001    /*
002     *  This file is part of the Jikes RVM project (http://jikesrvm.org).
003     *
004     *  This file is licensed to You under the Eclipse Public License (EPL);
005     *  You may not use this file except in compliance with the License. You
006     *  may obtain a copy of the License at
007     *
008     *      http://www.opensource.org/licenses/eclipse-1.0.php
009     *
010     *  See the COPYRIGHT.txt file distributed with this work for information
011     *  regarding copyright ownership.
012     */
013    package org.vmmagic.pragma;
014    
015    import java.lang.annotation.Retention;
016    import java.lang.annotation.Target;
017    import java.lang.annotation.RetentionPolicy;
018    import java.lang.annotation.ElementType;
019    import org.vmmagic.Pragma;
020    
021    /**
022     * A pragma that can be used to declare that a particular method is logically
023     * uninterruptible even though it contains bytecodes that are actually
024     * interruptible.<p>
025     *
026     * The effect of this pragma is to suppress warning messages about violations of
027     * uninterruptiblity when compiling a method that throws this exception. There
028     * are two cases in which using the pragma is justified.
029     * <ul>
030     * <li> Uninterruptibility is ensured via some other mechanism. For example, the
031     * method explicitly disables threadswitching around the interruptible regions
032     * (VM.sysWrite on String). Or the interruptible regions are not reachable when
033     * the VM is running (various VM.sysWrite that check VM.runningVM).
034     * <li> The interruptible regions represent an 'error' condition that will never
035     * be executed unless the VM is already in the process of reporting an error,
036     * for example RuntimeEntrypoints.raiseClassCastException.
037     * </ul>
038     * Extreme care must be exercised when using this pragma since it suppresses the
039     * checking of uninterruptibility.
040     * <p>
041     * Use of this pragma is being phased out since it lumps together two possible
042     * special cases. Use either {@link Unpreemptible} or
043     * {@link UninterruptibleNoWarn} instead.
044     * {@link <a href="http://jira.codehaus.org/browse/RVM-115">RVM-115</a>} for more
045     * context.
046     * @deprecated
047     */
048    @Retention(RetentionPolicy.RUNTIME)
049    @Target(ElementType.METHOD)
050    @Pragma
051    public @interface LogicallyUninterruptible { }