| // Copyright 2015 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.worker; |
| |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.flogger.GoogleLogger; |
| import com.google.devtools.build.lib.actions.UserExecException; |
| import com.google.devtools.build.lib.sandbox.CgroupsInfo; |
| import com.google.devtools.build.lib.sandbox.SandboxHelpers.SandboxInputs; |
| import com.google.devtools.build.lib.sandbox.SandboxHelpers.SandboxOutputs; |
| import com.google.devtools.build.lib.shell.Subprocess; |
| import com.google.devtools.build.lib.shell.SubprocessBuilder; |
| import com.google.devtools.build.lib.vfs.Path; |
| import com.google.devtools.build.lib.vfs.PathFragment; |
| import com.google.devtools.build.lib.worker.WorkerProtocol.WorkRequest; |
| import com.google.devtools.build.lib.worker.WorkerProtocol.WorkResponse; |
| import java.io.File; |
| import java.io.IOException; |
| import java.util.Optional; |
| import java.util.Set; |
| import javax.annotation.Nullable; |
| |
| /** |
| * Interface to a worker process running as a single child process. |
| * |
| * <p>A worker process must follow this protocol to be usable via this class: The worker process is |
| * spawned on demand. The worker process is free to exit whenever necessary, as new instances will |
| * be relaunched automatically. Communication happens via the WorkerProtocol protobuf, sent to and |
| * received from the worker process via stdin / stdout. |
| * |
| * <p>Other code in Blaze can talk to the worker process via input / output streams provided by this |
| * class. |
| */ |
| class SingleplexWorker extends Worker { |
| private static final GoogleLogger logger = GoogleLogger.forEnclosingClass(); |
| |
| /** The execution root of the worker. */ |
| protected final Path workDir; |
| |
| /** |
| * Stream for recording the WorkResponse as it's read, so that it can be printed in the case of |
| * parsing failures. |
| */ |
| @Nullable private RecordingInputStream recordingInputStream; |
| |
| /** The implementation of the worker protocol (JSON or Proto). */ |
| @Nullable private WorkerProtocolImpl workerProtocol; |
| |
| private Subprocess process; |
| |
| /** True if we deliberately destroyed this process. */ |
| private boolean wasDestroyed; |
| |
| /** |
| * Shutdown hook to make sure we wait for the process to finish on JVM shutdown, to avoid creating |
| * zombie processes. Unfortunately, shutdown hooks are not guaranteed to be called, but this is |
| * the best we can do. This must be set when a process is created. |
| */ |
| protected Thread shutdownHook; |
| |
| protected WorkerOptions options; |
| |
| SingleplexWorker( |
| WorkerKey workerKey, int workerId, final Path workDir, Path logFile, WorkerOptions options) { |
| super(workerKey, workerId, logFile, new WorkerProcessStatus()); |
| this.workDir = workDir; |
| this.options = options; |
| } |
| |
| protected Subprocess createProcess() throws IOException, InterruptedException, UserExecException { |
| ImmutableList<String> args = makeExecPathAbsolute(workerKey.getArgs()); |
| Subprocess process = createProcessBuilder(args).start(); |
| if (options.useCgroupsOnLinux && CgroupsInfo.isSupported()) { |
| cgroup = |
| CgroupsInfo.getBlazeSpawnsCgroup() |
| .createIndividualSpawnCgroup( |
| /* dirName= */ "worker_" + workerId, /* memoryLimitMb= */ 0); |
| if (cgroup.exists()) { |
| cgroup.addProcess(process.getProcessId()); |
| } |
| } |
| return process; |
| } |
| |
| protected SubprocessBuilder createProcessBuilder(ImmutableList<String> argv) { |
| SubprocessBuilder processBuilder = new SubprocessBuilder(); |
| processBuilder.setArgv(argv); |
| processBuilder.setWorkingDirectory(workDir.getPathFile()); |
| processBuilder.setStderr(logFile.getPathFile()); |
| processBuilder.setEnv(workerKey.getEnv()); |
| return processBuilder; |
| } |
| |
| @Override |
| public boolean isSandboxed() { |
| return false; |
| } |
| |
| @Override |
| public void prepareExecution( |
| SandboxInputs inputFiles, SandboxOutputs outputs, Set<PathFragment> workerFiles) |
| throws IOException, InterruptedException, UserExecException { |
| if (process == null) { |
| addShutdownHook(); |
| process = createProcess(); |
| status.maybeUpdateStatus(WorkerProcessStatus.Status.ALIVE); |
| recordingInputStream = new RecordingInputStream(process.getInputStream()); |
| } |
| if (workerProtocol == null) { |
| switch (workerKey.getProtocolFormat()) { |
| case JSON: |
| workerProtocol = new JsonWorkerProtocol(process.getOutputStream(), recordingInputStream); |
| break; |
| case PROTO: |
| workerProtocol = new ProtoWorkerProtocol(process.getOutputStream(), recordingInputStream); |
| break; |
| } |
| } |
| } |
| |
| void addShutdownHook() { |
| this.shutdownHook = |
| new Thread( |
| () -> { |
| this.shutdownHook = null; |
| this.destroy(); |
| }); |
| Runtime.getRuntime().addShutdownHook(shutdownHook); |
| } |
| |
| /** |
| * Makes sure that the executable (first element of argument list) is an absolute path. Necessary |
| * on Windows (https://github.com/bazelbuild/bazel/commit/8efc3ef0) |
| */ |
| protected ImmutableList<String> makeExecPathAbsolute(ImmutableList<String> args) { |
| File executable = new File(args.get(0)); |
| if (!executable.isAbsolute() && executable.getParent() != null) { |
| return ImmutableList.<String>builderWithExpectedSize(args.size()) |
| .add(new File(workDir.getPathFile(), args.get(0)).getAbsolutePath()) |
| .addAll(args.subList(1, args.size())) |
| .build(); |
| } else { |
| return args; |
| } |
| } |
| |
| @Override |
| void putRequest(WorkRequest request) throws IOException { |
| workerProtocol.putRequest(request); |
| } |
| |
| @Override |
| WorkResponse getResponse(int requestId) throws IOException, InterruptedException { |
| recordingInputStream.startRecording(4096); |
| while (recordingInputStream.available() == 0) { |
| Thread.sleep(10); |
| if (!process.isAlive()) { |
| throw new IOException( |
| String.format( |
| "Worker process for %s died while waiting for response", workerKey.getMnemonic())); |
| } |
| } |
| return workerProtocol.getResponse(); |
| } |
| |
| @Override |
| void destroy() { |
| if (workerProtocol != null) { |
| try { |
| workerProtocol.close(); |
| } catch (IOException e) { |
| logger.atWarning().withCause(e).log("Caught IOException while closing worker protocol."); |
| } |
| workerProtocol = null; |
| } |
| if (shutdownHook != null) { |
| try { |
| Runtime.getRuntime().removeShutdownHook(shutdownHook); |
| } catch (IllegalStateException e) { |
| // Can only happen if we're already in shutdown, in which case we don't care. |
| } |
| } |
| if (process != null) { |
| wasDestroyed = true; |
| process.destroyAndWait(); |
| } |
| status.setKilled(); |
| } |
| |
| /** Returns true if this process is dead but we didn't deliberately kill it. */ |
| @Override |
| boolean diedUnexpectedly() { |
| return process != null && !wasDestroyed && !process.isAlive(); |
| } |
| |
| @Override |
| public Optional<Integer> getExitValue() { |
| return process != null && !process.isAlive() |
| ? Optional.of(process.exitValue()) |
| : Optional.empty(); |
| } |
| |
| @Override |
| String getRecordingStreamMessage() { |
| recordingInputStream.readRemaining(); |
| return recordingInputStream.getRecordedDataAsString(); |
| } |
| |
| @Override |
| public String toString() { |
| return workerKey.getMnemonic() + " worker #" + workerId; |
| } |
| |
| @Override |
| public long getProcessId() { |
| if (process == null) { |
| return -1; |
| } |
| |
| return process.getProcessId(); |
| } |
| } |