Made the aligned malloc templated.

BUG=N/A

Review URL: https://webrtc-codereview.appspot.com/865004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@2866 4adac7df-926f-26a2-2b94-8c16560cd09d

src/system_wrappers/interface/aligned_malloc.h

@@ -34,7 +34,19 @@ void* GetRightAlign(const void* ptr, size_t alignment);
 // be de-allocated using AlignedFree.
 void* AlignedMalloc(size_t size, size_t alignment);
 // De-allocates memory created using the AlignedMalloc() API.
-void AlignedFree(void* memBlock);
+void AlignedFree(void* mem_block);
+
+// Templated versions to facilitate usage of aligned malloc without casting
+// to and from void*.
+template<typename T>
+T* GetRightAlign(const T* ptr, size_t alignment) {
+  return reinterpret_cast<T*>(GetRightAlign(reinterpret_cast<const void*>(ptr),
+                                            alignment));
+}
+template<typename T>
+T* AlignedMalloc(size_t size, size_t alignment) {
+  return reinterpret_cast<T*>(AlignedMalloc(size, alignment));
+}
 
 // Scoped pointer to AlignedMalloc-memory.
 template<typename T>

src/system_wrappers/source/aligned_malloc.cc

@@ -27,14 +27,14 @@ namespace webrtc {
 // TODO(henrike): better to create just one memory block and interpret the
 //                first sizeof(AlignedMemory) bytes as an AlignedMemory struct.
 struct AlignedMemory {
-  void* alignedBuffer;
-  void* memoryPointer;
+  void* aligned_buffer;
+  void* memory_pointer;
 };
 
-uintptr_t GetRightAlign(uintptr_t startPos, size_t alignment) {
+uintptr_t GetRightAlign(uintptr_t start_pos, size_t alignment) {
   // The pointer should be aligned with |alignment| bytes. The - 1 guarantees
   // that it is aligned towards the closest higher (right) address.
-  return (startPos + alignment - 1) & ~(alignment - 1);
+  return (start_pos + alignment - 1) & ~(alignment - 1);
 }
 
 // Alignment must be an integer power of two.
@@ -52,8 +52,8 @@ void* GetRightAlign(const void* ptr, size_t alignment) {
   if (!ValidAlignment(alignment)) {
     return NULL;
   }
-  uintptr_t startPos = reinterpret_cast<uintptr_t>(ptr);
-  return reinterpret_cast<void*>(GetRightAlign(startPos, alignment));
+  uintptr_t start_pos = reinterpret_cast<uintptr_t>(ptr);
+  return reinterpret_cast<void*>(GetRightAlign(start_pos, alignment));
 }
 
 void* AlignedMalloc(size_t size, size_t alignment) {
@@ -64,8 +64,8 @@ void* AlignedMalloc(size_t size, size_t alignment) {
     return NULL;
   }
 
-  AlignedMemory* returnValue = new AlignedMemory();
-  if (returnValue == NULL) {
+  AlignedMemory* return_value = new AlignedMemory();
+  if (return_value == NULL) {
     return NULL;
   }
 
@@ -73,46 +73,46 @@ void* AlignedMalloc(size_t size, size_t alignment) {
   // alignment - 1 bytes needs to be allocated.
   // A pointer to AlignedMemory must be stored so that it can be retreived for
   // deletion, ergo the sizeof(uintptr_t).
-  returnValue->memoryPointer = malloc(size + sizeof(uintptr_t) +
-                                      alignment - 1);
-  if (returnValue->memoryPointer == NULL) {
-    delete returnValue;
+  return_value->memory_pointer = malloc(size + sizeof(uintptr_t) +
+                                        alignment - 1);
+  if (return_value->memory_pointer == NULL) {
+    delete return_value;
     return NULL;
   }
 
   // Aligning after the sizeof(header) bytes will leave room for the header
   // in the same memory block.
-  uintptr_t alignStartPos =
-      reinterpret_cast<uintptr_t>(returnValue->memoryPointer);
-  alignStartPos += sizeof(uintptr_t);
-  uintptr_t alignedPos = GetRightAlign(alignStartPos, alignment);
-  returnValue->alignedBuffer = reinterpret_cast<void*>(alignedPos);
+  uintptr_t align_start_pos =
+      reinterpret_cast<uintptr_t>(return_value->memory_pointer);
+  align_start_pos += sizeof(uintptr_t);
+  uintptr_t aligned_pos = GetRightAlign(align_start_pos, alignment);
+  return_value->aligned_buffer = reinterpret_cast<void*>(aligned_pos);
 
   // Store the address to the AlignedMemory struct in the header so that a
   // it's possible to reclaim all memory.
-  uintptr_t headerPos = alignedPos;
-  headerPos -= sizeof(uintptr_t);
-  void* headerPtr = reinterpret_cast<void*>(headerPos);
-  uintptr_t headerValue = reinterpret_cast<uintptr_t>(returnValue);
-  memcpy(headerPtr,&headerValue,sizeof(uintptr_t));
-  return returnValue->alignedBuffer;
+  uintptr_t header_pos = aligned_pos;
+  header_pos -= sizeof(uintptr_t);
+  void* header_ptr = reinterpret_cast<void*>(header_pos);
+  uintptr_t header_value = reinterpret_cast<uintptr_t>(return_value);
+  memcpy(header_ptr, &header_value, sizeof(uintptr_t));
+  return return_value->aligned_buffer;
 }
 
-void AlignedFree(void* memBlock) {
-  if (memBlock == NULL) {
+void AlignedFree(void* mem_block) {
+  if (mem_block == NULL) {
     return;
   }
-  uintptr_t alignedPos = reinterpret_cast<uintptr_t>(memBlock);
-  uintptr_t headerPos = alignedPos - sizeof(uintptr_t);
+  uintptr_t aligned_pos = reinterpret_cast<uintptr_t>(mem_block);
+  uintptr_t header_pos = aligned_pos - sizeof(uintptr_t);
 
   // Read out the address of the AlignedMemory struct from the header.
-  uintptr_t* headerPtr = reinterpret_cast<uintptr_t*>(headerPos);
-  AlignedMemory* deleteMemory = reinterpret_cast<AlignedMemory*>(*headerPtr);
+  uintptr_t* header_ptr = reinterpret_cast<uintptr_t*>(header_pos);
+  AlignedMemory* delete_memory = reinterpret_cast<AlignedMemory*>(*header_ptr);
 
-  if (deleteMemory->memoryPointer != NULL) {
-    free(deleteMemory->memoryPointer);
+  if (delete_memory->memory_pointer != NULL) {
+    free(delete_memory->memory_pointer);
   }
-  delete deleteMemory;
+  delete delete_memory;
 }
 
 }  // namespace webrtc

src/system_wrappers/source/aligned_malloc_unittest.cc

@@ -23,7 +23,7 @@
 // Returns true if |size| and |alignment| are valid combinations.
 bool CorrectUsage(size_t size, size_t alignment) {
   webrtc::Allocator<char>::scoped_ptr_aligned scoped(
-    static_cast<char*> (webrtc::AlignedMalloc(size, alignment)));
+      webrtc::AlignedMalloc<char>(size, alignment));
   if (scoped.get() == NULL) {
     return false;
   }
@@ -36,14 +36,15 @@ TEST(AlignedMalloc, GetRightAlign) {
   const size_t alignment = 32;
   const size_t left_missalignment = 8;
   webrtc::Allocator<char>::scoped_ptr_aligned scoped(
-    static_cast<char*> (webrtc::AlignedMalloc(size, alignment)));
+      webrtc::AlignedMalloc<char>(size, alignment));
   EXPECT_TRUE(scoped.get() != NULL);
   const uintptr_t aligned_address = reinterpret_cast<uintptr_t> (scoped.get());
   const uintptr_t missaligned_address = aligned_address - left_missalignment;
-  const void* missaligned_ptr =  reinterpret_cast<void*> (missaligned_address);
-  const void* realignedPtr = webrtc::GetRightAlign(
-    missaligned_ptr, alignment);
-  EXPECT_EQ(scoped.get(), realignedPtr);
+  const char* missaligned_ptr = reinterpret_cast<const char*>(
+      missaligned_address);
+  const char* realigned_ptr = webrtc::GetRightAlign(
+      missaligned_ptr, alignment);
+  EXPECT_EQ(scoped.get(), realigned_ptr);
 }
 
 TEST(AlignedMalloc, IncorrectSize) {