Fix JAB freeze when navigating in JetBrains IDEs

source/JABHandler.py

@@ -1,5 +1,5 @@
 # A part of NonVisual Desktop Access (NVDA)
-# Copyright (C) 2007-2025 NV Access Limited, Peter Vágner, Renaud Paquay, Babbage B.V.
+# Copyright (C) 2007-2026 NV Access Limited, Peter Vágner, Renaud Paquay, Babbage B.V.
 # This file is covered by the GNU General Public License.
 # See the file COPYING for more details.
 
@@ -548,7 +548,34 @@ def _fixBridgeFuncs():
 
 
 def internalQueueFunction(func, *args, **kwargs):
-	internalFunctionQueue.put_nowait((func, args, kwargs))
+	"""Queue a function for execution on the main thread.
+
+	When the queue is full, the oldest event is evicted to make room.
+	JOBJECT64 handles owned by evicted events are released to avoid leaks.
+
+	.. note::
+		All queued handler functions except :func:`enterJavaWindow_helper`
+		follow the convention ``(vmID, accContext, ...)``, where ``args[1]``
+		is a JOBJECT64 handle.  If a new handler with a different signature
+		is added, the eviction cleanup below must be updated.
+	"""
+	try:
+		internalFunctionQueue.put_nowait((func, args, kwargs))
+	except queue.Full:
+		try:
+			evictedFunc, evictedArgs, _evictedKwargs = internalFunctionQueue.get_nowait()
+			# Release the JOBJECT64 accContext handle from the evicted event.
+			# All handlers except enterJavaWindow_helper have args[1] as accContext.
+			if evictedFunc is not enterJavaWindow_helper and len(evictedArgs) >= 2:
+				bridgeDll.releaseJavaObject(evictedArgs[0], evictedArgs[1])
+		except queue.Empty:
+			pass
+		try:
+			internalFunctionQueue.put_nowait((func, args, kwargs))
+		except queue.Full:
+			log.debugWarning("JAB internal function queue full, failed to re-queue after eviction")
+			return
+		log.debugWarning("JAB internal function queue full, evicted oldest event")
 	core.requestPump()
 
 
@@ -959,6 +986,8 @@ def internal_event_activeDescendantChange(vmID, event, source, oldDescendant, ne
 	sourceContext = JABContext(hwnd=hwnd, vmID=vmID, accContext=source)
 	if internal_hasFocus(sourceContext):
 		internalQueueFunction(event_gainFocus, vmID, newDescendant, hwnd)
+	else:
+		bridgeDll.releaseJavaObject(vmID, newDescendant)
 	for accContext in [event, oldDescendant]:
 		bridgeDll.releaseJavaObject(vmID, accContext)
 
@@ -972,8 +1001,13 @@ def internal_hasFocus(sourceContext):
 
 
 @AccessBridge_PropertyNameChangeFP
-def event_nameChange(vmID, event, source, oldVal, newVal):
-	jabContext = JABContext(vmID=vmID, accContext=source)
+def internal_event_nameChange(vmID, event, source, oldVal, newVal):
+	internalQueueFunction(event_nameChange, vmID, source)
+	bridgeDll.releaseJavaObject(vmID, event)
+
+
+def event_nameChange(vmID, accContext):
+	jabContext = JABContext(vmID=vmID, accContext=accContext)
 	if jabContext.hwnd:
 		focus = api.getFocusObject()
 		obj = (
@@ -985,12 +1019,16 @@ def event_nameChange(vmID, event, source, oldVal, newVal):
 			eventHandler.queueEvent("nameChange", obj)
 	else:
 		log.debugWarning("Unable to obtain window handle for accessible context")
-	bridgeDll.releaseJavaObject(vmID, event)
 
 
 @AccessBridge_PropertyDescriptionChangeFP
-def event_descriptionChange(vmID, event, source, oldVal, newVal):
-	jabContext = JABContext(vmID=vmID, accContext=source)
+def internal_event_descriptionChange(vmID, event, source, oldVal, newVal):
+	internalQueueFunction(event_descriptionChange, vmID, source)
+	bridgeDll.releaseJavaObject(vmID, event)
+
+
+def event_descriptionChange(vmID, accContext):
+	jabContext = JABContext(vmID=vmID, accContext=accContext)
 	if jabContext.hwnd:
 		focus = api.getFocusObject()
 		obj = (
@@ -1002,12 +1040,16 @@ def event_descriptionChange(vmID, event, source, oldVal, newVal):
 			eventHandler.queueEvent("descriptionChange", obj)
 	else:
 		log.debugWarning("Unable to obtain window handle for accessible context")
-	bridgeDll.releaseJavaObject(vmID, event)
 
 
 @AccessBridge_PropertyValueChangeFP
-def event_valueChange(vmID, event, source, oldVal, newVal):
-	jabContext = JABContext(vmID=vmID, accContext=source)
+def internal_event_valueChange(vmID, event, source, oldVal, newVal):
+	internalQueueFunction(event_valueChange, vmID, source)
+	bridgeDll.releaseJavaObject(vmID, event)
+
+
+def event_valueChange(vmID, accContext):
+	jabContext = JABContext(vmID=vmID, accContext=accContext)
 	if jabContext.hwnd:
 		focus = api.getFocusObject()
 		obj = (
@@ -1019,7 +1061,6 @@ def event_valueChange(vmID, event, source, oldVal, newVal):
 			eventHandler.queueEvent("valueChange", obj)
 	else:
 		log.debugWarning("Unable to obtain window handle for accessible context")
-	bridgeDll.releaseJavaObject(vmID, event)
 
 
 @AccessBridge_PropertyStateChangeFP
@@ -1155,9 +1196,9 @@ def initialize():
 	# Register java events
 	bridgeDll.setFocusGainedFP(internal_event_focusGained)
 	bridgeDll.setPropertyActiveDescendentChangeFP(internal_event_activeDescendantChange)
-	bridgeDll.setPropertyNameChangeFP(event_nameChange)
-	bridgeDll.setPropertyDescriptionChangeFP(event_descriptionChange)
-	bridgeDll.setPropertyValueChangeFP(event_valueChange)
+	bridgeDll.setPropertyNameChangeFP(internal_event_nameChange)
+	bridgeDll.setPropertyDescriptionChangeFP(internal_event_descriptionChange)
+	bridgeDll.setPropertyValueChangeFP(internal_event_valueChange)
 	bridgeDll.setPropertyStateChangeFP(internal_event_stateChange)
 	bridgeDll.setPropertyCaretChangeFP(internal_event_caretChange)
 	isRunning = True
@@ -1174,6 +1215,9 @@ def terminate():
 		return
 	bridgeDll.setFocusGainedFP(None)
 	bridgeDll.setPropertyActiveDescendentChangeFP(None)
+	bridgeDll.setPropertyNameChangeFP(None)
+	bridgeDll.setPropertyDescriptionChangeFP(None)
+	bridgeDll.setPropertyValueChangeFP(None)
 	bridgeDll.setPropertyStateChangeFP(None)
 	bridgeDll.setPropertyCaretChangeFP(None)
 	h = bridgeDll._handle

source/NVDAObjects/JAB/__init__.py

@@ -1,5 +1,5 @@
 # A part of NonVisual Desktop Access (NVDA)
-# Copyright (C) 2006-2025 NV Access Limited, Leonard de Ruijter, Joseph Lee, Renaud Paquay, pvagner, hwf1324
+# Copyright (C) 2006-2026 NV Access Limited, Leonard de Ruijter, Joseph Lee, Renaud Paquay, pvagner, hwf1324
 # This file is covered by the GNU General Public License.
 # See the file COPYING for more details.
 
@@ -248,13 +248,44 @@ def findOverlayClasses(self, clsList: list[NVDAObject]) -> None:
 			clsList.append(ComboBox)
 		elif role == "table":
 			clsList.append(Table)
-		elif self.parent and isinstance(self.parent, Table) and self.parent._jabTableInfo:
+		elif self._hasTableParent():
 			clsList.append(TableCell)
 		elif role == "progress bar":
 			clsList.append(ProgressBar)
 
 		clsList.append(JAB)
 
+	def _hasTableParent(self) -> bool:
+		"""Lightweight check if the immediate parent is a Table.
+
+		On the fast path (parent already cached), returns immediately
+		without any bridge calls.  On the first call, checks the parent's
+		role via a lightweight bridge call and only creates a full NVDAObject
+		when the role is "table" (which involves additional bridge calls).
+		"""
+		if hasattr(self, "_parent"):
+			parent = self._parent
+			return parent is not None and isinstance(parent, Table) and parent._jabTableInfo
+		parentContext = self.jabContext.getAccessibleParentFromContext()
+		if not parentContext:
+			return False
+		try:
+			parentInfo = parentContext.getAccessibleContextInfo()
+		except RuntimeError:
+			log.debugWarning("Could not get accessible context info for parent", exc_info=True)
+			return False
+		if parentInfo.role_en_US != "table":
+			return False
+		if self.indexInParent is None:
+			# Without indexInParent we cannot construct a valid JAB parent;
+			# _get_parent would also fall back to the Window ancestor here.
+			return False
+		# Parent is a table — create the full parent object reusing the context
+		# we already hold, so _get_parent doesn't make a redundant bridge call.
+		self._parent = JAB(jabContext=parentContext)
+		parent = self._parent
+		return parent is not None and isinstance(parent, Table) and parent._jabTableInfo
+
 	@classmethod
 	def kwargsFromSuper(cls, kwargs, relation: str | None = None) -> bool:
 		jabContext = None

user_docs/en/changes.md

@@ -58,6 +58,7 @@ This is more noticeable for Windows releases which are enablement packages on to
 * Configuration profile triggers now activate when the Add-on Store is open. (#19583, @bramd)
 * Decorative Unicode letters such as negative squared, negative circled, and regional indicator symbol characters are now normalized to their base Latin letters when Unicode normalization is enabled. (#19608, @bramd)
 * NVDA no longer crashes when the Add-on Store download directory cannot be cleaned up due to file permission errors. (#19202, @christopherpross)
+* Fixed NVDA freezing when navigating in JetBrains IDEs. (#16741, @christopherpross)
 
 ### Changes for Developers