Since several extensions named their errors like "BadFoo", this patch
results in names like XCB_EXT_BAD_BAD_FOO, which is really awful. Those
extensions are already kind of awful, as they produce structure names
like xcb_ext_bad_foo_error_t, which is redundant.

A patch that removes "Bad" from the XML extension descriptions, while
maintaining API and ABI compatibility in XCB, is needed before this
patch can be released.

This reverts commit 158c9b6b.

With this patch, `ico -threads 2` runs without deadlock.

Many thanks to Christoph Pfister <christophpfister@gmail.com> for
pointing out the problem, providing detailed analyses, explaining it to
me repeatedly until I understood what was going on, and proposing and
reviewing possible solutions.

Signed-off-by: Jamey Sharp <jamey@minilop.net>
Acked-by: Christoph Pfister <christophpfister@gmail.com>

This parallels the _xcb_lock_io and _xcb_unlock_io factoring.

But do still print a full backtrace, on platforms where that's
supported.

This commit follows the spirit of Novell's libxcb-sloppy-lock.diff.

I strongly opposed proposals like this one for a long time. Originally I
had a very good reason: libX11, when compiled to use XCB, would crash
soon after a locking correctness violation, so it was better to have an
informative assert failure than a mystifying crash soon after.

It took some time for me to realize that I'd changed the libX11
implementation (for unrelated reasons) so that it could survive most
invalid locking situations, as long as it wasn't actually being used
from multiple threads concurrently.

The other thing that has changed is that most of the code with incorrect
locking has now been fixed. The value of the assert is accordingly
lower.

However, remaining broken callers do need to be fixed. That's why libXCB
will still noisily print a stacktrace (if possible) on each assertion
failure, even when assert isn't actually invoked to abort() the program;
and that's why aborting is still default. This environment variable is
provided only for use as a temporary workaround for broken applications.

Signed-off-by: Jamey Sharp <jamey@minilop.net>
Acked-by: Josh Triplett <josh@freedesktop.org>

Egbert Eich authored Jul 19, 2007 and Matthias Hopf committed Jul 19, 2007

https://bugzilla.novell.com/show_bug.cgi?id=289007
This notion is used in a lot of scripts.

Christoph Pfister authored Jun 06, 2007 and Jamey Sharp committed Jun 06, 2007

As you know there are some nasty libs / apps doing locking
incorrectly. In order to improve the information given to the user
when he encounters such a situation (people don't run apps in gdb
normally) I created the patch attached.
It's very non-intrusive (and affects only xlib/xcb, Josh told me on
irc that it could be useful for other areas too, personally I don't
think that it's really needed at other places ...).

Some same outputs and the discussion of them:

    lxuser@pdln:/tmp$ ./main
    Got a backtrace:
    #0 /tmp/usr/lib/libxcb-xlib.so.0 [0xb7f9d728]
    #1 /tmp/usr/lib/libxcb-xlib.so.0(xcb_xlib_unlock+0x31) [0xb7f9d861]
    #2 ./test.so(function_a+0x11) [0xb7f9f3fd]
    #3 ./test.so(function_b+0x11) [0xb7f9f410]
    #4 ./main [0x80484a7]
    #5 /lib/libc.so.6(__libc_start_main+0xdc) [0xb7e60ebc]
    #6 ./main [0x80483f1]
    main: xcb_xlib.c:82: xcb_xlib_unlock: Assertion `c->xlib.lock' failed.
    Aborted

That's kinda the normal situation.

    lxuser@pdln:/tmp$ ./main
    Got a backtrace:
    #0 /tmp/usr/lib/libxcb-xlib.so.0 [0xb7f90728]
    #1 /tmp/usr/lib/libxcb-xlib.so.0(xcb_xlib_unlock+0x31) [0xb7f90861]
    #2 /tmp/test.so [0xb7f923cd]
    #3 /tmp/test.so(function_b+0x11) [0xb7f923e0]
    #4 ./main [0x80484ab]
    #5 /lib/libc.so.6(__libc_start_main+0xdc) [0xb7e53ebc]
    #6 ./main [0x80483f1]
    main: xcb_xlib.c:82: xcb_xlib_unlock: Assertion `c->xlib.lock' failed.
    Aborted

There are two possible reasons that the name doesn't appear in #2:
a) a hidden symbol or a symbol with statical linkage in a library
b) a symbol in an app not compiled with -rdynamic.
But in both cases you still know _where_ the caller is.

Note that in this example test.so was compiled with
-fomit-frame-pointer; this isn't an issue as _one_ (= the caller)
stack trace is still valid (as long as you don't have the insane idea
to compile xcb with -fo-f-p).

Another issue that may appear is "tail call elimination" (some entries
are mysteriously missing; this is quite ugly, but you still get enough
information so that you can do something useful with the issue e.g. by
disassembling the relevant parts with gdb).

Signed-off-by: Jamey Sharp <jamey@minilop.net>

(Closes: #407376)

Ian Osgood authored Nov 26, 2006 and Josh Triplett committed May 21, 2007

putenv() string must contain '='
environment failure test is invalid if argument is NULL

Changes for Debian package 1.0-2: incorporate Julien's NMU, add XS-Vcs-Browser, set distribution to unstable

* Incorporate NMU by Julien Cristau; thanks, Julien!
* Add XS-Vcs-Browser field to debian/control.
* Upload to unstable.

* Non-maintainer upload.
* libxcb1-dev needs a dependency on libpthread-stubs0-dev and versioned
  dependencies on libxau-dev and libxdmcp-dev, because they are needed by
  anything using xcb.pc (closes: #408409).

The previous constants remain for compatibility, but should be deprecated.

extensions with split names.  Tested with diff and found no difference with
previous stylesheet header-file output.

Eamon Walsh authored Mar 29, 2007 and Bart Massey committed Mar 29, 2007

for new attribute.  Tested with diff and found no difference with
previous stylesheet header-file output.

add the first step toward the documentation of the request/reply functions. The arguments of the requests are not found yet. Josh, can you look at it ?

Add version to Build-Depends on xsltproc, requiring 1.1.19-1 or newer, to get the fix for bug 398327.

Tilman Sauerbeck authored Nov 24, 2006 and Jamey Sharp committed Nov 27, 2006

Also set BUILD_DOCS in that branch. Now the disable-build-docs works
as expected.

Tilman Sauerbeck authored Nov 24, 2006 and Jamey Sharp committed Nov 27, 2006

Now at least enable_build_docs is set correctly.

putenv() string must contain '='
environment failure test is invalid if argument is NULL