@ -341,6 +341,7 @@ typedef enum
* ckpt */
PM_WAIT_XLOG_ARCHIVAL , /* waiting for archiver and walsenders to
* finish */
PM_WAIT_CHECKPOINTER , /* waiting for checkpointer to shut down */
PM_WAIT_DEAD_END , /* waiting for dead-end children to exit */
PM_NO_CHILDREN , /* all important children have exited */
} PMState ;
@ -2363,35 +2364,20 @@ process_pm_child_exit(void)
{
ReleasePostmasterChildSlot ( CheckpointerPMChild ) ;
CheckpointerPMChild = NULL ;
if ( EXIT_STATUS_0 ( exitstatus ) & & pmState = = PM_WAIT_XLOG_SHUTDOWN )
if ( EXIT_STATUS_0 ( exitstatus ) & & pmState = = PM_WAIT_CHECKPOINTER )
{
/*
* OK , we saw normal exit of the checkpointer after it ' s been
* told to shut down . We expect that it wrote a shutdown
* checkpoint . ( If for some reason it didn ' t , recovery will
* occur on next postmaster start . )
* told to shut down . We know checkpointer wrote a shutdown
* checkpoint , otherwise we ' d still be in
* PM_WAIT_XLOG_SHUTDOWN state .
*
* At this point we should have no normal backend children
* left ( else we ' d not be in PM_WAIT_XLOG_SHUTDOWN state ) but
* we might have dead - end children to wait for .
*
* If we have an archiver subprocess , tell it to do a last
* archive cycle and quit . Likewise , if we have walsender
* processes , tell them to send any remaining WAL and quit .
* At this point only dead - end children and logger should be
* left .
*/
Assert ( Shutdown > NoShutdown ) ;
/* Waken archiver for the last time */
if ( PgArchPMChild ! = NULL )
signal_child ( PgArchPMChild , SIGUSR2 ) ;
/*
* Waken walsenders for the last time . No regular backends
* should be around anymore .
*/
SignalChildren ( SIGUSR2 , btmask ( B_WAL_SENDER ) ) ;
UpdatePMState ( PM_WAIT_XLOG_ARCHIVAL ) ;
UpdatePMState ( PM_WAIT_DEAD_END ) ;
ConfigurePostmasterWaitSet ( false ) ;
SignalChildren ( SIGTERM , btmask_all_except ( B_LOGGER ) ) ;
}
else
{
@ -2737,6 +2723,7 @@ HandleFatalError(QuitSignalReason reason, bool consider_sigabrt)
case PM_WAIT_XLOG_SHUTDOWN :
case PM_WAIT_XLOG_ARCHIVAL :
case PM_WAIT_CHECKPOINTER :
/*
* NB : Similar code exists in PostmasterStateMachine ( ) ' s handling
@ -3012,10 +2999,10 @@ PostmasterStateMachine(void)
/* Start the checkpointer if not running */
if ( CheckpointerPMChild = = NULL )
CheckpointerPMChild = StartChildProcess ( B_CHECKPOINTER ) ;
/* And tell it to shut down */
/* And tell it to write the shutdown checkpoint */
if ( CheckpointerPMChild ! = NULL )
{
signal_child ( CheckpointerPMChild , SIGUSR2 ) ;
signal_child ( CheckpointerPMChild , SIGINT ) ;
UpdatePMState ( PM_WAIT_XLOG_SHUTDOWN ) ;
}
else
@ -3043,22 +3030,40 @@ PostmasterStateMachine(void)
}
}
/*
* The state transition from PM_WAIT_XLOG_SHUTDOWN to
* PM_WAIT_XLOG_ARCHIVAL is in process_pm_pmsignal ( ) , in response to
* PMSIGNAL_XLOG_IS_SHUTDOWN .
*/
if ( pmState = = PM_WAIT_XLOG_ARCHIVAL )
{
/*
* PM_WAIT_XLOG_ARCHIVAL state ends when there ' s no other children
* than dead - end children left . There shouldn ' t be any regular
* backends left by now anyway ; what we ' re really waiting for is
* walsenders and archiver .
* PM_WAIT_XLOG_ARCHIVAL state ends when there are no children other
* than checkpointer , dead - end children and logger left . There
* shouldn ' t be any regular backends left by now anyway ; what we ' re
* really waiting for is for walsenders and archiver to exit .
*/
if ( CountChildren ( btmask_all_except ( B_LOGGER , B_DEAD_END_BACKEND ) ) = = 0 )
if ( CountChildren ( btmask_all_except ( B_CHECKPOINTER , B_ LOGGER , B_DEAD_END_BACKEND ) ) = = 0 )
{
UpdatePMState ( PM_WAIT_DEAD_END ) ;
ConfigurePostmasterWaitSet ( false ) ;
SignalChildren ( SIGTERM , btmask_all_except ( B_LOGGER ) ) ;
UpdatePMState ( PM_WAIT_CHECKPOINTER ) ;
/*
* Now that the processes mentioned above are gone , tell
* checkpointer to shut down too . That allows checkpointer to
* perform some last bits of cleanup without other processes
* interfering .
*/
if ( CheckpointerPMChild ! = NULL )
signal_child ( CheckpointerPMChild , SIGUSR2 ) ;
}
}
/*
* The state transition from PM_WAIT_CHECKPOINTER to PM_WAIT_DEAD_END is
* in process_pm_child_exit ( ) .
*/
if ( pmState = = PM_WAIT_DEAD_END )
{
/*
@ -3195,6 +3200,7 @@ pmstate_name(PMState state)
PM_TOSTR_CASE ( PM_WAIT_XLOG_SHUTDOWN ) ;
PM_TOSTR_CASE ( PM_WAIT_XLOG_ARCHIVAL ) ;
PM_TOSTR_CASE ( PM_WAIT_DEAD_END ) ;
PM_TOSTR_CASE ( PM_WAIT_CHECKPOINTER ) ;
PM_TOSTR_CASE ( PM_NO_CHILDREN ) ;
}
# undef PM_TOSTR_CASE
@ -3613,6 +3619,8 @@ ExitPostmaster(int status)
static void
process_pm_pmsignal ( void )
{
bool request_state_update = false ;
pending_pm_pmsignal = false ;
ereport ( DEBUG2 ,
@ -3724,9 +3732,67 @@ process_pm_pmsignal(void)
WalReceiverRequested = true ;
}
if ( CheckPostmasterSignal ( PMSIGNAL_XLOG_IS_SHUTDOWN ) )
{
/* Checkpointer completed the shutdown checkpoint */
if ( pmState = = PM_WAIT_XLOG_SHUTDOWN )
{
/*
* If we have an archiver subprocess , tell it to do a last archive
* cycle and quit . Likewise , if we have walsender processes , tell
* them to send any remaining WAL and quit .
*/
Assert ( Shutdown > NoShutdown ) ;
/* Waken archiver for the last time */
if ( PgArchPMChild ! = NULL )
signal_child ( PgArchPMChild , SIGUSR2 ) ;
/*
* Waken walsenders for the last time . No regular backends should
* be around anymore .
*/
SignalChildren ( SIGUSR2 , btmask ( B_WAL_SENDER ) ) ;
UpdatePMState ( PM_WAIT_XLOG_ARCHIVAL ) ;
}
else if ( ! FatalError & & Shutdown ! = ImmediateShutdown )
{
/*
* Checkpointer only ought to perform the shutdown checkpoint
* during shutdown . If somehow checkpointer did so in another
* situation , we have no choice but to crash - restart .
*
* It ' s possible however that we get PMSIGNAL_XLOG_IS_SHUTDOWN
* outside of PM_WAIT_XLOG_SHUTDOWN if an orderly shutdown was
* " interrupted " by a crash or an immediate shutdown .
*/
ereport ( LOG ,
( errmsg ( " WAL was shut down unexpectedly " ) ) ) ;
/*
* Doesn ' t seem likely to help to take send_abort_for_crash into
* account here .
*/
HandleFatalError ( PMQUIT_FOR_CRASH , false ) ;
}
/*
* Need to run PostmasterStateMachine ( ) to check if we already can go
* to the next state .
*/
request_state_update = true ;
}
/*
* Try to advance postmaster ' s state machine , if a child requests it .
*
*/
if ( CheckPostmasterSignal ( PMSIGNAL_ADVANCE_STATE_MACHINE ) )
{
request_state_update = true ;
}
/*
* Be careful about the order of this action relative to this function ' s
* other actions . Generally , this should be after other actions , in case
* they have effects PostmasterStateMachine would need to know about .
@ -3734,7 +3800,7 @@ process_pm_pmsignal(void)
* cannot have any ( immediate ) effect on the state machine , but does
* depend on what state we ' re in now .
*/
if ( CheckPostmasterSignal ( PMSIGNAL_ADVANCE_STATE_MACHINE ) )
if ( request_state_update )
{
PostmasterStateMachine ( ) ;
}
@ -4045,6 +4111,7 @@ bgworker_should_start_now(BgWorkerStartTime start_time)
switch ( pmState )
{
case PM_NO_CHILDREN :
case PM_WAIT_CHECKPOINTER :
case PM_WAIT_DEAD_END :
case PM_WAIT_XLOG_ARCHIVAL :
case PM_WAIT_XLOG_SHUTDOWN :
Andres Freund
5 months ago