Bug 1608114 - Increase the priority of the TRR main thread events r=mayhemer

Differential Revision: https://phabricator.services.mozilla.com/D61306

--HG--
extra : moz-landing-system : lando

netwerk/protocol/http/nsHttpTransaction.cpp

@@ -32,6 +32,7 @@
 #include "nsIHttpActivityObserver.h"
 #include "nsIHttpAuthenticator.h"
 #include "nsIInputStream.h"
+#include "nsIInputStreamPriority.h"
 #include "nsIMultiplexInputStream.h"
 #include "nsIOService.h"
 #include "nsIPipe.h"
@@ -1898,6 +1899,14 @@ nsresult nsHttpTransaction::HandleContent(char* buf, uint32_t count,
     }
   }
 
+  if (mConnInfo->GetIsTrrServiceChannel()) {
+    // For the TRR channel we want to increase priority so a DoH response
+    // isn't blocked by other main thread events.
+    nsCOMPtr<nsIInputStreamPriority> pri = do_QueryInterface(mPipeIn);
+    if (pri) {
+      pri->SetPriority(nsIRunnablePriority::PRIORITY_MEDIUMHIGH);
+    }
+  }
   return NS_OK;
 }
 

xpcom/io/moz.build

@@ -17,6 +17,7 @@ XPIDL_SOURCES += [
     'nsIFile.idl',
     'nsIInputStream.idl',
     'nsIInputStreamLength.idl',
+    'nsIInputStreamPriority.idl',
     'nsIInputStreamTee.idl',
     'nsIIOUtil.idl',
     'nsILineInputStream.idl',

xpcom/io/nsIInputStreamPriority.idl

@@ -0,0 +1,17 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+#include "nsIRunnable.idl"
+
+[scriptable, uuid(daa45b24-98ee-4eb2-9cec-aad0bc023e9d)]
+interface nsIInputStreamPriority : nsISupports
+{
+    /**
+     * An input stream implementing this interface will dispatch runnable
+     * events with this priority. See nsIRunnablePriority.
+     */
+    attribute unsigned long priority;
+};

xpcom/io/nsPipe3.cpp

@@ -25,6 +25,7 @@
 #include "nsPipe.h"
 #include "nsIAsyncInputStream.h"
 #include "nsIAsyncOutputStream.h"
+#include "nsIInputStreamPriority.h"
 
 using namespace mozilla;
 
@@ -130,7 +131,8 @@ class nsPipeInputStream final : public nsIAsyncInputStream,
                                 public nsISearchableInputStream,
                                 public nsICloneableInputStream,
                                 public nsIClassInfo,
-                                public nsIBufferedInputStream {
+                                public nsIBufferedInputStream,
+                                public nsIInputStreamPriority {
  public:
   // Pipe input streams preserve their refcount changes when record/replaying,
   // as otherwise the thread which destroys the stream may vary between
@@ -143,6 +145,7 @@ class nsPipeInputStream final : public nsIAsyncInputStream,
   NS_DECL_NSICLONEABLEINPUTSTREAM
   NS_DECL_NSICLASSINFO
   NS_DECL_NSIBUFFEREDINPUTSTREAM
+  NS_DECL_NSIINPUTSTREAMPRIORITY
 
   explicit nsPipeInputStream(nsPipe* aPipe)
       : mPipe(aPipe),
@@ -150,7 +153,8 @@ class nsPipeInputStream final : public nsIAsyncInputStream,
         mInputStatus(NS_OK),
         mBlocking(true),
         mBlocked(false),
-        mCallbackFlags(0) {}
+        mCallbackFlags(0),
+        mPriority(nsIRunnablePriority::PRIORITY_NORMAL) {}
 
   explicit nsPipeInputStream(const nsPipeInputStream& aOther)
       : mPipe(aOther.mPipe),
@@ -159,7 +163,8 @@ class nsPipeInputStream final : public nsIAsyncInputStream,
         mBlocking(aOther.mBlocking),
         mBlocked(false),
         mCallbackFlags(0),
-        mReadState(aOther.mReadState) {}
+        mReadState(aOther.mReadState),
+        mPriority(nsIRunnablePriority::PRIORITY_NORMAL) {}
 
   nsresult Fill();
   void SetNonBlocking(bool aNonBlocking) { mBlocking = !aNonBlocking; }
@@ -205,6 +210,7 @@ class nsPipeInputStream final : public nsIAsyncInputStream,
 
   // requires pipe's monitor; usually treat as an opaque token to pass to nsPipe
   nsPipeReadState mReadState;
+  uint32_t mPriority;
 };
 
 //-----------------------------------------------------------------------------
@@ -1154,6 +1160,7 @@ NS_INTERFACE_TABLE_HEAD(nsPipeInputStream)
     NS_INTERFACE_TABLE_ENTRY(nsPipeInputStream, nsICloneableInputStream)
     NS_INTERFACE_TABLE_ENTRY(nsPipeInputStream, nsIBufferedInputStream)
     NS_INTERFACE_TABLE_ENTRY(nsPipeInputStream, nsIClassInfo)
+    NS_INTERFACE_TABLE_ENTRY(nsPipeInputStream, nsIInputStreamPriority)
     NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(nsPipeInputStream, nsIInputStream,
                                        nsIAsyncInputStream)
     NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(nsPipeInputStream, nsISupports,
@@ -1272,6 +1279,18 @@ nsPipeInputStream::CloseWithStatus(nsresult aReason) {
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsPipeInputStream::SetPriority(uint32_t priority) {
+  mPriority = priority;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsPipeInputStream::GetPriority(uint32_t* priority) {
+  *priority = mPriority;
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsPipeInputStream::Close() { return CloseWithStatus(NS_BASE_STREAM_CLOSED); }
 
@@ -1384,7 +1403,7 @@ nsPipeInputStream::AsyncWait(nsIInputStreamCallback* aCallback, uint32_t aFlags,
     nsCOMPtr<nsIInputStreamCallback> proxy;
     if (aTarget) {
       proxy = NS_NewInputStreamReadyEvent("nsPipeInputStream::AsyncWait",
-                                          aCallback, aTarget);
+                                          aCallback, aTarget, mPriority);
       aCallback = proxy;
     }
 

xpcom/io/nsStreamUtils.cpp

@@ -33,13 +33,17 @@ static NS_DEFINE_CID(kStreamTransportServiceCID, NS_STREAMTRANSPORTSERVICE_CID);
 // those can be shut down at any time, and in these cases, Cancel() is called
 // instead of Run().
 class nsInputStreamReadyEvent final : public CancelableRunnable,
-                                      public nsIInputStreamCallback {
+                                      public nsIInputStreamCallback,
+                                      public nsIRunnablePriority {
  public:
   NS_DECL_ISUPPORTS_INHERITED
 
   nsInputStreamReadyEvent(const char* aName, nsIInputStreamCallback* aCallback,
-                          nsIEventTarget* aTarget)
-      : CancelableRunnable(aName), mCallback(aCallback), mTarget(aTarget) {}
+                          nsIEventTarget* aTarget, uint32_t aPriority)
+      : CancelableRunnable(aName),
+        mCallback(aCallback),
+        mTarget(aTarget),
+        mPriority(aPriority) {}
 
  private:
   ~nsInputStreamReadyEvent() {
@@ -57,7 +61,7 @@ class nsInputStreamReadyEvent final : public CancelableRunnable,
     nsresult rv = mTarget->IsOnCurrentThread(&val);
     if (NS_FAILED(rv) || !val) {
       nsCOMPtr<nsIInputStreamCallback> event = NS_NewInputStreamReadyEvent(
-          "~nsInputStreamReadyEvent", mCallback, mTarget);
+          "~nsInputStreamReadyEvent", mCallback, mTarget, mPriority);
       mCallback = nullptr;
       if (event) {
         rv = event->OnInputStreamReady(nullptr);
@@ -98,14 +102,20 @@ class nsInputStreamReadyEvent final : public CancelableRunnable,
     return NS_OK;
   }
 
+  NS_IMETHOD GetPriority(uint32_t* aPriority) override {
+    *aPriority = mPriority;
+    return NS_OK;
+  }
+
  private:
   nsCOMPtr<nsIAsyncInputStream> mStream;
   nsCOMPtr<nsIInputStreamCallback> mCallback;
   nsCOMPtr<nsIEventTarget> mTarget;
+  uint32_t mPriority;
 };
 
 NS_IMPL_ISUPPORTS_INHERITED(nsInputStreamReadyEvent, CancelableRunnable,
-                            nsIInputStreamCallback)
+                            nsIInputStreamCallback, nsIRunnablePriority)
 
 //-----------------------------------------------------------------------------
 
@@ -193,11 +203,11 @@ NS_IMPL_ISUPPORTS_INHERITED(nsOutputStreamReadyEvent, CancelableRunnable,
 
 already_AddRefed<nsIInputStreamCallback> NS_NewInputStreamReadyEvent(
     const char* aName, nsIInputStreamCallback* aCallback,
-    nsIEventTarget* aTarget) {
+    nsIEventTarget* aTarget, uint32_t aPriority) {
   NS_ASSERTION(aCallback, "null callback");
   NS_ASSERTION(aTarget, "null target");
   RefPtr<nsInputStreamReadyEvent> ev =
-      new nsInputStreamReadyEvent(aName, aCallback, aTarget);
+      new nsInputStreamReadyEvent(aName, aCallback, aTarget, aPriority);
   return ev.forget();
 }
 

xpcom/io/nsStreamUtils.h

@@ -11,6 +11,7 @@
 #include "nsStringFwd.h"
 #include "nsIInputStream.h"
 #include "nsTArray.h"
+#include "nsIRunnable.h"
 
 class nsIAsyncInputStream;
 class nsIOutputStream;
@@ -27,10 +28,13 @@ class nsIEventTarget;
  *
  * This function is designed to be used to implement AsyncWait when the
  * aTarget parameter is non-null.
+ *
+ * The optional aPriority parameter allows the input stream runnable events
+ * to be dispatched with a different priority than normal.
  */
 extern already_AddRefed<nsIInputStreamCallback> NS_NewInputStreamReadyEvent(
-    const char* aName, nsIInputStreamCallback* aNotify,
-    nsIEventTarget* aTarget);
+    const char* aName, nsIInputStreamCallback* aNotify, nsIEventTarget* aTarget,
+    uint32_t aPriority = nsIRunnablePriority::PRIORITY_NORMAL);
 
 /**
  * A "one-shot" proxy of the OnOutputStreamReady callback.  The resulting