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https://issues.apache.org/jira/browse/MESOS-5882?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15961334#comment-15961334
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Joseph Wu commented on MESOS-5882:
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We use {{cloexec}} to change how subprocesses inherit file descriptors
(inherited by default on Posix, which we need to change in order to not leak
FDs). In contrast, FDs are *not* inherited by default on Windows, so we've
left {{cloexec}} as a no-op on Windows.
At the moment, this is fine. However, the introduction of the IO Switchboard
(for exec-ing into containers) added a case where we explicitly want to inherit
FDs. This is done with a ChildHook that unsets the {{O_CLOEXEC}} option on a
specific FD before creating a subprocess:
https://github.com/apache/mesos/blob/1.2.x/3rdparty/libprocess/include/process/subprocess_base.hpp#L212-L216
https://github.com/apache/mesos/blob/1.2.x/src/slave/containerizer/mesos/io/switchboard.cpp#L563-L565
This feature isn't supported in Windows, but we might want to support it at
some point in the future. That means we need to provide a way of selectively
inheriting FDs on Windows.
> `os::cloexec` does not exist on Windows
> ---------------------------------------
>
> Key: MESOS-5882
> URL: https://issues.apache.org/jira/browse/MESOS-5882
> Project: Mesos
> Issue Type: Bug
> Components: stout
> Reporter: Alex Clemmer
> Assignee: Joseph Wu
> Labels: mesosphere, stout
>
> `os::cloexec` does not work on Windows. It will never work at the OS level.
> Because of this, there are likely many important and hard-to-detect bugs
> hanging around the agent.
> This is extremely important to fix. Some possible solutions to investigate
> (some of which are _extremely_ risky):
> * Abstract out file descriptors into a class, implement cloexec in that class
> on Windows (since we can't rely on the OS to do it).
> * Refactor all the code that relies on `os::cloexec` to not rely on it.
> Of the two, the first seems less risky in the short term, because the cloexec
> code only affects Windows. Depending on the semantics of the implementation
> of the `FileDescriptor` class, it is possible that this is riskier to Windows
> in the longer term, as the semantics of `cloexec` may have subtle difference
> between Linux and Windows.
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