/Makefile.am               |    1 +
 udev/lib/libudev-cloexec.c         |  226 ++++++++++++++++++++++++
 udev/lib/libudev-ctrl.c            |    2 +-
 udev/lib/libudev-device-db-write.c |    2 +-
 udev/lib/libudev-device.c          |    6 +-
 udev/lib/libudev-monitor.c         |    4 +-
 udev/lib/libudev-private.h         |   13 ++
 udev/lib/libudev-queue.c           |    2 +-
 udev/lib/libudev-sysdeps.h         |   96 ++++++++++
 udev/lib/libudev.c                 |   18 ++-
 udev/test-udev.c                   |    7 -
 udev/udev-event.c                  |  335
+++++++++++++++++++++++++++++++++++-
 udev/udev-node.c                   |    2 +-
 udev/udev-rules.c                  |   53 +++---
 udev/udev-selinux.c                |    9 +-
 udev/udev-task.c                   |  295 +++++++++++++++++++++++++++++++
 udev/udev-util.c                   |  211 -----------------------
 udev/udev.h                        |   23 +++-
 udev/udevd.c                       |  323
++++++++++++++++++-----------------
 30 files changed, 1527 insertions(+), 426 deletions(-)
 create mode 100644 m4/acx_pthread.m4
 create mode 100644 udev/lib/libudev-cloexec.c
 create mode 100644 udev/lib/libudev-sysdeps.h
 create mode 100644 udev/udev-task.c