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Hudson commented on TIKA-4393: ------------------------------ SUCCESS: Integrated in Jenkins build Tika » tika-branch_2x-jdk11 #621 (See [https://ci-builds.apache.org/job/Tika/job/tika-branch_2x-jdk11/621/]) TIKA-4393 (#2163) (tallison: [https://github.com/apache/tika/commit/3d04698114a75b56ce2b1ee6546bbb75e0ab813c]) * (edit) tika-xmp/src/test/java/org/apache/tika/xmp/TikaToXMPTest.java * (edit) CHANGES.txt * (edit) tika-xmp/src/main/java/org/apache/tika/xmp/convert/TikaToXMP.java TIKA-4393 (#2163) -- checkstyle (tallison: [https://github.com/apache/tika/commit/10653fb3810cf4ce403400d9c313eb6ef1ca7449]) * (edit) tika-xmp/src/test/java/org/apache/tika/xmp/TikaToXMPTest.java > Thread-safety issue in TikaToXMP.getConverterMap() > -------------------------------------------------- > > Key: TIKA-4393 > URL: https://issues.apache.org/jira/browse/TIKA-4393 > Project: Tika > Issue Type: Bug > Components: tika-app > Affects Versions: 2.9.3, 3.1.0 > Environment: java 8, fedora 3.9, tika 2.9.3 > Reporter: Ghiles OUAREZKI > Priority: Minor > Fix For: 4.0.0, 3.1.1, 2.9.4 > > > h2. Description: > We execute TikaToXmp conversion in a multithreaded environment where we call > multiple conversion at the same time. According to new parser contribution > guide, there is nothing about thread-safety. During our test, a thread-safety > issue has been found in the getConverterMap() method of the TikaToXMP class > in the tika-xmp module. > > We are currently using the 2.9.3 version. We checked in the latest version > and we think the behavior is the same. > h2. Problem: > The method manipulates the static class variable converterMap, but it is not > thread-safe. Since there is no synchronization mechanism, multiple threads > can enter getConverterMap() at the same time and create different instances > of converterMap, leading to potential race conditions. > Current code: > {code:java} > private static Map<MediaType, Class<? extends ITikaToXMPConverter>> > converterMap; > private static Map<MediaType, Class<? extends ITikaToXMPConverter>> > getConverterMap() { > if (converterMap == null) { > converterMap = new HashMap<>(); > initialize(); > } > return converterMap; > } > {code} > If multiple threads call getConverterMap() simultaneously when converterMap > is still null, they might create multiple instances of converterMap, which > can lead to unexpected behavior. > h2. > Potential solution: > To ensure thread safety, we offer a simple patch : to synchronize > getConverterMap() so that only one thread can initialize converterMap at a > time. The fix consists of adding the *synchronized* keyword to the method: > {code:java} > private static synchronized Map<MediaType, Class<? extends > ITikaToXMPConverter>> getConverterMap() { > if (converterMap == null) { > converterMap = new HashMap<>(); > initialize(); > } > return converterMap; > }{code} > -- This message was sent by Atlassian Jira (v8.20.10#820010)