Package org.apache.hadoop.util

Class ExitUtil

java.lang.Object
org.apache.hadoop.util.ExitUtil
@LimitedPrivate({"HDFS","MapReduce","YARN"}) @Unstable public final class ExitUtil extends Object
Facilitates hooking process termination for tests, debugging and embedding. Hadoop code that attempts to call System.exit(int) or Runtime.halt(int) MUST invoke it via these methods.

  • Field Details

    • EXIT_EXCEPTION_MESSAGE

      public static final String EXIT_EXCEPTION_MESSAGE
      Message raised from an exit exception if none were provided: "ExitException".
      See Also:

    • HALT_EXCEPTION_MESSAGE

      public static final String HALT_EXCEPTION_MESSAGE
      Message raised from a halt exception if none were provided: "HaltException".
      See Also:

  • Method Details

    • disableSystemExit

      public static void disableSystemExit()
      Disable the use of System.exit for testing.

    • enableSystemExit

      public static void enableSystemExit()
      Enable the use of System.exit for testing.

    • disableSystemHalt

      public static void disableSystemHalt()
      Disable the use of Runtime.getRuntime().halt() for testing.

    • terminateCalled

      public static boolean terminateCalled()
      Returns:
      true if terminate has been called.

    • haltCalled

      public static boolean haltCalled()
      Returns:
      true if halt has been called.

    • getFirstExitException

      public static ExitUtil.ExitException getFirstExitException()
      Returns:
      the first ExitException thrown, null if none thrown yet.

    • getFirstHaltException

      public static ExitUtil.HaltException getFirstHaltException()
      Returns:
      the first HaltException thrown, null if none thrown yet.

    • resetFirstExitException

      public static void resetFirstExitException()
      Reset the tracking of process termination. This is for use in unit tests where one test in the suite expects an exit but others do not.

    • resetFirstHaltException

      public static void resetFirstHaltException()
      Reset the tracking of process termination. This is for use in unit tests where one test in the suite expects a halt but others do not.

    • terminate

      public static void terminate(ExitUtil.ExitException ee) throws ExitUtil.ExitException
      Exits the JVM if exit is enabled, rethrow provided exception or any raised error otherwise. Inner termination: either exit with the exception's exit code, or, if system exits are disabled, rethrow the exception.
      Parameters:
      ee - exit exception
      Throws:
      ExitUtil.ExitException - if System.exit(int) is disabled and not suppressed by an Error
      Error - if System.exit(int) is disabled and one Error arise, suppressing anything else, even ee

    • halt

      public static void halt(ExitUtil.HaltException he) throws ExitUtil.HaltException
      Halts the JVM if halt is enabled, rethrow provided exception or any raised error otherwise. If halt is disabled, this method throws either the exception argument if no error arise, the first error if at least one arise, suppressing he. If halt is enabled, all throwables are caught, even errors.
      Parameters:
      he - the exception containing the status code, message and any stack trace.
      Throws:
      ExitUtil.HaltException - if Runtime.halt(int) is disabled and not suppressed by an Error
      Error - if Runtime.halt(int) is disabled and one Error arise, suppressing anyuthing else, even he

    • terminate

      public static void terminate(int status, Throwable t) throws ExitUtil.ExitException
      Like terminate(int, String) but uses the given throwable to build the message to display or throw as an ExitUtil.ExitException.

      Parameters:
      status - exit code to use if the exception is not an ExitException.
      t - throwable which triggered the termination. If this exception is an ExitUtil.ExitException its status overrides that passed in.
      Throws:
      ExitUtil.ExitException - if System.exit(int) is disabled.

    • halt

      public static void halt(int status, Throwable t) throws ExitUtil.HaltException
      Forcibly terminates the currently running Java virtual machine.
      Parameters:
      status - exit code to use if the exception is not a HaltException.
      t - throwable which triggered the termination. If this exception is a ExitUtil.HaltException its status overrides that passed in.
      Throws:
      ExitUtil.HaltException - if System.exit(int) is disabled.

    • terminate

      public static void terminate(int status) throws ExitUtil.ExitException
      Like terminate(int, Throwable) without a message.
      Parameters:
      status - exit code
      Throws:
      ExitUtil.ExitException - if System.exit(int) is disabled.

    • terminate

      public static void terminate(int status, String msg) throws ExitUtil.ExitException
      Terminate the current process. Note that terminate is the *only* method that should be used to terminate the daemon processes.
      Parameters:
      status - exit code
      msg - message used to create the ExitException
      Throws:
      ExitUtil.ExitException - if System.exit(int) is disabled.

    • halt

      public static void halt(int status) throws ExitUtil.HaltException
      Forcibly terminates the currently running Java virtual machine.
      Parameters:
      status - status code
      Throws:
      ExitUtil.HaltException - if Runtime.halt(int) is disabled.

    • halt

      public static void halt(int status, String message) throws ExitUtil.HaltException
      Forcibly terminates the currently running Java virtual machine.
      Parameters:
      status - status code
      message - message
      Throws:
      ExitUtil.HaltException - if Runtime.halt(int) is disabled.

    • haltOnOutOfMemory

      public static void haltOnOutOfMemory(OutOfMemoryError oome)
      Handler for out of memory events -no attempt is made here to cleanly shutdown or support halt blocking; a robust printing of the event to stderr is all that can be done.
      Parameters:
      oome - out of memory event