* Introduced a per-team counter that is incremented whenever an image

is created or deleted (or exec*() has been invoked). The counter is
  sent with several debugger messages.
* Track the image event counter that is used when samples are added to
  the profiling buffer. If the current team counter differs, we flush
  the buffer first (sending an update message to the debugger), so that
  the debugger has a chance to match the addresses to the correct images.
* Disable profiling for a thread while it runs in the debugger support
  code. This fixes potential deadlocks which could occur when a
  profiling timer event occurred that would require the buffer to be
  flushed while the thread was just sending something to the debugger or
  waiting for a command. As it turns out, this is not sufficient either,
  since we should never try to flush the buffer when the timer event
  occurred in the kernel, since the thread might hold a lock that the
  debugger thread could try to acquire. Will implement a more general
  solution later.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27656 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/user_debugger.h

@@ -54,6 +54,8 @@ struct team_debug_info {
 	sem_id		debugger_write_lock;
 		// synchronizes writes to the debugger port with the setting (but not
 		// clearing) of the B_TEAM_DEBUG_DEBUGGER_HANDOVER flag
+	vint32		image_event;
+		// counter incremented whenever an image is created/deleted
 
 	struct arch_team_debug_info	arch_info;
 };
@@ -86,6 +88,11 @@ struct thread_debug_info {
 			// number of samples the buffer currently holds
 		int32			stack_depth;
 			// number of return addresses to record per timer interval
+		int32			image_event;
+			// number of the image event when the first sample was written into
+			// the buffer
+		int32			disabled;
+			// if > 0, profiling is temporarily disabled for the thread
 		bool			buffer_full;
 			// indicates that the sample buffer is full
 		union {