src/main/java/com/google/devtools/build/lib/actions/SpawnResult.java - bazel - Git at Google

 // Copyright 2017 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.base.Preconditions;
 import com.google.common.base.Strings;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
 import com.google.devtools.build.lib.shell.TerminationStatus;
 import java.io.InputStream;
 import java.time.Duration;
 import java.util.Locale;
 import java.util.Optional;
 import javax.annotation.Nullable;

 /**
  * The result of a spawn execution.
  *
  * <p>DO NOT IMPLEMENT THIS INTERFACE! Use {@link SpawnResult.Builder} to create instances instead.
  * This is a temporary situation as long as we still have separate internal and external
  * implementations - the plan is to merge the two into a single immutable, final class.
  */
 // TODO(ulfjack): Change this from an interface to an immutable, final class.
 public interface SpawnResult {
   /** The status of the attempted Spawn execution. */
   public enum Status {
     /** Subprocess executed successfully, and returned a zero exit code. */
     SUCCESS,

     /** Subprocess executed successfully, but returned a non-zero exit code. */
     NON_ZERO_EXIT(true),

     /** Subprocess execution timed out. */
     TIMEOUT(true),

     /**
      * The subprocess ran out of memory. On Linux systems, the kernel may kill processes in
      * low-memory situations, and this status is intended to report such a case back to Bazel.
      */
     OUT_OF_MEMORY(true),

     /**
      * Subprocess did not execute. This error is not catastrophic - Bazel will try to continue the
      * build if keep_going is enabled, possibly attempt to rerun the same spawn, and attempt to run
      * other actions.
      */
     EXECUTION_FAILED,

     /**
      * Subprocess did not execute. Do not retry, and exit immediately even if keep_going is enabled.
      */
     EXECUTION_FAILED_CATASTROPHICALLY,

     /**
      * Subprocess did not execute in a way that indicates that the user can fix it. For example, a
      * remote system may have denied the execution due to too many inputs or too large inputs.
      */
     EXECUTION_DENIED(true),

     /**
      * The remote execution system is overloaded and had to refuse execution for this Spawn.
      */
     REMOTE_EXECUTOR_OVERLOADED,

     /**
      * The result of the remotely executed Spawn could not be retrieved due to errors in the remote
      * caching layer.
      */
     REMOTE_CACHE_FAILED;

     private final boolean isUserError;

     private Status(boolean isUserError) {
       this.isUserError = isUserError;
     }

     private Status() {
       this(false);
     }

     public boolean isConsideredUserError() {
       return isUserError;
     }
   }

   /**
    * Returns whether the spawn was actually run, regardless of the exit code. I.e., returns
    * {@code true} if {@link #status} is any of {@link Status#SUCCESS}, {@link Status#NON_ZERO_EXIT},
    * {@link Status#TIMEOUT} or {@link Status#OUT_OF_MEMORY}.
    *
    * <p>Returns false if there were errors that prevented the spawn from being run, such as network
    * errors, missing local files, errors setting up sandboxing, etc.
    */
   boolean setupSuccess();

   /** Returns true if the status was {@link Status#EXECUTION_FAILED_CATASTROPHICALLY}. */
   boolean isCatastrophe();

   /** The status of the attempted Spawn execution. */
   Status status();

   /**
    * The exit code of the subprocess if the subprocess was executed. Should only be called if
    * {@link #status} returns {@link Status#SUCCESS} or {@link Status#NON_ZERO_EXIT}.
    *
    * <p>This method must return a non-zero exit code if the status is {@link Status#TIMEOUT} or
    * {@link Status#OUT_OF_MEMORY}. It is recommended to return 128 + 14 when the status is
    * {@link Status#TIMEOUT}, which corresponds to the Unix signal SIGALRM.
    *
    * <p>This method may throw {@link IllegalStateException} if called for any other status.
    */
   int exitCode();

   /**
    * The host name of the executor or {@code null}. This information is intended for debugging
    * purposes, especially for remote execution systems. Remote caches usually do not store the
    * original host name, so this is generally {@code null} for cache hits.
    */
   @Nullable String getExecutorHostName();

   /**
    * The name of the SpawnRunner that executed the spawn. It should always be defined, unless
    * isCacheHit is true, in which case the spawn was not actually run.
    */
   String getRunnerName();

   /**
    * Returns the wall time taken by the {@link Spawn}'s execution.
    *
    * @return the measurement, or empty in case of execution errors or when the measurement is not
    *     implemented for the current platform
    */
   Optional<Duration> getWallTime();

   /**
    * Returns the user time taken by the {@link Spawn}'s execution.
    *
    * @return the measurement, or empty in case of execution errors or when the measurement is not
    *     implemented for the current platform
    */
   Optional<Duration> getUserTime();

   /**
    * Returns the system time taken by the {@link Spawn}'s execution.
    *
    * @return the measurement, or empty in case of execution errors or when the measurement is not
    *     implemented for the current platform
    */
   Optional<Duration> getSystemTime();

   /**
    * Returns the number of block output operations during the {@link Spawn}'s execution.
    *
    * @return the measurement, or empty in case of execution errors or when the measurement is not
    *     implemented for the current platform
    */
   Optional<Long> getNumBlockOutputOperations();

   /**
    * Returns the number of block input operations during the {@link Spawn}'s execution.
    *
    * @return the measurement, or empty in case of execution errors or when the measurement is not
    *     implemented for the current platform
    */
   Optional<Long> getNumBlockInputOperations();

   /**
    * Returns the number of involuntary context switches during the {@link Spawn}'s execution.
    *
    * @return the measurement, or empty in case of execution errors or when the measurement is not
    *     implemented for the current platform
    */
   Optional<Long> getNumInvoluntaryContextSwitches();

   SpawnMetrics getMetrics();

   /** Whether the spawn result was a cache hit. */
   boolean isCacheHit();

   /** Returns an optional custom failure message for the result. */
   default String getFailureMessage() {
     return "";
   }

   /**
    * SpawnResults can optionally support returning outputs in-memory. Such outputs can be obtained
    * from this method if so. This behavior is optional, and can be triggered with
    * {@link ExecutionRequirements#REMOTE_EXECUTION_INLINE_OUTPUTS}.
    *
    * @param output
    */
   @Nullable
   default InputStream getInMemoryOutput(ActionInput output) {
     return null;
   }

   String getDetailMessage(
       String messagePrefix, String message, boolean catastrophe, boolean forciblyRunRemotely);

   /**
    * Basic implementation of {@link SpawnResult}.
    */
   @Immutable @ThreadSafe
   public static final class SimpleSpawnResult implements SpawnResult {
     private final int exitCode;
     private final Status status;
     private final String executorHostName;
     private final String runnerName;
     private final SpawnMetrics spawnMetrics;
     private final Optional<Duration> wallTime;
     private final Optional<Duration> userTime;
     private final Optional<Duration> systemTime;
     private final Optional<Long> numBlockOutputOperations;
     private final Optional<Long> numBlockInputOperations;
     private final Optional<Long> numInvoluntaryContextSwitches;
     private final boolean cacheHit;
     private final String failureMessage;

     SimpleSpawnResult(Builder builder) {
       this.exitCode = builder.exitCode;
       this.status = Preconditions.checkNotNull(builder.status);
       this.executorHostName = builder.executorHostName;
       this.runnerName = builder.runnerName;
       this.spawnMetrics = builder.spawnMetrics != null
           ? builder.spawnMetrics
           : SpawnMetrics.forLocalExecution(builder.wallTime.orElse(Duration.ZERO));
       this.wallTime = builder.wallTime;
       this.userTime = builder.userTime;
       this.systemTime = builder.systemTime;
       this.numBlockOutputOperations = builder.numBlockOutputOperations;
       this.numBlockInputOperations = builder.numBlockInputOperations;
       this.numInvoluntaryContextSwitches = builder.numInvoluntaryContextSwitches;
       this.cacheHit = builder.cacheHit;
       this.failureMessage = builder.failureMessage;
     }

     @Override
     public boolean setupSuccess() {
       return status == Status.SUCCESS
           || status == Status.NON_ZERO_EXIT
           || status == Status.TIMEOUT
           || status == Status.OUT_OF_MEMORY;
     }

     @Override
     public boolean isCatastrophe() {
       return status == Status.EXECUTION_FAILED_CATASTROPHICALLY;
     }

     @Override
     public int exitCode() {
       return exitCode;
     }

     @Override
     public Status status() {
       return status;
     }

     @Override
     public String getExecutorHostName() {
       return executorHostName;
     }

     @Override
     public String getRunnerName() {
       return runnerName;
     }

     @Override
     public SpawnMetrics getMetrics() {
       return spawnMetrics;
     }

     @Override
     public Optional<Duration> getWallTime() {
       return wallTime;
     }

     @Override
     public Optional<Duration> getUserTime() {
       return userTime;
     }

     @Override
     public Optional<Duration> getSystemTime() {
       return systemTime;
     }

     @Override
     public Optional<Long> getNumBlockOutputOperations() {
       return numBlockOutputOperations;
     }

     @Override
     public Optional<Long> getNumBlockInputOperations() {
       return numBlockInputOperations;
     }

     @Override
     public Optional<Long> getNumInvoluntaryContextSwitches() {
       return numInvoluntaryContextSwitches;
     }

     @Override
     public boolean isCacheHit() {
       return cacheHit;
     }

     @Override
     public String getFailureMessage() {
       return failureMessage;
     }

     @Override
     public String getDetailMessage(
         String messagePrefix, String message, boolean catastrophe, boolean forciblyRunRemotely) {
       TerminationStatus status = new TerminationStatus(
           exitCode(), status() == Status.TIMEOUT);
       String reason = " (" + status.toShortString() + ")"; // e.g " (Exit 1)"
       String explanation = status.exited() ? "" : ": " + message;

       if (!status().isConsideredUserError()) {
         String errorDetail = status().name().toLowerCase(Locale.US)
             .replace('_', ' ');
         explanation += ". Note: Remote connection/protocol failed with: " + errorDetail;
       }
       if (status() == Status.TIMEOUT) {
         if (getWallTime().isPresent()) {
           explanation +=
               String.format(
                   Locale.US,
                   " (failed due to timeout after %.2f seconds.)",
                   getWallTime().get().toMillis() / 1000.0);
         } else {
           explanation += " (failed due to timeout.)";
         }
       } else if (status() == Status.OUT_OF_MEMORY) {
         explanation += " (Remote action was terminated due to Out of Memory.)";
       }
       if (status() != Status.TIMEOUT && forciblyRunRemotely) {
         explanation += " Action tagged as local was forcibly run remotely and failed - it's "
             + "possible that the action simply doesn't work remotely";
       }
       if (!Strings.isNullOrEmpty(failureMessage)) {
         explanation += " " + failureMessage;
       }
       return messagePrefix + " failed" + reason + explanation;
     }
   }

   /**
    * Builder class for {@link SpawnResult}.
    */
   public static final class Builder {
     private int exitCode;
     private Status status;
     private String executorHostName;
     private String runnerName = "";
     private SpawnMetrics spawnMetrics;
     private Optional<Duration> wallTime = Optional.empty();
     private Optional<Duration> userTime = Optional.empty();
     private Optional<Duration> systemTime = Optional.empty();
     private Optional<Long> numBlockOutputOperations = Optional.empty();
     private Optional<Long> numBlockInputOperations = Optional.empty();
     private Optional<Long> numInvoluntaryContextSwitches = Optional.empty();
     private boolean cacheHit;
     private String failureMessage = "";

     public SpawnResult build() {
       Preconditions.checkArgument(!runnerName.isEmpty());
       if (status == Status.SUCCESS) {
         Preconditions.checkArgument(exitCode == 0);
       }
       if (status == Status.NON_ZERO_EXIT
           || status == Status.TIMEOUT
           || status == Status.OUT_OF_MEMORY) {
         Preconditions.checkArgument(exitCode != 0);
       }
       return new SimpleSpawnResult(this);
     }

     public Builder setExitCode(int exitCode) {
       this.exitCode = exitCode;
       return this;
     }

     public Builder setStatus(Status status) {
       this.status = status;
       return this;
     }

     public Builder setExecutorHostname(String executorHostName) {
       this.executorHostName = executorHostName;
       return this;
     }

     public Builder setRunnerName(String runnerName) {
       this.runnerName = runnerName;
       return this;
     }

     public Builder setSpawnMetrics(SpawnMetrics spawnMetrics) {
       this.spawnMetrics = spawnMetrics;
       return this;
     }

     public Builder setWallTime(Duration wallTime) {
       this.wallTime = Optional.of(wallTime);
       return this;
     }

     public Builder setUserTime(Duration userTime) {
       this.userTime = Optional.of(userTime);
       return this;
     }

     public Builder setSystemTime(Duration systemTime) {
       this.systemTime = Optional.of(systemTime);
       return this;
     }

     public Builder setNumBlockOutputOperations(long numBlockOutputOperations) {
       this.numBlockOutputOperations = Optional.of(numBlockOutputOperations);
       return this;
     }

     public Builder setNumBlockInputOperations(long numBlockInputOperations) {
       this.numBlockInputOperations = Optional.of(numBlockInputOperations);
       return this;
     }

     public Builder setNumInvoluntaryContextSwitches(long numInvoluntaryContextSwitches) {
       this.numInvoluntaryContextSwitches = Optional.of(numInvoluntaryContextSwitches);
       return this;
     }

     public Builder setWallTime(Optional<Duration> wallTime) {
       this.wallTime = wallTime;
       return this;
     }

     public Builder setUserTime(Optional<Duration> userTime) {
       this.userTime = userTime;
       return this;
     }

     public Builder setSystemTime(Optional<Duration> systemTime) {
       this.systemTime = systemTime;
       return this;
     }

     public Builder setCacheHit(boolean cacheHit) {
       this.cacheHit = cacheHit;
       return this;
     }

     public Builder setFailureMessage(String failureMessage) {
       this.failureMessage = failureMessage;
       return this;
     }
   }
 }
	// Copyright 2017 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.base.Preconditions;
	import com.google.common.base.Strings;
	import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
	import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
	import com.google.devtools.build.lib.shell.TerminationStatus;
	import java.io.InputStream;
	import java.time.Duration;
	import java.util.Locale;
	import java.util.Optional;
	import javax.annotation.Nullable;

	/**
	* The result of a spawn execution.
	*
	* <p>DO NOT IMPLEMENT THIS INTERFACE! Use {@link SpawnResult.Builder} to create instances instead.
	* This is a temporary situation as long as we still have separate internal and external
	* implementations - the plan is to merge the two into a single immutable, final class.
	*/
	// TODO(ulfjack): Change this from an interface to an immutable, final class.
	public interface SpawnResult {
	/** The status of the attempted Spawn execution. */
	public enum Status {
	/** Subprocess executed successfully, and returned a zero exit code. */
	SUCCESS,

	/** Subprocess executed successfully, but returned a non-zero exit code. */
	NON_ZERO_EXIT(true),

	/** Subprocess execution timed out. */
	TIMEOUT(true),

	/**
	* The subprocess ran out of memory. On Linux systems, the kernel may kill processes in
	* low-memory situations, and this status is intended to report such a case back to Bazel.
	*/
	OUT_OF_MEMORY(true),

	/**
	* Subprocess did not execute. This error is not catastrophic - Bazel will try to continue the
	* build if keep_going is enabled, possibly attempt to rerun the same spawn, and attempt to run
	* other actions.
	*/
	EXECUTION_FAILED,

	/**
	* Subprocess did not execute. Do not retry, and exit immediately even if keep_going is enabled.
	*/
	EXECUTION_FAILED_CATASTROPHICALLY,

	/**
	* Subprocess did not execute in a way that indicates that the user can fix it. For example, a
	* remote system may have denied the execution due to too many inputs or too large inputs.
	*/
	EXECUTION_DENIED(true),

	/**
	* The remote execution system is overloaded and had to refuse execution for this Spawn.
	*/
	REMOTE_EXECUTOR_OVERLOADED,

	/**
	* The result of the remotely executed Spawn could not be retrieved due to errors in the remote
	* caching layer.
	*/
	REMOTE_CACHE_FAILED;

	private final boolean isUserError;

	private Status(boolean isUserError) {
	this.isUserError = isUserError;
	}

	private Status() {
	this(false);
	}

	public boolean isConsideredUserError() {
	return isUserError;
	}
	}

	/**
	* Returns whether the spawn was actually run, regardless of the exit code. I.e., returns
	* {@code true} if {@link #status} is any of {@link Status#SUCCESS}, {@link Status#NON_ZERO_EXIT},
	* {@link Status#TIMEOUT} or {@link Status#OUT_OF_MEMORY}.
	*
	* <p>Returns false if there were errors that prevented the spawn from being run, such as network
	* errors, missing local files, errors setting up sandboxing, etc.
	*/
	boolean setupSuccess();

	/** Returns true if the status was {@link Status#EXECUTION_FAILED_CATASTROPHICALLY}. */
	boolean isCatastrophe();

	/** The status of the attempted Spawn execution. */
	Status status();

	/**
	* The exit code of the subprocess if the subprocess was executed. Should only be called if
	* {@link #status} returns {@link Status#SUCCESS} or {@link Status#NON_ZERO_EXIT}.
	*
	* <p>This method must return a non-zero exit code if the status is {@link Status#TIMEOUT} or
	* {@link Status#OUT_OF_MEMORY}. It is recommended to return 128 + 14 when the status is
	* {@link Status#TIMEOUT}, which corresponds to the Unix signal SIGALRM.
	*
	* <p>This method may throw {@link IllegalStateException} if called for any other status.
	*/
	int exitCode();

	/**
	* The host name of the executor or {@code null}. This information is intended for debugging
	* purposes, especially for remote execution systems. Remote caches usually do not store the
	* original host name, so this is generally {@code null} for cache hits.
	*/
	@Nullable String getExecutorHostName();

	/**
	* The name of the SpawnRunner that executed the spawn. It should always be defined, unless
	* isCacheHit is true, in which case the spawn was not actually run.
	*/
	String getRunnerName();

	/**
	* Returns the wall time taken by the {@link Spawn}'s execution.
	*
	* @return the measurement, or empty in case of execution errors or when the measurement is not
	* implemented for the current platform
	*/
	Optional<Duration> getWallTime();

	/**
	* Returns the user time taken by the {@link Spawn}'s execution.
	*
	* @return the measurement, or empty in case of execution errors or when the measurement is not
	* implemented for the current platform
	*/
	Optional<Duration> getUserTime();

	/**
	* Returns the system time taken by the {@link Spawn}'s execution.
	*
	* @return the measurement, or empty in case of execution errors or when the measurement is not
	* implemented for the current platform
	*/
	Optional<Duration> getSystemTime();

	/**
	* Returns the number of block output operations during the {@link Spawn}'s execution.
	*
	* @return the measurement, or empty in case of execution errors or when the measurement is not
	* implemented for the current platform
	*/
	Optional<Long> getNumBlockOutputOperations();

	/**
	* Returns the number of block input operations during the {@link Spawn}'s execution.
	*
	* @return the measurement, or empty in case of execution errors or when the measurement is not
	* implemented for the current platform
	*/
	Optional<Long> getNumBlockInputOperations();

	/**
	* Returns the number of involuntary context switches during the {@link Spawn}'s execution.
	*
	* @return the measurement, or empty in case of execution errors or when the measurement is not
	* implemented for the current platform
	*/
	Optional<Long> getNumInvoluntaryContextSwitches();

	SpawnMetrics getMetrics();

	/** Whether the spawn result was a cache hit. */
	boolean isCacheHit();

	/** Returns an optional custom failure message for the result. */
	default String getFailureMessage() {
	return "";
	}

	/**
	* SpawnResults can optionally support returning outputs in-memory. Such outputs can be obtained
	* from this method if so. This behavior is optional, and can be triggered with
	* {@link ExecutionRequirements#REMOTE_EXECUTION_INLINE_OUTPUTS}.
	*
	* @param output
	*/
	@Nullable
	default InputStream getInMemoryOutput(ActionInput output) {
	return null;
	}

	String getDetailMessage(
	String messagePrefix, String message, boolean catastrophe, boolean forciblyRunRemotely);

	/**
	* Basic implementation of {@link SpawnResult}.
	*/
	@Immutable @ThreadSafe
	public static final class SimpleSpawnResult implements SpawnResult {
	private final int exitCode;
	private final Status status;
	private final String executorHostName;
	private final String runnerName;
	private final SpawnMetrics spawnMetrics;
	private final Optional<Duration> wallTime;
	private final Optional<Duration> userTime;
	private final Optional<Duration> systemTime;
	private final Optional<Long> numBlockOutputOperations;
	private final Optional<Long> numBlockInputOperations;
	private final Optional<Long> numInvoluntaryContextSwitches;
	private final boolean cacheHit;
	private final String failureMessage;

	SimpleSpawnResult(Builder builder) {
	this.exitCode = builder.exitCode;
	this.status = Preconditions.checkNotNull(builder.status);
	this.executorHostName = builder.executorHostName;
	this.runnerName = builder.runnerName;
	this.spawnMetrics = builder.spawnMetrics != null
	? builder.spawnMetrics
	: SpawnMetrics.forLocalExecution(builder.wallTime.orElse(Duration.ZERO));
	this.wallTime = builder.wallTime;
	this.userTime = builder.userTime;
	this.systemTime = builder.systemTime;
	this.numBlockOutputOperations = builder.numBlockOutputOperations;
	this.numBlockInputOperations = builder.numBlockInputOperations;
	this.numInvoluntaryContextSwitches = builder.numInvoluntaryContextSwitches;
	this.cacheHit = builder.cacheHit;
	this.failureMessage = builder.failureMessage;
	}

	@Override
	public boolean setupSuccess() {
	return status == Status.SUCCESS
	\|\| status == Status.NON_ZERO_EXIT
	\|\| status == Status.TIMEOUT
	\|\| status == Status.OUT_OF_MEMORY;
	}

	@Override
	public boolean isCatastrophe() {
	return status == Status.EXECUTION_FAILED_CATASTROPHICALLY;
	}

	@Override
	public int exitCode() {
	return exitCode;
	}

	@Override
	public Status status() {
	return status;
	}

	@Override
	public String getExecutorHostName() {
	return executorHostName;
	}

	@Override
	public String getRunnerName() {
	return runnerName;
	}

	@Override
	public SpawnMetrics getMetrics() {
	return spawnMetrics;
	}

	@Override
	public Optional<Duration> getWallTime() {
	return wallTime;
	}

	@Override
	public Optional<Duration> getUserTime() {
	return userTime;
	}

	@Override
	public Optional<Duration> getSystemTime() {
	return systemTime;
	}

	@Override
	public Optional<Long> getNumBlockOutputOperations() {
	return numBlockOutputOperations;
	}

	@Override
	public Optional<Long> getNumBlockInputOperations() {
	return numBlockInputOperations;
	}

	@Override
	public Optional<Long> getNumInvoluntaryContextSwitches() {
	return numInvoluntaryContextSwitches;
	}

	@Override
	public boolean isCacheHit() {
	return cacheHit;
	}

	@Override
	public String getFailureMessage() {
	return failureMessage;
	}

	@Override
	public String getDetailMessage(
	String messagePrefix, String message, boolean catastrophe, boolean forciblyRunRemotely) {
	TerminationStatus status = new TerminationStatus(
	exitCode(), status() == Status.TIMEOUT);
	String reason = " (" + status.toShortString() + ")"; // e.g " (Exit 1)"
	String explanation = status.exited() ? "" : ": " + message;

	if (!status().isConsideredUserError()) {
	String errorDetail = status().name().toLowerCase(Locale.US)
	.replace('_', ' ');
	explanation += ". Note: Remote connection/protocol failed with: " + errorDetail;
	}
	if (status() == Status.TIMEOUT) {
	if (getWallTime().isPresent()) {
	explanation +=
	String.format(
	Locale.US,
	" (failed due to timeout after %.2f seconds.)",
	getWallTime().get().toMillis() / 1000.0);
	} else {
	explanation += " (failed due to timeout.)";
	}
	} else if (status() == Status.OUT_OF_MEMORY) {
	explanation += " (Remote action was terminated due to Out of Memory.)";
	}
	if (status() != Status.TIMEOUT && forciblyRunRemotely) {
	explanation += " Action tagged as local was forcibly run remotely and failed - it's "
	+ "possible that the action simply doesn't work remotely";
	}
	if (!Strings.isNullOrEmpty(failureMessage)) {
	explanation += " " + failureMessage;
	}
	return messagePrefix + " failed" + reason + explanation;
	}
	}

	/**
	* Builder class for {@link SpawnResult}.
	*/
	public static final class Builder {
	private int exitCode;
	private Status status;
	private String executorHostName;
	private String runnerName = "";
	private SpawnMetrics spawnMetrics;
	private Optional<Duration> wallTime = Optional.empty();
	private Optional<Duration> userTime = Optional.empty();
	private Optional<Duration> systemTime = Optional.empty();
	private Optional<Long> numBlockOutputOperations = Optional.empty();
	private Optional<Long> numBlockInputOperations = Optional.empty();
	private Optional<Long> numInvoluntaryContextSwitches = Optional.empty();
	private boolean cacheHit;
	private String failureMessage = "";

	public SpawnResult build() {
	Preconditions.checkArgument(!runnerName.isEmpty());
	if (status == Status.SUCCESS) {
	Preconditions.checkArgument(exitCode == 0);
	}
	if (status == Status.NON_ZERO_EXIT
	\|\| status == Status.TIMEOUT
	\|\| status == Status.OUT_OF_MEMORY) {
	Preconditions.checkArgument(exitCode != 0);
	}
	return new SimpleSpawnResult(this);
	}

	public Builder setExitCode(int exitCode) {
	this.exitCode = exitCode;
	return this;
	}

	public Builder setStatus(Status status) {
	this.status = status;
	return this;
	}

	public Builder setExecutorHostname(String executorHostName) {
	this.executorHostName = executorHostName;
	return this;
	}

	public Builder setRunnerName(String runnerName) {
	this.runnerName = runnerName;
	return this;
	}

	public Builder setSpawnMetrics(SpawnMetrics spawnMetrics) {
	this.spawnMetrics = spawnMetrics;
	return this;
	}

	public Builder setWallTime(Duration wallTime) {
	this.wallTime = Optional.of(wallTime);
	return this;
	}

	public Builder setUserTime(Duration userTime) {
	this.userTime = Optional.of(userTime);
	return this;
	}

	public Builder setSystemTime(Duration systemTime) {
	this.systemTime = Optional.of(systemTime);
	return this;
	}

	public Builder setNumBlockOutputOperations(long numBlockOutputOperations) {
	this.numBlockOutputOperations = Optional.of(numBlockOutputOperations);
	return this;
	}

	public Builder setNumBlockInputOperations(long numBlockInputOperations) {
	this.numBlockInputOperations = Optional.of(numBlockInputOperations);
	return this;
	}

	public Builder setNumInvoluntaryContextSwitches(long numInvoluntaryContextSwitches) {
	this.numInvoluntaryContextSwitches = Optional.of(numInvoluntaryContextSwitches);
	return this;
	}

	public Builder setWallTime(Optional<Duration> wallTime) {
	this.wallTime = wallTime;
	return this;
	}

	public Builder setUserTime(Optional<Duration> userTime) {
	this.userTime = userTime;
	return this;
	}

	public Builder setSystemTime(Optional<Duration> systemTime) {
	this.systemTime = systemTime;
	return this;
	}

	public Builder setCacheHit(boolean cacheHit) {
	this.cacheHit = cacheHit;
	return this;
	}

	public Builder setFailureMessage(String failureMessage) {
	this.failureMessage = failureMessage;
	return this;
	}
	}
	}