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https://issues.apache.org/jira/browse/HDFS-9265?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16410370#comment-16410370
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Hudson commented on HDFS-9265:
------------------------------
SUCCESS: Integrated in Jenkins build Hadoop-trunk-Commit #13869 (See
[https://builds.apache.org/job/Hadoop-trunk-Commit/13869/])
HDFS-9265. InputStreamImpl should hold a shared_ptr of the BlockReader.
(james.clampffer: rev a14d1f741ff7c83bd80aa73ce95a82e6c3032e96)
* (edit)
hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/fs/inputstream_impl.h
> InputStreamImpl should hold a shared_ptr of the BlockReader
> -----------------------------------------------------------
>
> Key: HDFS-9265
> URL: https://issues.apache.org/jira/browse/HDFS-9265
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Components: hdfs-client
> Reporter: James Clampffer
> Assignee: James Clampffer
> Priority: Blocker
> Fix For: HDFS-8707
>
> Attachments: HDFS-9265.HDFS-8707.000.patch
>
>
> The remote block reader relies on undefined behavior in how it uses
> enable_shared_from_this.
> http://en.cppreference.com/w/cpp/memory/enable_shared_from_this
> The spec states a shared_ptr to an object inheriting from
> enable_shared_from_this must be live before calling make_shared_from_this.
> Calling make_shared_from_this without an existing shared_ptr is undefined
> behavior and causes deterministic crashes when the code is built with GCC.
> example:
> class foo : public enable_shared_from_this {/*bar*/};
> safe:
> auto ptr1 = std::make_shared<foo>();
> auto ptr2 = foo->make_shared_from_this();
> broken:
> foo *ptr = new foo();
> auto ptr2 = foo->make_shared_from_this(); //no existing live shared_ptr
> In order to fix the input stream should call std::make_shared and hang onto a
> shared_ptr to the block reader. The block reader will then be free to call
> make_shared_from this as much as it wants without issue.
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