foundationdb/fdbserver/WaitFailure.actor.cpp

/*
 * WaitFailure.actor.cpp
 *
 * 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.
 */

#include "fdbrpc/FailureMonitor.h"
#include "flow/Deque.h"
#include "fdbserver/Knobs.h"
#include "flow/actorcompiler.h"  // This must be the last #include.

ACTOR Future<Void> waitFailureServer(FutureStream<ReplyPromise<Void>> waitFailure){
	// when this actor is cancelled, the promises in the queue will send broken_promise
	state Deque<ReplyPromise<Void>> queue;
	loop {
		ReplyPromise<Void> P = waitNext(waitFailure);
		queue.push_back(P);
		if (queue.size()>SERVER_KNOBS->MAX_OUTSTANDING_WAIT_FAILURE_REQUESTS){
			TEST(true); // wait server queue full
			queue.front().send(Void());
			queue.pop_front();
		}
	}
}

ACTOR Future<Void> waitFailureClient(RequestStream<ReplyPromise<Void>> waitFailure, double reactionTime, double reactionSlope, TaskPriority taskID){
	loop {
		try {
			state double start = now();
			ErrorOr<Void> x = wait(waitFailure.getReplyUnlessFailedFor(ReplyPromise<Void>(), reactionTime, reactionSlope, taskID));
			if (!x.present()) return Void();
			double w = start + SERVER_KNOBS->WAIT_FAILURE_DELAY_LIMIT - now();
			if (w > 0)
				wait( delay( w, taskID ) );
		} catch (Error &e){
			if (e.code() == error_code_actor_cancelled)
				throw;
			TraceEvent(SevError, "WaitFailureClientError").error(e);
			ASSERT(false); // unknown error from waitFailureServer
		}
	}
}

ACTOR Future<Void> waitFailureClientStrict(RequestStream<ReplyPromise<Void>> waitFailure, double failureReactionTime, TaskPriority taskID){
	loop {
		wait(waitFailureClient(waitFailure, 0, 0, taskID));
		wait(delay(failureReactionTime, taskID) || IFailureMonitor::failureMonitor().onStateEqual( waitFailure.getEndpoint(), FailureStatus(false)));
		if(IFailureMonitor::failureMonitor().getState( waitFailure.getEndpoint() ).isFailed()) {
			return Void();
		}
	}
}

ACTOR Future<Void> waitFailureTracker(RequestStream<ReplyPromise<Void>> waitFailure, Reference<AsyncVar<bool>> failed, double reactionTime, double reactionSlope, TaskPriority taskID){
	loop {
		try {	
			failed->set( IFailureMonitor::failureMonitor().getState(waitFailure.getEndpoint()).isFailed() );
			if( failed->get() ) {
				wait( IFailureMonitor::failureMonitor().onStateChanged(waitFailure.getEndpoint()) );
			} else {
				state double start = now();
				ErrorOr<Void> x = wait(waitFailure.getReplyUnlessFailedFor(ReplyPromise<Void>(), reactionTime, reactionSlope, taskID));
				if (x.present()) {
					double w = start + SERVER_KNOBS->WAIT_FAILURE_DELAY_LIMIT - now();
					if (w > 0)
						wait( delay( w, taskID ) );
				}
			}
		} catch (Error &e){
			if (e.code() == error_code_actor_cancelled)
				throw;
			TraceEvent(SevError, "WaitFailureClientError").error(e);
			ASSERT(false); // unknown error from waitFailureServer
		}
	}
}