Wait() returns -1 [SOLVED]

Working on GDB, I discover that IExec->Wait() often returns
-1. The docs say nothing about error conditions, so what could
this possibly mean?

This is the line:

sig = IExec->Wait(SIGBREAKF_CTRL_C|SIGBREAK_CTRL_D|1<<msgport->mp_SigBit);

EDIT: Byt the way, the port _has_ been created, and the sigbit is set.

@alfkil

Sorry for offtopic, but did you work on new/bug free version of GDB ?

@kas1e

I'm just fooling around. I managed to compile it and
fix a bug that made it crash every time it loaded some
code, but apart from that there's not so much progress.

@alfkil

Can upload it somethere ?

@alfkil

Hmmm... Are you sure it's not returning a -1 when there's a message already waiting when it's called, and a 0 when not? Or something along those lines?

@Daedalus

It should return the signal it receives. That is, if it receives SIGBREAKF_CTRL_C, then it returns that, if it receives a signal from the port, it returns a field with just the ports signal bit set. That's how it works in my test app, and that's how the docs describe it. Only place it doesn't work is in GDB. Strange...

@alfkil

On the other end the doc says Wait() is returning an ULONG (uint32) how comes you are getting -1 ?

@alfkil

The Wait() will return ALL the signal bits that are currently set, so in theory could have any number of bits set (up to 0xFFFFFFFF).

The -1 value is often used to signal an invalid signal bit number. The signal bit number can be anything from [0:31], and -1 is used in some calls (eg AllocSignal() to show failure. I wonder if the signal bit in your MsgPort has become corrupted, or perhaps the MsgPort has been deleted?

My sources can be downloaded at

http://dl.dropbox.com/u/5482530/gdb.lha

(in a few minutes). I didn't take the time to
organize it, so it is filled with .o files, .svn stuff
and a lot of other crap.

@tonyw:

I was thinking the same thing, that the port was
deleted, but why am I able to receive an actual
message from it a little later on?

@alfkil

Quote:

First of all that should be SIGBREAKF_CTRL_D and not SIGBREAK_CTRL_D. Also I suggest putting a parenthesis around "1<<msgport->mp_SigBit" as this will if nothing else make your code much more readable (I don't remember what the relative precedences of bitwise or and shifting are in C so I can't say if not having a parenthesis will cause the wrong value to be calculated or not).

As tonyw says 0xffffffff is a valid return value from IExec->Wait() and would mean that all the task's 32 signals have been set. Maybe this is what happened?

Also you haven't posted the code that you use to display the return value from IExec->Wait(). Maybe there is a bug there?

@salass00

Yeah, checking printouts is a good idea, and you
happen to be spot on... I must have been asleep
writing it... Doh!

@alfkil

you have a PM you didn't noticed for the last 6 days...

@abalaban

I finally got around to reply

@alfkil

Quote:

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We can't find the page you're looking for. Check out our FAQ or forums for help. Or maybe you should try heading home.

:(

@billt

are you wanting only a binary or the whole sources ?
Anyway MickJT have both and binary archive is online and directly downloadable, while for the source archive you must PM him.
All you need is in this thread : http://www.amigans.net/modules/newbb/ ... t_id=56044#forumpost56044