Files
xahaud/src/ripple/app/main/LoadManager.h
Howard Hinnant 3f45b8c3bd Switch deadlock detector to steady_clock
* Changes to system time should not trigger the deadlock detector.
* Fixes #3101
2019-10-15 12:01:37 -07:00

114 lines
3.5 KiB
C++

//------------------------------------------------------------------------------
/*
This file is part of rippled: https://github.com/ripple/rippled
Copyright (c) 2012, 2013 Ripple Labs Inc.
Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL , DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
#ifndef RIPPLE_APP_MAIN_LOADMANAGER_H_INCLUDED
#define RIPPLE_APP_MAIN_LOADMANAGER_H_INCLUDED
#include <ripple/core/Stoppable.h>
#include <memory>
#include <mutex>
#include <thread>
namespace ripple {
class Application;
/** Manages load sources.
This object creates an associated thread to maintain a clock.
When the server is overloaded by a particular peer it issues a warning
first. This allows friendly peers to reduce their consumption of resources,
or disconnect from the server.
The warning system is used instead of merely dropping, because hostile
peers can just reconnect anyway.
*/
class LoadManager : public Stoppable
{
LoadManager (Application& app, Stoppable& parent, beast::Journal journal);
public:
LoadManager () = delete;
LoadManager (LoadManager const&) = delete;
LoadManager& operator=(LoadManager const&) = delete;
/** Destroy the manager.
The destructor returns only after the thread has stopped.
*/
~LoadManager ();
/** Turn on deadlock detection.
The deadlock detector begins in a disabled state. After this function
is called, it will report deadlocks using a separate thread whenever
the reset function is not called at least once per 10 seconds.
@see resetDeadlockDetector
*/
// VFALCO NOTE it seems that the deadlock detector has an "armed" state
// to prevent it from going off during program startup if
// there's a lengthy initialization operation taking place?
//
void activateDeadlockDetector ();
/** Reset the deadlock detection timer.
A dedicated thread monitors the deadlock timer, and if too much
time passes it will produce log warnings.
*/
void resetDeadlockDetector ();
//--------------------------------------------------------------------------
// Stoppable members
void onPrepare () override;
void onStart () override;
void onStop () override;
private:
void run ();
private:
Application& app_;
beast::Journal journal_;
std::thread thread_;
std::mutex mutex_; // Guards deadLock_, armed_, and stop_.
std::chrono::steady_clock::time_point deadLock_; // Detect server deadlocks.
bool armed_;
bool stop_;
friend
std::unique_ptr<LoadManager>
make_LoadManager(Application& app, Stoppable& parent, beast::Journal journal);
};
std::unique_ptr<LoadManager>
make_LoadManager (
Application& app, Stoppable& parent, beast::Journal journal);
} // ripple
#endif