[PATCH] Fix debugger attach for threads

[Thomas Pfaff <tpfaff at gmx dot net>]

This patch allows a debugger to attach when an exception occurs in a 
thread other than the mainthread.

I am not happy about the wait in handle_exceptions, but it works on my 
machine. I think that a waitloop until the debugger is attached is 
cleaner, but there must be a reason why the debbugging loop is 
implemented this way.

Thomas

003-10-31  Thomas Pfaff  <tpfaff@gmx.net>

	* exceptions.cc (try_to_debug): Suspend/resume all threads when
	a debugger is attaching.
	(handle_exceptions): Give debugger CPU time to attach.

? suspend_all_on_stop.patch
? thread_try_to_debug.patch
Index: exceptions.cc
===================================================================
RCS file: /cvs/src/src/winsup/cygwin/exceptions.cc,v
retrieving revision 1.172
diff -u -p -r1.172 exceptions.cc
--- exceptions.cc	14 Oct 2003 09:21:55 -0000	1.172
+++ exceptions.cc	31 Oct 2003 20:50:31 -0000
@@ -360,9 +360,7 @@ try_to_debug (bool waitloop)
   si.dwFlags = 0;
   si.cb = sizeof (si);
 
-  /* FIXME: need to know handles of all running threads to
-     suspend_all_threads_except (current_thread_id);
-  */
+  pthread::suspend_all_except_self ();
 
   /* if any of these mutexes is owned, we will fail to start any cygwin app
      until trapped app exits */
@@ -400,7 +398,10 @@ try_to_debug (bool waitloop)
   else
     {
       if (!waitloop)
-	return 1;
+        {
+          pthread::resume_all ();
+          return 1;
+        }
       SetThreadPriority (GetCurrentThread (), THREAD_PRIORITY_IDLE);
       while (!being_debugged ())
 	Sleep (0);
@@ -409,9 +410,8 @@ try_to_debug (bool waitloop)
       SetThreadPriority (GetCurrentThread (), prio);
     }
 
-  /* FIXME: need to know handles of all running threads to
-    resume_all_threads_except (current_thread_id);
-  */
+  pthread::resume_all ();
+
   return 0;
 }
 
@@ -426,7 +426,15 @@ handle_exceptions (EXCEPTION_RECORD *e, 
 
   if (debugging && ++debugging < 500000)
     {
-      SetThreadPriority (hMainThread, THREAD_PRIORITY_NORMAL);
+      /*
+       * Give debugger a chance to attach
+       */
+      LONG prio = GetThreadPriority (GetCurrentThread ());
+      pthread::suspend_all_except_self ();
+      SetThreadPriority (GetCurrentThread (), THREAD_PRIORITY_IDLE);
+      Sleep (0);
+      SetThreadPriority (GetCurrentThread (), prio);
+      pthread::resume_all ();
       return 0;
     }