Message 407216 - Python tracker

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Author	eryksun
Recipients	christian.heimes, eryksun, vstinner
Date	2021-11-28.18:25:34
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<[email protected]>
In-reply-to

Content
In Windows, GetFileType((HANDLE)_get_osfhandle(fd)) is several times faster than close(dup(fd)). For example: #if defined(MS_WINDOWS) int type; _Py_BEGIN_SUPPRESS_IPH type = GetFileType((HANDLE)_get_osfhandle(fd)); _Py_END_SUPPRESS_IPH return type != FILE_TYPE_UNKNOWN; #endif If the C file descriptor isn't assigned and flagged FOPEN, then _get_osfhandle() returns (intptr_t)-1. This is the pseudohandle value for the current process, so GetFileType() will fail with an invalid handle error, as expected.

In Windows, GetFileType((HANDLE)_get_osfhandle(fd)) is several times faster than close(dup(fd)). For example:

#if defined(MS_WINDOWS)
    int type;
    _Py_BEGIN_SUPPRESS_IPH
    type = GetFileType((HANDLE)_get_osfhandle(fd));
    _Py_END_SUPPRESS_IPH
    return type != FILE_TYPE_UNKNOWN;
#endif

If the C file descriptor isn't assigned and flagged FOPEN, then _get_osfhandle() returns (intptr_t)-1. This is the pseudohandle value for the current process, so GetFileType() will fail with an invalid handle error, as expected.

History
Date	User	Action	Args
2021-11-28 19:23:14	eryksun	unlink	issue45915 messages
2021-11-28 18:25:34	eryksun	set	recipients: + eryksun, vstinner, christian.heimes
2021-11-28 18:25:34	eryksun	set	messageid: <[email protected]>
2021-11-28 18:25:34	eryksun	link	issue45915 messages
2021-11-28 18:25:34	eryksun	create