I've patched the Unix VM so that any part of the VM -- including plugins -- may now register file descriptors to be checked with select() whenever ioRelinquishProcessor() is called. I also updated the XWindows, sound, and sockets modules to use this general mechanism instead of their own private one.
The immediate benefit is that sound events, too, will wake up ioRelinquishProcessor(). A smaller benefit is that several hacks such as soundPollFunction() and the extraFd argument to socketPollFunction() are removed.
The longer-term benefit is that plugins don't need to modify the core VM as often. (To really do this right, there should also be a way to register a general polling function. I didn't get around to this, because it turned out not to be necessary for anything in the core VM.)
The code for all this is at the bottom of:
http://www.cc.gatech.edu/~lex/squeak/
It turned out to be pretty simple, since Ian already wrote the core mechanism for sqUnixSocket.c.
Cheers,
-Lex
Lex Spoon wrote:
I've patched the Unix VM so that any part of the VM -- including plugins -- may now register file descriptors to be checked with select() whenever ioRelinquishProcessor() is called. I also updated the XWindows, sound, and sockets modules to use this general mechanism instead of their own private one.
Excellent move; how did you handle the need for different nuymbers of arguments in the original code?
While you're tidying up, you might like to remove the calls to joystickInit(), serialInit() etc in sqXWindow.c - they're not needed at all with plugins since those functions are called by the plugin-local init code.If you leave them in and build a vm with the appropriate plugins external you get problems.
tim
On Sunday 28 January 2001 02:20, Lex Spoon wrote:
I've patched the Unix VM so that any part of the VM -- including plugins -- may now register file descriptors to be checked with select() whenever ioRelinquishProcessor() is called. I also updated the XWindows, sound, and sockets modules to use this general mechanism instead of their own private one.
This is great! I wanted to change the serial model, as well; perhaps this will help.
It would be nice if the Windows VM could also do this, but unfortunately select() only works on sockets there (there is a different mechanism for async IO otherwise).
The immediate benefit is that sound events, too, will wake up ioRelinquishProcessor(). A smaller benefit is that several hacks such as soundPollFunction() and the extraFd argument to socketPollFunction() are removed.
soundPollFunction is in the sqXWindow.c diff; did you mean for it to be there?
+ /* check descriptors being watched */ + aioPoll(0); + + /* check sound explicitly */ + if(soundPollFunction) { + soundPollFunction(); + } + + + /* process all window events */ + while (HandleEvents()) ; +
Tim Rowledge tim@sumeru.stanford.edu wrote:
Lex Spoon wrote:
I've patched the Unix VM so that any part of the VM -- including plugins -- may now register file descriptors to be checked with select() whenever ioRelinquishProcessor() is called. I also updated the XWindows, sound, and sockets modules to use this general mechanism instead of their own private one.
Excellent move; how did you handle the need for different nuymbers of arguments in the original code?
Hrm, I don't understand. What functions need different numbers of arguments?
In the code I've posted, modules register descriptors via two functions:
aioHandle(descriptor, handler, data, eventMask) aioStopHandling(descriptor)
When the "handler" is invoked, it will be passed the single argument "data", which was specified in the aioHandle() call. So, you can pass arbitrary amounts of data to the handler through this mechanism, by creating a struct for the purpose. Sockets are the only module that use this right now, and they already have a convenient struct around for the purpose.
Also, naturually, handler's are passed the values of the read, write, and exception flags that select() returns for the relevant descriptor.
Overall, there's nothing really clever here. It's just taking Ian's existing code, sticking it at global scope, and modifying some of the interfaces so that they aren't specific to sockets. If you're thinking of anything sophisticated, I probably didn't do it. :)
While you're tidying up, you might like to remove the calls to joystickInit(), serialInit() etc in sqXWindow.c - they're not needed at all with plugins since those functions are called by the plugin-local init code.If you leave them in and build a vm with the appropriate plugins external you get problems.
Good idea! I don't want to do it myself, though, because I'm already suggesting so many changes to Ian. One thing at a time....
-Lex
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Lex Spoon -
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Tim Rowledge