v8-0004-Remove-MyAuxProcType-use-MyBackendType-instead.patch

From fc86b8876e39fa3c2298fb03b716f0896d9ca5b8 Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Mon, 29 Jan 2024 20:58:52 +0200
Subject: [PATCH v8 4/5] Remove MyAuxProcType, use MyBackendType instead

MyAuxProcType was redundant with MyBackendType.

Reviewed-by: Reid Thompson, Andres Freund
Discussion: https://www.postgresql.org/message-id/f3ecd4cb-85ee-4e54-8278-5fabfb3a4ed0@iki.fi
---
 src/backend/postmaster/auxprocess.c | 58 +++++-------------------
 src/backend/postmaster/postmaster.c | 36 +++++++--------
 src/include/miscadmin.h             | 69 ++++++++++++++---------------
 src/include/postmaster/auxprocess.h |  2 +-
 src/tools/pgindent/typedefs.list    |  1 -
 5 files changed, 63 insertions(+), 103 deletions(-)

diff --git a/src/backend/postmaster/auxprocess.c b/src/backend/postmaster/auxprocess.c
index 39171fea06b..fc13cd76321 100644
--- a/src/backend/postmaster/auxprocess.c
+++ b/src/backend/postmaster/auxprocess.c
@@ -38,14 +38,6 @@
 static void ShutdownAuxiliaryProcess(int code, Datum arg);
 
 
-/* ----------------
- *		global variables
- * ----------------
- */
-
-AuxProcType MyAuxProcType = NotAnAuxProcess;	/* declared in miscadmin.h */
-
-
 /*
  *	 AuxiliaryProcessMain
  *
@@ -55,39 +47,11 @@ AuxProcType MyAuxProcType = NotAnAuxProcess;	/* declared in miscadmin.h */
  *	 This code is here just because of historical reasons.
  */
 void
-AuxiliaryProcessMain(AuxProcType auxtype)
+AuxiliaryProcessMain(BackendType auxtype)
 {
 	Assert(IsUnderPostmaster);
 
-	MyAuxProcType = auxtype;
-
-	switch (MyAuxProcType)
-	{
-		case StartupProcess:
-			MyBackendType = B_STARTUP;
-			break;
-		case ArchiverProcess:
-			MyBackendType = B_ARCHIVER;
-			break;
-		case BgWriterProcess:
-			MyBackendType = B_BG_WRITER;
-			break;
-		case CheckpointerProcess:
-			MyBackendType = B_CHECKPOINTER;
-			break;
-		case WalWriterProcess:
-			MyBackendType = B_WAL_WRITER;
-			break;
-		case WalReceiverProcess:
-			MyBackendType = B_WAL_RECEIVER;
-			break;
-		case WalSummarizerProcess:
-			MyBackendType = B_WAL_SUMMARIZER;
-			break;
-		default:
-			elog(PANIC, "unrecognized process type: %d", (int) MyAuxProcType);
-			MyBackendType = B_INVALID;
-	}
+	MyBackendType = auxtype;
 
 	init_ps_display(NULL);
 
@@ -126,38 +90,38 @@ AuxiliaryProcessMain(AuxProcType auxtype)
 
 	SetProcessingMode(NormalProcessing);
 
-	switch (MyAuxProcType)
+	switch (MyBackendType)
 	{
-		case StartupProcess:
+		case B_STARTUP:
 			StartupProcessMain();
 			proc_exit(1);
 
-		case ArchiverProcess:
+		case B_ARCHIVER:
 			PgArchiverMain();
 			proc_exit(1);
 
-		case BgWriterProcess:
+		case B_BG_WRITER:
 			BackgroundWriterMain();
 			proc_exit(1);
 
-		case CheckpointerProcess:
+		case B_CHECKPOINTER:
 			CheckpointerMain();
 			proc_exit(1);
 
-		case WalWriterProcess:
+		case B_WAL_WRITER:
 			WalWriterMain();
 			proc_exit(1);
 
-		case WalReceiverProcess:
+		case B_WAL_RECEIVER:
 			WalReceiverMain();
 			proc_exit(1);
 
-		case WalSummarizerProcess:
+		case B_WAL_SUMMARIZER:
 			WalSummarizerMain();
 			proc_exit(1);
 
 		default:
-			elog(PANIC, "unrecognized process type: %d", (int) MyAuxProcType);
+			elog(PANIC, "unrecognized process type: %d", (int) MyBackendType);
 			proc_exit(1);
 	}
 }
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index feb471dd1df..c51b6a1376a 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -440,7 +440,7 @@ static int	CountChildren(int target);
 static bool assign_backendlist_entry(RegisteredBgWorker *rw);
 static void maybe_start_bgworkers(void);
 static bool CreateOptsFile(int argc, char *argv[], char *fullprogname);
-static pid_t StartChildProcess(AuxProcType type);
+static pid_t StartChildProcess(BackendType type);
 static void StartAutovacuumWorker(void);
 static void MaybeStartWalReceiver(void);
 static void MaybeStartWalSummarizer(void);
@@ -561,13 +561,13 @@ static void ShmemBackendArrayAdd(Backend *bn);
 static void ShmemBackendArrayRemove(Backend *bn);
 #endif							/* EXEC_BACKEND */
 
-#define StartupDataBase()		StartChildProcess(StartupProcess)
-#define StartArchiver()			StartChildProcess(ArchiverProcess)
-#define StartBackgroundWriter() StartChildProcess(BgWriterProcess)
-#define StartCheckpointer()		StartChildProcess(CheckpointerProcess)
-#define StartWalWriter()		StartChildProcess(WalWriterProcess)
-#define StartWalReceiver()		StartChildProcess(WalReceiverProcess)
-#define StartWalSummarizer()	StartChildProcess(WalSummarizerProcess)
+#define StartupDataBase()		StartChildProcess(B_STARTUP)
+#define StartArchiver()			StartChildProcess(B_ARCHIVER)
+#define StartBackgroundWriter() StartChildProcess(B_BG_WRITER)
+#define StartCheckpointer()		StartChildProcess(B_CHECKPOINTER)
+#define StartWalWriter()		StartChildProcess(B_WAL_WRITER)
+#define StartWalReceiver()		StartChildProcess(B_WAL_RECEIVER)
+#define StartWalSummarizer()	StartChildProcess(B_WAL_SUMMARIZER)
 
 /* Macros to check exit status of a child process */
 #define EXIT_STATUS_0(st)  ((st) == 0)
@@ -4953,7 +4953,7 @@ SubPostmasterMain(int argc, char *argv[])
 	}
 	if (strcmp(argv[1], "--forkaux") == 0)
 	{
-		AuxProcType auxtype;
+		BackendType auxtype;
 
 		Assert(argc == 4);
 
@@ -5292,7 +5292,7 @@ CountChildren(int target)
  * to start subprocess.
  */
 static pid_t
-StartChildProcess(AuxProcType type)
+StartChildProcess(BackendType type)
 {
 	pid_t		pid;
 
@@ -5344,31 +5344,31 @@ StartChildProcess(AuxProcType type)
 		errno = save_errno;
 		switch (type)
 		{
-			case StartupProcess:
+			case B_STARTUP:
 				ereport(LOG,
 						(errmsg("could not fork startup process: %m")));
 				break;
-			case ArchiverProcess:
+			case B_ARCHIVER:
 				ereport(LOG,
 						(errmsg("could not fork archiver process: %m")));
 				break;
-			case BgWriterProcess:
+			case B_BG_WRITER:
 				ereport(LOG,
 						(errmsg("could not fork background writer process: %m")));
 				break;
-			case CheckpointerProcess:
+			case B_CHECKPOINTER:
 				ereport(LOG,
 						(errmsg("could not fork checkpointer process: %m")));
 				break;
-			case WalWriterProcess:
+			case B_WAL_WRITER:
 				ereport(LOG,
 						(errmsg("could not fork WAL writer process: %m")));
 				break;
-			case WalReceiverProcess:
+			case B_WAL_RECEIVER:
 				ereport(LOG,
 						(errmsg("could not fork WAL receiver process: %m")));
 				break;
-			case WalSummarizerProcess:
+			case B_WAL_SUMMARIZER:
 				ereport(LOG,
 						(errmsg("could not fork WAL summarizer process: %m")));
 				break;
@@ -5382,7 +5382,7 @@ StartChildProcess(AuxProcType type)
 		 * fork failure is fatal during startup, but there's no need to choke
 		 * immediately if starting other child types fails.
 		 */
-		if (type == StartupProcess)
+		if (type == B_STARTUP)
 			ExitPostmaster(1);
 		return 0;
 	}
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index cbdc61b8576..4ecae4f834e 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -321,29 +321,57 @@ extern void InitProcessLocalLatch(void);
 extern void SwitchToSharedLatch(void);
 extern void SwitchBackToLocalLatch(void);
 
+/*
+ * MyBackendType indicates what kind of a backend this is.
+ */
 typedef enum BackendType
 {
 	B_INVALID = 0,
-	B_ARCHIVER,
+
+	/* Backends and other backend-like processes */
+	B_BACKEND,
 	B_AUTOVAC_LAUNCHER,
 	B_AUTOVAC_WORKER,
-	B_BACKEND,
 	B_BG_WORKER,
+	B_WAL_SENDER,
+
+	B_STANDALONE_BACKEND,
+
+	/*
+	 * Auxiliary processes. These have PGPROC entries, but they are not
+	 * attached to any particular database. There can be only one of each of
+	 * these running at a time.
+	 *
+	 * If you modify these, make sure to update NUM_AUXILIARY_PROCS and the
+	 * glossary in the docs.
+	 */
+	B_ARCHIVER,
 	B_BG_WRITER,
 	B_CHECKPOINTER,
-	B_LOGGER,
-	B_STANDALONE_BACKEND,
 	B_STARTUP,
 	B_WAL_RECEIVER,
-	B_WAL_SENDER,
 	B_WAL_SUMMARIZER,
 	B_WAL_WRITER,
+
+	/*
+	 * Logger is not connected to shared memory and does not have a PGPROC
+	 * entry.
+	 */
+	B_LOGGER,
 } BackendType;
 
 #define BACKEND_NUM_TYPES (B_WAL_WRITER + 1)
 
 extern PGDLLIMPORT BackendType MyBackendType;
 
+#define AmStartupProcess()			(MyBackendType == B_STARTUP)
+#define AmBackgroundWriterProcess() (MyBackendType == B_BG_WRITER)
+#define AmArchiverProcess()			(MyBackendType == B_ARCHIVER)
+#define AmCheckpointerProcess()		(MyBackendType == B_CHECKPOINTER)
+#define AmWalWriterProcess()		(MyBackendType == B_WAL_WRITER)
+#define AmWalReceiverProcess()		(MyBackendType == B_WAL_RECEIVER)
+#define AmWalSummarizerProcess()	(MyBackendType == B_WAL_SUMMARIZER)
+
 extern const char *GetBackendTypeDesc(BackendType backendType);
 
 extern void SetDatabasePath(const char *path);
@@ -426,37 +454,6 @@ extern PGDLLIMPORT ProcessingMode Mode;
 	} while(0)
 
 
-/*
- * Auxiliary-process type identifiers.  These used to be in bootstrap.h
- * but it seems saner to have them here, with the ProcessingMode stuff.
- * The MyAuxProcType global is defined and set in auxprocess.c.
- *
- * Make sure to list in the glossary any items you add here.
- */
-
-typedef enum
-{
-	NotAnAuxProcess = -1,
-	StartupProcess = 0,
-	BgWriterProcess,
-	ArchiverProcess,
-	CheckpointerProcess,
-	WalWriterProcess,
-	WalReceiverProcess,
-	WalSummarizerProcess,
-} AuxProcType;
-
-extern PGDLLIMPORT AuxProcType MyAuxProcType;
-
-#define AmStartupProcess()			(MyAuxProcType == StartupProcess)
-#define AmBackgroundWriterProcess() (MyAuxProcType == BgWriterProcess)
-#define AmArchiverProcess()			(MyAuxProcType == ArchiverProcess)
-#define AmCheckpointerProcess()		(MyAuxProcType == CheckpointerProcess)
-#define AmWalWriterProcess()		(MyAuxProcType == WalWriterProcess)
-#define AmWalReceiverProcess()		(MyAuxProcType == WalReceiverProcess)
-#define AmWalSummarizerProcess()	(MyAuxProcType == WalSummarizerProcess)
-
-
 /*****************************************************************************
  *	  pinit.h --															 *
  *			POSTGRES initialization and cleanup definitions.                 *
diff --git a/src/include/postmaster/auxprocess.h b/src/include/postmaster/auxprocess.h
index 1fdde3bb77b..3e443edde70 100644
--- a/src/include/postmaster/auxprocess.h
+++ b/src/include/postmaster/auxprocess.h
@@ -15,6 +15,6 @@
 
 #include "miscadmin.h"
 
-extern void AuxiliaryProcessMain(AuxProcType auxtype) pg_attribute_noreturn();
+extern void AuxiliaryProcessMain(BackendType auxtype) pg_attribute_noreturn();
 
 #endif							/* AUXPROCESS_H */
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 90b37b919c2..9645c7b735c 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -173,7 +173,6 @@ AutoVacOpts
 AutoVacuumShmemStruct
 AutoVacuumWorkItem
 AutoVacuumWorkItemType
-AuxProcType
 BF_ctx
 BF_key
 BF_word
-- 
2.39.2