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     */
021    package 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)
031    public 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    }