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https://issues.apache.org/jira/browse/HADOOP-10027?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14343874#comment-14343874
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Colin Patrick McCabe commented on HADOOP-10027:
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bq. Chris wrote: My best friend, the git blame log, tells me that this traces
back to commit 9e22afd8704f62e312e749ebdb882455569de560, which was HADOOP-3604
from 2008. We should be able to use the information in that issue to trace back
to specific JVM versions that exhibited this bug. Assuming those are all very
old JVM versions, then I am +1 for the approach of removing this locking
completely. Thanks for taking this on Hui Zheng.
Thanks, Chris. Very good research. Indeed, the "fix version" on all those
java bugs is somewhere between 1.3 and 1.5, inclusive. Since our min JDK
version is 1.7 now (or possibly 1.6 if we backport this to 2.6.x), it should be
an issue.
I agree that the new {{testZlibCompressDecompressInMultiThreads}} function
needs some work. We definitely should be joining those threads before the end
of the test. Does it make sense to commit what we have now (minus the new unit
test), and create a new JIRA for adding proper bzip2 test coverage? That might
keep the scope more manageable. I am certainly +1 on the non-unit-test part of
the patch as-is.
> *Compressor_deflateBytesDirect passes instance instead of jclass to
> GetStaticObjectField
> ----------------------------------------------------------------------------------------
>
> Key: HADOOP-10027
> URL: https://issues.apache.org/jira/browse/HADOOP-10027
> Project: Hadoop Common
> Issue Type: Bug
> Components: native
> Reporter: Eric Abbott
> Assignee: Hui Zheng
> Priority: Minor
> Attachments: HADOOP-10027.1.patch, HADOOP-10027.2.patch
>
>
> http://svn.apache.org/viewvc/hadoop/common/trunk/hadoop-common-project/hadoop-common/src/main/native/src/org/apache/hadoop/io/compress/zlib/ZlibCompressor.c?view=markup
> This pattern appears in all the native compressors.
> // Get members of ZlibCompressor
> jobject clazz = (*env)->GetStaticObjectField(env, this,
> ZlibCompressor_clazz);
> The 2nd argument to GetStaticObjectField is supposed to be a jclass, not a
> jobject. Adding the JVM param -Xcheck:jni will cause "FATAL ERROR in native
> method: JNI received a class argument that is not a class" and a core dump
> such as the following.
> (gdb)
> #0 0x00007f02e4aef8a5 in raise () from /lib64/libc.so.6
> #1 0x00007f02e4af1085 in abort () from /lib64/libc.so.6
> #2 0x00007f02e45bd727 in os::abort(bool) () from
> /opt/jdk1.6.0_31/jre/lib/amd64/server/libjvm.so
> #3 0x00007f02e43cec63 in jniCheck::validate_class(JavaThread*, _jclass*,
> bool) () from /opt/jdk1.6.0_31/jre/lib/amd64/server/libjvm.so
> #4 0x00007f02e43ea669 in checked_jni_GetStaticObjectField () from
> /opt/jdk1.6.0_31/jre/lib/amd64/server/libjvm.so
> #5 0x00007f02d38eaf79 in
> Java_org_apache_hadoop_io_compress_zlib_ZlibCompressor_deflateBytesDirect ()
> from /usr/lib/hadoop/lib/native/libhadoop.so.1.0.0
> In addition, that clazz object is only used for synchronization. In the case
> of the native method _deflateBytesDirect, the result is a class wide lock
> used to access the instance field uncompressed_direct_buf. Perhaps using the
> instance as the sync point is more appropriate?
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