Move kInvalidOffset to RingBufferAllocator namespace.

BUG=dawn:27

Change-Id: I1c580d8e41c4f9bb10b638297b4c3a3fa61a0d93
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/11680
Commit-Queue: Austin Eng <enga@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>

src/dawn_native/DynamicUploader.cpp

@@ -44,14 +44,14 @@ namespace dawn_native {
             }
         }
 
-        size_t startOffset = kInvalidOffset;
+        size_t startOffset = RingBufferAllocator::kInvalidOffset;
         if (targetRingBuffer != nullptr) {
             startOffset = targetRingBuffer->mAllocator.Allocate(allocationSize, serial);
         }
 
         // Upon failure, append a newly created (and much larger) ring buffer to fulfill the
         // request.
-        if (startOffset == kInvalidOffset) {
+        if (startOffset == RingBufferAllocator::kInvalidOffset) {
             // Compute the new max size (in powers of two to preserve alignment).
             size_t newMaxSize = targetRingBuffer->mAllocator.GetSize() * 2;
             while (newMaxSize < allocationSize) {
@@ -66,7 +66,7 @@ namespace dawn_native {
             startOffset = targetRingBuffer->mAllocator.Allocate(allocationSize, serial);
         }
 
-        ASSERT(startOffset != kInvalidOffset);
+        ASSERT(startOffset != RingBufferAllocator::kInvalidOffset);
 
         // Allocate the staging buffer backing the ringbuffer.
         // Note: the first ringbuffer will be lazily created.

src/dawn_native/RingBufferAllocator.h

@@ -23,8 +23,6 @@
 // RingBufferAllocator is the front-end implementation used to manage a ring buffer in GPU memory.
 namespace dawn_native {
 
-    static constexpr size_t kInvalidOffset = std::numeric_limits<size_t>::max();
-
     class RingBufferAllocator {
       public:
         RingBufferAllocator(size_t maxSize);
@@ -37,6 +35,8 @@ namespace dawn_native {
         bool Empty() const;
         size_t GetUsedSize() const;
 
+        static constexpr size_t kInvalidOffset = std::numeric_limits<size_t>::max();
+
       private:
         struct Request {
             size_t endOffset;

src/tests/unittests/RingBufferAllocatorTests.cpp

@@ -18,6 +18,8 @@
 
 using namespace dawn_native;
 
+constexpr size_t RingBufferAllocator::kInvalidOffset;
+
 // Number of basic tests for Ringbuffer
 TEST(RingBufferAllocatorTests, BasicTest) {
     constexpr size_t sizeInBytes = 64000;
@@ -29,14 +31,14 @@ TEST(RingBufferAllocatorTests, BasicTest) {
     ASSERT_EQ(allocator.GetSize(), sizeInBytes);
 
     // Ensure failure upon sub-allocating an oversized request.
-    ASSERT_EQ(allocator.Allocate(sizeInBytes + 1, 0), kInvalidOffset);
+    ASSERT_EQ(allocator.Allocate(sizeInBytes + 1, 0), RingBufferAllocator::kInvalidOffset);
 
     // Fill the entire buffer with two requests of equal size.
     ASSERT_EQ(allocator.Allocate(sizeInBytes / 2, 1), 0u);
     ASSERT_EQ(allocator.Allocate(sizeInBytes / 2, 2), 32000u);
 
     // Ensure the buffer is full.
-    ASSERT_EQ(allocator.Allocate(1, 3), kInvalidOffset);
+    ASSERT_EQ(allocator.Allocate(1, 3), RingBufferAllocator::kInvalidOffset);
 }
 
 // Tests that several ringbuffer allocations do not fail.
@@ -104,7 +106,8 @@ TEST(RingBufferAllocatorTests, RingBufferSubAlloc) {
     //
 
     // Ensure an oversized allocation fails (only 8 bytes left)
-    ASSERT_EQ(allocator.Allocate(frameSizeInBytes * 3, serial + 1), kInvalidOffset);
+    ASSERT_EQ(allocator.Allocate(frameSizeInBytes * 3, serial + 1),
+              RingBufferAllocator::kInvalidOffset);
     ASSERT_EQ(allocator.GetUsedSize(), frameSizeInBytes * 8);
 
     // Reclaim the first 3 frames.
@@ -130,7 +133,8 @@ TEST(RingBufferAllocatorTests, RingBufferSubAlloc) {
     ASSERT_EQ(allocator.GetUsedSize(), frameSizeInBytes * maxNumOfFrames);
 
     // Ensure we are full.
-    ASSERT_EQ(allocator.Allocate(frameSizeInBytes, serial + 1), kInvalidOffset);
+    ASSERT_EQ(allocator.Allocate(frameSizeInBytes, serial + 1),
+              RingBufferAllocator::kInvalidOffset);
 
     // Reclaim the next two frames.
     allocator.Deallocate(5);
@@ -152,7 +156,8 @@ TEST(RingBufferAllocatorTests, RingBufferSubAlloc) {
     //
 
     // Ensure we are full.
-    ASSERT_EQ(allocator.Allocate(frameSizeInBytes, serial + 1), kInvalidOffset);
+    ASSERT_EQ(allocator.Allocate(frameSizeInBytes, serial + 1),
+              RingBufferAllocator::kInvalidOffset);
 
     // Reclaim all.
     allocator.Deallocate(maxNumOfFrames);