hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "James Clampffer (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HDFS-10188) libhdfs++: Implement debug allocators
Date Thu, 12 May 2016 13:27:12 GMT

    [ https://issues.apache.org/jira/browse/HDFS-10188?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15281513#comment-15281513

James Clampffer commented on HDFS-10188:

New patch looks good to me, +1.  I'll commit momentarily. 

> libhdfs++: Implement debug allocators
> -------------------------------------
>                 Key: HDFS-10188
>                 URL: https://issues.apache.org/jira/browse/HDFS-10188
>             Project: Hadoop HDFS
>          Issue Type: Sub-task
>          Components: hdfs-client
>            Reporter: James Clampffer
>            Assignee: Xiaowei Zhu
>         Attachments: HDFS-10188.HDFS-8707.000.patch, HDFS-10188.HDFS-8707.001.patch
> I propose implementing a set of memory new/delete pairs with additional checking to detect
double deletes, read-after-delete, and write-after-deletes to help debug resource ownership
issues and prevent new ones from entering the library.
> One of the most common issues we have is use-after-free issues.  The continuation pattern
makes these really tricky to debug because by the time a segsegv is raised the context of
what has caused the error is long gone.
> The plan is to add allocators that can be turned on that can do the following, in order
of runtime cost.
> 1: no-op, forward through to default new/delete
> 2: make sure the memory given to the constructor is dirty, memset free'd memory to 0
> 3: implement operator new with mmap, lock that region of memory once it's been deleted;
obviously this can't be left to run forever because the memory is never unmapped
> This should also put some groundwork in place for implementing specialized allocators
for tiny objects that we churn through like std::string.

This message was sent by Atlassian JIRA

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

View raw message