postgresql/src/backend/storage/ipc
Tom Lane 87bd956385 Restructure smgr API as per recent proposal. smgr no longer depends on
the relcache, and so the notion of 'blind write' is gone.  This should
improve efficiency in bgwriter and background checkpoint processes.
Internal restructuring in md.c to remove the not-very-useful array of
MdfdVec objects --- might as well just use pointers.
Also remove the long-dead 'persistent main memory' storage manager (mm.c),
since it seems quite unlikely to ever get resurrected.
2004-02-10 01:55:27 +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 Restructure smgr API as per recent proposal. smgr no longer depends on 2004-02-10 01:55:27 +00:00
Makefile $Header: -> $PostgreSQL Changes ... 2003-11-29 19:52:15 +00:00
pmsignal.c Win32 signals cleanup. Patch by Magnus Hagander, with input from Claudio 2004-02-08 22:28:57 +00:00
README $Header: -> $PostgreSQL Changes ... 2003-11-29 19:52:15 +00:00
shmem.c Drops in the CreateProcess calls for Win32 (essentially wrapping up the 2004-01-11 03:49:31 +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

$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.