So if it returns and exit() is immediately called, how does that cause a
crash ?
It seems to be just the same as if the handler called exit() directly
and so did not return.
I would have thought a crash more likely if it didn't return and tried
to keep the program running,
which might be effectively what you temporarily do if you call JVM_Halt().
-phil.
On 6/7/21 11:21 AM, Maxim Kartashev wrote:
When the X server suddenly dies, Xlib would usually (or maybe always)
discover this as an I/O error. It will then call the function
installed with XSetIOErrorHandler() and expects that the function will
not return ("the called routine should not return" from
https://tronche.com/gui/x/xlib/event-handling/protocol-errors/XSetIOErrorHandler.html
<https://tronche.com/gui/x/xlib/event-handling/protocol-errors/XSetIOErrorHandler.html>).
If the handler returns, Xlib will simply call ::exit().
AWT installs awt_GraphicsEnv.c`xioerror_handler() as such a function
and it _does_ return. I was wondering if it would be prudent to
properly terminate VM from the handler (with JVM_Halt(), perhaps)? We
are getting many reports of JVM crashes on Linux that seem to be
connected with the sudden disappearance of the X server, but I wasn't
able to reproduce this so can't be sure that this is the issue we are
facing.
