mirror of
https://github.com/reactos/reactos.git
synced 2024-08-19 18:02:55 +00:00
80 lines
2.9 KiB
Plaintext
80 lines
2.9 KiB
Plaintext
References:
|
|
-----------
|
|
|
|
window -> desktop
|
|
window -> class
|
|
|
|
thread_input -> thread
|
|
|
|
thread -> process
|
|
process -> winsta
|
|
thread -> desktop
|
|
desktop -> winsta
|
|
winsta -> session
|
|
|
|
NOTE: Message queue has 1:1 relationship with (w32)thread and need no ref. count.
|
|
-If the (w32)thread is destroyed, so is the message queue.
|
|
-If the (w32)thread exist, so does the message queue.
|
|
So if you want the queue to hang around, you reference the thread instead.
|
|
|
|
^ This is wrong, one can attach message queue to different thread using
|
|
AttachThreadInput. The number of threads sharing a queue is stored in the
|
|
message queue structure and can be considered a reference count. Also on
|
|
Windows systems there is maintained a global list of thread attachments.
|
|
|
|
Above references create following dependencies:
|
|
-----------------------------------------------
|
|
|
|
window -> desktop -> winsta -> session
|
|
window -> class
|
|
|
|
thread -> process -> winsta -> session
|
|
thread -> desktop -> winsta -> session
|
|
|
|
process -> winsta -> session
|
|
|
|
NtUser/NtGdi/win32k syscalls
|
|
----------------------------
|
|
|
|
A process and/or thread automatically gets converted to a GUI thread /
|
|
process when the first syscall from the shadow service table is called (ie.
|
|
any NtUser* or NtGdi* call). GUI threads have bigger kernel stack (FIXME:
|
|
not the case on ReactOS yet) and have associated storage for the Win32
|
|
structures. The conversion itself happens in the syscall handler and the
|
|
win32k callbacks (registered with PsEstablishWin32Callouts) are called
|
|
accordingly.
|
|
|
|
A process automatically establishes a connection to a window station on the
|
|
GUI thread conversion. The Win32 process initialization callback routine
|
|
also creates and initializes the W32PROCESS structure and associates it with
|
|
the process.
|
|
|
|
Similary for thread the callback routine automatically assigns a desktop
|
|
when the thread is converted to GUI thread. The thread also gets a W32THREAD
|
|
structure, a message queue and a thread input structures.
|
|
|
|
Beware that there is an exception to these rules and that's WinLogon. Since
|
|
at the time the process starts no window stations or desktops exist, none
|
|
are assigned to the the initial thread / process. The first Win32k calls
|
|
the thread does are to create the window station and desktop and to associate
|
|
them with itself.
|
|
|
|
FIXME: At the time of this writing there's a second exception, a "primitive
|
|
message queue" thread in CSRSS that is created before any window stations
|
|
exist and is used to capture keyboard input in console mode. Eventually we
|
|
should get rid of it and replace is with hidden window w/ focus or something
|
|
similar.
|
|
|
|
Generally this means that when you are in a Win32k syscall function (other
|
|
than the window station or desktop functions) you can be 100% sure that the
|
|
following exists:
|
|
|
|
- Process window station
|
|
- Win32 process structure
|
|
- Win32 thread structure
|
|
- Thread message queue
|
|
- Thread input
|
|
- Thread desktop
|
|
|
|
There is no need to validate any of these values, because they MUST EXIST!
|