Commitbe75581

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When a background worker exists with code 0, unregister it.

The previous behavior was to restart immediately, which was generallyviewed as less useful.Petr Jelinek, with some adjustments by me.

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+23

-11

lines changed

+23

-11

lines changed

Lines changed: 10 additions & 4 deletions

Original file line number	Diff line number	Diff line change
`@@ -166,10 +166,16 @@ typedef struct BackgroundWorker`
`166`	`166`	`</para>`
`167`	`167`
`168`	`168`	`<para>`
`169`		`- Background workers are expected to be continuously running; if they exit`
`170`		`- cleanly, <command>postgres</> will restart them immediately. Consider doing`
`171`		`- interruptible sleep when they have nothing to do; this can be achieved by`
`172`		`- calling <function>WaitLatch()</function>. Make sure the`
	`169`	`+ If <structfield>bgw_restart_time</structfield> for a background worker is`
	`170`	`+ configured as <literal>BGW_NEVER_RESTART</>, or if it exits with an exit`
	`171`	`+ code of 0 or is terminated by <function>TerminateBackgroundWorker</>,`
	`172`	`+ it will be automatically unregistered by the postmaster on exit.`
	`173`	`+ Otherwise, it will be restarted after the time period configured via`
	`174`	`+ <structfield>bgw_restart_time</>, or immediately if the postmaster`
	`175`	`+ reinitializes the cluster due to a backend failure. Backends which need`
	`176`	`+ to suspend execution only temporarily should use an interruptible sleep`
	`177`	`+ rather than exiting; this can be achieved by calling`
	`178`	`+ <function>WaitLatch()</function>. Make sure the`
`173`	`179`	`<literal>WL_POSTMASTER_DEATH</> flag is set when calling that function, and`
`174`	`180`	`verify the return code for a prompt exit in the emergency case that`
`175`	`181`	`<command>postgres</> itself has terminated.`

Lines changed: 2 additions & 2 deletions

Original file line number	Diff line number	Diff line change
`@@ -884,8 +884,8 @@ RegisterDynamicBackgroundWorker(BackgroundWorker *worker,`
`884`	`884`	`* running but is no longer.`
`885`	`885`	`*`
`886`	`886`	`* In the latter case, the worker may be stopped temporarily (if it is`
`887`		`- * configured for automatic restart, or if itexitedwith code 0) or gone`
`888`		`- *forgood (if itis configured not to restart and exited with code 1).`
	`887`	`+ * configured for automatic restart andexitednon-zero) or gone for`
	`888`	`+ * good (if itexited with code 0 or if it is configured not to restart).`
`889`	`889`	`*/`
`890`	`890`	`BgwHandleStatus`
`891`	`891`	`GetBackgroundWorkerPid(BackgroundWorkerHandlehandle,pid_tpidp)`

Lines changed: 7 additions & 1 deletion

Original file line number	Diff line number	Diff line change
`@@ -2845,11 +2845,17 @@ CleanupBackgroundWorker(int pid,`
`2845`	`2845`	`snprintf(namebuf,MAXPGPATH,"%s: %s",_("worker process"),`
`2846`	`2846`	`rw->rw_worker.bgw_name);`
`2847`	`2847`
`2848`		`-/* Delay restarting any bgworker that exits with a nonzero status. */`
`2849`	`2848`	`if (!EXIT_STATUS_0(exitstatus))`
	`2849`	`+{`
	`2850`	`+/* Record timestamp, so we know when to restart the worker. */`
`2850`	`2851`	`rw->rw_crashed_at=GetCurrentTimestamp();`
	`2852`	`+}`
`2851`	`2853`	`else`
	`2854`	`+{`
	`2855`	`+/* Zero exit status means terminate */`
`2852`	`2856`	`rw->rw_crashed_at=0;`
	`2857`	`+rw->rw_terminate= true;`
	`2858`	`+}`
`2853`	`2859`
`2854`	`2860`	`/*`
`2855`	`2861`	`* Additionally, for shared-memory-connected workers, just like a`

Lines changed: 4 additions & 4 deletions

Original file line number	Diff line number	Diff line change
`@@ -16,10 +16,10 @@`
`16`	`16`	`* that the failure can only be transient (fork failure due to high load,`
`17`	`17`	`* memory pressure, too many processes, etc); more permanent problems, like`
`18`	`18`	`* failure to connect to a database, are detected later in the worker and dealt`
`19`		`- * with just by having the worker exit normally.A worker which exits with a`
`20`		`- * return code of 0 will beimmediatelyrestartedby the postmaster. A worker`
`21`		`- * which exits with a return code of 1 will be restarted after the configured`
`22`		`- * restart interval, or never ifthat interval isset toBGW_NEVER_RESTART.`
	`19`	`+ * with just by having the worker exit normally. A worker which exits with`
	`20`	`+ *areturn code of 0 willneverbe restartedand will be removed from worker`
	`21`	`+ *list. A workerwhich exits with a return code of 1 will be restarted after`
	`22`	`+ *the configuredrestart interval (unlessthat interval is BGW_NEVER_RESTART).`
`23`	`23`	`* The TerminateBackgroundWorker() function can be used to terminate a`
`24`	`24`	`* dynamically registered background worker; the worker will be sent a SIGTERM`
`25`	`25`	`* and will not be restarted after it exits. Whenever the postmaster knows`

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