chromium/components/performance_manager/public/graph/process_node.h

// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_PERFORMANCE_MANAGER_PUBLIC_GRAPH_PROCESS_NODE_H_
#define COMPONENTS_PERFORMANCE_MANAGER_PUBLIC_GRAPH_PROCESS_NODE_H_

#include "base/containers/enum_set.h"
#include "base/containers/flat_set.h"
#include "base/observer_list_types.h"
#include "base/process/process.h"
#include "base/task/task_traits.h"
#include "components/performance_manager/public/graph/node.h"
#include "components/performance_manager/public/graph/node_set_view.h"
#include "components/performance_manager/public/render_process_host_id.h"
#include "components/performance_manager/public/resource_attribution/process_context.h"
#include "content/public/common/process_type.h"

namespace base {
class Process;
}  // namespace base

namespace performance_manager {

class FrameNode;
class WorkerNode;
class ProcessNodeObserver;
class RenderProcessHostProxy;
class BrowserChildProcessHostProxy;

// A process node follows the lifetime of a RenderProcessHost.
// It may reference zero or one processes at a time, but during its lifetime, it
// may reference more than one process. This can happen if the associated
// renderer crashes, and an associated frame is then reloaded or re-navigated.
// The state of the process node goes through:
// 1. Created, no PID.
// 2. Process started, have PID - in the case where the associated render
//    process fails to start, this state may not occur.
// 3. Process died or failed to start, have exit status.
// 4. Back to 2.
//
// It is only valid to access this object on the sequence of the graph that owns
// it.
class ProcessNode : public TypedNode<ProcessNode> { … };

// Pure virtual observer interface. Derive from this if you want to be forced to
// implement the entire interface.
class ProcessNodeObserver : public base::CheckedObserver { … };

// Default implementation of observer that provides dummy versions of each
// function. Derive from this if you only need to implement a few of the
// functions.
class ProcessNode::ObserverDefaultImpl : public ProcessNodeObserver { … };

}  // namespace performance_manager

#endif  // COMPONENTS_PERFORMANCE_MANAGER_PUBLIC_GRAPH_PROCESS_NODE_H_