foundationdb/fdbserver/Orderer.actor.h

75 lines
2.2 KiB
C++

/*
* Orderer.actor.h
*
* This source file is part of the FoundationDB open source project
*
* Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
// When actually compiled (NO_INTELLISENSE), include the generated version of this file. In intellisense use the source version.
#if defined(NO_INTELLISENSE) && !defined(FDBSERVER_ORDERER_ACTOR_G_H)
#define FDBSERVER_ORDERER_ACTOR_G_H
#include "Orderer.actor.g.h"
#elif !defined(FDBSERVER_ORDERER_ACTOR_H)
#define FDBSERVER_ORDERER_ACTOR_H
#include "fdbclient/Notified.h"
#include "flow/actorcompiler.h"
template <class Seq>
class Orderer {
public:
explicit Orderer( Seq s ) : ready(s), started(false) {}
void reset( Seq s ) {
ready = NotifiedVersion(s);
started = false;
}
Future<bool> order( Seq s, int taskID = TaskDefaultYield ) {
if ( ready.get() < s )
return waitAndOrder( this, s, taskID );
else
return dedup(s);
}
void complete( Seq s ) {
ASSERT( s == ready.get() && started );
started = false;
ready.set(s+1);
}
Seq getNextSequence() { return ready.get(); } // Returns the next sequence number which has *not* been returned from order()
Future<Void> whenNextSequenceAtLeast( Seq v ) {
return ready.whenAtLeast(v);
}
private:
ACTOR static Future<bool> waitAndOrder( Orderer<Seq>* self, Seq s, int taskID ) {
Void _ = wait( self->ready.whenAtLeast(s) );
Void _ = wait( yield( taskID ) || self->shutdown.getFuture() );
return self->dedup(s);
}
bool dedup( Seq s ) {
if (s != ready.get() || started)
return false;
started = true;
return true;
}
bool started;
NotifiedVersion ready; // FIXME: Notified<Seq>
Promise<Void> shutdown; // Never set, only broken on destruction
};
#endif