Linked by Thom Holwerda on Sat 28th Jun 2008 22:09 UTC, submitted by diegocg
X11, Window Managers "Maybe I'm just naive, but designing a graphics API such that all image data had to be sent over a socket to another process every time the image needed to be drawn seems like complete idiocy. Unfortunately, that is precisely what the X Window System forces a program to do, and exactly what Cairo does when drawing images in Linux - a full copy of the image data, send to another process, no less, every time it is drawn. One would think there would be some room for improvement. Unsurprisingly, others felt the same way about X, and decided to write an extension, Xlib Shm or XShm for short, that allows images to placed in a shared memory segment from which the X server reads which allows the program to avoid the memory copy. GTK already makes use of the XShm extension, and it seems like a good idea to see if Gecko couldn't do the same."
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Overstated conclusion
by sbergman27 on Sun 29th Jun 2008 00:04 UTC
sbergman27
Member since:
2005-07-24

1. I agree that using XShm when the client is local is good.

2. I'm surprised that Cairo did not already use it.

However, it looks to me like XShm reduced the total time by only about 20% and the author concluded that the original way was "idiocy", which seems a bit over the top, especially considering the extra flexibility of the socket approach.

Despite all the moaning about X I hear on this site, not one of the 40 or so users I have running complete desktops via remote X over 100mbit lan has ever once complained to me about their screen update speeds.

Edited 2008-06-29 00:08 UTC

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