Обсуждение: ProcSignalSlot vs. PGPROC

Hi,

do I understand correctly that a BackendId is just an index into the 
ProcSignalSlots array and not (necessarily) the same as the index into 
ProcArrayStruct's procs?

If yes, could these be synchronized? Why is ProcSignalSlot not part of 
PGPROC at all? Both are shared memory structures per backend (plus 
NUM_AUXILIARY_PROCS). What am I missing?

Regards

Markus Wanner

Markus Wanner <markus@bluegap.ch> writes:
> do I understand correctly that a BackendId is just an index into the 
> ProcSignalSlots array and not (necessarily) the same as the index into 
> ProcArrayStruct's procs?

> If yes, could these be synchronized? Why is ProcSignalSlot not part of 
> PGPROC at all? Both are shared memory structures per backend (plus 
> NUM_AUXILIARY_PROCS). What am I missing?

It's easier to keep those modules separate.  I believe also that there
are (or could be) processes that have entries in one array but not the
other.
        regards, tom lane