+++ /dev/null
-/*
- * Copyright (c) 2013 Cisco Systems, Inc. and others. All rights reserved.
- *
- * This program and the accompanying materials are made available under the
- * terms of the Eclipse Public License v1.0 which accompanies this distribution,
- * and is available at http://www.eclipse.org/legal/epl-v10.html
- */
-package org.opendaylight.protocol.framework;
-
-import io.netty.util.concurrent.EventExecutor;
-import io.netty.util.concurrent.Future;
-
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;
-
-import javax.annotation.concurrent.GuardedBy;
-import javax.annotation.concurrent.ThreadSafe;
-
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import com.google.common.base.Preconditions;
-
-/**
- * Swiss army knife equivalent for reconnect strategies.
- *
- * This strategy continues to schedule reconnect attempts, each having to complete in a fixed time (connectTime).
- *
- * Initial sleep time is specified as minSleep. Each subsequent unsuccessful attempt multiplies this time by a constant
- * factor (sleepFactor) -- this allows for either constant reconnect times (sleepFactor = 1), or various degrees of
- * exponential back-off (sleepFactor > 1). Maximum sleep time between attempts can be capped to a specific value
- * (maxSleep).
- *
- * The strategy can optionally give up based on two criteria:
- *
- * A preset number of connection retries (maxAttempts) has been reached, or
- *
- * A preset absolute deadline is reached (deadline nanoseconds, as reported by System.nanoTime(). In this specific case,
- * both connectTime and maxSleep will be controlled such that the connection attempt is resolved as closely to the
- * deadline as possible.
- *
- * Both these caps can be combined, with the strategy giving up as soon as the first one is reached.
- */
-@Deprecated
-@ThreadSafe
-public final class TimedReconnectStrategy implements ReconnectStrategy {
- private static final Logger LOG = LoggerFactory.getLogger(TimedReconnectStrategy.class);
- private final EventExecutor executor;
- private final Long deadline, maxAttempts, maxSleep;
- private final double sleepFactor;
- private final int connectTime;
- private final long minSleep;
-
- @GuardedBy("this")
- private long attempts;
-
- @GuardedBy("this")
- private long lastSleep;
-
- @GuardedBy("this")
- private boolean scheduled;
-
- public TimedReconnectStrategy(final EventExecutor executor, final int connectTime, final long minSleep, final double sleepFactor,
- final Long maxSleep, final Long maxAttempts, final Long deadline) {
- Preconditions.checkArgument(maxSleep == null || minSleep <= maxSleep);
- Preconditions.checkArgument(sleepFactor >= 1);
- Preconditions.checkArgument(connectTime >= 0);
- this.executor = Preconditions.checkNotNull(executor);
- this.deadline = deadline;
- this.maxAttempts = maxAttempts;
- this.minSleep = minSleep;
- this.maxSleep = maxSleep;
- this.sleepFactor = sleepFactor;
- this.connectTime = connectTime;
- }
-
- @Override
- public synchronized Future<Void> scheduleReconnect(final Throwable cause) {
- LOG.debug("Connection attempt failed", cause);
-
- // Check if a reconnect attempt is scheduled
- Preconditions.checkState(!this.scheduled);
-
- // Get a stable 'now' time for deadline calculations
- final long now = System.nanoTime();
-
- // Obvious stop conditions
- if (this.maxAttempts != null && this.attempts >= this.maxAttempts) {
- return this.executor.newFailedFuture(new Throwable("Maximum reconnection attempts reached"));
- }
- if (this.deadline != null && this.deadline <= now) {
- return this.executor.newFailedFuture(new TimeoutException("Reconnect deadline reached"));
- }
-
- /*
- * First connection attempt gets initialized to minimum sleep,
- * each subsequent is exponentially backed off by sleepFactor.
- */
- if (this.attempts != 0) {
- this.lastSleep *= this.sleepFactor;
- } else {
- this.lastSleep = this.minSleep;
- }
-
- // Cap the sleep time to maxSleep
- if (this.maxSleep != null && this.lastSleep > this.maxSleep) {
- LOG.debug("Capped sleep time from {} to {}", this.lastSleep, this.maxSleep);
- this.lastSleep = this.maxSleep;
- }
-
- this.attempts++;
-
- // Check if the reconnect attempt is within the deadline
- if (this.deadline != null && this.deadline <= now + TimeUnit.MILLISECONDS.toNanos(this.lastSleep)) {
- return this.executor.newFailedFuture(new TimeoutException("Next reconnect would happen after deadline"));
- }
-
- LOG.debug("Connection attempt {} sleeping for {} milliseconds", this.attempts, this.lastSleep);
-
- // If we are not sleeping at all, return an already-succeeded future
- if (this.lastSleep == 0) {
- return this.executor.newSucceededFuture(null);
- }
-
- // Need to retain a final reference to this for locking purposes,
- // also set the scheduled flag.
- final Object lock = this;
- this.scheduled = true;
-
- // Schedule a task for the right time. It will also clear the flag.
- return this.executor.schedule(() -> {
- synchronized (lock) {
- Preconditions.checkState(TimedReconnectStrategy.this.scheduled);
- TimedReconnectStrategy.this.scheduled = false;
- }
-
- return null;
- }, this.lastSleep, TimeUnit.MILLISECONDS);
- }
-
- @Override
- public synchronized void reconnectSuccessful() {
- Preconditions.checkState(!this.scheduled);
- this.attempts = 0;
- }
-
- @Override
- public int getConnectTimeout() throws TimeoutException {
- int timeout = this.connectTime;
-
- if (this.deadline != null) {
-
- // If there is a deadline, we may need to cap the connect
- // timeout to meet the deadline.
- final long now = System.nanoTime();
- if (now >= this.deadline) {
- throw new TimeoutException("Reconnect deadline already passed");
- }
-
- final long left = TimeUnit.NANOSECONDS.toMillis(this.deadline - now);
- if (left < 1) {
- throw new TimeoutException("Connect timeout too close to deadline");
- }
-
- /*
- * A bit of magic:
- * - if time left is less than the timeout, set it directly
- * - if there is no timeout, and time left is:
- * - less than maximum integer, set timeout to time left
- * - more than maximum integer, set timeout Integer.MAX_VALUE
- */
- if (timeout > left) {
- timeout = (int) left;
- } else if (timeout == 0) {
- timeout = left <= Integer.MAX_VALUE ? (int) left : Integer.MAX_VALUE;
- }
- }
- return timeout;
- }
-}
Code Review / controller.git / blobdiff