Glibc 2.20 Has Performance Improvements, File Description Locks

[phoronix]

Phoronix: Glibc 2.20 Has Performance Improvements, File Description Locks

Allan McRae announced the release of version 2.20 of the GNU C Library (glibc) this Monday morning...

http://www.phoronix.com/vr.php?view=MTc4MzI

[curaga]

Too bad about the valgrind situation.

[sthalik]

Fixed in valgrind HEAD.

If anything liked Drepper more than the rest of the bunch.

[nanonyme]

Whoever thought of the term file description had to hate beginner developers. Way too close to file descriptor

[sthalik]

Why do entitled new developers matter?

Not a care in the world for entitled new developers here.

[xeekei]

Why do entitled new developers matter?

Not a care in the world for entitled new developers here.

You seem awfully hateful for someone that doesn't care.

[jabl]

Whoever thought of the term file description had to hate beginner developers. Way too close to file descriptor

It's from POSIX actually. See e.g. http://pubs.opengroup.org/onlinepubs...ions/open.html . And yes, there is a difference between a file description and a file descriptor. From the GLIBC manual section about these new-fangled open file description locks:

It is important to distinguish between the open file description (an instance of an open file, usually created by a call to open) and an open file descriptor, which is a numeric value that refers to the open file description. The locks described here are associated with the open file description and not the open file descriptor.

Using dup (see Duplicating Descriptors) to copy a file descriptor does not give you a new open file description, but rather copies a reference to an existing open file description and assigns it to a new file descriptor. Thus, open file description locks set on a file descriptor cloned by dup will never conflict with open file description locks set on the original descriptor since they refer to the same open file description. Depending on the range and type of lock involved, the original lock may be modified by a F_OFD_SETLK or F_OFD_SETLKW command in this situation however.

But yeah, about fscking time. The old POSIX fcntl lock semantics are insane.