On 03/04/2014 02:09 PM, LE PICARD NICOLAS wrote:
I didn't know for jdk8 functions destroy and the new one destroyForcibly...
And Jonathan was right in his previous answer, I was looking for a solution in Java, I
mean a portable one like in Process class, like the "destroyGracefully".
I am looking to signals because it seems to be a simple way to achieve this
"portable" solution, maybe I'm wrong.
It would be useful (as you said) to have a function to kill "gracefully"
through Process class, no ?
Nicolas Le Picard
Hi Nicolas,
So you're spawning a Java sub-process from a Java master process using
java.lang.Process, do I understand correctly?
Are you in control of the code that represents the child sub-process? Is
this code already using System.in (STDIN) stream for anything? If the
answers are YES and NO respectively, then you may be able to use the
System.in in the sub-process (spawn a special monitoring thread) and
Process.getOutputStream() in the master process to establish a one way
channel for passing commands in direction: master process ->
sub-process. One of those commands could be "shutdown" for example, that
would trigger a System.exit() in the sub-process. This way you could
make the shut-down hooks in sub-process be executed before exiting...
Regards, Peter
-----Message d'origine-----
De : Alan Bateman [mailto:[email protected]]
Envoyé : mardi 4 mars 2014 13:12
À : Krystal Mok
Cc : LE PICARD NICOLAS; [email protected]
Objet : Re: How to close a Process and having shutdown hooks called ?
On 04/03/2014 11:51, Krystal Mok wrote:
Hi Nicolas,
Looks like a well discussed question. On Posix systems, SIGTERM should
work for you. That's the default signal sent by the 'kill' command on Linux.
e.g. please take a look here:
http://stackoverflow.com/questions/2541597/how-to-gracefully-handle-th
e-sigkill-signal-in-java
- Kris
I think he's on Windows and is looking for destroy to use something other than
TerminateProcess.
As background, the destroy method was confusingly specified to kill the
sub-process forcibly but it wasn't implemented this way everywhere. On
Unix/Linux then the long standing implementation used SIGTERM and so no
guarantee that it would cause the sub-process to terminate. This mismatch was
examined in JDK 8 (you'll need to go through the archives of this mailing list
to see the discussion) and the javadoc updated to make it clear that it is
implementation specific as to whether it is done forcibly or not. In addition a
new destroyForcibly was added to do the SIGKILL or TerminateProcess for cases
where you really want to kill the child. There isn't a corresponding
destroyGracefully but clearly this would be useful if were feasible to
implement everywhere.
-Alan.
