Two threads trying to send fds at the same time could interfere. To guarantee a correct ordering, we have to use correct locking. The code in send_fds() missed one case: If there was another thread already writing requests, we slept on the "done with writing" condition variable (c->out.cond). This would allow other threads to re-acquire the iolock before us and could cause fds to be sent out of order. To fix this, at the beginning of send_fds() we now make sure that no other thread is already writing requests. This is what prepare_socket_request() does. Additionally, it gets the socket back in case xcb_take_socket() was called, which is a good thing, too, since fds are only sent with corresponding requests. |
||
|---|---|---|
| doc | ||
| m4 | ||
| man | ||
| src | ||
| tests | ||
| tools | ||
| .autom4te.cfg | ||
| .gitignore | ||
| COPYING | ||
| Makefile.am | ||
| NEWS | ||
| README | ||
| autogen.sh | ||
| check-pc-requires | ||
| configure.ac | ||
| xcb-composite.pc.in | ||
| xcb-damage.pc.in | ||
| xcb-dpms.pc.in | ||
| xcb-dri2.pc.in | ||
| xcb-dri3.pc.in | ||
| xcb-glx.pc.in | ||
| xcb-present.pc.in | ||
| xcb-randr.pc.in | ||
| xcb-record.pc.in | ||
| xcb-render.pc.in | ||
| xcb-res.pc.in | ||
| xcb-screensaver.pc.in | ||
| xcb-shape.pc.in | ||
| xcb-shm.pc.in | ||
| xcb-sync.pc.in | ||
| xcb-xevie.pc.in | ||
| xcb-xf86dri.pc.in | ||
| xcb-xfixes.pc.in | ||
| xcb-xinerama.pc.in | ||
| xcb-xinput.pc.in | ||
| xcb-xkb.pc.in | ||
| xcb-xprint.pc.in | ||
| xcb-xselinux.pc.in | ||
| xcb-xtest.pc.in | ||
| xcb-xv.pc.in | ||
| xcb-xvmc.pc.in | ||
| xcb.pc.in | ||
About libxcb
============
libxcb provides an interface to the X Window System protocol, which
replaces the current Xlib interface. It has several advantages over
Xlib, including:
- size: small, simple library, and lower memory footprint
- latency hiding: batch several requests and wait for the replies later
- direct protocol access: interface and protocol correspond exactly
- proven thread support: transparently access XCB from multiple threads
- easy extension implementation: interfaces auto-generated from XML-XCB
Xlib can also use XCB as a transport layer, allowing software to make
requests and receive responses with both, which eases porting to XCB.
However, client programs, libraries, and toolkits will gain the most
benefit from a native XCB port.
Please report any issues you find to the freedesktop.org bug tracker,
at:
<https://bugs.freedesktop.org/enter_bug.cgi?product=XCB>
Discussion about XCB occurs on the XCB mailing list:
<mailto:xcb at lists.freedesktop.org>
<http://lists.freedesktop.org/mailman/listinfo/xcb>
You can obtain the latest development versions of XCB using GIT.
For anonymous checkouts, use:
git clone git://anongit.freedesktop.org/git/xcb/libxcb
For developers, use:
git clone git+ssh://git.freedesktop.org/git/xcb/libxcb