1 files changed, 28 insertions, 3 deletions

diff --git a/lisp/progmodes/gdb-mi.el b/lisp/progmodes/gdb-mi.el
index 4994a5a37ea..2174c8d7908 100644
--- a/lisp/progmodes/gdb-mi.el
+++ b/lisp/progmodes/gdb-mi.el
@@ -403,6 +403,20 @@ triggers in `gdb-handler-list'."
          (gdb-wait-for-pending func)
        (funcall func)))))
 
+(defun gdb-start-wait-for-pending (var func)
+  "Start waiting for pending GDB commands with VAR and FUNC.
+This calls `gdb-wait-for-pending' if there isn't already a timer waiting
+for running the same FUNC, as indicated by a non-nil value of VAR.
+VAR should be a symbol of a boolean variable.
+The assumption is that when FUNC will be called, it will do the job for
+all the events that need to run FUNC after the pending GDB commands are
+finished.
+FUNC should reset VAR to nil, so further events of the same kind will
+be handled after FUNC exits."
+  (when (null (symbol-value var))
+    (set var t)
+    (gdb-wait-for-pending func)))
+
 ;; Publish-subscribe
 
 (defmacro gdb-add-subscriber (publisher subscriber)
@@ -2638,6 +2652,9 @@ means to decode using the coding-system set for the GDB process."
 
 (defun gdb-ignored-notification (_token _output-field))
 
+(defvar gdb--update-threads-queued-p nil
+  "If non-nil, we already queued the `update-threads' signal.")
+
 ;; gdb-invalidate-threads is defined to accept 'update-threads signal
 (defun gdb-thread-created (_token _output-field))
 (defun gdb-thread-exited (_token output-field)
@@ -2649,9 +2666,17 @@ Unset `gdb-thread-number' if current thread exited and update threads list."
     ;; When we continue current thread and it quickly exits,
     ;; the pending triggers in gdb-handler-list left after gdb-running
     ;; disallow us to properly call -thread-info without --thread option.
-    ;; Thus we need to use gdb-wait-for-pending.
-    (gdb-wait-for-pending
-     (lambda () (gdb-emit-signal gdb-buf-publisher 'update-threads)))))
+    ;; Thus we need to use gdb-wait-for-pending.  But we should start
+    ;; waiting only once if we get a long series of =thread-exited
+    ;; notifications during the wait period, because otherwise we will
+    ;; flood the Emacs main loop with many timers.  When the time
+    ;; expires, it will process all the threads that exited meanwhile,
+    ;; and the next =thread-exited notification will start a new wait.
+    (gdb-start-wait-for-pending
+     'gdb--update-threads-queued-p
+     (lambda ()
+       (setq gdb--update-threads-queued-p nil)
+       (gdb-emit-signal gdb-buf-publisher 'update-threads)))))
 
 (defun gdb-thread-selected (_token output-field)
   "Handler for =thread-selected MI output record.