From e541a6d2c8481cd9f9c75fb2328e8e6031cddac6 Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Mon, 29 Jul 2024 23:13:56 +0300 Subject: [PATCH v2 2/4] Minor refactoring of assign_backendlist_entry() Make assign_backendlist_entry() responsible just for allocating the Backend struct. Linking it to the RegisteredBgWorker is the caller's responsibility now. Seems more clear that way. Discussion: https://www.postgresql.org/message-id/835232c0-a5f7-4f20-b95b-5b56ba57d741@iki.fi --- src/backend/postmaster/postmaster.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index 02442a4b85..a3e9e8fdc0 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -416,7 +416,7 @@ static void TerminateChildren(int signal); #define SignalChildren(sig) SignalSomeChildren(sig, BACKEND_TYPE_ALL) static int CountChildren(int target); -static bool assign_backendlist_entry(RegisteredBgWorker *rw); +static Backend *assign_backendlist_entry(void); static void maybe_start_bgworkers(void); static bool CreateOptsFile(int argc, char *argv[], char *fullprogname); static pid_t StartChildProcess(BackendType type); @@ -4028,6 +4028,7 @@ MaxLivePostmasterChildren(void) static bool do_start_bgworker(RegisteredBgWorker *rw) { + Backend *bn; pid_t worker_pid; Assert(rw->rw_pid == 0); @@ -4042,11 +4043,14 @@ do_start_bgworker(RegisteredBgWorker *rw) * tried again right away, most likely we'd find ourselves hitting the * same resource-exhaustion condition. */ - if (!assign_backendlist_entry(rw)) + bn = assign_backendlist_entry(); + if (bn == NULL) { rw->rw_crashed_at = GetCurrentTimestamp(); return false; } + rw->rw_backend = bn; + rw->rw_child_slot = bn->child_slot; ereport(DEBUG1, (errmsg_internal("starting background worker process \"%s\"", @@ -4119,12 +4123,10 @@ bgworker_should_start_now(BgWorkerStartTime start_time) * Allocate the Backend struct for a connected background worker, but don't * add it to the list of backends just yet. * - * On failure, return false without changing any worker state. - * - * Some info from the Backend is copied into the passed rw. + * On failure, return NULL. */ -static bool -assign_backendlist_entry(RegisteredBgWorker *rw) +static Backend * +assign_backendlist_entry(void) { Backend *bn; @@ -4138,7 +4140,7 @@ assign_backendlist_entry(RegisteredBgWorker *rw) ereport(LOG, (errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED), errmsg("no slot available for new background worker process"))); - return false; + return NULL; } bn = palloc_extended(sizeof(Backend), MCXT_ALLOC_NO_OOM); @@ -4147,7 +4149,7 @@ assign_backendlist_entry(RegisteredBgWorker *rw) ereport(LOG, (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of memory"))); - return false; + return NULL; } bn->child_slot = MyPMChildSlot = AssignPostmasterChildSlot(); @@ -4155,10 +4157,7 @@ assign_backendlist_entry(RegisteredBgWorker *rw) bn->dead_end = false; bn->bgworker_notify = false; - rw->rw_backend = bn; - rw->rw_child_slot = bn->child_slot; - - return true; + return bn; } /* -- 2.39.2