Rename INVALID_OFFSET to kInvalidOffset.

BUG=dawn:27

Change-Id: Ida590a2b3cf3da17bbedf6ef61d72eaaa443bc4b
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/11561
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

src/dawn_native/BuddyAllocator.cpp

@@ -91,7 +91,7 @@ namespace dawn_native {
                 break;
             }
         }
-        return INVALID_OFFSET;  // No free block exists at any level.
+        return kInvalidOffset;  // No free block exists at any level.
     }
 
     // Inserts existing free block into the free-list.
@@ -141,7 +141,7 @@ namespace dawn_native {
 
     uint64_t BuddyAllocator::Allocate(uint64_t allocationSize, uint64_t alignment) {
         if (allocationSize == 0 || allocationSize > mMaxBlockSize) {
-            return INVALID_OFFSET;
+            return kInvalidOffset;
         }
 
         // Compute the level
@@ -152,8 +152,8 @@ namespace dawn_native {
         uint64_t currBlockLevel = GetNextFreeAlignedBlock(allocationSizeToLevel, alignment);
 
         // Error when no free blocks exist (allocator is full)
-        if (currBlockLevel == INVALID_OFFSET) {
+        if (currBlockLevel == kInvalidOffset) {
-            return INVALID_OFFSET;
+            return kInvalidOffset;
         }
 
         // Split free blocks level-by-level.

src/dawn_native/BuddyAllocator.h

@@ -22,9 +22,7 @@
 
 namespace dawn_native {
 
-    static constexpr uint64_t INVALID_OFFSET = std::numeric_limits<uint64_t>::max();
+    // Buddy allocator uses the buddy memory allocation technique to satisfy an allocation request.
-
-    // Buddy allocator uses the buddy memory allocation technique to satisify an allocation request.
     // Memory is split into halves until just large enough to fit to the request. This
     // requires the allocation size to be a power-of-two value. The allocator "allocates" a block by
     // returning the starting offset whose size is guaranteed to be greater than or equal to the
@@ -47,6 +45,8 @@ namespace dawn_native {
         // For testing purposes only.
         uint64_t ComputeTotalNumOfFreeBlocksForTesting() const;
 
+        static constexpr uint64_t kInvalidOffset = std::numeric_limits<uint64_t>::max();
+
       private:
         uint32_t ComputeLevelFromBlockSize(uint64_t blockSize) const;
         uint64_t GetNextFreeAlignedBlock(size_t allocationBlockLevel, uint64_t alignment) const;

src/tests/unittests/BuddyAllocatorTests.cpp

@@ -17,6 +17,8 @@
 
 using namespace dawn_native;
 
+constexpr uint64_t BuddyAllocator::kInvalidOffset;
+
 // Verify the buddy allocator with a basic test.
 TEST(BuddyAllocatorTests, SingleBlock) {
     // After one 32 byte allocation:
@@ -29,17 +31,17 @@ TEST(BuddyAllocatorTests, SingleBlock) {
     BuddyAllocator allocator(maxBlockSize);
 
     // Check that we cannot allocate a oversized block.
-    ASSERT_EQ(allocator.Allocate(maxBlockSize * 2), INVALID_OFFSET);
+    ASSERT_EQ(allocator.Allocate(maxBlockSize * 2), BuddyAllocator::kInvalidOffset);
 
     // Check that we cannot allocate a zero sized block.
-    ASSERT_EQ(allocator.Allocate(0u), INVALID_OFFSET);
+    ASSERT_EQ(allocator.Allocate(0u), BuddyAllocator::kInvalidOffset);
 
     // Allocate the block.
     uint64_t blockOffset = allocator.Allocate(maxBlockSize);
     ASSERT_EQ(blockOffset, 0u);
 
     // Check that we are full.
-    ASSERT_EQ(allocator.Allocate(maxBlockSize), INVALID_OFFSET);
+    ASSERT_EQ(allocator.Allocate(maxBlockSize), BuddyAllocator::kInvalidOffset);
     ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 0u);
 
     // Deallocate the block.
@@ -86,7 +88,7 @@ TEST(BuddyAllocatorTests, SingleSplitBlock) {
     ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 1u);
 
     // Check that we cannot allocate a block that is oversized.
-    ASSERT_EQ(allocator.Allocate(maxBlockSize * 2), INVALID_OFFSET);
+    ASSERT_EQ(allocator.Allocate(maxBlockSize * 2), BuddyAllocator::kInvalidOffset);
 
     // Re-allocate the largest block allowed after merging.
     blockOffset = allocator.Allocate(maxBlockSize);
@@ -188,7 +190,7 @@ TEST(BuddyAllocatorTests, MultipleSplitBlockIncreasingSize) {
     ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 0u);
 
     // Check if we're full.
-    ASSERT_EQ(allocator.Allocate(32), INVALID_OFFSET);
+    ASSERT_EQ(allocator.Allocate(32), BuddyAllocator::kInvalidOffset);
 }
 
 // Verify very small allocations using a larger allocator works correctly.
@@ -284,7 +286,7 @@ TEST(BuddyAllocatorTests, SameSizeVariousAlignment) {
     ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 2u);
 
     // Check that we cannot fit another.
-    ASSERT_EQ(allocator.Allocate(8, 16), INVALID_OFFSET);
+    ASSERT_EQ(allocator.Allocate(8, 16), BuddyAllocator::kInvalidOffset);
 
     // Allocate Ac (zero splits and Ab's buddy is now the first free block).
     ASSERT_EQ(allocator.Allocate(8, 8), 24u);