| // Copyright 2014 The Bazel Authors. All rights reserved. |
| // |
| // 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. |
| |
| package com.google.devtools.build.lib.server; |
| |
| import com.google.common.collect.Iterables; |
| import com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.LockingMode; |
| import com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.ShutdownMethod; |
| import com.google.devtools.build.lib.util.Preconditions; |
| import com.google.devtools.build.lib.util.io.OutErr; |
| |
| import java.util.List; |
| import java.util.logging.Logger; |
| |
| /** |
| * An RPCService is a Java object that can process RPC requests. Requests may |
| * be of the form: |
| * <pre> |
| * blaze <blaze-arguments> |
| * </pre> |
| * Requests are delegated to the ServerCommand instance provided |
| * to the constructor. |
| */ |
| public final class RPCService { |
| |
| private static final Logger LOG = Logger.getLogger(RPCService.class.getName()); |
| private final ServerCommand appCommand; |
| private ShutdownMethod shutdown = ShutdownMethod.NONE; |
| |
| public RPCService(ServerCommand appCommand) { |
| this.appCommand = appCommand; |
| } |
| |
| /** |
| * The {@link #executeRequest(List, OutErr, long)} method may |
| * throw this exception if a command is unknown to the RPC service. |
| */ |
| public static class UnknownCommandException extends Exception { |
| private static final long serialVersionUID = 1L; |
| UnknownCommandException(String command) { |
| super("Unknown command: " + command); |
| } |
| } |
| |
| /** |
| * Executes the request; returns Unix like return codes (0 means success). May |
| * also throw arbitrary exceptions. |
| */ |
| public int executeRequest(List<String> request, |
| OutErr outErr, |
| long firstContactTime) throws Exception { |
| if (shutdown != ShutdownMethod.NONE) { |
| throw new IllegalStateException("Received request after shutdown."); |
| } |
| String command = Iterables.getFirst(request, ""); |
| if (appCommand != null && command.equals("blaze")) { // an application request |
| // Blocking is done in the client for AF_UNIX communications, so if blockForLock would block, |
| // something went wrong |
| int result = appCommand.exec( |
| request.subList(1, request.size()), outErr, LockingMode.ERROR_OUT, "AF_UNIX client", |
| firstContactTime); |
| ShutdownMethod commandShutdown = appCommand.shutdown(); |
| if (commandShutdown != ShutdownMethod.NONE) { // an application shutdown request |
| shutdown(commandShutdown); |
| } |
| return result; |
| } else { |
| throw new UnknownCommandException(command); |
| } |
| } |
| |
| /** |
| * After executing this function, further requests will fail, and |
| * {@link #getShutdown()} will the shutdown method passed in. |
| */ |
| public void shutdown(ShutdownMethod method) { |
| Preconditions.checkState(method != ShutdownMethod.NONE); |
| if (shutdown != ShutdownMethod.NONE) { |
| return; |
| } |
| LOG.info("RPC Service: shutting down ..."); |
| shutdown = method; |
| } |
| |
| /** |
| * Has this service been shutdown. If so, any call to |
| * {@link #executeRequest(List, OutErr, long)} will result in an |
| * {@link IllegalStateException} |
| */ |
| public ShutdownMethod getShutdown() { |
| return shutdown; |
| } |
| |
| } |