[3/5] incubator-impala git commit: Fix a potential crash in Frontend & Catalog JNI startup

[mi...@apache.org]

Fix a potential crash in Frontend & Catalog JNI startup

Bug: In the startup of the Frontend and the Catalog JVMs, we
incorrectly use a local reference that can potentially be
GC'ed by the JVM. Any usage of that reference can result in
an undefined behavior or a JVM crash.

Fix: In GetThriftBackendGflags(), don't push the current JNI
env into a local frame as that might GC the local references
once SerializeThriftMsg() returns.

Testing:  We can reliably reproduce this crash with the dynamic
log levels patch [1] in the following backend tests which start
multiple Frontend instances in parallel.

- buffered-block-mgr-test
- buffered-tuple-stream-test
- buffer-pool-test

With this patch, all the above tests pass.

[1] https://gerrit.cloudera.org/#/c/5792/

Change-Id: I35398a8efdb6fdbf7932a32489b2ad8d99b6d76f
Reviewed-on: http://gerrit.cloudera.org:8080/6264
Reviewed-by: Bharath Vissapragada <bh...@cloudera.com>
Tested-by: Impala Public Jenkins


Project: http://git-wip-us.apache.org/repos/asf/incubator-impala/repo
Commit: http://git-wip-us.apache.org/repos/asf/incubator-impala/commit/ba2613ab
Tree: http://git-wip-us.apache.org/repos/asf/incubator-impala/tree/ba2613ab
Diff: http://git-wip-us.apache.org/repos/asf/incubator-impala/diff/ba2613ab

Branch: refs/heads/master
Commit: ba2613abfb39357843e0a6e5dfd2d5ed49b36ea3
Parents: 61c32a9
Author: Bharath Vissapragada <bh...@cloudera.com>
Authored: Sun Mar 5 13:56:45 2017 -0800
Committer: Impala Public Jenkins <im...@gerrit.cloudera.org>
Committed: Tue Mar 7 04:11:27 2017 +0000

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 be/src/util/backend-gflag-util.cc | 2 --
 1 file changed, 2 deletions(-)
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http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/ba2613ab/be/src/util/backend-gflag-util.cc
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diff --git a/be/src/util/backend-gflag-util.cc b/be/src/util/backend-gflag-util.cc
index da62b61..0781393 100644
--- a/be/src/util/backend-gflag-util.cc
+++ b/be/src/util/backend-gflag-util.cc
@@ -70,8 +70,6 @@ Status GetThriftBackendGflags(JNIEnv* jni_env, jbyteArray* cfg_bytes) {
   cfg.__set_lineage_event_log_dir(FLAGS_lineage_event_log_dir);
   cfg.__set_local_library_path(FLAGS_local_library_dir);
   cfg.__set_kudu_operation_timeout_ms(FLAGS_kudu_operation_timeout_ms);
-  JniLocalFrame jni_frame;
-  RETURN_IF_ERROR(jni_frame.push(jni_env));
   RETURN_IF_ERROR(SerializeThriftMsg(jni_env, &cfg, cfg_bytes));
   return Status::OK();
 }