@ -35,7 +35,7 @@
* worker and dealt with just by having the worker exit normally . The launcher
* will launch a new worker again later , per schedule .
*
* When the worker is done vacuuming it sends SIGUSR1 to the launcher . The
* When the worker is done vacuuming it sends SIGUSR2 to the launcher . The
* launcher then wakes up and is able to launch another worker , if the schedule
* is so tight that a new worker is needed immediately . At this time the
* launcher can also balance the settings for the various remaining workers '
@ -55,7 +55,7 @@
*
*
* IDENTIFICATION
* $ PostgreSQL : pgsql / src / backend / postmaster / autovacuum . c , v 1.103 2009 / 08 / 27 17 : 18 : 44 alvherre Exp $
* $ PostgreSQL : pgsql / src / backend / postmaster / autovacuum . c , v 1.104 2009 / 08 / 31 19 : 40 : 59 tgl Exp $
*
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
*/
@ -67,18 +67,15 @@
# include <time.h>
# include <unistd.h>
# include "access/genam.h"
# include "access/heapam.h"
# include "access/reloptions.h"
# include "access/transam.h"
# include "access/xact.h"
# include "catalog/dependency.h"
# include "catalog/indexing.h"
# include "catalog/namespace.h"
# include "catalog/pg_database.h"
# include "commands/dbcommands.h"
# include "commands/vacuum.h"
# include "libpq/hba.h"
# include "libpq/pqsignal.h"
# include "miscadmin.h"
# include "pgstat.h"
@ -86,20 +83,17 @@
# include "postmaster/fork_process.h"
# include "postmaster/postmaster.h"
# include "storage/bufmgr.h"
# include "storage/fd.h"
# include "storage/ipc.h"
# include "storage/pmsignal.h"
# include "storage/proc.h"
# include "storage/procarray.h"
# include "storage/procsignal.h"
# include "storage/sinvaladt.h"
# include "tcop/tcopprot.h"
# include "utils/dynahash.h"
# include "utils/flatfiles.h"
# include "utils/fmgroids.h"
# include "utils/lsyscache.h"
# include "utils/memutils.h"
# include "utils/ps_status.h"
# include "utils/snapmgr.h"
# include "utils/syscache.h"
# include "utils/tqual.h"
@ -133,7 +127,7 @@ static bool am_autovacuum_worker = false;
/* Flags set by signal handlers */
static volatile sig_atomic_t got_SIGHUP = false ;
static volatile sig_atomic_t got_SIGUSR1 = false ;
static volatile sig_atomic_t got_SIGUSR2 = false ;
static volatile sig_atomic_t got_SIGTERM = false ;
/* Comparison point for determining whether freeze_max_age is exceeded */
@ -303,9 +297,8 @@ static PgStat_StatTabEntry *get_pgstat_tabentry_relid(Oid relid, bool isshared,
PgStat_StatDBEntry * dbentry ) ;
static void autovac_report_activity ( autovac_table * tab ) ;
static void avl_sighup_handler ( SIGNAL_ARGS ) ;
static void avl_sigusr1 _handler ( SIGNAL_ARGS ) ;
static void avl_sigusr2 _handler ( SIGNAL_ARGS ) ;
static void avl_sigterm_handler ( SIGNAL_ARGS ) ;
static void avl_quickdie ( SIGNAL_ARGS ) ;
static void autovac_refresh_stats ( void ) ;
@ -407,6 +400,9 @@ AutoVacLauncherMain(int argc, char *argv[])
/* Identify myself via ps */
init_ps_display ( " autovacuum launcher process " , " " , " " , " " ) ;
ereport ( LOG ,
( errmsg ( " autovacuum launcher started " ) ) ) ;
if ( PostAuthDelay )
pg_usleep ( PostAuthDelay * 1000000L ) ;
@ -424,20 +420,20 @@ AutoVacLauncherMain(int argc, char *argv[])
# endif
/*
* Set up signal handlers . Since this is an auxiliary process , it has
* particular signal requirements - - no deadlock checker or sinval
* catchup , for example .
* Set up signal handlers . We operate on databases much like a regular
* backend , so we use the same signal handling . See equivalent code in
* tcop / postgres . c .
*/
pqsignal ( SIGHUP , avl_sighup_handler ) ;
pqsignal ( SIGINT , SIG_IGN ) ;
pqsignal ( SIGINT , StatementCancelHandler ) ;
pqsignal ( SIGTERM , avl_sigterm_handler ) ;
pqsignal ( SIGQUIT , avl_quickdie ) ;
pqsignal ( SIGALRM , SIG_IGN ) ;
pqsignal ( SIGQUIT , quickdie ) ;
pqsignal ( SIGALRM , handle_sig_alarm ) ;
pqsignal ( SIGPIPE , SIG_IGN ) ;
pqsignal ( SIGUSR1 , av l_sigusr1_handler ) ;
pqsignal ( SIGUSR2 , SIG_IGN ) ;
pqsignal ( SIGUSR1 , procsign al_sigusr1_handler) ;
pqsignal ( SIGUSR2 , avl_sigusr2_handler ) ;
pqsignal ( SIGFPE , FloatExceptionHandler ) ;
pqsignal ( SIGCHLD , SIG_DFL ) ;
@ -451,9 +447,13 @@ AutoVacLauncherMain(int argc, char *argv[])
* had to do some stuff with LWLocks ) .
*/
# ifndef EXEC_BACKEND
InitAuxiliary Process ( ) ;
InitProcess ( ) ;
# endif
InitPostgres ( NULL , InvalidOid , NULL , NULL ) ;
SetProcessingMode ( NormalProcessing ) ;
/*
* Create a memory context that we will do all our work in . We do this so
* that we can reset the context during error recovery and thereby avoid
@ -466,11 +466,10 @@ AutoVacLauncherMain(int argc, char *argv[])
ALLOCSET_DEFAULT_MAXSIZE ) ;
MemoryContextSwitchTo ( AutovacMemCxt ) ;
/*
* If an exception is encountered , processing resumes here .
*
* This code is heavily based on bgwriter . c , q . v .
* This code is a stripped down version of PostgresMain error recovery .
*/
if ( sigsetjmp ( local_sigjmp_buf , 1 ) ! = 0 )
{
@ -480,17 +479,16 @@ AutoVacLauncherMain(int argc, char *argv[])
/* Prevents interrupts while cleaning up */
HOLD_INTERRUPTS ( ) ;
/* Forget any pending QueryCancel request */
QueryCancelPending = false ;
disable_sig_alarm ( true ) ;
QueryCancelPending = false ; /* again in case timeout occurred */
/* Report the error to the server log */
EmitErrorReport ( ) ;
/*
* These operations are really just a minimal subset of
* AbortTransaction ( ) . We don ' t have very many resources to worry
* about , but we do have LWLocks .
*/
LWLockReleaseAll ( ) ;
AtEOXact_Files ( ) ;
AtEOXact_HashTables ( false ) ;
/* Abort the current transaction in order to recover */
AbortCurrentTransaction ( ) ;
/*
* Now return to normal top - level context and clear ErrorContext for
@ -525,9 +523,6 @@ AutoVacLauncherMain(int argc, char *argv[])
/* We can now handle ereport(ERROR) */
PG_exception_stack = & local_sigjmp_buf ;
ereport ( LOG ,
( errmsg ( " autovacuum launcher started " ) ) ) ;
/* must unblock signals before calling rebuild_database_list */
PG_SETMASK ( & UnBlockSig ) ;
@ -561,11 +556,14 @@ AutoVacLauncherMain(int argc, char *argv[])
* necessity for manual cleanup of all postmaster children .
*/
if ( ! PostmasterIsAlive ( true ) )
exit ( 1 ) ;
proc_ exit( 1 ) ;
launcher_determine_sleep ( ( AutoVacuumShmem - > av_freeWorkers ! = NULL ) ,
false , & nap ) ;
/* Allow sinval catchup interrupts while sleeping */
EnableCatchupInterrupt ( ) ;
/*
* Sleep for a while according to schedule .
*
@ -595,12 +593,14 @@ AutoVacLauncherMain(int argc, char *argv[])
* necessity for manual cleanup of all postmaster children .
*/
if ( ! PostmasterIsAlive ( true ) )
exit ( 1 ) ;
proc_ exit( 1 ) ;
if ( got_SIGTERM | | got_SIGHUP | | got_SIGUSR1 )
if ( got_SIGTERM | | got_SIGHUP | | got_SIGUSR2 )
break ;
}
DisableCatchupInterrupt ( ) ;
/* the normal shutdown case */
if ( got_SIGTERM )
break ;
@ -610,7 +610,7 @@ AutoVacLauncherMain(int argc, char *argv[])
got_SIGHUP = false ;
ProcessConfigFile ( PGC_SIGHUP ) ;
/* shutdown requested in config file */
/* shutdown requested in config file? */
if ( ! AutoVacuumingActive ( ) )
break ;
@ -627,9 +627,9 @@ AutoVacLauncherMain(int argc, char *argv[])
* a worker finished , or postmaster signalled failure to start a
* worker
*/
if ( got_SIGUSR1 )
if ( got_SIGUSR2 )
{
got_SIGUSR1 = false ;
got_SIGUSR2 = false ;
/* rebalance cost limits, if needed */
if ( AutoVacuumShmem - > av_signal [ AutoVacRebalance ] )
@ -1306,7 +1306,7 @@ launch_worker(TimestampTz now)
/*
* Called from postmaster to signal a failure to fork a process to become
* worker . The postmaster should kill ( SIGUSR1 ) the launcher shortly
* worker . The postmaster should kill ( SIGUSR2 ) the launcher shortly
* after calling this function .
*/
void
@ -1322,11 +1322,11 @@ avl_sighup_handler(SIGNAL_ARGS)
got_SIGHUP = true ;
}
/* SIGUSR1 : a worker is up and running, or just finished, or failed to fork */
/* SIGUSR2 : a worker is up and running, or just finished, or failed to fork */
static void
avl_sigusr1 _handler ( SIGNAL_ARGS )
avl_sigusr2 _handler ( SIGNAL_ARGS )
{
got_SIGUSR1 = true ;
got_SIGUSR2 = true ;
}
/* SIGTERM: time to die */
@ -1336,38 +1336,6 @@ avl_sigterm_handler(SIGNAL_ARGS)
got_SIGTERM = true ;
}
/*
* avl_quickdie occurs when signalled SIGQUIT from postmaster .
*
* Some backend has bought the farm , so we need to stop what we ' re doing
* and exit .
*/
static void
avl_quickdie ( SIGNAL_ARGS )
{
PG_SETMASK ( & BlockSig ) ;
/*
* We DO NOT want to run proc_exit ( ) callbacks - - we ' re here because
* shared memory may be corrupted , so we don ' t want to try to clean up our
* transaction . Just nail the windows shut and get out of town . Now that
* there ' s an atexit callback to prevent third - party code from breaking
* things by calling exit ( ) directly , we have to reset the callbacks
* explicitly to make this work as intended .
*/
on_exit_reset ( ) ;
/*
* Note we do exit ( 2 ) not exit ( 0 ) . This is to force the postmaster into a
* system reset cycle if some idiot DBA sends a manual SIGQUIT to a random
* backend . This is necessary precisely because we don ' t clean up our
* shared memory state . ( The " dead man switch " mechanism in pmsignal . c
* should ensure the postmaster sees this as a crash , too , but no harm in
* being doubly sure . )
*/
exit ( 2 ) ;
}
/********************************************************************
* AUTOVACUUM WORKER CODE
@ -1590,7 +1558,7 @@ AutoVacWorkerMain(int argc, char *argv[])
/* wake up the launcher */
if ( AutoVacuumShmem - > av_launcherpid ! = 0 )
kill ( AutoVacuumShmem - > av_launcherpid , SIGUSR1 ) ;
kill ( AutoVacuumShmem - > av_launcherpid , SIGUSR2 ) ;
}
else
{
@ -1784,46 +1752,57 @@ autovac_balance_cost(void)
/*
* get_database_list
* Return a list of all databases found in pg_database .
*
* Return a list of all databases . Note we cannot use pg_database ,
* because we aren ' t connected ; we use the flat database file .
* Note : this is the only function in which the autovacuum launcher uses a
* transaction . Although we aren ' t attached to any particular database and
* therefore can ' t access most catalogs , we do have enough infrastructure
* to do a seqscan on pg_database .
*/
static List *
get_database_list ( void )
{
char * filename ;
List * dblist = NIL ;
char thisname [ NAMEDATALEN ] ;
FILE * db_file ;
Oid db_id ;
Oid db_tablespace ;
TransactionId db_frozenxid ;
filename = database_getflatfilename ( ) ;
db_file = AllocateFile ( filename , " r " ) ;
if ( db_file = = NULL )
ereport ( FATAL ,
( errcode_for_file_access ( ) ,
errmsg ( " could not open file \" %s \" : %m " , filename ) ) ) ;
Relation rel ;
HeapScanDesc scan ;
HeapTuple tup ;
/*
* Start a transaction so we can access pg_database , and get a snapshot .
* We don ' t have a use for the snapshot itself , but we ' re interested in
* the secondary effect that it sets RecentGlobalXmin . ( This is critical
* for anything that reads heap pages , because HOT may decide to prune
* them even if the process doesn ' t attempt to modify any tuples . )
*/
StartTransactionCommand ( ) ;
( void ) GetTransactionSnapshot ( ) ;
/* Allocate our results in AutovacMemCxt, not transaction context */
MemoryContextSwitchTo ( AutovacMemCxt ) ;
while ( read_pg_database_line ( db_file , thisname , & db_id ,
& db_tablespace , & db_frozenxid ) )
rel = heap_open ( DatabaseRelationId , AccessShareLock ) ;
scan = heap_beginscan ( rel , SnapshotNow , 0 , NULL ) ;
while ( HeapTupleIsValid ( tup = heap_getnext ( scan , ForwardScanDirection ) ) )
{
avw_dbase * avdb ;
Form_pg_database pgdatabase = ( Form_pg_database ) GETSTRUCT ( tup ) ;
avw_dbase * avdb ;
avdb = ( avw_dbase * ) palloc ( sizeof ( avw_dbase ) ) ;
avdb - > adw_datid = db_id ;
avdb - > adw_name = pstrdup ( thisname ) ;
avdb - > adw_frozenxid = db_ frozenxid;
avdb - > adw_datid = HeapTupleGetOid ( tup ) ;
avdb - > adw_name = pstrdup ( NameStr ( pgdatabase - > datname ) ) ;
avdb - > adw_frozenxid = pgdatabase - > dat frozenxid;
/* this gets set later: */
avdb - > adw_entry = NULL ;
dblist = lappend ( dblist , avdb ) ;
}
FreeFile ( db_file ) ;
pfree ( filename ) ;
heap_endscan ( scan ) ;
heap_close ( rel , AccessShareLock ) ;
CommitTransactionCommand ( ) ;
return dblist ;
}
Tom Lane
16 years ago