send_request may only write to out.queue if no other thread is busy writing to the network (as that thread may be writing from out.queue). send_request may only allocate request sequence numbers if XCB owns the socket. Therefore, send_request must make sure that both conditions are true when it holds iolock, which can only be done by looping until both conditions are true without having dropped the lock waiting for the second condition. We choose to get the socket back from Xlib first as get_socket_back has a complicated test and checking for other threads writing is a simple in-lined check. This also changes the sequence number checks (64k requests with no reply, 4M request wrapping) to ensure that both conditions are true before queueing the request. Signed-off-by: Keith Packard <keithp@keithp.com> Reviewed-by: Uli Schlachter <psychon@znc.in> |
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doc | ||
m4 | ||
man | ||
src | ||
tests | ||
tools | ||
.autom4te.cfg | ||
.gitignore | ||
COPYING | ||
INSTALL | ||
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