Bug 1605895 - Advance the diagnostic assertion to check status of background channel event queues, r=michal,necko-reviewers

Differential Revision: https://phabricator.services.mozilla.com/D80639

netwerk/protocol/http/HttpBackgroundChannelChild.cpp

@@ -70,6 +70,14 @@ void HttpBackgroundChannelChild::OnChannelClosed() {
   LOG(("HttpBackgroundChannelChild::OnChannelClosed [this=%p]\n", this));
   MOZ_ASSERT(OnSocketThread());
 
+#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
+  if (mChannelChild) {
+    mChannelChild->mBackgroundChildQueueFinalState =
+        mQueuedRunnables.IsEmpty() ? HttpChannelChild::BCKCHILD_EMPTY
+                                   : HttpChannelChild::BCKCHILD_NON_EMPTY;
+  }
+#endif
+
   // HttpChannelChild is not going to handle any incoming message.
   mChannelChild = nullptr;
 

netwerk/protocol/http/HttpChannelChild.cpp

@@ -175,6 +175,9 @@ HttpChannelChild::HttpChannelChild()
       mIsRacing(false),
       mCacheNeedToReportBytesReadInitialized(false),
       mNeedToReportBytesRead(true),
+#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
+      mBackgroundChildQueueFinalState(BCKCHILD_UNKNOWN),
+#endif
       mCacheEntryAvailable(false),
       mAltDataCacheEntryAvailable(false),
       mSendResumeAt(false),
@@ -228,10 +231,13 @@ HttpChannelChild::~HttpChannelChild() {
         (mInterceptedRedirectListener ? 1 << 7 : 0) | (mCanceled ? 1 << 8 : 0) |
         (mRedirectChannelChild ? 1 << 9 : 0) |
         (mEventQ->IsEmpty() ? 1 << 10 : 0) | (nullBgChild ? 1 << 11 : 0) |
-        (emptyBgChildQueue ? 1 << 12 : 0);
+        (emptyBgChildQueue ? 1 << 12 : 0) |
+        (mOnStartRequestCalled ? 1 << 13 : 0) |
+        (mBackgroundChildQueueFinalState == BCKCHILD_EMPTY ? 1 << 14 : 0) |
+        (mBackgroundChildQueueFinalState == BCKCHILD_NON_EMPTY ? 1 << 15 : 0);
     MOZ_CRASH_UNSAFE_PRINTF(
         "~HttpChannelChild, mOnStopRequestCalled=false, mStatus=0x%08x, "
-        "mActorDestroyReason=%d, 20200601 flags=%u",
+        "mActorDestroyReason=%d, 20200618 flags=%u",
         static_cast<uint32_t>(nsresult(mStatus)),
         static_cast<int32_t>(mActorDestroyReason ? *mActorDestroyReason : -1),
         flags);

netwerk/protocol/http/HttpChannelChild.h

@@ -420,6 +420,16 @@ class HttpChannelChild final : public PHttpChannelChild,
   bool mDoDiagnosticAssertWhenOnStopNotCalledOnDestroy = false;
   bool mAsyncOpenSucceeded = false;
   bool mSuccesfullyRedirected = false;
+  // State of the HttpBackgroundChannelChild's event queue during destruction.
+  enum BckChildQueueStatus {
+    // BckChild never told us
+    BCKCHILD_UNKNOWN,
+    // BckChild was empty at the time of destruction
+    BCKCHILD_EMPTY,
+    // BckChild was keeping events in the queue at the destruction time!
+    BCKCHILD_NON_EMPTY
+  };
+  Atomic<BckChildQueueStatus> mBackgroundChildQueueFinalState;
   Maybe<ActorDestroyReason> mActorDestroyReason;
 #endif