[New-bugs-announce] [issue26770] _Py_set_inheritable(): do nothing if the FD_CLOEXEC close is already set/cleared

[STINNER Victor]

New submission from STINNER Victor:

Attached patch is avoids a syscall in os.set_inheritable() if the FD_CLOEXEC flag is already set/cleared.

The change only impacts platforms using fcntl() in _Py_set_inheritable(). Windows has a different implementation, and Linux uses ioctl() for example.

The same "optimization" is used in socket.socket.setblocking(): see the issue #19827.

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files: set_inheritable_fcntl.patch
keywords: patch
messages: 263493
nosy: haypo
priority: normal
severity: normal
status: open
title: _Py_set_inheritable(): do nothing if the FD_CLOEXEC close is already set/cleared
type: performance
versions: Python 3.6
Added file: http://bugs.python.org/file42472/set_inheritable_fcntl.patch

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<http://bugs.python.org/issue26770>
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