[antlr-interest] ANTLRWorks editor slow down

[Terence Parr]

Hi,

Jean and I are re-factoring ANTLRWorks to be much simpler in anticipation of me taking over maintenance and adding features. The first thing I want to do is find out why AW sometimes slows to a crawl. I can't seem to reproduce it when I want to, although it was really really slow the other day before I decided to debug it! ;)  

So, I need your help to figure out when it occurs so that it will give me a clue about where to look in the source code.   My impression is that one of the triggers seems to be when there are lots of errors. But, when I added a whole bunch of grammar windows and then started randomly inserting errors all over the grammar, memory usage didn't really go up and it didn't slow down at all (lots other errors to the console, but that's it). I wonder though if it was getting more memory available to it in the debugger than when I run it from the jar file. Also, I note that sometimes undo is extremely slow, so that is also a potential area to look.

My current candidates for slowdown:

* running out of memory and thrashing
* undo mechanism is tracking too much or something
* error mechanism somehow  tracks too much or has too much work to do

Each keystroke triggers colorizing the editor window, but Jean tells me he's sure that the parser itself is okay. might be the error handling though.

Can anybody reproduce a case where you start ANTLRWorks and then do some stuff in the editor window with a grammar (of any size) and it starts to get really slow to type? Even if you can't send me your grammar, I can send you an instrumented version of AW that will turn out some information about what is going on.

Thanks! This is my highest priority for AW since I'm using it to build v4 ANTLR.

Thanks,
Ter