postgresql

mirror of https://git.postgresql.org/git/postgresql.git synced 2024-08-27 11:47:19 +02:00

History

Tom Lane e8aa10ee47 ShmemInitHash forgot to specify HASH_ALLOC flag bit in its hash_create call. You'd think this would cause some problems, but because of the way hash_create is coded, the only side-effect was creation of a useless memory context for the hashtable.		2003-12-30 00:03:03 +00:00
..
ipc.c	This patch properly sets the prototype for the on_shmem_exit and	2003-12-12 18:45:10 +00:00
ipci.c	This patch is the next step towards (re)allowing fork/exec.	2003-12-20 17:31:21 +00:00
Makefile	$Header: -> $PostgreSQL Changes ...	2003-11-29 19:52:15 +00:00
pmsignal.c	This patch is the next step towards (re)allowing fork/exec.	2003-12-20 17:31:21 +00:00
README	$Header: -> $PostgreSQL Changes ...	2003-11-29 19:52:15 +00:00
shmem.c	ShmemInitHash forgot to specify HASH_ALLOC flag bit in its hash_create	2003-12-30 00:03:03 +00:00
shmqueue.c	$Header: -> $PostgreSQL Changes ...	2003-11-29 19:52:15 +00:00
sinval.c	$Header: -> $PostgreSQL Changes ...	2003-11-29 19:52:15 +00:00
sinvaladt.c	This patch is the next step towards (re)allowing fork/exec.	2003-12-20 17:31:21 +00:00

README

$PostgreSQL: pgsql/src/backend/storage/ipc/README,v 1.4 2003/11/29 19:51:56 pgsql Exp $
Mon Jul 18 11:09:22 PDT 1988  W.KLAS

Cache invalidation synchronization routines:
===========================================

The cache synchronization is done using a message queue. Every
backend can register a message which then has to be read by
all backends. A message read by all backends is removed from the 
queue automatically. If a message has been lost because the buffer
was full, all backends that haven't read this message will be
told that they have to reset their cache state. This is done
at the time when they try to read the message queue.

The message queue is implemented as a shared buffer segment. Actually,
the queue is a circle to allow fast inserting, reading (invalidate data) and
maintaining the buffer.