commit dbb777a03ab24552f9b98506c5e30f2f9a23287b
author yzshen@chromium.org <yzshen@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> Tue May 06 14:42:38 2014 +0900
committer Qijiang Fan <fqj@google.com> Thu Jun 04 16:37:19 2020 +0900
tree b40080d35e97adef39f35bb482d458f0011ef5d7
parent 1b5c96deea1ba95448a5da4507dee0440c580cfa

Revert 268405 "Make sure that ScratchBuffer::Allocate() always r..."

> Make sure that ScratchBuffer::Allocate() always return 8-byte aligned addresses.
> 
> BUG=None
> TEST=None
> 
> Review URL: https://codereview.chromium.org/265403003

TBR=yzshen@chromium.org

Review URL: https://codereview.chromium.org/265823012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@268434 0039d316-1c4b-4281-b951-d872f2087c98


CrOS-Libchrome-Original-Commit: c178a234601bc745351061294b9a66690cc9d2cb

mojo/public/cpp/bindings/lib/scratch_buffer.cc

diff --git a/mojo/public/cpp/bindings/lib/scratch_buffer.cc b/mojo/public/cpp/bindings/lib/scratch_buffer.cc
index dee048f..9d23dcb 100644
--- a/mojo/public/cpp/bindings/lib/scratch_buffer.cc
+++ b/mojo/public/cpp/bindings/lib/scratch_buffer.cc
@@ -80,12 +80,11 @@
     return false;
 
   // Ensure segment buffer is aligned.
-  size_t padded_segment_size = internal::Align(sizeof(Segment));
-  Segment* segment = static_cast<Segment*>(
-      malloc(padded_segment_size + delta));
+  size_t segment_size = internal::Align(sizeof(Segment)) + delta;
+  Segment* segment = static_cast<Segment*>(malloc(segment_size));
   if (segment) {
     segment->next = overflow_;
-    segment->cursor = reinterpret_cast<char*>(segment) + padded_segment_size;
+    segment->cursor = reinterpret_cast<char*>(segment + 1);
     segment->end = segment->cursor + delta;
     overflow_ = segment;
     return true;

mojo/public/cpp/bindings/tests/buffer_unittest.cc

diff --git a/mojo/public/cpp/bindings/tests/buffer_unittest.cc b/mojo/public/cpp/bindings/tests/buffer_unittest.cc
index 1487ced..7ef7520 100644
--- a/mojo/public/cpp/bindings/tests/buffer_unittest.cc
+++ b/mojo/public/cpp/bindings/tests/buffer_unittest.cc
@@ -53,23 +53,6 @@
   EXPECT_TRUE(!overflow);
 }
 
-TEST(ScratchBufferTest, Alignment) {
-  Environment env;
-
-  internal::ScratchBuffer buf;
-  // Test that small allocations on the stack are aligned properly.
-  void* small = buf.Allocate(1);
-  EXPECT_EQ(0, reinterpret_cast<ptrdiff_t>(small) % 8);
-  small = buf.Allocate(2);
-  EXPECT_EQ(0, reinterpret_cast<ptrdiff_t>(small) % 8);
-
-  // Test that large allocations on the heap are aligned properly.
-  void* large = buf.Allocate(10*1024);
-  EXPECT_EQ(0, reinterpret_cast<ptrdiff_t>(large) % 8);
-  large = buf.Allocate(100*1024);
-  EXPECT_EQ(0, reinterpret_cast<ptrdiff_t>(large) % 8);
-}
-
 // Tests that Buffer::current() returns the correct value.
 TEST(ScratchBufferTest, Stacked) {
   Environment env;