RFR: 8234262: Unmask SIGQUIT in a child process [v2]

[Roger Riggs]

On Wed, 21 Sep 2022 23:12:13 GMT, David Holmes <dholmes at openjdk.org> wrote:

> Hi Roger, Using the spawn attributes seems more far reaching than simply temporarily changing the signal mask of the calling thread. I'd be concerned this has some unintended side-effects.

@dholmes-ora The signal masks for threads are currently initialized and managed by the VM. I was concerned about application actions and Java code changing and then restoring the mask in the face of possible async behaviors. It seemed cleaner for the changes to affect only the child.

Posix_spawn is used on all platforms and is very specific about its actions.
I considered just resetting the mask for SIGQUIT, copying the rest of the signal mask from the parent, but then it might come up that some other signal was masked and should not be.

The launching of a new executable is a two+ step process. A small executable (jspawnhelper) is spawned and it does the exec of the requested executable. 
An alternate implementation is to have jspawnhelper reset its own signal mask before exec'ing the target application.

-------------

PR: https://git.openjdk.org/jdk/pull/10379