Re: [RFC] Patch for QUIT macro support

[Fred Fish <fnf at specifix dot com>]

On Friday 13 October 2006 06:30, Daniel Jacobowitz wrote:
> Do you mean the big async patch?  If so it's still worth fixing this in
> isolation.

Yes, just search for the couple of hunks that make changes to "quit_flag".

The key difference between my patch and Nick's is the test in async_request_quit
to avoid call quit twice (once from the QUIT macro and once when the event
loop gets around to checking the signal handlers).

Here's the patch I'm now testing.

-Fred

Index: gdb/event-top.c
===================================================================
RCS file: /cvs/src/src/gdb/event-top.c,v
retrieving revision 1.46
diff -c -r1.46 event-top.c
*** gdb/event-top.c	21 Jul 2006 14:46:53 -0000	1.46
--- gdb/event-top.c	13 Oct 2006 07:49:52 -0000
***************
*** 958,963 ****
--- 1002,1017 ----
  {
    signal (sig, handle_sigint);
  
+   /* We used to set the quit flag in async_request_quit, which is either
+      called when immediate_quit is 1, or when we get back to the event
+      loop.  This is wrong, because you could be running in a loop reading
+      in symfiles or something, and it could be quite a while before you 
+      get to the event loop.  Instead, set quit_flag to 1 here, then mark
+      the sigint handler as ready.  Then if somebody calls QUIT before you
+      get to the event loop, they will unwind as expected.  */
+ 
+   quit_flag = 1;
+ 
    /* If immediate_quit is set, we go ahead and process the SIGINT right
       away, even if we usually would defer this to the event loop. The
       assumption here is that it is safe to process ^C immediately if
***************
*** 986,992 ****
  void
  async_request_quit (gdb_client_data arg)
  {
!   quit_flag = 1;
    quit ();
  }
  
--- 1040,1053 ----
  void
  async_request_quit (gdb_client_data arg)
  {
!   /* If the quit_flag has gotten reset back to 0 by the time we get
!      back here, that means that an exception was thrown to unwind
!      the current command before we got back to the event loop.  So
!      there is no reason to call quit again here. */
! 
!   if (quit_flag == 0)
!     return;
! 
    quit ();
  }