dom/webgpu/Buffer.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef GPU_BUFFER_H_
   7 #define GPU_BUFFER_H_
   8
   9 #include "js/RootingAPI.h"
  10 #include "mozilla/dom/Nullable.h"
  11 #include "mozilla/webgpu/WebGPUTypes.h"
  12 #include "nsTArray.h"
  13 #include "ObjectModel.h"
  14 #include "mozilla/ipc/RawShmem.h"
  15 #include <memory>
  16
  17 namespace mozilla {
  18 class ErrorResult;
  19
  20 namespace dom {
  21 struct GPUBufferDescriptor;
  22 template <typename T>
  23 class Optional;
  24 enum class GPUBufferMapState : uint8_t;
  25 }  // namespace dom
  26
  27 namespace webgpu {
  28
  29 class Device;
  30
  31 struct MappedInfo {
  32   // True if mapping is requested for writing.
  33   bool mWritable = false;
  34   // Populated by `GetMappedRange`.
  35   nsTArray<JS::Heap<JSObject*>> mArrayBuffers;
  36   BufferAddress mOffset;
  37   BufferAddress mSize;
  38   MappedInfo() = default;
  39   MappedInfo(const MappedInfo&) = delete;
  40 };
  41
  42 class Buffer final : public ObjectBase, public ChildOf<Device> {
  43  public:
  44   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(Buffer)
  45   NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(Buffer)
  46   GPU_DECL_JS_WRAP(Buffer)
  47
  48   static already_AddRefed<Buffer> Create(Device* aDevice, RawId aDeviceId,
  49                                          const dom::GPUBufferDescriptor& aDesc,
  50                                          ErrorResult& aRv);
  51
  52   already_AddRefed<dom::Promise> MapAsync(uint32_t aMode, uint64_t aOffset,
  53                                           const dom::Optional<uint64_t>& aSize,
  54                                           ErrorResult& aRv);
  55   void GetMappedRange(JSContext* aCx, uint64_t aOffset,
  56                       const dom::Optional<uint64_t>& aSize,
  57                       JS::Rooted<JSObject*>* aObject, ErrorResult& aRv);
  58   void Unmap(JSContext* aCx, ErrorResult& aRv);
  59   void Destroy(JSContext* aCx, ErrorResult& aRv);
  60
  61   const RawId mId;
  62
  63   uint64_t Size() const { return mSize; }
  64   uint32_t Usage() const { return mUsage; }
  65   dom::GPUBufferMapState MapState() const;
  66
  67  private:
  68   Buffer(Device* const aParent, RawId aId, BufferAddress aSize, uint32_t aUsage,
  69          ipc::WritableSharedMemoryMapping&& aShmem);
  70   virtual ~Buffer();
  71   Device& GetDevice() { return *mParent; }
  72   void Drop();
  73   void UnmapArrayBuffers(JSContext* aCx, ErrorResult& aRv);
  74   void RejectMapRequest(dom::Promise* aPromise, nsACString& message);
  75   void AbortMapRequest();
  76   void SetMapped(BufferAddress aOffset, BufferAddress aSize, bool aWritable);
  77
  78   // Note: we can't map a buffer with the size that don't fit into `size_t`
  79   // (which may be smaller than `BufferAddress`), but general not all buffers
  80   // are mapped.
  81   const BufferAddress mSize;
  82   const uint32_t mUsage;
  83   nsString mLabel;
  84   // Information about the currently active mapping.
  85   Maybe<MappedInfo> mMapped;
  86   RefPtr<dom::Promise> mMapRequest;
  87   // mShmem does not point to a shared memory segment if the buffer is not
  88   // mappable.
  89   std::shared_ptr<ipc::WritableSharedMemoryMapping> mShmem;
  90 };
  91
  92 }  // namespace webgpu
  93 }  // namespace mozilla
  94
  95 #endif  // GPU_BUFFER_H_