Instead of passing the PIDs back and forth in a handshake "Greet"
message, just use getsockopt(SO_PEERCRED) on both sides to get the same
information from the kernel.
This is a nice little simplification of the IPC protocol, although it
does not get rid of the handshake since we still have to pass the
"client ID" from the server to each client so they know how to refer
to themselves. This might not be necessary and we might be able to get
rid of this later on.
This patch introduces code generation for the WindowServer IPC with
its clients. The client/server endpoints are defined by the two .ipc
files in Servers/WindowServer/: WindowServer.ipc and WindowClient.ipc
It now becomes significantly easier to add features and capabilities
to WindowServer since you don't have to know nearly as much about all
the intricate paths that IPC messages take between LibGUI and WSWindow.
The new system also uses significantly less IPC bandwidth since we're
now doing packed serialization instead of passing fixed-sized structs
of ~600 bytes for each message.
Some repaint coalescing optimizations are lost in this conversion and
we'll need to look at how to implement those in the new world.
The old CoreIPC::Client::Connection and CoreIPC::Server::Connection
classes are removed by this patch and replaced by use of ConnectionNG,
which will be renamed eventually.
Goodbye, old WindowServer IPC. You served us well :^)
