Bug 5958

Summary:	XCB should zero out padding bytes
Product:	XCB	Reporter:	Jamey Sharp <jamey>
Component:	Library	Assignee:	Jamey Sharp <jamey>
Status:	RESOLVED MOVED	QA Contact:
Severity:	enhancement
Priority:	low
Version:	unspecified
Hardware:	All
OS:	All
Whiteboard:
i915 platform:		i915 features:

Description Jamey Sharp 2006-02-20 08:03:06 UTC

To make valgrind quit complaining and, supposedly, improve protocol stream
compression, padding bytes in requests generated by XCB should be zeroed before
transmission.

Comment 1 Jamey Sharp 2006-11-20 02:04:24 UTC

Most issues are fixed now, but gcc auto-pads the end of the fixed-length
portions of requests, and we don't get to initialize those padding bytes. So for
requests with a fixed-length part that does not end on a four-byte boundary,
valgrind will still warn for now.

We need to have our code generator explicitly place a padding field on the end
of such structures. Doing so also allows us to eliminate one iovec from every
request stub, cutting the number of memcpy's in half for requests without lists.
In my measurements this is a pretty good performance win for small requests.

Comment 2 chemtech 2013-03-15 14:25:31 UTC

Jamey Sharp
Do you still experience this issue with newer soft ?
Please check the status of your issue.

Comment 3 GitLab Migration User 2019-02-16 19:41:55 UTC

-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

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