Backed out changeset 8bfa7127e064 (bug 1629457) for WPT and Mochitest failures. CLOSED TREE

netwerk/base/nsDNSPrefetch.cpp

@@ -54,8 +54,7 @@ nsDNSPrefetch::nsDNSPrefetch(nsIURI* aURI,
     : mOriginAttributes(aOriginAttributes),
       mStoreTiming(storeTiming),
       mTRRMode(aTRRMode),
-      mListener(aListener),
-      mTarget(GetCurrentThreadEventTarget()) {
+      mListener(do_GetWeakReference(aListener)) {
   aURI->GetAsciiHost(mHostname);
   mIsHttps = aURI->SchemeIs("https");
 }
@@ -72,11 +71,12 @@ nsresult nsDNSPrefetch::Prefetch(uint32_t flags) {
   // then our timing will be useless. However, in such a case,
   // mEndTimestamp will be a null timestamp and callers should check
   // TimingsValid() before using the timing.
+  nsCOMPtr<nsIEventTarget> target = mozilla::GetCurrentThreadEventTarget();
 
   flags |= nsIDNSService::GetFlagsFromTRRMode(mTRRMode);
 
   nsresult rv = sDNSService->AsyncResolveNative(
-      mHostname, flags | nsIDNSService::RESOLVE_SPECULATE, this, mTarget,
+      mHostname, flags | nsIDNSService::RESOLVE_SPECULATE, this, target,
       mOriginAttributes, getter_AddRefs(tmpOutstanding));
   if (NS_FAILED(rv)) {
     return rv;
@@ -89,7 +89,7 @@ nsresult nsDNSPrefetch::Prefetch(uint32_t flags) {
     esniHost.Append(mHostname);
     sDNSService->AsyncResolveByTypeNative(
         esniHost, nsIDNSService::RESOLVE_TYPE_TXT,
-        flags | nsIDNSService::RESOLVE_SPECULATE, this, mTarget,
+        flags | nsIDNSService::RESOLVE_SPECULATE, this, target,
         mOriginAttributes, getter_AddRefs(tmpOutstanding));
   }
   return NS_OK;
@@ -114,16 +114,16 @@ NS_IMPL_ISUPPORTS(nsDNSPrefetch, nsIDNSListener)
 NS_IMETHODIMP
 nsDNSPrefetch::OnLookupComplete(nsICancelable* request, nsIDNSRecord* rec,
                                 nsresult status) {
-  MOZ_ASSERT(mTarget->IsOnCurrentThread());
-
   if (mStoreTiming) {
     mEndTimestamp = mozilla::TimeStamp::Now();
   }
-
-  nsCOMPtr<nsIDNSListener> listener;
-  mListener.swap(listener);
-
-  MOZ_ASSERT(listener);
+  nsCOMPtr<nsIDNSListener> listener = do_QueryReferent(mListener);
+  if (listener) {
     listener->OnLookupComplete(request, rec, status);
+  }
+  // OnLookupComplete should be called on the target thread, so we release
+  // mListener here to make sure mListener is also released on the target
+  // thread.
+  mListener = nullptr;
   return NS_OK;
 }

netwerk/base/nsDNSPrefetch.h

@@ -6,6 +6,7 @@
 #ifndef nsDNSPrefetch_h___
 #define nsDNSPrefetch_h___
 
+#include "nsIWeakReferenceUtils.h"
 #include "nsString.h"
 #include "mozilla/TimeStamp.h"
 #include "mozilla/Attributes.h"
@@ -52,8 +53,7 @@ class nsDNSPrefetch final : public nsIDNSListener {
   nsIRequest::TRRMode mTRRMode;
   mozilla::TimeStamp mStartTimestamp;
   mozilla::TimeStamp mEndTimestamp;
-  nsCOMPtr<nsIDNSListener> mListener;
-  nsCOMPtr<nsIEventTarget> mTarget;
+  nsWeakPtr mListener;
 
   nsresult Prefetch(uint32_t flags);
 };

netwerk/protocol/http/nsHttpChannel.cpp

@@ -439,6 +439,7 @@ void nsHttpChannel::ReleaseMainThreadOnlyReferences() {
   arrayToRelease.AppendElement(mAuthProvider.forget());
   arrayToRelease.AppendElement(mRedirectChannel.forget());
   arrayToRelease.AppendElement(mPreflightChannel.forget());
+  arrayToRelease.AppendElement(mDNSPrefetch.forget());
 
   NS_DispatchToMainThread(new ProxyReleaseRunnable(std::move(arrayToRelease)));
 }