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RE: libcurl on QNX 6

From: <>
Date: Wed, 2 Jan 2002 14:36:08 -0000

Firstly, happy new year.

Secondly, some progress on this QNX6-libcurl fault.

After some mucking about with core dumps & gdb, it was found to be the
select(..) call in the function waitconnect(sockfd,timeout_msec) (in
connect.c) what was crashing.

It turns out that QNX sets FD_SETSIZE to only 32 in its <sys/select.h>
header, and as sockfd is passed in with a value of 40+, and as the
documentation states, socket descriptors > FD_SETSIZE screw up the
FD_ZERO/FD_SET macros, which I'm sure in turn will shaft select(..).

By setting FD_SETSIZE early in connect.c to override the QNX value
alleviates the crash.


> -----Original Message-----
> From: Bjorn Reese []
> Sent: Friday 21 December 2001 04:31 PM
> To:
> Subject: Re: libcurl on QNX 6
> Daniel Stenberg wrote:
> >
> > On Fri, 21 Dec 2001 wrote:
> > > To me this all seems to point to a stack problem. The fact the fault
> moves
> > > by removing a few valid executions from the execution path implies
> there is
> > > nothing particularly nasty within socketerror() but delays the point
> at
> > > which the stack craps out. I have also sort of assumed that the dodgy
> value
> > > in the port number is due to stack corruption too.
> >
> > This does indeed sounds like some kind of stack problem. Have you
> measured
> > how much stack it uses and much stack you have (left)?
> There is a very high probability that this is a stack problem. I had a
> similar problem with trio on QNX, where one array on the stack used some
> 100 Kb. The problem was fixed by making the array smaller.
> I don't know what the default stack size on QNX is though.
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Received on 2002-01-02