I have been working on integrating pg_autovacuum into the backend. I
have used Tom's recent work on the bgwriter as an example. This patch
accomplishes the following:
* pg_autovacuum is now started and stopped by the postmaster
* pg_autovacuum is no longer a stand alone executable
* pg_autovacuum now uses elog
I am submitting this patch for review to make sure that I'm headed in
the right direction, so please give it a cursory glance and tell me if
you see any glaring problems.
I am planning on doing much more in the next few days including:
* creating pg_autovacuum related guc variables
* create a new system table for pg_autovacuum settings
* alter pg_class (or create another new system table) to store
additional per table pg_autovacuum data which will allow per table
settings and persistent data
To use this patch, move pg_autovacuum.c into src/backend/postmaster,
move pg_autovacuum.h into src/include/postmaster and apply the patch.
Matthew O'Connor
ps, I am hoping to get this work in before feature freeze.
*** ./src/backend/bootstrap/bootstrap.c.orig 2004-06-05 15:32:02.0 -0400
--- ./src/backend/bootstrap/bootstrap.c 2004-06-05 15:33:13.0 -0400
***
*** 34,39
--- 34,40
#include libpq/pqsignal.h
#include miscadmin.h
#include postmaster/bgwriter.h
+ #include postmaster/pg_autovacuum.h
#include storage/freespace.h
#include storage/ipc.h
#include storage/pg_shmem.h
***
*** 358,363
--- 359,367
case BS_XLOG_BGWRITER:
statmsg = writer process;
break;
+ case BS_XLOG_AUTOVAC:
+ statmsg = auto vacuum process;
+ break;
default:
statmsg = ??? process;
break;
***
*** 394,399
--- 398,406
case BS_XLOG_BGWRITER:
InitDummyProcess(DUMMY_PROC_BGWRITER);
break;
+ case BS_XLOG_AUTOVAC:
+ InitDummyProcess(DUMMY_PROC_AUTOVAC);
+ break;
default:
InitDummyProcess(DUMMY_PROC_DEFAULT);
***
*** 430,435
--- 437,448
BackgroundWriterMain();
proc_exit(1); /* should never return */
+ case BS_XLOG_AUTOVAC:
+ /* don't set signals, autovac has its own agenda */
+ InitXLOGAccess();
+ AutoVacMain();
+ proc_exit(1); /* should never return */
+
default:
elog(PANIC, unrecognized XLOG op: %d, xlogop);
proc_exit(1);
*** ./src/backend/Makefile.orig 2004-06-07 01:21:43.515373849 -0400
--- ./src/backend/Makefile 2004-06-05 13:46:24.0 -0400
***
*** 29,41
##
! all: submake-libpgport postgres $(POSTGRES_IMP)
ifneq ($(PORTNAME), cygwin)
ifneq ($(PORTNAME), win32)
postgres: $(OBJS)
! $(CC) $(CFLAGS) $(LDFLAGS) $(export_dynamic) $^ $(LIBS) -o $@
endif
endif
--- 29,41
##
! all: submake-libpgport submake-libpq postgres $(POSTGRES_IMP)
ifneq ($(PORTNAME), cygwin)
ifneq ($(PORTNAME), win32)
postgres: $(OBJS)
! $(CC) $(CFLAGS) $(LDFLAGS) -I $(libpq_srcdir) $(export_dynamic) $^ $(LIBS) $(libpq) -o $@
endif
endif
*** ./src/backend/postmaster/Makefile.orig 2004-06-05 00:58:08.0 -0400
--- ./src/backend/postmaster/Makefile 2004-06-05 13:45:20.0 -0400
***
*** 12,18
top_builddir = ../../..
include $(top_builddir)/src/Makefile.global
! OBJS = postmaster.o bgwriter.o pgstat.o
all: SUBSYS.o
--- 12,18
top_builddir = ../../..
include $(top_builddir)/src/Makefile.global
! OBJS = postmaster.o bgwriter.o pgstat.o pg_autovacuum.o
all: SUBSYS.o
*** ./src/backend/postmaster/pg_autovacuum.c.orig 2004-06-07 00:39:57.0 -0400
--- ./src/backend/postmaster/pg_autovacuum.c 2004-06-07 00:35:51.0 -0400
***
*** 1,65
! /* pg_autovacuum.c
* All the code for the pg_autovacuum program
* (c) 2003 Matthew T. O'Connor
* Revisions by Christopher B. Browne, Liberty RMS
*/
! #include pg_autovacuum.h
- FILE *LOGOUTPUT;
char logbuffer[4096];
! static void
! log_entry(const char *logentry)
{
! time_t curtime;
! struct tm *loctime;
! char timebuffer[128];
!
! curtime = time(NULL);
! loctime = localtime(curtime);
! strftime(timebuffer, sizeof(timebuffer), %Y-%m-%d %H:%M:%S %Z, loctime);
! fprintf(LOGOUTPUT, [%s] %s\n, timebuffer, logentry);
}
/*
! * Function used to detach the pg_autovacuum daemon from the tty and go into
! * the background.
*
! * This code is mostly ripped directly from pm_dameonize in postmaster.c with
! * unneeded code removed.
*/
static void
! daemonize()
{
! pid_t pid;
! pid = fork();
! if (pid == (pid_t) -1)
! {
! log_entry(Error: cannot disassociate from controlling TTY);
! fflush(LOGOUTPUT);
! _exit(1);
! }
! else if (pid)
! { /* parent */
! /* Parent should just exit, without doing any atexit cleanup */
!
