root/content/common/gpu/texture_image_transport_surface.cc

DEFINITIONS

1. IsContextValid
2. did_unschedule_
3. Initialize
4. Destroy
5. DeferDraws
6. IsOffscreen
7. GetBackingFrameBufferObject
8. SetBackbufferAllocation
9. SetFrontbufferAllocation
10. GetShareHandle
11. GetDisplay
12. GetConfig
13. OnResize
14. OnWillDestroyStub
15. SetLatencyInfo
16. WakeUpGpu
17. SwapBuffers
18. PostSubBuffer
19. SupportsPostSubBuffer
20. GetSize
21. GetHandle
22. GetFormat
23. OnBufferPresented
24. BufferPresentedImpl
25. OnResizeViewACK
26. ReleaseBackTexture
27. ReleaseFrontTexture
28. CreateBackTexture
29. AttachBackTextureToFBO

// 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.

#include "content/common/gpu/texture_image_transport_surface.h"

#include <string>
#include <vector>

#include "base/command_line.h"
#include "content/common/gpu/gpu_channel.h"
#include "content/common/gpu/gpu_channel_manager.h"
#include "content/common/gpu/gpu_messages.h"
#include "content/common/gpu/sync_point_manager.h"
#include "content/public/common/content_switches.h"
#include "gpu/command_buffer/service/context_group.h"
#include "gpu/command_buffer/service/gpu_scheduler.h"
#include "gpu/command_buffer/service/mailbox_manager.h"
#include "ui/gl/scoped_binders.h"

using gpu::gles2::ContextGroup;
using gpu::gles2::GLES2Decoder;
using gpu::gles2::MailboxManager;
using gpu::gles2::Texture;
using gpu::gles2::TextureManager;
using gpu::gles2::TextureRef;
using gpu::Mailbox;

namespace content {
namespace {

bool IsContextValid(ImageTransportHelper* helper) {
  return helper->stub()->decoder()->GetGLContext()->IsCurrent(NULL);
}

}  // namespace

TextureImageTransportSurface::TextureImageTransportSurface(
    GpuChannelManager* manager,
    GpuCommandBufferStub* stub,
    const gfx::GLSurfaceHandle& handle)
      : fbo_id_(0),
        current_size_(1, 1),
        scale_factor_(1.f),
        stub_destroyed_(false),
        backbuffer_suggested_allocation_(true),
        frontbuffer_suggested_allocation_(true),
        handle_(handle),
        is_swap_buffers_pending_(false),
        did_unschedule_(false) {
  helper_.reset(new ImageTransportHelper(this,
                                         manager,
                                         stub,
                                         gfx::kNullPluginWindow));
}

TextureImageTransportSurface::~TextureImageTransportSurface() {
  DCHECK(stub_destroyed_);
  Destroy();
}

bool TextureImageTransportSurface::Initialize() {
  mailbox_manager_ =
      helper_->stub()->decoder()->GetContextGroup()->mailbox_manager();

  GpuChannelManager* manager = helper_->manager();
  surface_ = manager->GetDefaultOffscreenSurface();
  if (!surface_.get())
    return false;

  if (!helper_->Initialize())
    return false;

  GpuChannel* parent_channel = manager->LookupChannel(handle_.parent_client_id);
  if (parent_channel) {
    const CommandLine* command_line = CommandLine::ForCurrentProcess();
    if (command_line->HasSwitch(switches::kUIPrioritizeInGpuProcess))
      helper_->SetPreemptByFlag(parent_channel->GetPreemptionFlag());
  }

  return true;
}

void TextureImageTransportSurface::Destroy() {
  if (surface_.get())
    surface_ = NULL;

  helper_->Destroy();
}

bool TextureImageTransportSurface::DeferDraws() {
  // The command buffer hit a draw/clear command that could clobber the
  // texture in use by the UI compositor. If a Swap is pending, abort
  // processing of the command by returning true and unschedule until the Swap
  // Ack arrives.
  DCHECK(!did_unschedule_);
  if (is_swap_buffers_pending_) {
    did_unschedule_ = true;
    helper_->SetScheduled(false);
    return true;
  }
  return false;
}

bool TextureImageTransportSurface::IsOffscreen() {
  return true;
}

unsigned int TextureImageTransportSurface::GetBackingFrameBufferObject() {
  DCHECK(IsContextValid(helper_.get()));
  if (!fbo_id_) {
    glGenFramebuffersEXT(1, &fbo_id_);
    glBindFramebufferEXT(GL_FRAMEBUFFER, fbo_id_);
    helper_->stub()->AddDestructionObserver(this);
    CreateBackTexture();
  }

  return fbo_id_;
}

bool TextureImageTransportSurface::SetBackbufferAllocation(bool allocation) {
  DCHECK(!is_swap_buffers_pending_);
  if (backbuffer_suggested_allocation_ == allocation)
     return true;
  backbuffer_suggested_allocation_ = allocation;

  if (backbuffer_suggested_allocation_) {
    DCHECK(!backbuffer_.get());
    CreateBackTexture();
  } else {
    ReleaseBackTexture();
  }

  return true;
}

void TextureImageTransportSurface::SetFrontbufferAllocation(bool allocation) {
  if (frontbuffer_suggested_allocation_ == allocation)
    return;
  frontbuffer_suggested_allocation_ = allocation;

  // If a swapbuffers is in flight, wait for the ack before releasing the front
  // buffer:
  // - we don't know yet which texture the browser will want to keep
  // - we want to ensure we don't destroy a texture that is in flight before the
  // browser got a reference on it.
  if (!frontbuffer_suggested_allocation_ &&
      !is_swap_buffers_pending_ &&
      helper_->MakeCurrent()) {
    ReleaseFrontTexture();
  }
}

void* TextureImageTransportSurface::GetShareHandle() {
  return GetHandle();
}

void* TextureImageTransportSurface::GetDisplay() {
  return surface_.get() ? surface_->GetDisplay() : NULL;
}

void* TextureImageTransportSurface::GetConfig() {
  return surface_.get() ? surface_->GetConfig() : NULL;
}

void TextureImageTransportSurface::OnResize(gfx::Size size,
                                            float scale_factor) {
  DCHECK_GE(size.width(), 1);
  DCHECK_GE(size.height(), 1);
  current_size_ = size;
  scale_factor_ = scale_factor;
  if (backbuffer_suggested_allocation_)
    CreateBackTexture();
}

void TextureImageTransportSurface::OnWillDestroyStub() {
  bool have_context = IsContextValid(helper_.get());
  helper_->stub()->RemoveDestructionObserver(this);

  // We are losing the stub owning us, this is our last chance to clean up the
  // resources we allocated in the stub's context.
  if (have_context) {
    ReleaseBackTexture();
    ReleaseFrontTexture();
  } else {
    backbuffer_ = NULL;
    back_mailbox_ = Mailbox();
    frontbuffer_ = NULL;
    front_mailbox_ = Mailbox();
  }

  if (fbo_id_ && have_context) {
    glDeleteFramebuffersEXT(1, &fbo_id_);
    CHECK_GL_ERROR();
  }
  fbo_id_ = 0;

  stub_destroyed_ = true;
}

void TextureImageTransportSurface::SetLatencyInfo(
    const std::vector<ui::LatencyInfo>& latency_info) {
  for (size_t i = 0; i < latency_info.size(); i++)
    latency_info_.push_back(latency_info[i]);
}

void TextureImageTransportSurface::WakeUpGpu() {
  NOTIMPLEMENTED();
}

bool TextureImageTransportSurface::SwapBuffers() {
  DCHECK(IsContextValid(helper_.get()));
  DCHECK(backbuffer_suggested_allocation_);

  if (!frontbuffer_suggested_allocation_)
    return true;

  if (!backbuffer_.get()) {
    LOG(ERROR) << "Swap without valid backing.";
    return true;
  }

  DCHECK(backbuffer_size() == current_size_);
  GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params params;
  params.size = backbuffer_size();
  params.scale_factor = scale_factor_;
  params.mailbox = back_mailbox_;

  glFlush();

  params.latency_info.swap(latency_info_);
  helper_->SendAcceleratedSurfaceBuffersSwapped(params);

  DCHECK(!is_swap_buffers_pending_);
  is_swap_buffers_pending_ = true;
  return true;
}

bool TextureImageTransportSurface::PostSubBuffer(
    int x, int y, int width, int height) {
  DCHECK(IsContextValid(helper_.get()));
  DCHECK(backbuffer_suggested_allocation_);
  if (!frontbuffer_suggested_allocation_)
    return true;
  const gfx::Rect new_damage_rect(x, y, width, height);
  DCHECK(gfx::Rect(gfx::Point(), current_size_).Contains(new_damage_rect));

  // An empty damage rect is a successful no-op.
  if (new_damage_rect.IsEmpty())
    return true;

  if (!backbuffer_.get()) {
    LOG(ERROR) << "Swap without valid backing.";
    return true;
  }

  DCHECK(current_size_ == backbuffer_size());
  GpuHostMsg_AcceleratedSurfacePostSubBuffer_Params params;
  params.surface_size = backbuffer_size();
  params.surface_scale_factor = scale_factor_;
  params.x = x;
  params.y = y;
  params.width = width;
  params.height = height;
  params.mailbox = back_mailbox_;

  glFlush();

  params.latency_info.swap(latency_info_);
  helper_->SendAcceleratedSurfacePostSubBuffer(params);

  DCHECK(!is_swap_buffers_pending_);
  is_swap_buffers_pending_ = true;
  return true;
}

bool TextureImageTransportSurface::SupportsPostSubBuffer() {
  return true;
}

gfx::Size TextureImageTransportSurface::GetSize() {
  return current_size_;
}

void* TextureImageTransportSurface::GetHandle() {
  return surface_.get() ? surface_->GetHandle() : NULL;
}

unsigned TextureImageTransportSurface::GetFormat() {
  return surface_.get() ? surface_->GetFormat() : 0;
}

void TextureImageTransportSurface::OnBufferPresented(
    const AcceleratedSurfaceMsg_BufferPresented_Params& params) {
  if (params.sync_point == 0) {
    BufferPresentedImpl(params.mailbox);
  } else {
    helper_->manager()->sync_point_manager()->AddSyncPointCallback(
        params.sync_point,
        base::Bind(&TextureImageTransportSurface::BufferPresentedImpl,
                   this,
                   params.mailbox));
  }
}

void TextureImageTransportSurface::BufferPresentedImpl(const Mailbox& mailbox) {
  DCHECK(is_swap_buffers_pending_);
  is_swap_buffers_pending_ = false;

  // When we wait for a sync point, we may get called back after the stub is
  // destroyed. In that case there's no need to do anything with the returned
  // mailbox.
  if (stub_destroyed_)
    return;

  // We should not have allowed the backbuffer to be discarded while the ack
  // was pending.
  DCHECK(backbuffer_suggested_allocation_);
  DCHECK(backbuffer_.get());

  bool swap = true;
  if (!mailbox.IsZero()) {
    if (mailbox == back_mailbox_) {
      // The browser has skipped the frame to unblock the GPU process, waiting
      // for one of the right size, and returned the back buffer, so don't swap.
      swap = false;
    }
  }
  if (swap) {
    std::swap(backbuffer_, frontbuffer_);
    std::swap(back_mailbox_, front_mailbox_);
  }

  // We're relying on the fact that the parent context is
  // finished with its context when it inserts the sync point that
  // triggers this callback.
  if (helper_->MakeCurrent()) {
    if (frontbuffer_.get() && !frontbuffer_suggested_allocation_)
      ReleaseFrontTexture();
    if (!backbuffer_.get() || backbuffer_size() != current_size_)
      CreateBackTexture();
    else
      AttachBackTextureToFBO();
  }

  // Even if MakeCurrent fails, schedule anyway, to trigger the lost context
  // logic.
  if (did_unschedule_) {
    did_unschedule_ = false;
    helper_->SetScheduled(true);
  }
}

void TextureImageTransportSurface::OnResizeViewACK() {
  NOTREACHED();
}

void TextureImageTransportSurface::ReleaseBackTexture() {
  DCHECK(IsContextValid(helper_.get()));
  backbuffer_ = NULL;
  back_mailbox_ = Mailbox();
  glFlush();
  CHECK_GL_ERROR();
}

void TextureImageTransportSurface::ReleaseFrontTexture() {
  DCHECK(IsContextValid(helper_.get()));
  frontbuffer_ = NULL;
  front_mailbox_ = Mailbox();
  glFlush();
  CHECK_GL_ERROR();
  helper_->SendAcceleratedSurfaceRelease();
}

void TextureImageTransportSurface::CreateBackTexture() {
  DCHECK(IsContextValid(helper_.get()));
  // If |is_swap_buffers_pending| we are waiting for our backbuffer
  // in the mailbox, so we shouldn't be reallocating it now.
  DCHECK(!is_swap_buffers_pending_);

  if (backbuffer_.get() && backbuffer_size() == current_size_)
    return;

  VLOG(1) << "Allocating new backbuffer texture";

  GLES2Decoder* decoder = helper_->stub()->decoder();
  TextureManager* texture_manager =
      decoder->GetContextGroup()->texture_manager();
  if (!backbuffer_.get()) {
    back_mailbox_ = gpu::Mailbox::Generate();
    GLuint service_id;
    glGenTextures(1, &service_id);
    backbuffer_ = TextureRef::Create(texture_manager, 0, service_id);
    texture_manager->SetTarget(backbuffer_.get(), GL_TEXTURE_2D);
    Texture* texture = texture_manager->Produce(backbuffer_.get());
    mailbox_manager_->ProduceTexture(GL_TEXTURE_2D, back_mailbox_, texture);
  }

  {
    gfx::ScopedTextureBinder texture_binder(GL_TEXTURE_2D,
                                            backbuffer_->service_id());
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA,
        current_size_.width(), current_size_.height(), 0,
        GL_RGBA, GL_UNSIGNED_BYTE, NULL);
    gpu::gles2::ErrorState* error_state = decoder->GetErrorState();
    texture_manager->SetParameteri("Backbuffer",
                                   error_state,
                                   backbuffer_.get(),
                                   GL_TEXTURE_MIN_FILTER,
                                   GL_LINEAR);
    texture_manager->SetParameteri("Backbuffer",
                                   error_state,
                                   backbuffer_.get(),
                                   GL_TEXTURE_MAG_FILTER,
                                   GL_LINEAR);
    texture_manager->SetParameteri("Backbuffer",
                                   error_state,
                                   backbuffer_.get(),
                                   GL_TEXTURE_WRAP_S,
                                   GL_CLAMP_TO_EDGE);
    texture_manager->SetParameteri("Backbuffer",
                                   error_state,
                                   backbuffer_.get(),
                                   GL_TEXTURE_WRAP_T,
                                   GL_CLAMP_TO_EDGE);
    texture_manager->SetLevelInfo(backbuffer_.get(),
                                  GL_TEXTURE_2D,
                                  0,
                                  GL_RGBA,
                                  current_size_.width(),
                                  current_size_.height(),
                                  1,
                                  0,
                                  GL_RGBA,
                                  GL_UNSIGNED_BYTE,
                                  true);
    DCHECK(texture_manager->CanRender(backbuffer_.get()));
    CHECK_GL_ERROR();
  }

  AttachBackTextureToFBO();
}

void TextureImageTransportSurface::AttachBackTextureToFBO() {
  DCHECK(IsContextValid(helper_.get()));
  DCHECK(backbuffer_.get());
  gfx::ScopedFrameBufferBinder fbo_binder(fbo_id_);
  glFramebufferTexture2DEXT(GL_FRAMEBUFFER,
      GL_COLOR_ATTACHMENT0,
      GL_TEXTURE_2D,
      backbuffer_->service_id(),
      0);
  CHECK_GL_ERROR();

#ifndef NDEBUG
  GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER);
  if (status != GL_FRAMEBUFFER_COMPLETE) {
    DLOG(FATAL) << "Framebuffer incomplete: " << status;
  }
#endif
}

}  // namespace content