Re: lock in qnx rtp.

At 16:30 23.05.01 -0400, Tom Lane wrote:
>"Leandro Medina" <lmedina@ingdesi.com> writes:
> >     I'm porting posgresql for QNX RTP. Compiling is ok, but
> > "/usr/local/pqsql/bin/initdb -D data" command say:
>
> > FATAL: s_lock(0x081e6029) at spin.c:162, stuck spinlock. Aborting.
>
>Hm.  The existing QNX spinlock functions do work for some people.
>Is the slock_t datatype declared correctly for your platform in the
>port header file?
Just to throw in my $0.02 :

- from the source snippet it looks like it is using semaphores for
   spinlocks. This is one of the quirks that my patch corrected. See
   http://www.ca.postgresql.org/mhonarc/pgsql-ports/2001-05/msg00069.html
   and
   http://www.ca.postgresql.org/mhonarc/pgsql-ports/2001-05/msg00078.html
   Without it 7.1 failed with a similar problem on QNX4.

- RTP is probably more different from QNX4 than Solaris 2 from SunOS 4,
   so code that works on QNX4 may fail on RTP. It is much closer to
   modern unices and supports shared libraries, elf executables, etc. .
   AFAIK no SysV IPC interface, though. The RTP version could be much
   more fully featured that the QNX4 version.

- QNX (both versions) is a RTOS. If you were to use RR or FIFO
   scheduling, spinlocks probably won't work.


>                         regards, tom lane