From 0d071474e12a70ff8113c7b0731c5b97fec45007 Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Wed, 29 Nov 2023 23:47:25 +0200 Subject: [PATCH v3 3/7] Refactor how InitProcess is called The order of process initialization steps is now more consistent between !EXEC_BACKEND and EXEC_BACKEND modes. InitProcess() is called at the same place in either mode. We can now also move the AttachSharedMemoryStructs() call into InitProcess() itself. This reduces the number of "#ifdef EXEC_BACKEND" blocks. Reviewed-by: Tristan Partin, Andres Freund Discussion: https://www.postgresql.org/message-id/7a59b073-5b5b-151e-7ed3-8b01ff7ce9ef@iki.fi --- src/backend/postmaster/autovacuum.c | 16 +++------- src/backend/postmaster/auxprocess.c | 5 +--- src/backend/postmaster/bgworker.c | 8 ++--- src/backend/postmaster/postmaster.c | 45 ++++------------------------- src/backend/storage/lmgr/proc.c | 12 ++++++++ 5 files changed, 25 insertions(+), 61 deletions(-) diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c index 86a3b3d8be2..2f54485c217 100644 --- a/src/backend/postmaster/autovacuum.c +++ b/src/backend/postmaster/autovacuum.c @@ -476,14 +476,10 @@ AutoVacLauncherMain(int argc, char *argv[]) pqsignal(SIGCHLD, SIG_DFL); /* - * Create a per-backend PGPROC struct in shared memory, except in the - * EXEC_BACKEND case where this was done in SubPostmasterMain. We must do - * this before we can use LWLocks (and in the EXEC_BACKEND case we already - * had to do some stuff with LWLocks). + * Create a per-backend PGPROC struct in shared memory. We must do this + * before we can use LWLocks or access any shared memory. */ -#ifndef EXEC_BACKEND InitProcess(); -#endif /* Early initialization */ BaseInit(); @@ -1548,14 +1544,10 @@ AutoVacWorkerMain(int argc, char *argv[]) pqsignal(SIGCHLD, SIG_DFL); /* - * Create a per-backend PGPROC struct in shared memory, except in the - * EXEC_BACKEND case where this was done in SubPostmasterMain. We must do - * this before we can use LWLocks (and in the EXEC_BACKEND case we already - * had to do some stuff with LWLocks). + * Create a per-backend PGPROC struct in shared memory. We must do this + * before we can use LWLocks or access any shared memory. */ -#ifndef EXEC_BACKEND InitProcess(); -#endif /* Early initialization */ BaseInit(); diff --git a/src/backend/postmaster/auxprocess.c b/src/backend/postmaster/auxprocess.c index cae6feb3562..bae6f68c402 100644 --- a/src/backend/postmaster/auxprocess.c +++ b/src/backend/postmaster/auxprocess.c @@ -97,12 +97,9 @@ AuxiliaryProcessMain(AuxProcType auxtype) */ /* - * Create a PGPROC so we can use LWLocks. In the EXEC_BACKEND case, this - * was already done by SubPostmasterMain(). + * Create a PGPROC so we can use LWLocks and access shared memory. */ -#ifndef EXEC_BACKEND InitAuxiliaryProcess(); -#endif BaseInit(); diff --git a/src/backend/postmaster/bgworker.c b/src/backend/postmaster/bgworker.c index b3c2e65ba9f..3fbc8f503cb 100644 --- a/src/backend/postmaster/bgworker.c +++ b/src/backend/postmaster/bgworker.c @@ -810,14 +810,10 @@ BackgroundWorkerMain(void) PG_exception_stack = &local_sigjmp_buf; /* - * Create a per-backend PGPROC struct in shared memory, except in the - * EXEC_BACKEND case where this was done in SubPostmasterMain. We must do - * this before we can use LWLocks (and in the EXEC_BACKEND case we already - * had to do some stuff with LWLocks). + * Create a per-backend PGPROC struct in shared memory. We must do this + * before we can use LWLocks or access any shared memory. */ -#ifndef EXEC_BACKEND InitProcess(); -#endif /* * Early initialization. diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index ac0e2c0a35b..dd290d06e3d 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -4097,15 +4097,6 @@ BackendStartup(Port *port) /* Perform additional initialization and collect startup packet */ BackendInitialize(port); - /* - * Create a per-backend PGPROC struct in shared memory. We must do - * this before we can use LWLocks. In the !EXEC_BACKEND case (here) - * this could be delayed a bit further, but EXEC_BACKEND needs to do - * stuff with LWLocks before PostgresMain(), so we do it here as well - * for symmetry. - */ - InitProcess(); - /* And run the backend */ BackendRun(port); } @@ -4416,6 +4407,12 @@ BackendInitialize(Port *port) static void BackendRun(Port *port) { + /* + * Create a per-backend PGPROC struct in shared memory. We must do this + * before we can use LWLocks or access any shared memory. + */ + InitProcess(); + /* * Make sure we aren't in PostmasterContext anymore. (We can't delete it * just yet, though, because InitPostgres will need the HBA data.) @@ -4911,12 +4908,6 @@ SubPostmasterMain(int argc, char *argv[]) /* Restore basic shared memory pointers */ InitShmemAccess(UsedShmemSegAddr); - /* Need a PGPROC to run AttachSharedMemoryStructs */ - InitProcess(); - - /* Attach process to shared data structures */ - AttachSharedMemoryStructs(); - /* And run the backend */ BackendRun(&port); /* does not return */ } @@ -4929,12 +4920,6 @@ SubPostmasterMain(int argc, char *argv[]) /* Restore basic shared memory pointers */ InitShmemAccess(UsedShmemSegAddr); - /* Need a PGPROC to run AttachSharedMemoryStructs */ - InitAuxiliaryProcess(); - - /* Attach process to shared data structures */ - AttachSharedMemoryStructs(); - auxtype = atoi(argv[3]); AuxiliaryProcessMain(auxtype); /* does not return */ } @@ -4943,12 +4928,6 @@ SubPostmasterMain(int argc, char *argv[]) /* Restore basic shared memory pointers */ InitShmemAccess(UsedShmemSegAddr); - /* Need a PGPROC to run AttachSharedMemoryStructs */ - InitProcess(); - - /* Attach process to shared data structures */ - AttachSharedMemoryStructs(); - AutoVacLauncherMain(argc - 2, argv + 2); /* does not return */ } if (strcmp(argv[1], "--forkavworker") == 0) @@ -4956,12 +4935,6 @@ SubPostmasterMain(int argc, char *argv[]) /* Restore basic shared memory pointers */ InitShmemAccess(UsedShmemSegAddr); - /* Need a PGPROC to run AttachSharedMemoryStructs */ - InitProcess(); - - /* Attach process to shared data structures */ - AttachSharedMemoryStructs(); - AutoVacWorkerMain(argc - 2, argv + 2); /* does not return */ } if (strncmp(argv[1], "--forkbgworker", 14) == 0) @@ -4972,12 +4945,6 @@ SubPostmasterMain(int argc, char *argv[]) /* Restore basic shared memory pointers */ InitShmemAccess(UsedShmemSegAddr); - /* Need a PGPROC to run AttachSharedMemoryStructs */ - InitProcess(); - - /* Attach process to shared data structures */ - AttachSharedMemoryStructs(); - BackgroundWorkerMain(); } if (strcmp(argv[1], "--forklog") == 0) diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index cdfdd6fbe1d..6c708777dde 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -461,6 +461,12 @@ InitProcess(void) */ InitLWLockAccess(); InitDeadLockChecking(); + +#ifdef EXEC_BACKEND + /* Attach process to shared data structures */ + if (IsUnderPostmaster) + AttachSharedMemoryStructs(); +#endif } /* @@ -614,6 +620,12 @@ InitAuxiliaryProcess(void) * Arrange to clean up at process exit. */ on_shmem_exit(AuxiliaryProcKill, Int32GetDatum(proctype)); + +#ifdef EXEC_BACKEND + /* Attach process to shared data structures */ + if (IsUnderPostmaster) + AttachSharedMemoryStructs(); +#endif } /* -- 2.39.2