Henry Robinson created HDFS-11851:
-------------------------------------

             Summary: getGlobalJNIEnv() may deadlock if exception is thrown
                 Key: HDFS-11851
                 URL: https://issues.apache.org/jira/browse/HDFS-11851
             Project: Hadoop HDFS
          Issue Type: Bug
          Components: libhdfs
            Reporter: Henry Robinson
            Priority: Blocker


HDFS-11529 introduced a deadlock into {{getGlobalJNIEnv()}} if an exception is 
thrown. {{getGlobalJNIEnv()}} holds {{jvmMutex}}, but 
{{printExceptionAndFree()}} will eventually try to acquire that lock in 
{{setTLSExceptionStrings()}}.

The exception might get caught from {{loadFileSystems}}:

{code}
jthr = invokeMethod(env, NULL, STATIC, NULL,
                         "org/apache/hadoop/fs/FileSystem",
                         "loadFileSystems", "()V");
        if (jthr) {
            printExceptionAndFree(env, jthr, PRINT_EXC_ALL, "loadFileSystems");
        }
    }
{code}

and here's the relevant parts of the stack trace from where I call this API in 
Impala, which uses {{libhdfs}}:

{code}
#0  __lll_lock_wait () at 
../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:135
#1  0x00007ffff4a8d657 in _L_lock_909 () from 
/lib/x86_64-linux-gnu/libpthread.so.0
#2  0x00007ffff4a8d480 in __GI___pthread_mutex_lock (mutex=0x47ce960 
<jvmMutex>) at ../nptl/pthread_mutex_lock.c:79
#3  0x0000000002f06056 in mutexLock (m=<optimized out>) at 
/data/2/jenkins/workspace/impala-hadoop-dependency/hadoop/hadoop-hdfs-project/hadoop-hdfs/src/main/native/libhdfs/os/posix/mutexes.c:28
#4  0x0000000002efe817 in setTLSExceptionStrings (rootCause=0x0, 
stackTrace=0x0) at 
/data/2/jenkins/workspace/impala-hadoop-dependency/hadoop/hadoop-hdfs-project/hadoop-hdfs/src/main/native/libhdfs/jni_helper.c:581
#5  0x0000000002f065d7 in printExceptionAndFreeV (env=0x513c1e8, exc=0x508a8c0, 
noPrintFlags=<optimized out>, fmt=0x34349cf "loadFileSystems", 
ap=0x7fffffffb660)
    at 
/data/2/jenkins/workspace/impala-hadoop-dependency/hadoop/hadoop-hdfs-project/hadoop-hdfs/src/main/native/libhdfs/exception.c:183
#6  0x0000000002f0683d in printExceptionAndFree (env=<optimized out>, 
exc=<optimized out>, noPrintFlags=<optimized out>, fmt=<optimized out>)
    at 
/data/2/jenkins/workspace/impala-hadoop-dependency/hadoop/hadoop-hdfs-project/hadoop-hdfs/src/main/native/libhdfs/exception.c:213
#7  0x0000000002eff60f in getGlobalJNIEnv () at 
/data/2/jenkins/workspace/impala-hadoop-dependency/hadoop/hadoop-hdfs-project/hadoop-hdfs/src/main/native/libhdfs/jni_helper.c:463
{code}



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org

Reply via email to