Upgrade AlignedMemory to support dynamic allocations.

Adds two new methods: AlignedAlloc and AlignedFree for creating and
destroying dynamic aligned allocations respectively.  Also adds a
helper class, ScopedPtrAlignedFree, for use with scoped_ptr_malloc.

AlignedAlloc uses posix_memalign for OS X (now that we're targeting
10.6), Linux and _aligned_alloc() on Windows.  Android and NaCl use
memalign() since they do not expose posix_memalign() and memalign()
is safe to use with free() on those platforms.

Also hacks around a bug in Visual C++ where __alignof will sometimes
return zero:
http://connect.microsoft.com/VisualStudio/feedback/details/682695/c-alignof-fails-to-properly-evalute-alignment-of-dependent-types

BUG=none
TEST=base_unittests + new test, trybots.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=147988

Review URL: https://chromiumcodereview.appspot.com/10796020

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@148483 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 29 insertions, 0 deletions

diff --git a/base/memory/aligned_memory_unittest.cc b/base/memory/aligned_memory_unittest.cc
index 8c1eb61..c337751 100644
--- a/base/memory/aligned_memory_unittest.cc
+++ b/base/memory/aligned_memory_unittest.cc
@@ -51,4 +51,33 @@ TEST(AlignedMemoryTest, StackAlignment) {
 #endif  // !(defined(OS_IOS) && defined(ARCH_CPU_ARM_FAMILY))
 }
 
+TEST(AlignedMemoryTest, DynamicAllocation) {
+  void* p = base::AlignedAlloc(8, 8);
+  EXPECT_TRUE(p);
+  EXPECT_ALIGNED(p, 8);
+  base::AlignedFree(p);
+
+  p = base::AlignedAlloc(8, 16);
+  EXPECT_TRUE(p);
+  EXPECT_ALIGNED(p, 16);
+  base::AlignedFree(p);
+
+  p = base::AlignedAlloc(8, 256);
+  EXPECT_TRUE(p);
+  EXPECT_ALIGNED(p, 256);
+  base::AlignedFree(p);
+
+  p = base::AlignedAlloc(8, 4096);
+  EXPECT_TRUE(p);
+  EXPECT_ALIGNED(p, 4096);
+  base::AlignedFree(p);
+}
+
+TEST(AlignedMemoryTest, ScopedDynamicAllocation) {
+  scoped_ptr_malloc<float, base::ScopedPtrAlignedFree> p(
+      static_cast<float*>(base::AlignedAlloc(8, 8)));
+  EXPECT_TRUE(p.get());
+  EXPECT_ALIGNED(p.get(), 8);
+}
+
 }  // namespace