mozilla-inbound: changeset 371245:702f9dbca19f3a8f31b628909fa4f75001a2f184

author	Daniel Holbert <dholbert@cs.stanford.edu>
	Wed, 26 Jul 2017 12:47:53 -0700
changeset 371245	702f9dbca19f3a8f31b628909fa4f75001a2f184
parent 371244	e68cb2040ee39bc0240a0f27b2bae1cf9f9dbb20
child 371246	d9e5fd58d089cbf9504cdd510d8a7fb31a8e46ea
push id	93049
push user	cbook@mozilla.com
push date	Thu, 27 Jul 2017 09:30:07 +0000
treeherder	mozilla-inbound@5e9f7561c2eb [default view] [failures only]
perfherder	[talos] [build metrics] [platform microbench] (compared to previous push)
reviewers	jfkthame
bugs	1384669
milestone	56.0a1
first release with	nightly linux32 e5693cea1ec9 / 56.0a1 / 20170727100240 / files nightly linux64 e5693cea1ec9 / 56.0a1 / 20170727100240 / files nightly mac 5845151f1a2c / 56.0a1 / 20170728100358 / files nightly win32 e5693cea1ec9 / 56.0a1 / 20170727100347 / files nightly win64 e5693cea1ec9 / 56.0a1 / 20170727100347 / files
last release without	nightly linux32 e8400551c2e3 / 56.0a1 / 20170726100241 / files nightly linux64 e8400551c2e3 / 56.0a1 / 20170726100241 / files nightly mac e8400551c2e3 / 56.0a1 / 20170726100322 / files nightly win32 388d81ed93fa / 56.0a1 / 20170726155629 / files nightly win64 388d81ed93fa / 56.0a1 / 20170726155629 / files

Bug 1384669: Reduce refcount churn in BidiParagraphData by using non-refcounted pointer hash keys. r=jfkthame We don't need to bother with refcounting for these pointers, because they're pointing to DOM elements, and the DOM is basically immutable during reflow. And BidiParagraphData is a stack-only class which only lives for a short period of reflow - so it can assume these pointers' targets will stick around for its whole life. MozReview-Commit-ID: J3SfRYoRweX

--- a/layout/base/nsBidiPresUtils.cpp
+++ b/layout/base/nsBidiPresUtils.cpp
@@ -11,16 +11,17 @@
 #include "nsFontMetrics.h"
 #include "nsGkAtoms.h"
 #include "nsPresContext.h"
 #include "nsBidiUtils.h"
 #include "nsCSSFrameConstructor.h"
 #include "nsContainerFrame.h"
 #include "nsInlineFrame.h"
 #include "nsPlaceholderFrame.h"
+#include "nsPointerHashKeys.h"
 #include "nsFirstLetterFrame.h"
 #include "nsUnicodeProperties.h"
 #include "nsTextFrame.h"
 #include "nsBlockFrame.h"
 #include "nsIFrameInlines.h"
 #include "nsStyleStructInlines.h"
 #include "RubyUtils.h"
 #include "nsRubyFrame.h"
@@ -127,17 +128,18 @@ GetBidiControl(nsStyleContext* aStyleCon
 }
 
 struct MOZ_STACK_CLASS BidiParagraphData
 {
   nsAutoString        mBuffer;
   AutoTArray<char16_t, 16> mEmbeddingStack;
   AutoTArray<nsIFrame*, 16> mLogicalFrames;
   AutoTArray<nsLineBox*, 16> mLinePerFrame;
-  nsDataHashtable<nsISupportsHashKey, int32_t> mContentToFrameIndex;
+  nsDataHashtable<nsPtrHashKey<const nsIContent>, int32_t>
+    mContentToFrameIndex;
   // Cached presentation context for the frames we're processing.
   nsPresContext*      mPresContext;
   bool                mIsVisual;
   bool                mRequiresBidi;
   nsBidiLevel         mParaLevel;
   nsIContent*         mPrevContent;
   nsIFrame*           mPrevFrame;
 #ifdef DEBUG