From 666a1b73db31582227c0f0f59be31e382b8bebd7 Mon Sep 17 00:00:00 2001
From: Eden Chuang <echuang@mozilla.com>
Date: Mon, 15 Jan 2024 15:53:56 +0000
Subject: [PATCH] Bug 1874080 - Nullify WebTaskSchedulerWorker::mWorkerPrivate
 while Disconnect(). r=smaug, a=RyanVM

Differential Revision: https://phabricator.services.mozilla.com/D198569
---
 dom/webscheduling/WebTaskScheduler.h         |  2 +-
 dom/webscheduling/WebTaskSchedulerWorker.cpp | 13 +++++++++++++
 dom/webscheduling/WebTaskSchedulerWorker.h   |  2 ++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/dom/webscheduling/WebTaskScheduler.h b/dom/webscheduling/WebTaskScheduler.h
index fcddd09d365b..92e0bb6a44b3 100644
--- a/dom/webscheduling/WebTaskScheduler.h
+++ b/dom/webscheduling/WebTaskScheduler.h
@@ -113,7 +113,7 @@ class WebTaskScheduler : public nsWrapperCache, public SupportsWeakPtr {
 
   WebTask* GetNextTask() const;
 
-  void Disconnect();
+  virtual void Disconnect();
 
   void RunTaskSignalPriorityChange(TaskSignal* aTaskSignal);
 
diff --git a/dom/webscheduling/WebTaskSchedulerWorker.cpp b/dom/webscheduling/WebTaskSchedulerWorker.cpp
index 89fbb6169f0d..479d12cf7bb9 100644
--- a/dom/webscheduling/WebTaskSchedulerWorker.cpp
+++ b/dom/webscheduling/WebTaskSchedulerWorker.cpp
@@ -36,6 +36,9 @@ bool WebTaskWorkerRunnable::WorkerRun(JSContext* aCx,
 
 nsresult WebTaskSchedulerWorker::SetTimeoutForDelayedTask(WebTask* aTask,
                                                           uint64_t aDelay) {
+  if (!mWorkerPrivate) {
+    return NS_ERROR_UNEXPECTED;
+  }
   JSContext* cx = nsContentUtils::GetCurrentJSContext();
   if (!cx) {
     return NS_ERROR_UNEXPECTED;
@@ -52,8 +55,18 @@ nsresult WebTaskSchedulerWorker::SetTimeoutForDelayedTask(WebTask* aTask,
 }
 
 bool WebTaskSchedulerWorker::DispatchEventLoopRunnable() {
+  if (!mWorkerPrivate) {
+    return false;
+  }
   RefPtr<WebTaskWorkerRunnable> runnable =
       new WebTaskWorkerRunnable(mWorkerPrivate, this);
   return runnable->Dispatch();
 }
+
+void WebTaskSchedulerWorker::Disconnect() {
+  if (mWorkerPrivate) {
+    mWorkerPrivate = nullptr;
+  }
+  WebTaskScheduler::Disconnect();
+}
 }  // namespace mozilla::dom
diff --git a/dom/webscheduling/WebTaskSchedulerWorker.h b/dom/webscheduling/WebTaskSchedulerWorker.h
index 4af987736ea5..b27b1250ffa9 100644
--- a/dom/webscheduling/WebTaskSchedulerWorker.h
+++ b/dom/webscheduling/WebTaskSchedulerWorker.h
@@ -34,6 +34,8 @@ class WebTaskSchedulerWorker final : public WebTaskScheduler {
  public:
   explicit WebTaskSchedulerWorker(WorkerPrivate* aWorkerPrivate);
 
+  void Disconnect() override;
+
  private:
   ~WebTaskSchedulerWorker() = default;