Revert of Global Resource Coordinator: Basic service internals

services/resource_coordinator/coordination_unit/coordination_unit_impl.cc

-// Copyright 2017 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 "services/resource_coordinator/coordination_unit/coordination_unit_impl.h"
-
-#include <memory>
-#include <utility>
-
-#include "base/logging.h"
-#include "base/process/process_handle.h"
-#include "base/strings/string_number_conversions.h"
-#include "base/unguessable_token.h"
-#include "mojo/public/cpp/bindings/strong_binding.h"
-#include "services/resource_coordinator/public/cpp/coordination_unit_id.h"
-
-namespace resource_coordinator {
-
-namespace {
-
-using CUIDMap = std::unordered_map<CoordinationUnitID, CoordinationUnitImpl*>;
-
-CUIDMap& g_cu_map() {
-  static CUIDMap* instance = new CUIDMap();
-  return *instance;
-}
-
-}  // namespace
-
-CoordinationUnitImpl::CoordinationUnitImpl(
-    const CoordinationUnitID& id,
-    std::unique_ptr<service_manager::ServiceContextRef> service_ref) {
-  if (!id.id) {
-    id_ = CoordinationUnitID(id.type,
-                             base::UnguessableToken().Create().ToString());
-  } else {
-    id_ = id;
-  }
-
-  auto it = g_cu_map().insert(std::make_pair(id_, this));
-  DCHECK(it.second);  // Inserted successfully
-
-  service_ref_ = std::move(service_ref);
-}
-
-CoordinationUnitImpl::~CoordinationUnitImpl() {
-  g_cu_map().erase(id_);
-
-  for (CoordinationUnitImpl* child : children_) {
-    child->RemoveParent(this);
-  }
-
-  for (CoordinationUnitImpl* parent : parents_) {
-    parent->RemoveChild(this);
-  }
-}
-
-bool CoordinationUnitImpl::SelfOrParentHasFlagSet(StateFlags state) {
-  const base::Optional<bool>& state_flag = state_flags_[state];
-  if (state_flag && *state_flag) {
-    return true;
-  }
-
-  for (CoordinationUnitImpl* parent : parents_) {
-    if (parent->SelfOrParentHasFlagSet(state)) {
-      return true;
-    }
-  }
-
-  return false;
-}
-
-void CoordinationUnitImpl::RecalcCoordinationPolicy() {
-  for (CoordinationUnitImpl* child : children_) {
-    child->RecalcCoordinationPolicy();
-  }
-
-  if (!policy_callback_) {
-    return;
-  }
-
-  bool background_priority = !SelfOrParentHasFlagSet(kTabVisible) &&
-                             !SelfOrParentHasFlagSet(kAudioPlaying);
-
-  // Send the priority to the client if it's new or changed.
-  if (!current_policy_) {
-    current_policy_ = mojom::CoordinationPolicy::New();
-  } else if ((current_policy_->use_background_priority ==
-              background_priority) &&
-             !SelfOrParentHasFlagSet(StateFlags::kTestState)) {
-    return;
-  }
-
-  // current_policy_ should be kept in sync with the policy we
-  // send to the client, to avoid redundant updates.
-  // TODO(oysteine): Once this object becomes more complex, make
-  // copying more robust.
-  mojom::CoordinationPolicyPtr policy = mojom::CoordinationPolicy::New();
-  policy->use_background_priority = background_priority;
-  current_policy_->use_background_priority = background_priority;
-
-  policy_callback_->SetCoordinationPolicy(std::move(policy));
-}
-
-void CoordinationUnitImpl::SendEvent(mojom::EventPtr event) {
-  switch (event->type) {
-    case mojom::EventType::kOnWebContentsShown:
-      state_flags_[kTabVisible] = true;
-      break;
-    case mojom::EventType::kOnWebContentsHidden:
-      state_flags_[kTabVisible] = false;
-      break;
-    case mojom::EventType::kOnProcessAudioStarted:
-      state_flags_[kAudioPlaying] = true;
-      break;
-    case mojom::EventType::kOnProcessAudioStopped:
-      state_flags_[kAudioPlaying] = false;
-      break;
-    case mojom::EventType::kTestEvent:
-      state_flags_[kTestState] = true;
-      break;
-    default:
-      return;
-  }
-
-  RecalcCoordinationPolicy();
-}
-
-void CoordinationUnitImpl::GetID(const GetIDCallback& callback) {
-  callback.Run(id_);
-}
-
-void CoordinationUnitImpl::Duplicate(mojom::CoordinationUnitRequest request) {
-  bindings_.AddBinding(this, std::move(request));
-}
-
-void CoordinationUnitImpl::AddChild(const CoordinationUnitID& child_id) {
-  if (child_id == id_) {
-    return;
-  }
-
-  auto child_iter = g_cu_map().find(child_id);
-  if (child_iter != g_cu_map().end()) {
-    CoordinationUnitImpl* child = child_iter->second;
-    if (HasParent(child) || HasChild(child)) {
-      return;
-    }
-
-    DCHECK(child->id_ == child_id);
-    DCHECK(child != this);
-
-    if (AddChild(child)) {
-      child->AddParent(this);
-    }
-  }
-}
-
-bool CoordinationUnitImpl::AddChild(CoordinationUnitImpl* child) {
-  // We don't recalculate the policy here as policies are only dependent
-  // on the current CU or its parents, not its children. In other words,
-  // policies only bubble down.
-  return children_.count(child) ? false : children_.insert(child).second;
-}
-
-void CoordinationUnitImpl::RemoveChild(CoordinationUnitImpl* child) {
-  size_t children_removed = children_.erase(child);
-  DCHECK_EQ(1u, children_removed);
-}
-
-void CoordinationUnitImpl::AddParent(CoordinationUnitImpl* parent) {
-  DCHECK_EQ(0u, parents_.count(parent));
-  parents_.insert(parent);
-
-  RecalcCoordinationPolicy();
-}
-
-void CoordinationUnitImpl::RemoveParent(CoordinationUnitImpl* parent) {
-  size_t parents_removed = parents_.erase(parent);
-  DCHECK_EQ(1u, parents_removed);
-
-  RecalcCoordinationPolicy();
-}
-
-bool CoordinationUnitImpl::HasParent(CoordinationUnitImpl* unit) {
-  for (CoordinationUnitImpl* parent : parents_) {
-    if (parent == unit || parent->HasParent(unit)) {
-      return true;
-    }
-  }
-
-  return false;
-}
-
-bool CoordinationUnitImpl::HasChild(CoordinationUnitImpl* unit) {
-  for (CoordinationUnitImpl* child : children_) {
-    if (child == unit || child->HasChild(unit)) {
-      return true;
-    }
-  }
-
-  return false;
-}
-
-void CoordinationUnitImpl::SetCoordinationPolicyCallback(
-    mojom::CoordinationPolicyCallbackPtr callback) {
-  callback.set_connection_error_handler(
-      base::Bind(&CoordinationUnitImpl::UnregisterCoordinationPolicyCallback,
-                 base::Unretained(this)));
-
-  policy_callback_ = std::move(callback);
-
-  RecalcCoordinationPolicy();
-}
-
-void CoordinationUnitImpl::UnregisterCoordinationPolicyCallback() {
-  policy_callback_.reset();
-  current_policy_.reset();
-}
-
-}  // namespace resource_coordinator