| // Copyright 2016 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.actions; |
| |
| import com.google.common.collect.ImmutableList; |
| import javax.annotation.Nullable; |
| |
| /** |
| * A context that allows execution of {@link Spawn} instances similar to {@link SpawnStrategy}, but |
| * with the additional restriction that during execution the {@link Spawn} must not be allowed to |
| * modify the current execution root of the build. Instead, the {@link Spawn} should be executed in |
| * a sandbox or on a remote system and its output files only be moved to the execution root. |
| */ |
| public interface SandboxedSpawnStrategy extends SpawnStrategy { |
| |
| /** Lambda interface to stop other instances of the same spawn before writing outputs. */ |
| @FunctionalInterface |
| interface StopConcurrentSpawns { |
| /** |
| * Stops other instances of the same spawn before writing outputs. |
| * |
| * <p>This should be called once by each of the concurrent spawns to ensure that the others are |
| * stopped, thus preventing conflicts when writing to the output tree. |
| */ |
| void stop() throws InterruptedException; |
| } |
| |
| /** |
| * Executes the given spawn. |
| * |
| * <p>When the {@link SpawnStrategy} is about to write output files into the execroot, it first |
| * asks any other concurrent instances of this same spawn (handled by other spawn runners when |
| * dynamic scheduling is enabled) to stop by invoking the {@code stopConcurrentSpawns} lambda. |
| * |
| * @return a List of {@link SpawnResult}s containing metadata about the Spawn's execution. This |
| * will typically contain one element, but could contain no elements if spawn execution did |
| * not complete, or contain multiple elements if multiple sub-spawns were executed |
| */ |
| ImmutableList<SpawnResult> exec( |
| Spawn spawn, |
| ActionExecutionContext actionExecutionContext, |
| // TODO(jmmv): Inject an empty lambda instead of allowing this to be null. Need to find a way |
| // to deal with non-null implying speculation in e.g. AbstractSpawnStrategy (if it matters). |
| @Nullable StopConcurrentSpawns stopConcurrentSpawns) |
| throws ExecException, InterruptedException; |
| } |