debugging insanity

Smart GWT Technical Q&A
1

I am seeing something really peculiar:

If I do something at some point of the code,
other debugging messages
that I write out earlier (using SC.logWarn) disappear.

(I repeat: I write out the messages first, and then do something,
and depending on this something, the messages I wrote out earlier
either appear or disappear.)

Because I do not beleive in reserved casuality, I assume there is a buffer somewhere (at some level of processing) for the messages written by SC.logWrite, and I somehow manage to break the mechanism that is supposed to flush this buffer later.

What on Earth could cause this?

(ps. I would supply more detailed information, if I could, but currently, this happens at different, interrelated points of a twenty-something thousand line code-base. If/when I manage to narrow this down, I will tell you more.)

S’GWT Power nightly from 04-30, FF 3.5.9, Linux

2

I left out one of the strangest bits:

the magic action (that makes previously-written debug messages disappear) is actually not doing somthing: this happens when I comment out some code.

(While investigating an other problem, I was trying to simplify things, so I commented out some action, and this is what I got. %-)

3

The log messages are stored as a JavaScript Array on isc.Log under an obfuscated variable name (originally _messageCache). We can’t really suggest a mechanism for what you’re seeing however.

4

mystery solved

No, my impression was wrong: the code I was modifying was (somewhat accidentally) also invoked at an earlier point, and this is how it caused the difference later on.

So, no reverse causality here :slight_smile: I am relieved.