gpu/command_buffer/client/implementation_base.cc - chromium/src - Git at Google

 // Copyright 2018 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.

 #include "gpu/command_buffer/client/implementation_base.h"

 #include <algorithm>

 #include "base/bind.h"
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "base/trace_event/trace_event.h"
 #include "gpu/command_buffer/client/cmd_buffer_helper.h"
 #include "gpu/command_buffer/client/gpu_control.h"
 #include "gpu/command_buffer/client/mapped_memory.h"
 #include "gpu/command_buffer/client/query_tracker.h"
 #include "gpu/command_buffer/client/shared_memory_limits.h"
 #include "gpu/command_buffer/common/sync_token.h"

 namespace gpu {

 #if !defined(_MSC_VER)
 const uint32_t ImplementationBase::kMaxSizeOfSimpleResult;
 const uint32_t ImplementationBase::kStartingOffset;
 #endif

 ImplementationBase::ImplementationBase(CommandBufferHelper* helper,
                                        TransferBufferInterface* transfer_buffer,
                                        GpuControl* gpu_control)
     : transfer_buffer_(transfer_buffer),
       gpu_control_(gpu_control),
       capabilities_(gpu_control->GetCapabilities()),
       helper_(helper) {}

 ImplementationBase::~ImplementationBase() {
   // The gpu_control_ outlives this class, so clear the client on it before we
   // self-destruct.
   gpu_control_->SetGpuControlClient(nullptr);
 }

 void ImplementationBase::FreeUnusedSharedMemory() {
   mapped_memory_->FreeUnused();
 }

 void ImplementationBase::FreeEverything() {
   query_tracker_->Shrink(helper_);
   FreeUnusedSharedMemory();
   transfer_buffer_->Free();
   helper_->FreeRingBuffer();
 }

 void ImplementationBase::SetLostContextCallback(base::OnceClosure callback) {
   lost_context_callback_ = std::move(callback);
 }

 void ImplementationBase::FlushPendingWork() {
   gpu_control_->FlushPendingWork();
 }

 void ImplementationBase::SignalSyncToken(const SyncToken& sync_token,
                                          base::OnceClosure callback) {
   SyncToken verified_sync_token;
   if (sync_token.HasData() &&
       GetVerifiedSyncTokenForIPC(sync_token, &verified_sync_token)) {
     // We can only send verified sync tokens across IPC.
     gpu_control_->SignalSyncToken(
         verified_sync_token,
         base::BindOnce(&ImplementationBase::RunIfContextNotLost,
                        weak_ptr_factory_.GetWeakPtr(), std::move(callback)));
   } else {
     // Invalid sync token, just call the callback immediately.
     std::move(callback).Run();
   }
 }

 // This may be called from any thread. It's safe to access gpu_control_ without
 // the lock because it is const.
 bool ImplementationBase::IsSyncTokenSignaled(const SyncToken& sync_token) {
   // Check that the sync token belongs to this context.
   DCHECK_EQ(gpu_control_->GetNamespaceID(), sync_token.namespace_id());
   DCHECK_EQ(gpu_control_->GetCommandBufferID(), sync_token.command_buffer_id());
   return gpu_control_->IsFenceSyncReleased(sync_token.release_count());
 }

 void ImplementationBase::GenSyncToken(GLbyte* sync_token) {
   if (!sync_token) {
     SetGLError(GL_INVALID_VALUE, "glGenSyncTokenCHROMIUM", "empty sync_token");
     return;
   }

   uint64_t fence_sync = gpu_control_->GenerateFenceSyncRelease();
   helper_->InsertFenceSync(fence_sync);
   helper_->CommandBufferHelper::OrderingBarrier();
   gpu_control_->EnsureWorkVisible();

   // Copy the data over after setting the data to ensure alignment.
   SyncToken sync_token_data(gpu_control_->GetNamespaceID(),
                             gpu_control_->GetCommandBufferID(), fence_sync);
   sync_token_data.SetVerifyFlush();
   memcpy(sync_token, &sync_token_data, sizeof(sync_token_data));
 }

 void ImplementationBase::GenUnverifiedSyncToken(GLbyte* sync_token) {
   if (!sync_token) {
     SetGLError(GL_INVALID_VALUE, "glGenUnverifiedSyncTokenCHROMIUM",
                "empty sync_token");
     return;
   }

   uint64_t fence_sync = gpu_control_->GenerateFenceSyncRelease();
   helper_->InsertFenceSync(fence_sync);
   helper_->CommandBufferHelper::OrderingBarrier();

   // Copy the data over after setting the data to ensure alignment.
   SyncToken sync_token_data(gpu_control_->GetNamespaceID(),
                             gpu_control_->GetCommandBufferID(), fence_sync);
   memcpy(sync_token, &sync_token_data, sizeof(sync_token_data));
 }

 void ImplementationBase::VerifySyncTokens(GLbyte** sync_tokens, GLsizei count) {
   bool requires_synchronization = false;
   for (GLsizei i = 0; i < count; ++i) {
     if (sync_tokens[i]) {
       SyncToken sync_token;
       memcpy(&sync_token, sync_tokens[i], sizeof(sync_token));

       if (sync_token.HasData() && !sync_token.verified_flush()) {
         if (!GetVerifiedSyncTokenForIPC(sync_token, &sync_token)) {
           SetGLError(GL_INVALID_VALUE, "glVerifySyncTokensCHROMIUM",
                      "Cannot verify sync token using this context.");
           return;
         }
         requires_synchronization = true;
         DCHECK(sync_token.verified_flush());
       }

       // Set verify bit on empty sync tokens too.
       sync_token.SetVerifyFlush();

       memcpy(sync_tokens[i], &sync_token, sizeof(sync_token));
     }
   }

   // Ensure all the fence syncs are visible on GPU service.
   if (requires_synchronization)
     gpu_control_->EnsureWorkVisible();
 }

 void ImplementationBase::WaitSyncToken(const GLbyte* sync_token_data) {
   if (!sync_token_data)
     return;

   // Copy the data over before data access to ensure alignment.
   SyncToken sync_token, verified_sync_token;
   memcpy(&sync_token, sync_token_data, sizeof(SyncToken));

   if (!sync_token.HasData())
     return;

   if (!GetVerifiedSyncTokenForIPC(sync_token, &verified_sync_token)) {
     SetGLError(GL_INVALID_VALUE, "glWaitSyncTokenCHROMIUM",
                "Cannot wait on sync_token which has not been verified");
     return;
   }

   // Enqueue sync token in flush after inserting command so that it's not
   // included in an automatic flush.
   gpu_control_->WaitSyncToken(verified_sync_token);
 }

 void ImplementationBase::SignalQuery(uint32_t query,
                                      base::OnceClosure callback) {
   // Flush previously entered commands to ensure ordering with any
   // glBeginQueryEXT() calls that may have been put into the context.
   IssueShallowFlush();
   gpu_control_->SignalQuery(
       query,
       base::BindOnce(&ImplementationBase::RunIfContextNotLost,
                      weak_ptr_factory_.GetWeakPtr(), std::move(callback)));
 }

 void ImplementationBase::GetGpuFence(
     uint32_t gpu_fence_id,
     base::OnceCallback<void(std::unique_ptr<gfx::GpuFence>)> callback) {
   // This ShallowFlush is required to ensure that the GetGpuFence
   // call is processed after the preceding CreateGpuFenceCHROMIUM call.
   IssueShallowFlush();
   gpu_control_->GetGpuFence(gpu_fence_id, std::move(callback));
 }

 bool ImplementationBase::OnMemoryDump(
     const base::trace_event::MemoryDumpArgs& args,
     base::trace_event::ProcessMemoryDump* pmd) {
   using base::trace_event::MemoryAllocatorDump;
   using base::trace_event::MemoryDumpLevelOfDetail;

   // Dump owned MappedMemoryManager memory as well.
   mapped_memory_->OnMemoryDump(args, pmd);

   if (!transfer_buffer_->HaveBuffer())
     return true;

   const uint64_t tracing_process_id =
       base::trace_event::MemoryDumpManager::GetInstance()
           ->GetTracingProcessId();

   MemoryAllocatorDump* dump = pmd->CreateAllocatorDump(base::StringPrintf(
       "gpu/transfer_buffer_memory/buffer_%d", transfer_buffer_->GetShmId()));
   dump->AddScalar(MemoryAllocatorDump::kNameSize,
                   MemoryAllocatorDump::kUnitsBytes,
                   transfer_buffer_->GetSize());

   if (args.level_of_detail != MemoryDumpLevelOfDetail::BACKGROUND) {
     dump->AddScalar("free_size", MemoryAllocatorDump::kUnitsBytes,
                     transfer_buffer_->GetFragmentedFreeSize());
     auto shared_memory_guid = transfer_buffer_->shared_memory_guid();
     const int kImportance = 2;
     if (!shared_memory_guid.is_empty()) {
       pmd->CreateSharedMemoryOwnershipEdge(dump->guid(), shared_memory_guid,
                                            kImportance);
     } else {
       auto guid = GetBufferGUIDForTracing(tracing_process_id,
                                           transfer_buffer_->GetShmId());
       pmd->CreateSharedGlobalAllocatorDump(guid);
       pmd->AddOwnershipEdge(dump->guid(), guid, kImportance);
     }
   }

   return true;
 }

 gpu::ContextResult ImplementationBase::Initialize(
     const SharedMemoryLimits& limits) {
   TRACE_EVENT0("gpu", "ImplementationBase::Initialize");
   DCHECK_GE(limits.start_transfer_buffer_size, limits.min_transfer_buffer_size);
   DCHECK_LE(limits.start_transfer_buffer_size, limits.max_transfer_buffer_size);
   DCHECK_GE(limits.min_transfer_buffer_size, kStartingOffset);

   gpu_control_->SetGpuControlClient(this);

   if (!transfer_buffer_->Initialize(
           limits.start_transfer_buffer_size, kStartingOffset,
           limits.min_transfer_buffer_size, limits.max_transfer_buffer_size,
           kAlignment)) {
     // TransferBuffer::Initialize doesn't fail for transient reasons such as if
     // the context was lost. See http://crrev.com/c/720269
     LOG(ERROR) << "ContextResult::kFatalFailure: "
                << "TransferBuffer::Initialize() failed";
     return gpu::ContextResult::kFatalFailure;
   }

   mapped_memory_ = std::make_unique<MappedMemoryManager>(
       helper_, limits.mapped_memory_reclaim_limit);
   mapped_memory_->set_chunk_size_multiple(limits.mapped_memory_chunk_size);
   query_tracker_ = std::make_unique<gles2::QueryTracker>(mapped_memory_.get());

   return gpu::ContextResult::kSuccess;
 }

 void ImplementationBase::WaitForCmd() {
   TRACE_EVENT0("gpu", "ImplementationBase::WaitForCmd");
   helper_->Finish();
 }

 int32_t ImplementationBase::GetResultShmId() {
   return transfer_buffer_->GetShmId();
 }

 bool ImplementationBase::GetBucketContents(uint32_t bucket_id,
                                            std::vector<int8_t>* data) {
   TRACE_EVENT0("gpu", "ImplementationBase::GetBucketContents");
   DCHECK(data);
   const uint32_t kStartSize = 32 * 1024;
   ScopedTransferBufferPtr buffer(kStartSize, helper_, transfer_buffer_);
   if (!buffer.valid()) {
     return false;
   }
   uint32_t size = 0;
   {
     // The Result pointer must be scoped to this block because it can be
     // invalidated below if resizing the ScopedTransferBufferPtr causes the
     // transfer buffer to be reallocated.
     typedef cmd::GetBucketStart::Result Result;
     auto result = GetResultAs<Result>();
     if (!result) {
       return false;
     }
     *result = 0;
     helper_->GetBucketStart(bucket_id, GetResultShmId(), result.offset(),
                             buffer.size(), buffer.shm_id(), buffer.offset());
     WaitForCmd();
     size = *result;
   }
   data->resize(size);
   if (size > 0u) {
     uint32_t offset = 0;
     while (size) {
       if (!buffer.valid()) {
         buffer.Reset(size);
         if (!buffer.valid()) {
           return false;
         }
         helper_->GetBucketData(bucket_id, offset, buffer.size(),
                                buffer.shm_id(), buffer.offset());
         WaitForCmd();
       }
       uint32_t size_to_copy = std::min(size, buffer.size());
       memcpy(&(*data)[offset], buffer.address(), size_to_copy);
       offset += size_to_copy;
       size -= size_to_copy;
       buffer.Release();
     }
     // 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(bucket_id, 0);
   }
   return true;
 }

 void ImplementationBase::SetBucketContents(uint32_t bucket_id,
                                            const void* data,
                                            uint32_t size) {
   DCHECK(data);
   helper_->SetBucketSize(bucket_id, size);
   if (size > 0u) {
     uint32_t offset = 0;
     while (size) {
       ScopedTransferBufferPtr buffer(size, helper_, transfer_buffer_);
       if (!buffer.valid()) {
         return;
       }
       memcpy(buffer.address(), static_cast<const int8_t*>(data) + offset,
              buffer.size());
       helper_->SetBucketData(bucket_id, offset, buffer.size(), buffer.shm_id(),
                              buffer.offset());
       offset += buffer.size();
       size -= buffer.size();
     }
   }
 }

 void ImplementationBase::SetBucketAsCString(uint32_t bucket_id,
                                             const char* str) {
   // NOTE: strings are passed NULL terminated. That means the empty
   // string will have a size of 1 and no-string will have a size of 0
   if (str) {
     base::CheckedNumeric<uint32_t> len = strlen(str);
     len += 1;
     SetBucketContents(bucket_id, str, len.ValueOrDefault(0));
   } else {
     helper_->SetBucketSize(bucket_id, 0);
   }
 }

 bool ImplementationBase::GetBucketAsString(uint32_t bucket_id,
                                            std::string* str) {
   DCHECK(str);
   std::vector<int8_t> data;
   // NOTE: strings are passed NULL terminated. That means the empty
   // string will have a size of 1 and no-string will have a size of 0
   if (!GetBucketContents(bucket_id, &data)) {
     return false;
   }
   if (data.empty()) {
     return false;
   }
   str->assign(&data[0], &data[0] + data.size() - 1);
   return true;
 }

 void ImplementationBase::SetBucketAsString(uint32_t bucket_id,
                                            const std::string& str) {
   // NOTE: strings are passed NULL terminated. That means the empty
   // string will have a size of 1 and no-string will have a size of 0
   base::CheckedNumeric<uint32_t> len = str.size();
   len += 1;
   SetBucketContents(bucket_id, str.c_str(), len.ValueOrDefault(0));
 }

 bool ImplementationBase::GetVerifiedSyncTokenForIPC(
     const SyncToken& sync_token,
     SyncToken* verified_sync_token) {
   DCHECK(sync_token.HasData());
   DCHECK(verified_sync_token);

   if (!sync_token.verified_flush() &&
       !gpu_control_->CanWaitUnverifiedSyncToken(sync_token))
     return false;

   *verified_sync_token = sync_token;
   verified_sync_token->SetVerifyFlush();
   return true;
 }

 void ImplementationBase::RunIfContextNotLost(base::OnceClosure callback) {
   if (!lost_context_callback_run_) {
     std::move(callback).Run();
   }
 }

 void ImplementationBase::SetGrContext(GrContext* gr) {}

 bool ImplementationBase::HasGrContextSupport() const {
   return false;
 }

 void ImplementationBase::WillCallGLFromSkia() {
   // Should only be called on subclasses that have GrContextSupport
   NOTREACHED();
 }

 void ImplementationBase::DidCallGLFromSkia() {
   // Should only be called on subclasses that have GrContextSupport
   NOTREACHED();
 }

 void ImplementationBase::SetDisplayTransform(gfx::OverlayTransform transform) {
   helper_->Flush();
   gpu_control_->SetDisplayTransform(transform);
 }

 }  // namespace gpu
	// Copyright 2018 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.

	#include "gpu/command_buffer/client/implementation_base.h"

	#include <algorithm>

	#include "base/bind.h"
	#include "base/strings/stringprintf.h"
	#include "base/trace_event/memory_dump_manager.h"
	#include "base/trace_event/trace_event.h"
	#include "gpu/command_buffer/client/cmd_buffer_helper.h"
	#include "gpu/command_buffer/client/gpu_control.h"
	#include "gpu/command_buffer/client/mapped_memory.h"
	#include "gpu/command_buffer/client/query_tracker.h"
	#include "gpu/command_buffer/client/shared_memory_limits.h"
	#include "gpu/command_buffer/common/sync_token.h"

	namespace gpu {

	#if !defined(_MSC_VER)
	const uint32_t ImplementationBase::kMaxSizeOfSimpleResult;
	const uint32_t ImplementationBase::kStartingOffset;
	#endif

	ImplementationBase::ImplementationBase(CommandBufferHelper* helper,
	TransferBufferInterface* transfer_buffer,
	GpuControl* gpu_control)
	: transfer_buffer_(transfer_buffer),
	gpu_control_(gpu_control),
	capabilities_(gpu_control->GetCapabilities()),
	helper_(helper) {}

	ImplementationBase::~ImplementationBase() {
	// The gpu_control_ outlives this class, so clear the client on it before we
	// self-destruct.
	gpu_control_->SetGpuControlClient(nullptr);
	}

	void ImplementationBase::FreeUnusedSharedMemory() {
	mapped_memory_->FreeUnused();
	}

	void ImplementationBase::FreeEverything() {
	query_tracker_->Shrink(helper_);
	FreeUnusedSharedMemory();
	transfer_buffer_->Free();
	helper_->FreeRingBuffer();
	}

	void ImplementationBase::SetLostContextCallback(base::OnceClosure callback) {
	lost_context_callback_ = std::move(callback);
	}

	void ImplementationBase::FlushPendingWork() {
	gpu_control_->FlushPendingWork();
	}

	void ImplementationBase::SignalSyncToken(const SyncToken& sync_token,
	base::OnceClosure callback) {
	SyncToken verified_sync_token;
	if (sync_token.HasData() &&
	GetVerifiedSyncTokenForIPC(sync_token, &verified_sync_token)) {
	// We can only send verified sync tokens across IPC.
	gpu_control_->SignalSyncToken(
	verified_sync_token,
	base::BindOnce(&ImplementationBase::RunIfContextNotLost,
	weak_ptr_factory_.GetWeakPtr(), std::move(callback)));
	} else {
	// Invalid sync token, just call the callback immediately.
	std::move(callback).Run();
	}
	}

	// This may be called from any thread. It's safe to access gpu_control_ without
	// the lock because it is const.
	bool ImplementationBase::IsSyncTokenSignaled(const SyncToken& sync_token) {
	// Check that the sync token belongs to this context.
	DCHECK_EQ(gpu_control_->GetNamespaceID(), sync_token.namespace_id());
	DCHECK_EQ(gpu_control_->GetCommandBufferID(), sync_token.command_buffer_id());
	return gpu_control_->IsFenceSyncReleased(sync_token.release_count());
	}

	void ImplementationBase::GenSyncToken(GLbyte* sync_token) {
	if (!sync_token) {
	SetGLError(GL_INVALID_VALUE, "glGenSyncTokenCHROMIUM", "empty sync_token");
	return;
	}

	uint64_t fence_sync = gpu_control_->GenerateFenceSyncRelease();
	helper_->InsertFenceSync(fence_sync);
	helper_->CommandBufferHelper::OrderingBarrier();
	gpu_control_->EnsureWorkVisible();

	// Copy the data over after setting the data to ensure alignment.
	SyncToken sync_token_data(gpu_control_->GetNamespaceID(),
	gpu_control_->GetCommandBufferID(), fence_sync);
	sync_token_data.SetVerifyFlush();
	memcpy(sync_token, &sync_token_data, sizeof(sync_token_data));
	}

	void ImplementationBase::GenUnverifiedSyncToken(GLbyte* sync_token) {
	if (!sync_token) {
	SetGLError(GL_INVALID_VALUE, "glGenUnverifiedSyncTokenCHROMIUM",
	"empty sync_token");
	return;
	}

	uint64_t fence_sync = gpu_control_->GenerateFenceSyncRelease();
	helper_->InsertFenceSync(fence_sync);
	helper_->CommandBufferHelper::OrderingBarrier();

	// Copy the data over after setting the data to ensure alignment.
	SyncToken sync_token_data(gpu_control_->GetNamespaceID(),
	gpu_control_->GetCommandBufferID(), fence_sync);
	memcpy(sync_token, &sync_token_data, sizeof(sync_token_data));
	}

	void ImplementationBase::VerifySyncTokens(GLbyte** sync_tokens, GLsizei count) {
	bool requires_synchronization = false;
	for (GLsizei i = 0; i < count; ++i) {
	if (sync_tokens[i]) {
	SyncToken sync_token;
	memcpy(&sync_token, sync_tokens[i], sizeof(sync_token));

	if (sync_token.HasData() && !sync_token.verified_flush()) {
	if (!GetVerifiedSyncTokenForIPC(sync_token, &sync_token)) {
	SetGLError(GL_INVALID_VALUE, "glVerifySyncTokensCHROMIUM",
	"Cannot verify sync token using this context.");
	return;
	}
	requires_synchronization = true;
	DCHECK(sync_token.verified_flush());
	}

	// Set verify bit on empty sync tokens too.
	sync_token.SetVerifyFlush();

	memcpy(sync_tokens[i], &sync_token, sizeof(sync_token));
	}
	}

	// Ensure all the fence syncs are visible on GPU service.
	if (requires_synchronization)
	gpu_control_->EnsureWorkVisible();
	}

	void ImplementationBase::WaitSyncToken(const GLbyte* sync_token_data) {
	if (!sync_token_data)
	return;

	// Copy the data over before data access to ensure alignment.
	SyncToken sync_token, verified_sync_token;
	memcpy(&sync_token, sync_token_data, sizeof(SyncToken));

	if (!sync_token.HasData())
	return;

	if (!GetVerifiedSyncTokenForIPC(sync_token, &verified_sync_token)) {
	SetGLError(GL_INVALID_VALUE, "glWaitSyncTokenCHROMIUM",
	"Cannot wait on sync_token which has not been verified");
	return;
	}

	// Enqueue sync token in flush after inserting command so that it's not
	// included in an automatic flush.
	gpu_control_->WaitSyncToken(verified_sync_token);
	}

	void ImplementationBase::SignalQuery(uint32_t query,
	base::OnceClosure callback) {
	// Flush previously entered commands to ensure ordering with any
	// glBeginQueryEXT() calls that may have been put into the context.
	IssueShallowFlush();
	gpu_control_->SignalQuery(
	query,
	base::BindOnce(&ImplementationBase::RunIfContextNotLost,
	weak_ptr_factory_.GetWeakPtr(), std::move(callback)));
	}

	void ImplementationBase::GetGpuFence(
	uint32_t gpu_fence_id,
	base::OnceCallback<void(std::unique_ptr<gfx::GpuFence>)> callback) {
	// This ShallowFlush is required to ensure that the GetGpuFence
	// call is processed after the preceding CreateGpuFenceCHROMIUM call.
	IssueShallowFlush();
	gpu_control_->GetGpuFence(gpu_fence_id, std::move(callback));
	}

	bool ImplementationBase::OnMemoryDump(
	const base::trace_event::MemoryDumpArgs& args,
	base::trace_event::ProcessMemoryDump* pmd) {
	using base::trace_event::MemoryAllocatorDump;
	using base::trace_event::MemoryDumpLevelOfDetail;

	// Dump owned MappedMemoryManager memory as well.
	mapped_memory_->OnMemoryDump(args, pmd);

	if (!transfer_buffer_->HaveBuffer())
	return true;

	const uint64_t tracing_process_id =
	base::trace_event::MemoryDumpManager::GetInstance()
	->GetTracingProcessId();

	MemoryAllocatorDump* dump = pmd->CreateAllocatorDump(base::StringPrintf(
	"gpu/transfer_buffer_memory/buffer_%d", transfer_buffer_->GetShmId()));
	dump->AddScalar(MemoryAllocatorDump::kNameSize,
	MemoryAllocatorDump::kUnitsBytes,
	transfer_buffer_->GetSize());

	if (args.level_of_detail != MemoryDumpLevelOfDetail::BACKGROUND) {
	dump->AddScalar("free_size", MemoryAllocatorDump::kUnitsBytes,
	transfer_buffer_->GetFragmentedFreeSize());
	auto shared_memory_guid = transfer_buffer_->shared_memory_guid();
	const int kImportance = 2;
	if (!shared_memory_guid.is_empty()) {
	pmd->CreateSharedMemoryOwnershipEdge(dump->guid(), shared_memory_guid,
	kImportance);
	} else {
	auto guid = GetBufferGUIDForTracing(tracing_process_id,
	transfer_buffer_->GetShmId());
	pmd->CreateSharedGlobalAllocatorDump(guid);
	pmd->AddOwnershipEdge(dump->guid(), guid, kImportance);
	}
	}

	return true;
	}

	gpu::ContextResult ImplementationBase::Initialize(
	const SharedMemoryLimits& limits) {
	TRACE_EVENT0("gpu", "ImplementationBase::Initialize");
	DCHECK_GE(limits.start_transfer_buffer_size, limits.min_transfer_buffer_size);
	DCHECK_LE(limits.start_transfer_buffer_size, limits.max_transfer_buffer_size);
	DCHECK_GE(limits.min_transfer_buffer_size, kStartingOffset);

	gpu_control_->SetGpuControlClient(this);

	if (!transfer_buffer_->Initialize(
	limits.start_transfer_buffer_size, kStartingOffset,
	limits.min_transfer_buffer_size, limits.max_transfer_buffer_size,
	kAlignment)) {
	// TransferBuffer::Initialize doesn't fail for transient reasons such as if
	// the context was lost. See http://crrev.com/c/720269
	LOG(ERROR) << "ContextResult::kFatalFailure: "
	<< "TransferBuffer::Initialize() failed";
	return gpu::ContextResult::kFatalFailure;
	}

	mapped_memory_ = std::make_unique<MappedMemoryManager>(
	helper_, limits.mapped_memory_reclaim_limit);
	mapped_memory_->set_chunk_size_multiple(limits.mapped_memory_chunk_size);
	query_tracker_ = std::make_unique<gles2::QueryTracker>(mapped_memory_.get());

	return gpu::ContextResult::kSuccess;
	}

	void ImplementationBase::WaitForCmd() {
	TRACE_EVENT0("gpu", "ImplementationBase::WaitForCmd");
	helper_->Finish();
	}

	int32_t ImplementationBase::GetResultShmId() {
	return transfer_buffer_->GetShmId();
	}

	bool ImplementationBase::GetBucketContents(uint32_t bucket_id,
	std::vector<int8_t>* data) {
	TRACE_EVENT0("gpu", "ImplementationBase::GetBucketContents");
	DCHECK(data);
	const uint32_t kStartSize = 32 * 1024;
	ScopedTransferBufferPtr buffer(kStartSize, helper_, transfer_buffer_);
	if (!buffer.valid()) {
	return false;
	}
	uint32_t size = 0;
	{
	// The Result pointer must be scoped to this block because it can be
	// invalidated below if resizing the ScopedTransferBufferPtr causes the
	// transfer buffer to be reallocated.
	typedef cmd::GetBucketStart::Result Result;
	auto result = GetResultAs<Result>();
	if (!result) {
	return false;
	}
	*result = 0;
	helper_->GetBucketStart(bucket_id, GetResultShmId(), result.offset(),
	buffer.size(), buffer.shm_id(), buffer.offset());
	WaitForCmd();
	size = *result;
	}
	data->resize(size);
	if (size > 0u) {
	uint32_t offset = 0;
	while (size) {
	if (!buffer.valid()) {
	buffer.Reset(size);
	if (!buffer.valid()) {
	return false;
	}
	helper_->GetBucketData(bucket_id, offset, buffer.size(),
	buffer.shm_id(), buffer.offset());
	WaitForCmd();
	}
	uint32_t size_to_copy = std::min(size, buffer.size());
	memcpy(&(*data)[offset], buffer.address(), size_to_copy);
	offset += size_to_copy;
	size -= size_to_copy;
	buffer.Release();
	}
	// 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(bucket_id, 0);
	}
	return true;
	}

	void ImplementationBase::SetBucketContents(uint32_t bucket_id,
	const void* data,
	uint32_t size) {
	DCHECK(data);
	helper_->SetBucketSize(bucket_id, size);
	if (size > 0u) {
	uint32_t offset = 0;
	while (size) {
	ScopedTransferBufferPtr buffer(size, helper_, transfer_buffer_);
	if (!buffer.valid()) {
	return;
	}
	memcpy(buffer.address(), static_cast<const int8_t*>(data) + offset,
	buffer.size());
	helper_->SetBucketData(bucket_id, offset, buffer.size(), buffer.shm_id(),
	buffer.offset());
	offset += buffer.size();
	size -= buffer.size();
	}
	}
	}

	void ImplementationBase::SetBucketAsCString(uint32_t bucket_id,
	const char* str) {
	// NOTE: strings are passed NULL terminated. That means the empty
	// string will have a size of 1 and no-string will have a size of 0
	if (str) {
	base::CheckedNumeric<uint32_t> len = strlen(str);
	len += 1;
	SetBucketContents(bucket_id, str, len.ValueOrDefault(0));
	} else {
	helper_->SetBucketSize(bucket_id, 0);
	}
	}

	bool ImplementationBase::GetBucketAsString(uint32_t bucket_id,
	std::string* str) {
	DCHECK(str);
	std::vector<int8_t> data;
	// NOTE: strings are passed NULL terminated. That means the empty
	// string will have a size of 1 and no-string will have a size of 0
	if (!GetBucketContents(bucket_id, &data)) {
	return false;
	}
	if (data.empty()) {
	return false;
	}
	str->assign(&data[0], &data[0] + data.size() - 1);
	return true;
	}

	void ImplementationBase::SetBucketAsString(uint32_t bucket_id,
	const std::string& str) {
	// NOTE: strings are passed NULL terminated. That means the empty
	// string will have a size of 1 and no-string will have a size of 0
	base::CheckedNumeric<uint32_t> len = str.size();
	len += 1;
	SetBucketContents(bucket_id, str.c_str(), len.ValueOrDefault(0));
	}

	bool ImplementationBase::GetVerifiedSyncTokenForIPC(
	const SyncToken& sync_token,
	SyncToken* verified_sync_token) {
	DCHECK(sync_token.HasData());
	DCHECK(verified_sync_token);

	if (!sync_token.verified_flush() &&
	!gpu_control_->CanWaitUnverifiedSyncToken(sync_token))
	return false;

	*verified_sync_token = sync_token;
	verified_sync_token->SetVerifyFlush();
	return true;
	}

	void ImplementationBase::RunIfContextNotLost(base::OnceClosure callback) {
	if (!lost_context_callback_run_) {
	std::move(callback).Run();
	}
	}

	void ImplementationBase::SetGrContext(GrContext* gr) {}

	bool ImplementationBase::HasGrContextSupport() const {
	return false;
	}

	void ImplementationBase::WillCallGLFromSkia() {
	// Should only be called on subclasses that have GrContextSupport
	NOTREACHED();
	}

	void ImplementationBase::DidCallGLFromSkia() {
	// Should only be called on subclasses that have GrContextSupport
	NOTREACHED();
	}

	void ImplementationBase::SetDisplayTransform(gfx::OverlayTransform transform) {
	helper_->Flush();
	gpu_control_->SetDisplayTransform(transform);
	}

	} // namespace gpu