Re: Issue with gdbserver --multi / remote-extended on Windows XP

[Pedro Alves <pedro@codesourcery.com>]

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Hi,

Rolf told me that this does indeed work as expected.  I just
finished a testsuite run against a native cygwin gdbserver
on XP, and spotted no regressions.

Daniel, OK to commit?

On Wednesday 05 November 2008 01:03:22, Pedro Alves wrote:
> On Wednesday 17 September 2008 18:35:15, Dr. Rolf Jansen wrote:
> > I experimented a little bit with gdbserver --multi in remote-xtended  
> > mode on Windows XP and I had one major problem in debugging a gui  
> > application. If I regularly quit the gui app, to which gdbserver is  
> > attached, its open windows remain at the screen, and while although  
> > inresponsive they are still part of the window hierarchy of Windows.
> > 
> > 
> > Observations:
> > - the gui app is terminates itself by calling exit(0).
> > - if I quit gdbserver, the open zombie-windows disappear
> > - in non-multi/remote-extended-mode gdbserver this problem
> >    does not appear, because gdbserver terminates itself
> >    together with the application
> > 
> > 
> > I found a solution that works for me, although, there might be better  
> > ways.
> > 
> > At line 1456 of win32-low.c I added:
> > 
> >        TerminateProcess (current_process_handle,
> >                          current_event.u.ExitProcess.dwExitCode);
> >        child_continue (DBG_TERMINATE_PROCESS, -1);
> > 
> > 
> > 
> > This code is added in event-handler switch() of  
> > get_child_debug_event() and the respective case block looks now like:
> > 
> >      case EXIT_PROCESS_DEBUG_EVENT:
> >        OUTMSG2 (("gdbserver: kernel event EXIT_PROCESS_DEBUG_EVENT "
> > 		"for pid=%d tid=%x\n",
> > 		(unsigned) current_event.dwProcessId,
> > 		(unsigned) current_event.dwThreadId));
> >        ourstatus->kind = TARGET_WAITKIND_EXITED;
> >        ourstatus->value.integer =  
> > current_event.u.ExitProcess.dwExitCode;
> 
> 
> 
> >        TerminateProcess (current_process_handle,
> >                          current_event.u.ExitProcess.dwExitCode);
> >        child_continue (DBG_TERMINATE_PROCESS, -1);
> 
> 
> Hmm, I haven't tried this, but, are you sure you need to
> terminate the process like this?  Wouldn't a
> child_continue (DBG_CONTINUE, -1) work here?  It's what
> native gdb does (it's in win32_mourn_inferior).
> I can't find it now, but I'm almost sure that's documented somewhere
> as required for the debugger to do (I scratched my head once at why
> was win32_mourn_inferior telling the dead process to continue, and found
> that out).  Well, I could be wrong though.
> 

-- 
Pedro Alves

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2009-01-13  Pedro Alves  <pedro@codesourcery.com>

	* win32-low.c (get_child_debug_event): Issue a final DBG_CONTINUE
	when handling a EXIT_PROCESS_DEBUG_EVENT.

---
 gdb/gdbserver/win32-low.c |    1 +
 1 file changed, 1 insertion(+)

Index: src/gdb/gdbserver/win32-low.c
===================================================================
--- src.orig/gdb/gdbserver/win32-low.c
+++ src/gdb/gdbserver/win32-low.c
@@ -1453,6 +1453,7 @@ get_child_debug_event (struct target_wai
 		(unsigned) current_event.dwThreadId));
       ourstatus->kind = TARGET_WAITKIND_EXITED;
       ourstatus->value.integer = current_event.u.ExitProcess.dwExitCode;
+      child_continue (DBG_CONTINUE, -1);
       CloseHandle (current_process_handle);
       current_process_handle = NULL;
       break;