001/*
002 * Copyright 2009-2014 UnboundID Corp.
003 * All Rights Reserved.
004 */
005/*
006 * Copyright (C) 2009-2014 UnboundID Corp.
007 *
008 * This program is free software; you can redistribute it and/or modify
009 * it under the terms of the GNU General Public License (GPLv2 only)
010 * or the terms of the GNU Lesser General Public License (LGPLv2.1 only)
011 * as published by the Free Software Foundation.
012 *
013 * This program is distributed in the hope that it will be useful,
014 * but WITHOUT ANY WARRANTY; without even the implied warranty of
015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
016 * GNU General Public License for more details.
017 *
018 * You should have received a copy of the GNU General Public License
019 * along with this program; if not, see <http://www.gnu.org/licenses>.
020 */
021package com.unboundid.util;
022
023
024
025/**
026 * This enumeration defines a set of thread safety levels that may be used to
027 * indicate whether the associated code is safe to be accessed concurrently
028 * by multiple threads.
029 */
030@ThreadSafety(level=ThreadSafetyLevel.COMPLETELY_THREADSAFE)
031public enum ThreadSafetyLevel
032{
033  /**
034   * The associated code is completely threadsafe and may be accessed
035   * concurrently by any number of threads, subject to the constraints described
036   * in the {@link ThreadSafety} documentation.
037   */
038  COMPLETELY_THREADSAFE,
039
040
041
042  /**
043   * The associated code is mostly threadsafe, but there may be some methods
044   * which are not safe to be invoked when multiple threads are accessing an
045   * instance concurrently.  The class-level documentation for a class including
046   * this thread safety level should include comments indicating which methods
047   * are not threadsafe, and those methods should also be marked with their own
048   * {@code ThreadSafety} annotations using the {@link #METHOD_NOT_THREADSAFE}
049   * level.
050   */
051  MOSTLY_THREADSAFE,
052
053
054
055  /**
056   * The associated code is mostly not threadsafe, but there may be some methods
057   * which are safe to be invoked concurrently by multiple threads.  The
058   * class-level documentation for a class including this thread safety level
059   * should include comments indicating which methods are threadsafe, and those
060   * methods should also be marked with their own {@code ThreadSafety}
061   * annotations using the {@link #METHOD_THREADSAFE} level.
062   */
063  MOSTLY_NOT_THREADSAFE,
064
065
066
067  /**
068   * The associated code is not threadsafe.  Unless otherwise noted, multiple
069   * threads may not attempt to invoke methods on the same instance of objects
070   * of this type without external synchronization.
071   */
072  NOT_THREADSAFE,
073
074
075
076  /**
077   * Methods declared in the associated interface or abstract class must be
078   * threadsafe in classes which implement that interface or extend that
079   * abstract class.  No guarantees will be made about the thread safety of
080   * other methods contained in that class which are not declared in the parent
081   * interface or superclass.
082   */
083  INTERFACE_THREADSAFE,
084
085
086
087  /**
088   * Methods declared in the associated interface or abstract class are not
089   * required to be threadsafe and classes which call them must not rely on the
090   * ability to concurrently invoke those methods on the same object instance
091   * without any external synchronization.
092   */
093  INTERFACE_NOT_THREADSAFE,
094
095
096
097  /**
098   * The associated method may be considered threadsafe and may be invoked
099   * concurrently by multiple threads, subject to the constraints described in
100   * the {@link ThreadSafety} documentation, and in any additional notes
101   * contained in the method-level javadoc.
102   */
103  METHOD_THREADSAFE,
104
105
106
107  /**
108   * The associated method may not be considered threadsafe and should not be
109   * invoked concurrently by multiple threads.
110   */
111  METHOD_NOT_THREADSAFE
112}