The update callback for the file descriptors was always a bit awkward and
un-intuitive. The idea was that whenever the protocol code needed to
write data to the fd it would call the 'update' function. This function
would adjust the mainloop so that it polls for POLLOUT on the fd so we
can eventually flush the data to the socket.
The problem is that in multi-threaded applications, any thread can issue
a request, which writes data to the output buffer and thus triggers the
update callback. Thus, we'll be calling out with the display mutex
held and may call from any thread.
The solution is to eliminate the udpate callback and just require that
the application or server flushes all connection buffers before blocking.
This turns out to be a simpler API, although we now require clients to
deal with EAGAIN and non-blocking writes. It also saves a few syscalls,
since the socket will be writable most of the time and most writes will
complete, so we avoid changing epoll to poll for POLLOUT, then write and
then change it back for each write.
The core libwayland libraries should not handle logging, only passing
the error messages to subscribed functions.
An application linked to libwayland-server or libwayland-client
will be able to set own functions (one per library) to handle error
messages.
Change in this series: make the wl_log return int, because
of compatibility with printf. It will return the number of bytes logged.
This adds a public header so that applications can get the Wayland
version number at compile time. This can be used to make applications
that support compiling against multiple versions of Wayland.
There is a separate installed header called cogl-version.h which gets
included by both wayland-client.h and wayland-server.h
The canonical place for the version number is the configure.ac script
which splits it into three separate m4 defines for the major, minor
and micro version. These are copied into the generated
wayland-version.h header using AC_SUBST. There is also a string form
of the complete version number.
The version number is now also automatically copied into the two .pc
files.
Because the major, minor and micro parts are required it is no longer
possible to leave the version number as 'master' when building from
git. Most projects seem to immediately bump the git repo to a fake
version number (usually odd) after making a release so that there is
always a relative number that can be used for comparison. This patch
sets the git version to 0.99.0 under the assumption that the next
release will be 1.0.0.
This avoids the clash with the wayland-server version with the same
name, and allows linking against both wayland-client and wayland-server
at the same time, which can be useful for unit testing purposes as
well as for nested compositing.
Without this there will be crashes as the wrong wl_display_destroy()
is called.
We set aside a range of the object ID space for use by the server. This
allows the server to bind an object to an ID for a client and pass that
object to the client. The client can use the object immediately and the
server can emit events to the object immdiately.
So obvious in retrospect. The object system can do all the work for us
and keep track of pending calls as regular objects and we don't need to
abuse the resource system to get them cleaned up on client exit. We
don't need the custom key management or (broken) lookup, we just sue
object IDs. And last but not least, anybody can receive the callback,
not just display listeners.
