os, runtime: CTRL_CLOSE_EVENT should generate SIGTERM on Windows

[gopherbot]

by anacrolix@google.com:

On Windows a CTRL_CLOSE_EVENT message is sent prior to unavoidable termination. This
should be represented by notifying the process with a SIGTERM.

http://msdn.microsoft.com/en-us/library/windows/desktop/ms683242(v=vs.85).aspx

[gopherbot]

Comment 1 by sgellerde:

fyi,
after applying [1] and doing dev tests it looks like CTRL_CLOSE_EVENT can only be
received for a console process in Windows 7 when using some nasty hacks [2]. Pre Win7
the event seems receivable. If desired I would test it under Win8+. Or did I miss
anything obvious in my diff?
[1] https://gist.github.com/sgeller/10196571
[2]
http://social.msdn.microsoft.com/Forums/windowsdesktop/en-US/abf09824-4e4c-4f2c-ae1e-5981f06c9c6e/windows-7-console-application-has-no-way-of-trapping-logoffshutdown-event?forum=windowscompatibility

[gopherbot]

Comment 2 by anacrolix@google.com:

That's strange it works for me and I'm using Windows 7 32bit. From the thread it looks
like the big spanners you can throw in are:
 * Your app is a GUI/full-fledge Win32 app (this requires a flag to the go linker).
 * You're invoking other Win32 APIs such as service-related and event-loop related stuff.
None of the above were true in my testing.
The patch you want is https://codereview.appspot.com/download/issue71900043_40001.diff
Your gist generates SIGINT for CTRL_CLOSE_EVENT which isn't optimal, the patch generates
SIGTERM for reasons given in the source. Either way you must also catch the signal with
os.Notify. There's a test program here:
https://bitbucket.org/anacrolix/dms/src/8d6ab94e3c8032d11b870867609ba9dd618e79fc/play/termsig/?at=default
If you pipe the output to a file from a terminal, and then close the terminal you should
see the termination signal in the file.

[ianlancetaylor]

Comment 3:

Labels changed: added repo-main, release-none, os-windows.

[gopherbot]

Comment 5 by RetroModular:

FYI // I have just been having a discussion about this with some guys in one of the Go
Google groups because I was looking for a solution to catch the console being closed (on
Windows) while a Go app is running.
This is the discussion:
https://groups.google.com/forum/#!topic/golang-nuts/S_RDVG3lcdI
Java appears to be handling this in a sensible way by listening for CLOSE and SHUTDOWN
events then firing a SIGTERM signal:
http://hg.openjdk.java.net/jdk9/dev/hotspot/file/9b3f5e4f3372/src/os/windows/vm/os_windows.cpp#l1883
It would be really helpful if this could be implemented in Go.

[alexbrainman]

Comment 6:

I am happy to try and implement this functionality (after go1.4 is released), but I need
some input:
- which extra events we should handle?
- which syscall or os signals these new events should me mapped into?
I have very little experience with these, and I don't want to influence that decision.
Alex