gpu: Reuse transfer buffers more aggresively

gpu/command_buffer/client/gles2_implementation.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // A class to emulate GLES2 over command buffers.
 
 #include "gpu/command_buffer/client/gles2_implementation.h"
 
 #include <algorithm>
 #include <map>
 #include <queue>
 #include <set>
 #include <limits>
 #include <stdio.h>
 #include <string.h>
 #include <GLES2/gl2ext.h>
 #include <GLES2/gl2extchromium.h>
+#include "base/bind.h"
 #include "gpu/command_buffer/client/buffer_tracker.h"
 #include "gpu/command_buffer/client/gpu_memory_buffer_tracker.h"
 #include "gpu/command_buffer/client/program_info_manager.h"
 #include "gpu/command_buffer/client/query_tracker.h"
 #include "gpu/command_buffer/client/transfer_buffer.h"
 #include "gpu/command_buffer/client/vertex_array_object_manager.h"
 #include "gpu/command_buffer/common/gles2_cmd_utils.h"
 #include "gpu/command_buffer/common/gpu_control.h"
 #include "gpu/command_buffer/common/trace_event.h"
 #include "ui/gfx/gpu_memory_buffer.h"
@@ skipping 72 matching lines @@
       unpack_skip_pixels_(0),
       pack_reverse_row_order_(false),
       active_texture_unit_(0),
       bound_framebuffer_(0),
       bound_read_framebuffer_(0),
       bound_renderbuffer_(0),
       current_program_(0),
       bound_array_buffer_id_(0),
       bound_pixel_pack_transfer_buffer_id_(0),
       bound_pixel_unpack_transfer_buffer_id_(0),
+      async_upload_token_(0),
+      async_upload_sync_(NULL),
       error_bits_(0),
       debug_(false),
       use_count_(0),
       error_message_callback_(NULL),
       gpu_control_(gpu_control),
       surface_visible_(true),
       free_everything_when_invisible_(free_everything_when_invisible),
       capabilities_(gpu_control->GetCapabilities()),
       weak_ptr_factory_(this) {
   DCHECK(helper);
@@ skipping 27 matching lines @@
   if (!transfer_buffer_->Initialize(
       starting_transfer_buffer_size,
       kStartingOffset,
       min_transfer_buffer_size,
       max_transfer_buffer_size,
       kAlignment,
       kSizeToFlush)) {
     return false;
   }
 
-  mapped_memory_.reset(new MappedMemoryManager(helper_, mapped_memory_limit));
+  mapped_memory_.reset(
+      new MappedMemoryManager(
+          helper_,
+          base::Bind(&GLES2Implementation::PollAsyncUploads,
+                     // The mapped memory manager is owned by |this| here, and
+                     // since its destroyed before before we destroy ourselves
+                     // we don't need extra safety measures for this closure.
+                     base::Unretained(this)),
+          mapped_memory_limit));
 
   unsigned chunk_size = 2 * 1024 * 1024;
   if (mapped_memory_limit != kNoLimit) {
     // Use smaller chunks if the client is very memory conscientious.
     chunk_size = std::min(mapped_memory_limit / 4, chunk_size);
   }
   mapped_memory_->set_chunk_size_multiple(chunk_size);
 
   if (!QueryAndCacheStaticState())
     return false;
@@ skipping 102 matching lines @@
   // by the queries. The GPU process when validating that memory is still
   // shared will fail and abort (ie, it will stop running).
   WaitForCmd();
   query_tracker_.reset();
 
 #if defined(GLES2_SUPPORT_CLIENT_SIDE_ARRAYS)
   DeleteBuffers(arraysize(reserved_ids_), &reserved_ids_[0]);
 #endif
   buffer_tracker_.reset();
 
+  // Free all completed unmanaged async uploads buffers.
+  PollAsyncUploads();
+
+  // Synchronously free rest of the unmanaged async upload buffers.
+  if (!detached_async_upload_memory_.empty()) {
+    WaitAllAsyncTexImage2DCHROMIUM();
+    WaitForCmd();
+    PollAsyncUploads();
+  }

[piman, 2014/02/20 01:52:37]

It would be nice to do this in FreeEverything too. FreeEverything is called when
a tab goes offscreen, so:
1- it's ok to take long (i.e. waiting for things to happen).
2- we want to free as much as possible at that point

+
+  if (async_upload_sync_) {
+    mapped_memory_->Free(async_upload_sync_);
+    async_upload_sync_ = NULL;
+  }
+
   // Make sure the commands make it the service.
   WaitForCmd();
 }
 
 GLES2CmdHelper* GLES2Implementation::helper() const {
   return helper_;
 }
 
 IdHandlerInterface* GLES2Implementation::GetIdHandler(int namespace_id) const {
   return share_group_->GetIdHandler(namespace_id);
@@ skipping 1081 matching lines @@
     return;
   }
 
   GLuint buffer_id;
   if (GetBoundPixelTransferBuffer(target, "glBufferData", &buffer_id)) {
     if (!buffer_id) {
       return;
     }
 
     BufferTracker::Buffer* buffer = buffer_tracker_->GetBuffer(buffer_id);
-    if (buffer) {
-      // Free buffer memory, pending the passage of a token.
-      buffer_tracker_->FreePendingToken(buffer, helper_->InsertToken());
-
-      // Remove old buffer.
-      buffer_tracker_->RemoveBuffer(buffer_id);
-    }
+    if (buffer)
+      RemoveTransferBuffer(buffer);
 
     // Create new buffer.
     buffer = buffer_tracker_->CreateBuffer(buffer_id, size);
     DCHECK(buffer);
     if (buffer->address() && data)
       memcpy(buffer->address(), data, size);
     return;
   }
 
   if (size == 0) {
@@ skipping 107 matching lines @@
     GLenum target, GLintptr offset, GLsizeiptr size, const void* data) {
   GPU_CLIENT_SINGLE_THREAD_CHECK();
   GPU_CLIENT_LOG("[" << GetLogPrefix() << "] glBufferSubData("
       << GLES2Util::GetStringBufferTarget(target) << ", "
       << offset << ", " << size << ", "
       << static_cast<const void*>(data) << ")");
   BufferSubDataHelper(target, offset, size, data);
   CheckGLError();
 }
 
+void GLES2Implementation::RemoveTransferBuffer(BufferTracker::Buffer* buffer) {
+  int32 token = buffer->last_usage_token();
+  uint32 async_token = buffer->last_async_upload_token();
+
+  base::subtle::MemoryBarrier();

[piman, 2014/02/20 01:52:37]

Because the necessary memory barrier is handled in HasAsyncUploadTokenPassed,
you can remove this.

+
+  if (async_token) {
+    if (HasAsyncUploadTokenPassed(async_token)) {
+      buffer_tracker_->Free(buffer);
+    } else {
+      detached_async_upload_memory_.push_back(
+          std::make_pair(buffer->address(), async_token));
+      buffer_tracker_->Unmanage(buffer);
+    }
+  } else if (token) {
+    if (helper_->HasTokenPassed(token))
+      buffer_tracker_->Free(buffer);
+    else
+      buffer_tracker_->FreePendingToken(buffer, token);
+  } else {
+      buffer_tracker_->Free(buffer);
+  }
+
+  buffer_tracker_->RemoveBuffer(buffer->id());
+}
+
 bool GLES2Implementation::GetBoundPixelTransferBuffer(
     GLenum target,
     const char* function_name,
     GLuint* buffer_id) {
   *buffer_id = 0;
 
   switch (target) {
     case GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM:
       *buffer_id = bound_pixel_pack_transfer_buffer_id_;
       break;
@@ skipping 55 matching lines @@
   // CompressedTexImage2D.
   if (bound_pixel_unpack_transfer_buffer_id_) {
     GLuint offset = ToGLuint(data);
     BufferTracker::Buffer* buffer = GetBoundPixelUnpackTransferBufferIfValid(
         bound_pixel_unpack_transfer_buffer_id_,
         "glCompressedTexImage2D", offset, image_size);
     if (buffer && buffer->shm_id() != -1) {
       helper_->CompressedTexImage2D(
           target, level, internalformat, width, height, border, image_size,
           buffer->shm_id(), buffer->shm_offset() + offset);
-      buffer->set_transfer_ready_token(helper_->InsertToken());
+      buffer->set_last_usage_token(helper_->InsertToken());
     }
     return;
   }
   SetBucketContents(kResultBucketId, data, image_size);
   helper_->CompressedTexImage2DBucket(
       target, level, internalformat, width, height, border, kResultBucketId);
   // Free the bucket. This is not required but it does free up the memory.
   // and we don't have to wait for the result so from the client's perspective
   // it's cheap.
   helper_->SetBucketSize(kResultBucketId, 0);
@@ skipping 20 matching lines @@
   // CompressedTexSubImage2D.
   if (bound_pixel_unpack_transfer_buffer_id_) {
     GLuint offset = ToGLuint(data);
     BufferTracker::Buffer* buffer = GetBoundPixelUnpackTransferBufferIfValid(
         bound_pixel_unpack_transfer_buffer_id_,
         "glCompressedTexSubImage2D", offset, image_size);
     if (buffer && buffer->shm_id() != -1) {
       helper_->CompressedTexSubImage2D(
           target, level, xoffset, yoffset, width, height, format, image_size,
           buffer->shm_id(), buffer->shm_offset() + offset);
-      buffer->set_transfer_ready_token(helper_->InsertToken());
+      buffer->set_last_usage_token(helper_->InsertToken());
       CheckGLError();
     }
     return;
   }
   SetBucketContents(kResultBucketId, data, image_size);
   helper_->CompressedTexSubImage2DBucket(
       target, level, xoffset, yoffset, width, height, format, kResultBucketId);
   // Free the bucket. This is not required but it does free up the memory.
   // and we don't have to wait for the result so from the client's perspective
   // it's cheap.
@@ skipping 66 matching lines @@
   // If there's a pixel unpack buffer bound use it when issuing TexImage2D.
   if (bound_pixel_unpack_transfer_buffer_id_) {
     GLuint offset = ToGLuint(pixels);
     BufferTracker::Buffer* buffer = GetBoundPixelUnpackTransferBufferIfValid(
         bound_pixel_unpack_transfer_buffer_id_,
         "glTexImage2D", offset, size);
     if (buffer && buffer->shm_id() != -1) {
       helper_->TexImage2D(
           target, level, internalformat, width, height, border, format, type,
           buffer->shm_id(), buffer->shm_offset() + offset);
-      buffer->set_transfer_ready_token(helper_->InsertToken());
+      buffer->set_last_usage_token(helper_->InsertToken());
       CheckGLError();
     }
     return;
   }
 
   // If there's no data just issue TexImage2D
   if (!pixels) {
     helper_->TexImage2D(
        target, level, internalformat, width, height, border, format, type,
        0, 0);
@@ skipping 85 matching lines @@
   // If there's a pixel unpack buffer bound use it when issuing TexSubImage2D.
   if (bound_pixel_unpack_transfer_buffer_id_) {
     GLuint offset = ToGLuint(pixels);
     BufferTracker::Buffer* buffer = GetBoundPixelUnpackTransferBufferIfValid(
         bound_pixel_unpack_transfer_buffer_id_,
         "glTexSubImage2D", offset, temp_size);
     if (buffer && buffer->shm_id() != -1) {
       helper_->TexSubImage2D(
           target, level, xoffset, yoffset, width, height, format, type,
           buffer->shm_id(), buffer->shm_offset() + offset, false);
-      buffer->set_transfer_ready_token(helper_->InsertToken());
+      buffer->set_last_usage_token(helper_->InsertToken());
       CheckGLError();
     }
     return;
   }
 
   // compute the advance bytes per row for the src pixels
   uint32 src_padded_row_size;
   if (unpack_row_length_ > 0) {
     if (!GLES2Util::ComputeImagePaddedRowSize(
         unpack_row_length_, format, type, unpack_alignment_,
@@ skipping 562 matching lines @@
 }
 
 // NOTE #1: On old versions of OpenGL, calling glBindXXX with an unused id
 // generates a new resource. On newer versions of OpenGL they don't. The code
 // related to binding below will need to change if we switch to the new OpenGL
 // model. Specifically it assumes a bind will succeed which is always true in
 // the old model but possibly not true in the new model if another context has
 // deleted the resource.
 
 bool GLES2Implementation::BindBufferHelper(
-    GLenum target, GLuint buffer) {
+    GLenum target, GLuint buffer_id) {
   // TODO(gman): See note #1 above.
   bool changed = false;
   switch (target) {
     case GL_ARRAY_BUFFER:
-      if (bound_array_buffer_id_ != buffer) {
-        bound_array_buffer_id_ = buffer;
+      if (bound_array_buffer_id_ != buffer_id) {
+        bound_array_buffer_id_ = buffer_id;
         changed = true;
       }
       break;
     case GL_ELEMENT_ARRAY_BUFFER:
-      changed = vertex_array_object_manager_->BindElementArray(buffer);
+      changed = vertex_array_object_manager_->BindElementArray(buffer_id);
       break;
     case GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM:
-      bound_pixel_pack_transfer_buffer_id_ = buffer;
+      bound_pixel_pack_transfer_buffer_id_ = buffer_id;
       break;
     case GL_PIXEL_UNPACK_TRANSFER_BUFFER_CHROMIUM:
-      bound_pixel_unpack_transfer_buffer_id_ = buffer;
+      bound_pixel_unpack_transfer_buffer_id_ = buffer_id;
       break;
     default:
       changed = true;
       break;
   }
   // TODO(gman): There's a bug here. If the target is invalid the ID will not be
   // used even though it's marked it as used here.
-  GetIdHandler(id_namespaces::kBuffers)->MarkAsUsedForBind(buffer);
+  GetIdHandler(id_namespaces::kBuffers)->MarkAsUsedForBind(buffer_id);
   return changed;
 }
 
 bool GLES2Implementation::BindFramebufferHelper(
     GLenum target, GLuint framebuffer) {
   // TODO(gman): See note #1 above.
   bool changed = false;
   switch (target) {
     case GL_FRAMEBUFFER:
       if (bound_framebuffer_ != framebuffer ||
@@ skipping 113 matching lines @@
     SetGLError(
         GL_INVALID_VALUE,
         "glDeleteBuffers", "id not created by this context.");
     return;
   }
   for (GLsizei ii = 0; ii < n; ++ii) {
     if (buffers[ii] == bound_array_buffer_id_) {
       bound_array_buffer_id_ = 0;
     }
     vertex_array_object_manager_->UnbindBuffer(buffers[ii]);
+
     BufferTracker::Buffer* buffer = buffer_tracker_->GetBuffer(buffers[ii]);
-    if (buffer) {
-      // Free buffer memory, pending the passage of a token.
-      buffer_tracker_->FreePendingToken(buffer, helper_->InsertToken());
-      // Remove buffer.
-      buffer_tracker_->RemoveBuffer(buffers[ii]);
-    }
+    if (buffer)
+      RemoveTransferBuffer(buffer);
+
     if (buffers[ii] == bound_pixel_unpack_transfer_buffer_id_) {
       bound_pixel_unpack_transfer_buffer_id_ = 0;
     }
   }
 }
 
 void GLES2Implementation::DeleteBuffersStub(
     GLsizei n, const GLuint* buffers) {
   helper_->DeleteBuffersImmediate(n, buffers);
 }
@@ skipping 1001 matching lines @@
   }
   if (buffer->mapped()) {
     SetGLError(GL_INVALID_OPERATION, "glMapBufferCHROMIUM", "already mapped");
     return NULL;
   }
   // Here we wait for previous transfer operations to be finished.
   // TODO(hubbe): AsyncTex(Sub)Image2dCHROMIUM does not currently work
   // with this method of synchronization. Until this is fixed,
   // MapBufferCHROMIUM will not block even if the transfer is not ready
   // for these calls.
-  if (buffer->transfer_ready_token()) {
-    helper_->WaitForToken(buffer->transfer_ready_token());
-    buffer->set_transfer_ready_token(0);
+  if (buffer->last_usage_token()) {
+    helper_->WaitForToken(buffer->last_usage_token());
+    buffer->set_last_usage_token(0);
   }
   buffer->set_mapped(true);
 
   GPU_CLIENT_LOG("  returned " << buffer->address());
   CheckGLError();
   return buffer->address();
 }
 
 GLboolean GLES2Implementation::UnmapBufferCHROMIUM(GLuint target) {
   GPU_CLIENT_SINGLE_THREAD_CHECK();
@@ skipping 13 matching lines @@
   }
   if (!buffer->mapped()) {
     SetGLError(GL_INVALID_OPERATION, "glUnmapBufferCHROMIUM", "not mapped");
     return false;
   }
   buffer->set_mapped(false);
   CheckGLError();
   return true;
 }
 
+bool GLES2Implementation::EnsureAsyncUploadSync() {
+  if (async_upload_sync_)
+    return true;
+
+  int32 shm_id;
+  unsigned int shm_offset;
+  void* mem = mapped_memory_->Alloc(sizeof(AsyncUploadSync),
+                                    &shm_id,
+                                    &shm_offset);
+  if (!mem)
+    return false;
+
+  async_upload_sync_shm_id_ = shm_id;
+  async_upload_sync_shm_offset_ = shm_offset;
+  async_upload_sync_ = static_cast<AsyncUploadSync*>(mem);
+  async_upload_sync_->Reset();
+
+  return true;
+}
+
+uint32 GLES2Implementation::NextAsyncUploadToken() {
+  async_upload_token_++;
+  if (async_upload_token_ == 0)
+    async_upload_token_++;
+  return async_upload_token_;
+}
+
+void GLES2Implementation::PollAsyncUploads() {
+  if (!async_upload_sync_)
+    return;
+
+  if (helper_->IsContextLost()) {
+    DetachedAsyncUploadMemoryList::iterator it =
+        detached_async_upload_memory_.begin();
+    while (it != detached_async_upload_memory_.end()) {
+      mapped_memory_->Free(it->first);
+      it = detached_async_upload_memory_.erase(it);
+    }
+    return;
+  }
+
+  DetachedAsyncUploadMemoryList::iterator it =
+      detached_async_upload_memory_.begin();
+  while (it != detached_async_upload_memory_.end()) {
+    if (HasAsyncUploadTokenPassed(it->second)) {
+      mapped_memory_->Free(it->first);
+      it = detached_async_upload_memory_.erase(it);
+    } else {
+      break;
+    }
+  }
+}
+
 void GLES2Implementation::AsyncTexImage2DCHROMIUM(
     GLenum target, GLint level, GLint internalformat, GLsizei width,
     GLsizei height, GLint border, GLenum format, GLenum type,
     const void* pixels) {
   GPU_CLIENT_SINGLE_THREAD_CHECK();
   GPU_CLIENT_LOG("[" << GetLogPrefix() << "] glTexImage2D("
       << GLES2Util::GetStringTextureTarget(target) << ", "
       << level << ", "
       << GLES2Util::GetStringTextureInternalFormat(internalformat) << ", "
       << width << ", " << height << ", " << border << ", "
@@ skipping 11 matching lines @@
           width, height, format, type, unpack_alignment_, &size,
           &unpadded_row_size, &padded_row_size)) {
     SetGLError(GL_INVALID_VALUE, "glTexImage2D", "image size too large");
     return;
   }
 
   // If there's no data/buffer just issue the AsyncTexImage2D
   if (!pixels && !bound_pixel_unpack_transfer_buffer_id_) {
     helper_->AsyncTexImage2DCHROMIUM(
        target, level, internalformat, width, height, border, format, type,
-       0, 0);
+       0, 0, 0, 0, 0);
     return;
   }
 
+  if (!EnsureAsyncUploadSync()) {
+    SetGLError(GL_OUT_OF_MEMORY, "glTexImage2D", "out of memory");
+    return;
+  }
+
   // Otherwise, async uploads require a transfer buffer to be bound.
   // TODO(hubbe): Make MapBufferCHROMIUM block if someone tries to re-use
   // the buffer before the transfer is finished. (Currently such
   // synchronization has to be handled manually.)
   GLuint offset = ToGLuint(pixels);
   BufferTracker::Buffer* buffer = GetBoundPixelUnpackTransferBufferIfValid(
       bound_pixel_unpack_transfer_buffer_id_,
       "glAsyncTexImage2DCHROMIUM", offset, size);
   if (buffer && buffer->shm_id() != -1) {
+    uint32 async_token = NextAsyncUploadToken();
+    buffer->set_last_async_upload_token(async_token);
     helper_->AsyncTexImage2DCHROMIUM(
         target, level, internalformat, width, height, border, format, type,
-        buffer->shm_id(), buffer->shm_offset() + offset);
+        buffer->shm_id(), buffer->shm_offset() + offset,
+        async_token,
+        async_upload_sync_shm_id_, async_upload_sync_shm_offset_);
   }
 }
 
 void GLES2Implementation::AsyncTexSubImage2DCHROMIUM(
     GLenum target, GLint level, GLint xoffset, GLint yoffset, GLsizei width,
     GLsizei height, GLenum format, GLenum type, const void* pixels) {
   GPU_CLIENT_SINGLE_THREAD_CHECK();
   GPU_CLIENT_LOG("[" << GetLogPrefix() << "] glAsyncTexSubImage2DCHROMIUM("
       << GLES2Util::GetStringTextureTarget(target) << ", "
       << level << ", "
@@ skipping 12 matching lines @@
   uint32 unpadded_row_size;
   uint32 padded_row_size;
   if (!GLES2Util::ComputeImageDataSizes(
         width, height, format, type, unpack_alignment_, &size,
         &unpadded_row_size, &padded_row_size)) {
     SetGLError(
         GL_INVALID_VALUE, "glAsyncTexSubImage2DCHROMIUM", "size to large");
     return;
   }
 
+  if (!EnsureAsyncUploadSync()) {
+    SetGLError(GL_OUT_OF_MEMORY, "glTexImage2D", "out of memory");
+    return;
+  }
+
   // Async uploads require a transfer buffer to be bound.
   // TODO(hubbe): Make MapBufferCHROMIUM block if someone tries to re-use
   // the buffer before the transfer is finished. (Currently such
   // synchronization has to be handled manually.)
   GLuint offset = ToGLuint(pixels);
   BufferTracker::Buffer* buffer = GetBoundPixelUnpackTransferBufferIfValid(
       bound_pixel_unpack_transfer_buffer_id_,
       "glAsyncTexSubImage2DCHROMIUM", offset, size);
   if (buffer && buffer->shm_id() != -1) {
+    uint32 async_token = NextAsyncUploadToken();
+    buffer->set_last_async_upload_token(async_token);
     helper_->AsyncTexSubImage2DCHROMIUM(
         target, level, xoffset, yoffset, width, height, format, type,
-        buffer->shm_id(), buffer->shm_offset() + offset);
+        buffer->shm_id(), buffer->shm_offset() + offset,
+        async_token,
+        async_upload_sync_shm_id_, async_upload_sync_shm_offset_);
   }
 }
 
 void GLES2Implementation::WaitAsyncTexImage2DCHROMIUM(GLenum target) {
   GPU_CLIENT_SINGLE_THREAD_CHECK();
   GPU_CLIENT_LOG("[" << GetLogPrefix() << "] glWaitAsyncTexImage2DCHROMIUM("
       << GLES2Util::GetStringTextureTarget(target) << ")");
   helper_->WaitAsyncTexImage2DCHROMIUM(target);
   CheckGLError();
 }
 
+void GLES2Implementation::WaitAllAsyncTexImage2DCHROMIUM() {
+  GPU_CLIENT_SINGLE_THREAD_CHECK();
+  GPU_CLIENT_LOG("[" << GetLogPrefix()
+      << "] glWaitAllAsyncTexImage2DCHROMIUM()");
+  helper_->WaitAllAsyncTexImage2DCHROMIUM();
+  CheckGLError();
+}
+
 GLuint GLES2Implementation::InsertSyncPointCHROMIUM() {
   GPU_CLIENT_SINGLE_THREAD_CHECK();
   GPU_CLIENT_LOG("[" << GetLogPrefix() << "] glInsertSyncPointCHROMIUM");
   helper_->CommandBufferHelper::Flush();
   return gpu_control_->InsertSyncPoint();
 }
 
 GLuint GLES2Implementation::CreateImageCHROMIUMHelper(
     GLsizei width, GLsizei height, GLenum internalformat) {
   if (width <= 0) {
@@ skipping 155 matching lines @@
   CheckGLError();
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "gpu/command_buffer/client/gles2_implementation_impl_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu