From 96ad5dcd77bb8d2e4c9c3ca06ae4dcf43017defe Mon Sep 17 00:00:00 2001
From: Justin Pryzby <pryzbyj@telsasoft.com>
Date: Tue, 14 Feb 2023 15:29:41 -0600
Subject: [PATCH v4 2/2] f! convert to an enum

---
 doc/src/sgml/config.sgml            |  2 +-
 src/backend/utils/misc/guc_tables.c | 32 ++++++++++++++++++-----------
 src/include/storage/pg_shmem.h      |  8 ++++++++
 3 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 3ff301edf8a..1f6f71a2826 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -10681,23 +10681,23 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
         macro <symbol>USE_ASSERT_CHECKING</symbol> is defined
         when <productname>PostgreSQL</productname> is built (accomplished
         e.g., by the <command>configure</command> option
         <option>--enable-cassert</option>). By
         default <productname>PostgreSQL</productname> is built without
         assertions.
        </para>
       </listitem>
      </varlistentry>
 
      <varlistentry id="guc-huge-pages-active" xreflabel="huge_pages_active">
-      <term><varname>huge_pages_active</varname> (<type>string</type>)
+      <term><varname>huge_pages_active</varname> (<type>enum</type>)
       <indexterm>
        <primary><varname>huge_pages_active</varname> configuration parameter</primary>
       </indexterm>
       </term>
       <listitem>
        <para>
         Reports whether huge pages are in use by the current instance.
         See <xref linkend="guc-huge-pages"/> for more information.
        </para>
       </listitem>
      </varlistentry>
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 1a298f16c81..f9c98997492 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -339,22 +339,29 @@ static const struct config_enum_entry huge_pages_options[] = {
 	{"on", HUGE_PAGES_ON, false},
 	{"try", HUGE_PAGES_TRY, false},
 	{"true", HUGE_PAGES_ON, true},
 	{"false", HUGE_PAGES_OFF, true},
 	{"yes", HUGE_PAGES_ON, true},
 	{"no", HUGE_PAGES_OFF, true},
 	{"1", HUGE_PAGES_ON, true},
 	{"0", HUGE_PAGES_OFF, true},
 	{NULL, 0, false}
 };
 
+static const struct config_enum_entry huge_pages_active_options[] = {
+	{"unknown", HUGE_PAGES_ACTIVE_UNKNOWN, false},
+	{"false", HUGE_PAGES_ACTIVE_FALSE, false},
+	{"true", HUGE_PAGES_ACTIVE_TRUE, false},
+	{NULL, 0, false}
+};
+
 static const struct config_enum_entry recovery_prefetch_options[] = {
 	{"off", RECOVERY_PREFETCH_OFF, false},
 	{"on", RECOVERY_PREFETCH_ON, false},
 	{"try", RECOVERY_PREFETCH_TRY, false},
 	{"true", RECOVERY_PREFETCH_ON, true},
 	{"false", RECOVERY_PREFETCH_OFF, true},
 	{"yes", RECOVERY_PREFETCH_ON, true},
 	{"no", RECOVERY_PREFETCH_OFF, true},
 	{"1", RECOVERY_PREFETCH_ON, true},
 	{"0", RECOVERY_PREFETCH_OFF, true},
 	{NULL, 0, false}
@@ -527,22 +534,24 @@ int			tcp_user_timeout;
  * renegotiation and therefore always try to zero it.
  */
 int			ssl_renegotiation_limit;
 
 /*
  * This really belongs in pg_shmem.c, but is defined here so that it doesn't
  * need to be duplicated in all the different implementations of pg_shmem.c.
  */
 int			huge_pages = HUGE_PAGES_TRY;
 int			huge_page_size;
 
+int			huge_pages_active = HUGE_PAGES_ACTIVE_UNKNOWN;
+
 /*
  * These variables are all dummies that don't do anything, except in some
  * cases provide the value for SHOW to display.  The real state is elsewhere
  * and is kept in sync by assign_hooks.
  */
 static char *syslog_ident_str;
 static double phony_random_seed;
 static char *client_encoding_string;
 static char *datestyle_string;
 static char *locale_collate;
 static char *locale_ctype;
@@ -554,23 +563,22 @@ static int	server_version_num;
 #define	DEFAULT_SYSLOG_FACILITY LOG_LOCAL0
 #else
 #define	DEFAULT_SYSLOG_FACILITY 0
 #endif
 static int	syslog_facility = DEFAULT_SYSLOG_FACILITY;
 
 static char *timezone_string;
 static char *log_timezone_string;
 static char *timezone_abbreviations_string;
 static char *data_directory;
 static char *session_authorization_string;
-static char *huge_pages_active = "unknown"; /* dynamically set */
 static int	max_function_args;
 static int	max_index_keys;
 static int	max_identifier_length;
 static int	block_size;
 static int	segment_size;
 static int	shared_memory_size_mb;
 static int	shared_memory_size_in_huge_pages;
 static int	wal_block_size;
 static bool data_checksums;
 static bool integer_datetimes;
 
@@ -4517,33 +4525,22 @@ struct config_string ConfigureNamesString[] =
 	{
 		{"backtrace_functions", PGC_SUSET, DEVELOPER_OPTIONS,
 			gettext_noop("Log backtrace for errors in these functions."),
 			NULL,
 			GUC_NOT_IN_SAMPLE
 		},
 		&backtrace_functions,
 		"",
 		check_backtrace_functions, assign_backtrace_functions, NULL
 	},
 
-	{
-		{"huge_pages_active", PGC_INTERNAL, PRESET_OPTIONS,
-			gettext_noop("Indicates whether huge pages are in use."),
-			NULL,
-			GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE | GUC_RUNTIME_COMPUTED
-		},
-		&huge_pages_active,
-		"unknown",
-		NULL, NULL, NULL
-	},
-
 	/* End-of-list marker */
 	{
 		{NULL, 0, 0, NULL, NULL}, NULL, NULL, NULL, NULL, NULL
 	}
 };
 
 
 struct config_enum ConfigureNamesEnum[] =
 {
 	{
 		{"backslash_quote", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
@@ -4845,22 +4842,33 @@ struct config_enum ConfigureNamesEnum[] =
 
 	{
 		{"huge_pages", PGC_POSTMASTER, RESOURCES_MEM,
 			gettext_noop("Use of huge pages on Linux or Windows."),
 			NULL
 		},
 		&huge_pages,
 		HUGE_PAGES_TRY, huge_pages_options,
 		NULL, NULL, NULL
 	},
 
+	{
+		{"huge_pages_active", PGC_INTERNAL, PRESET_OPTIONS,
+			gettext_noop("Indicates whether huge pages are in use."),
+			NULL,
+			GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE | GUC_RUNTIME_COMPUTED
+		},
+		&huge_pages_active,
+		HUGE_PAGES_ACTIVE_UNKNOWN, huge_pages_active_options,
+		NULL, NULL, NULL
+	},
+
 	{
 		{"recovery_prefetch", PGC_SIGHUP, WAL_RECOVERY,
 			gettext_noop("Prefetch referenced blocks during recovery."),
 			gettext_noop("Look ahead in the WAL to find references to uncached data.")
 		},
 		&recovery_prefetch,
 		RECOVERY_PREFETCH_TRY, recovery_prefetch_options,
 		check_recovery_prefetch, assign_recovery_prefetch, NULL
 	},
 
 	{
diff --git a/src/include/storage/pg_shmem.h b/src/include/storage/pg_shmem.h
index 4dd05f156d5..1699bf64238 100644
--- a/src/include/storage/pg_shmem.h
+++ b/src/include/storage/pg_shmem.h
@@ -46,22 +46,30 @@ extern PGDLLIMPORT int shared_memory_type;
 extern PGDLLIMPORT int huge_pages;
 extern PGDLLIMPORT int huge_page_size;
 
 /* Possible values for huge_pages */
 typedef enum
 {
 	HUGE_PAGES_OFF,
 	HUGE_PAGES_ON,
 	HUGE_PAGES_TRY
 }			HugePagesType;
 
+/* Possible values for huge_pages_active */
+typedef enum
+{
+	HUGE_PAGES_ACTIVE_UNKNOWN,
+	HUGE_PAGES_ACTIVE_FALSE,
+	HUGE_PAGES_ACTIVE_TRUE,
+}			HugePagesActiveType;
+
 /* Possible values for shared_memory_type */
 typedef enum
 {
 	SHMEM_TYPE_WINDOWS,
 	SHMEM_TYPE_SYSV,
 	SHMEM_TYPE_MMAP
 }			PGShmemType;
 
 #ifndef WIN32
 extern PGDLLIMPORT unsigned long UsedShmemSegID;
 #else
-- 
2.34.1

