// Copyright 2014 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 "android_webview/browser/shared_renderer_state.h"

#include "android_webview/browser/browser_view_renderer_client.h"
#include "base/bind.h"
#include "base/lazy_instance.h"
#include "base/location.h"

namespace android_webview {

namespace internal {

class RequestDrawGLTracker {
 public:
  RequestDrawGLTracker();
  bool ShouldRequestOnNoneUiThread(SharedRendererState* state);
  bool ShouldRequestOnUiThread(SharedRendererState* state);
  void DidRequestOnUiThread();
  void ResetPending();

 private:
  base::Lock lock_;
  SharedRendererState* pending_ui_;
  SharedRendererState* pending_non_ui_;
};

RequestDrawGLTracker::RequestDrawGLTracker()
    : pending_ui_(NULL), pending_non_ui_(NULL) {
}

bool RequestDrawGLTracker::ShouldRequestOnNoneUiThread(
    SharedRendererState* state) {
  base::AutoLock lock(lock_);
  if (pending_ui_ || pending_non_ui_)
    return false;
  pending_non_ui_ = state;
  return true;
}

bool RequestDrawGLTracker::ShouldRequestOnUiThread(SharedRendererState* state) {
  base::AutoLock lock(lock_);
  if (pending_non_ui_) {
    pending_non_ui_->ResetRequestDrawGLCallback();
    pending_non_ui_ = NULL;
  }
  if (pending_ui_)
    return false;
  pending_ui_ = state;
  return true;
}

void RequestDrawGLTracker::ResetPending() {
  base::AutoLock lock(lock_);
  pending_non_ui_ = NULL;
  pending_ui_ = NULL;
}

}  // namespace internal

namespace {

base::LazyInstance<internal::RequestDrawGLTracker> g_request_draw_gl_tracker =
    LAZY_INSTANCE_INITIALIZER;

}

DrawGLInput::DrawGLInput() : width(0), height(0) {
}

DrawGLInput::~DrawGLInput() {
}

SharedRendererState::SharedRendererState(
    scoped_refptr<base::MessageLoopProxy> ui_loop,
    BrowserViewRendererClient* client)
    : ui_loop_(ui_loop),
      client_on_ui_(client),
      weak_factory_on_ui_thread_(this),
      ui_thread_weak_ptr_(weak_factory_on_ui_thread_.GetWeakPtr()),
      inside_hardware_release_(false),
      share_context_(NULL) {
  DCHECK(ui_loop_->BelongsToCurrentThread());
  DCHECK(client_on_ui_);
  ResetRequestDrawGLCallback();
}

SharedRendererState::~SharedRendererState() {
  DCHECK(ui_loop_->BelongsToCurrentThread());
}

void SharedRendererState::ClientRequestDrawGL() {
  if (ui_loop_->BelongsToCurrentThread()) {
    if (!g_request_draw_gl_tracker.Get().ShouldRequestOnUiThread(this))
      return;
    ClientRequestDrawGLOnUIThread();
  } else {
    if (!g_request_draw_gl_tracker.Get().ShouldRequestOnNoneUiThread(this))
      return;
    base::Closure callback;
    {
      base::AutoLock lock(lock_);
      callback = request_draw_gl_closure_;
    }
    ui_loop_->PostTask(FROM_HERE, callback);
  }
}

void SharedRendererState::DidDrawGLProcess() {
  g_request_draw_gl_tracker.Get().ResetPending();
}

void SharedRendererState::ResetRequestDrawGLCallback() {
  DCHECK(ui_loop_->BelongsToCurrentThread());
  base::AutoLock lock(lock_);
  request_draw_gl_cancelable_closure_.Reset(
      base::Bind(&SharedRendererState::ClientRequestDrawGLOnUIThread,
                 base::Unretained(this)));
  request_draw_gl_closure_ = request_draw_gl_cancelable_closure_.callback();
}

void SharedRendererState::ClientRequestDrawGLOnUIThread() {
  DCHECK(ui_loop_->BelongsToCurrentThread());
  ResetRequestDrawGLCallback();
  if (!client_on_ui_->RequestDrawGL(NULL, false)) {
    g_request_draw_gl_tracker.Get().ResetPending();
    LOG(ERROR) << "Failed to request GL process. Deadlock likely";
  }
}

void SharedRendererState::UpdateParentDrawConstraintsOnUIThread() {
  DCHECK(ui_loop_->BelongsToCurrentThread());
  client_on_ui_->UpdateParentDrawConstraints();
}

void SharedRendererState::SetDrawGLInput(scoped_ptr<DrawGLInput> input) {
  base::AutoLock lock(lock_);
  DCHECK(!draw_gl_input_.get());
  draw_gl_input_ = input.Pass();
}

scoped_ptr<DrawGLInput> SharedRendererState::PassDrawGLInput() {
  base::AutoLock lock(lock_);
  return draw_gl_input_.Pass();
}

void SharedRendererState::PostExternalDrawConstraintsToChildCompositor(
    const ParentCompositorDrawConstraints& parent_draw_constraints) {
  {
    base::AutoLock lock(lock_);
    parent_draw_constraints_ = parent_draw_constraints;
  }

  // No need to hold the lock_ during the post task.
  ui_loop_->PostTask(
      FROM_HERE,
      base::Bind(&SharedRendererState::UpdateParentDrawConstraintsOnUIThread,
                 ui_thread_weak_ptr_));
}

const ParentCompositorDrawConstraints
SharedRendererState::ParentDrawConstraints() const {
  base::AutoLock lock(lock_);
  return parent_draw_constraints_;
}

void SharedRendererState::SetInsideHardwareRelease(bool inside) {
  base::AutoLock lock(lock_);
  inside_hardware_release_ = inside;
}

bool SharedRendererState::IsInsideHardwareRelease() const {
  base::AutoLock lock(lock_);
  return inside_hardware_release_;
}

void SharedRendererState::SetSharedContext(gpu::GLInProcessContext* context) {
  base::AutoLock lock(lock_);
  DCHECK(!share_context_ || !context);
  share_context_ = context;
}

gpu::GLInProcessContext* SharedRendererState::GetSharedContext() const {
  base::AutoLock lock(lock_);
  DCHECK(share_context_);
  return share_context_;
}

void SharedRendererState::InsertReturnedResources(
    const cc::ReturnedResourceArray& resources) {
  base::AutoLock lock(lock_);
  returned_resources_.insert(
      returned_resources_.end(), resources.begin(), resources.end());
}

void SharedRendererState::SwapReturnedResources(
    cc::ReturnedResourceArray* resources) {
  DCHECK(resources->empty());
  base::AutoLock lock(lock_);
  resources->swap(returned_resources_);
}

bool SharedRendererState::ReturnedResourcesEmpty() const {
  base::AutoLock lock(lock_);
  return returned_resources_.empty();
}

InsideHardwareReleaseReset::InsideHardwareReleaseReset(
    SharedRendererState* shared_renderer_state)
    : shared_renderer_state_(shared_renderer_state) {
  DCHECK(!shared_renderer_state_->IsInsideHardwareRelease());
  shared_renderer_state_->SetInsideHardwareRelease(true);
}

InsideHardwareReleaseReset::~InsideHardwareReleaseReset() {
  shared_renderer_state_->SetInsideHardwareRelease(false);
}

}  // namespace android_webview