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https://issues.apache.org/jira/browse/HDFS-7207?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14169097#comment-14169097
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Zhanwei Wang commented on HDFS-7207:
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In my previous patch, InputStream/OutputStream keep a shared_ptr of
FileSystemImpl for an important reason, which is to avoid to use an invalid
pointer of FileSystemImpl if the filesystem is destroyed before
InputStream/OutputStream.
{code}
DB *db = DB::Open();
Iterator *it = db->(...);
delete db; // bails out because the iterator it has leaked.
{code}
This way is good in my opinion, it makes the user to be more aware of the
leaks, but a shared_ptr of DBImpl is still need to keep in Iterator to avoid
the core dump if the user continue to use the iterator after {{delete db}}
> libhdfs3 should not expose exceptions in public C++ API
> -------------------------------------------------------
>
> Key: HDFS-7207
> URL: https://issues.apache.org/jira/browse/HDFS-7207
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Reporter: Haohui Mai
> Assignee: Colin Patrick McCabe
> Priority: Blocker
> Attachments: HDFS-7207.001.patch
>
>
> There are three major disadvantages of exposing exceptions in the public API:
> * Exposing exceptions in public APIs forces the downstream users to be
> compiled with {{-fexceptions}}, which might be infeasible in many use cases.
> * It forces other bindings to properly handle all C++ exceptions, which might
> be infeasible especially when the binding is generated by tools like SWIG.
> * It forces the downstream users to properly handle all C++ exceptions, which
> can be cumbersome as in certain cases it will lead to undefined behavior
> (e.g., throwing an exception in a destructor is undefined.)
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