Rename global variable backing DSA area

danielgustafsson · danielgustafsson · commit 55ef7abf88c0 · 2025-04-10T22:40:27.000+02:00
The global variable backing the DSA area for Memory Context stats reporting had a too generic name, rename to be more descriptive. Independently reported by Peter and Laurenz. Author: Daniel Gustafsson <daniel@yesql.se> Reported-by: Peter Eisentraut <peter@eisentraut.org> Reported-by: Laurenz Albe <laurenz.albe@cybertec.at> Discussion: https://postgr.es/m/d51172bd4e7f4b07a18a0288ca1b1c28a71a5f6a.camel@cybertec.at Discussion: https://postgr.es/m/25095db5-b595-4b85-9100-d358907c25b5@eisentraut.org
diff --git a/src/backend/utils/adt/mcxtfuncs.c b/src/backend/utils/adt/mcxtfuncs.c
@@ -533,21 +533,21 @@ pg_get_process_memory_contexts(PG_FUNCTION_ARGS)
 	 */
 	Assert(memCxtArea->memstats_dsa_handle != DSA_HANDLE_INVALID);
 	/* Attach to the dsa area if we have not already done so */
-	if (area == NULL)
+	if (MemoryStatsDsaArea == NULL)
 	{
 		MemoryContext oldcontext = CurrentMemoryContext;
 
 		MemoryContextSwitchTo(TopMemoryContext);
-		area = dsa_attach(memCxtArea->memstats_dsa_handle);
+		MemoryStatsDsaArea = dsa_attach(memCxtArea->memstats_dsa_handle);
 		MemoryContextSwitchTo(oldcontext);
-		dsa_pin_mapping(area);
+		dsa_pin_mapping(MemoryStatsDsaArea);
 	}
 
 	/*
 	 * Backend has finished publishing the stats, project them.
 	 */
 	memcxt_info = (MemoryStatsEntry *)
-		dsa_get_address(area, memCxtState[procNumber].memstats_dsa_pointer);
+		dsa_get_address(MemoryStatsDsaArea, memCxtState[procNumber].memstats_dsa_pointer);
 
 #define PG_GET_PROCESS_MEMORY_CONTEXTS_COLS	12
 	for (int i = 0; i < memCxtState[procNumber].total_stats; i++)
@@ -566,15 +566,15 @@ pg_get_process_memory_contexts(PG_FUNCTION_ARGS)
 
 		if (DsaPointerIsValid(memcxt_info[i].name))
 		{
-			name = (char *) dsa_get_address(area, memcxt_info[i].name);
+			name = (char *) dsa_get_address(MemoryStatsDsaArea, memcxt_info[i].name);
 			values[0] = CStringGetTextDatum(name);
 		}
 		else
 			nulls[0] = true;
 
 		if (DsaPointerIsValid(memcxt_info[i].ident))
 		{
-			ident = (char *) dsa_get_address(area, memcxt_info[i].ident);
+			ident = (char *) dsa_get_address(MemoryStatsDsaArea, memcxt_info[i].ident);
 			values[1] = CStringGetTextDatum(ident);
 		}
 		else
@@ -586,7 +586,7 @@ pg_get_process_memory_contexts(PG_FUNCTION_ARGS)
 		path_datum = (Datum *) palloc(path_length * sizeof(Datum));
 		if (DsaPointerIsValid(memcxt_info[i].path))
 		{
-			path_int = (int *) dsa_get_address(area, memcxt_info[i].path);
+			path_int = (int *) dsa_get_address(MemoryStatsDsaArea, memcxt_info[i].path);
 			for (int j = 0; j < path_length; j++)
 				path_datum[j] = Int32GetDatum(path_int[j]);
 			path_array = construct_array_builtin(path_datum, path_length, INT4OID);
diff --git a/src/backend/utils/mmgr/mcxt.c b/src/backend/utils/mmgr/mcxt.c
@@ -172,7 +172,7 @@ MemoryContext CurTransactionContext = NULL;
 
 /* This is a transient link to the active portal's memory context: */
 MemoryContext PortalContext = NULL;
-dsa_area   *area = NULL;
+dsa_area   *MemoryStatsDsaArea = NULL;
 
 static void MemoryContextDeleteOnly(MemoryContext context);
 static void MemoryContextCallResetCallbacks(MemoryContext context);
@@ -1499,19 +1499,19 @@ ProcessGetMemoryContextInterrupt(void)
 
 		MemoryContextSwitchTo(TopMemoryContext);
 
-		area = dsa_create(memCxtArea->lw_lock.tranche);
+		MemoryStatsDsaArea = dsa_create(memCxtArea->lw_lock.tranche);
 
-		handle = dsa_get_handle(area);
+		handle = dsa_get_handle(MemoryStatsDsaArea);
 		MemoryContextSwitchTo(oldcontext);
 
-		dsa_pin_mapping(area);
+		dsa_pin_mapping(MemoryStatsDsaArea);
 
 		/*
 		 * Pin the DSA area, this is to make sure the area remains attachable
 		 * even if current backend exits. This is done so that the statistics
 		 * are published even if the process exits while a client is waiting.
 		 */
-		dsa_pin(area);
+		dsa_pin(MemoryStatsDsaArea);
 
 		/* Set the handle in shared memory */
 		memCxtArea->memstats_dsa_handle = handle;
@@ -1521,14 +1521,14 @@ ProcessGetMemoryContextInterrupt(void)
 	 * If DSA exists, created by another process publishing statistics, attach
 	 * to it.
 	 */
-	else if (area == NULL)
+	else if (MemoryStatsDsaArea == NULL)
 	{
 		MemoryContext oldcontext = CurrentMemoryContext;
 
 		MemoryContextSwitchTo(TopMemoryContext);
-		area = dsa_attach(memCxtArea->memstats_dsa_handle);
+		MemoryStatsDsaArea = dsa_attach(memCxtArea->memstats_dsa_handle);
 		MemoryContextSwitchTo(oldcontext);
-		dsa_pin_mapping(area);
+		dsa_pin_mapping(MemoryStatsDsaArea);
 	}
 	LWLockRelease(&memCxtArea->lw_lock);
 
@@ -1545,7 +1545,7 @@ ProcessGetMemoryContextInterrupt(void)
 		 * Free any previous allocations, free the name, ident and path
 		 * pointers before freeing the pointer that contains them.
 		 */
-		free_memorycontextstate_dsa(area, memCxtState[idx].total_stats,
+		free_memorycontextstate_dsa(MemoryStatsDsaArea, memCxtState[idx].total_stats,
 									memCxtState[idx].memstats_dsa_pointer);
 	}
 
@@ -1556,10 +1556,10 @@ ProcessGetMemoryContextInterrupt(void)
 	 */
 	memCxtState[idx].total_stats = stats_num;
 	memCxtState[idx].memstats_dsa_pointer =
-		dsa_allocate0(area, stats_num * sizeof(MemoryStatsEntry));
+		dsa_allocate0(MemoryStatsDsaArea, stats_num * sizeof(MemoryStatsEntry));
 
 	meminfo = (MemoryStatsEntry *)
-		dsa_get_address(area, memCxtState[idx].memstats_dsa_pointer);
+		dsa_get_address(MemoryStatsDsaArea, memCxtState[idx].memstats_dsa_pointer);
 
 	if (summary)
 	{
@@ -1572,7 +1572,7 @@ ProcessGetMemoryContextInterrupt(void)
 											 &stat, true);
 		path = lcons_int(1, path);
 		PublishMemoryContext(meminfo, cxt_id, TopMemoryContext, path, stat,
-							 1, area, 100);
+							 1, MemoryStatsDsaArea, 100);
 		cxt_id = cxt_id + 1;
 
 		/*
@@ -1602,7 +1602,7 @@ ProcessGetMemoryContextInterrupt(void)
 			 */
 			memCxtState[idx].total_stats = cxt_id++;
 			PublishMemoryContext(meminfo, cxt_id, c, path,
-								 grand_totals, num_contexts, area, 100);
+								 grand_totals, num_contexts, MemoryStatsDsaArea, 100);
 		}
 		memCxtState[idx].total_stats = cxt_id;
 
@@ -1632,7 +1632,7 @@ ProcessGetMemoryContextInterrupt(void)
 		if (context_id < (max_stats - 1) || stats_count <= max_stats)
 		{
 			/* Copy statistics to DSA memory */
-			PublishMemoryContext(meminfo, context_id, cur, path, stat, 1, area, 100);
+			PublishMemoryContext(meminfo, context_id, cur, path, stat, 1, MemoryStatsDsaArea, 100);
 		}
 		else
 		{
@@ -1657,8 +1657,8 @@ ProcessGetMemoryContextInterrupt(void)
 			int			namelen = strlen("Remaining Totals");
 
 			num_individual_stats = context_id + 1;
-			meminfo[max_stats - 1].name = dsa_allocate(area, namelen + 1);
-			nameptr = dsa_get_address(area, meminfo[max_stats - 1].name);
+			meminfo[max_stats - 1].name = dsa_allocate(MemoryStatsDsaArea, namelen + 1);
+			nameptr = dsa_get_address(MemoryStatsDsaArea, meminfo[max_stats - 1].name);
 			strncpy(nameptr, "Remaining Totals", namelen);
 			meminfo[max_stats - 1].ident = InvalidDsaPointer;
 			meminfo[max_stats - 1].path = InvalidDsaPointer;
@@ -1921,18 +1921,18 @@ AtProcExit_memstats_cleanup(int code, Datum arg)
 	}
 
 	/* If the dsa mapping could not be found, attach to the area */
-	if (area == NULL)
-		area = dsa_attach(memCxtArea->memstats_dsa_handle);
+	if (MemoryStatsDsaArea == NULL)
+		MemoryStatsDsaArea = dsa_attach(memCxtArea->memstats_dsa_handle);
 
 	/*
 	 * Free the memory context statistics, free the name, ident and path
 	 * pointers before freeing the pointer that contains these pointers and
 	 * integer statistics.
 	 */
-	free_memorycontextstate_dsa(area, memCxtState[idx].total_stats,
+	free_memorycontextstate_dsa(MemoryStatsDsaArea, memCxtState[idx].total_stats,
 								memCxtState[idx].memstats_dsa_pointer);
 
-	dsa_detach(area);
+	dsa_detach(MemoryStatsDsaArea);
 	LWLockRelease(&memCxtState[idx].lw_lock);
 }
 
diff --git a/src/include/utils/memutils.h b/src/include/utils/memutils.h
@@ -394,11 +394,11 @@ typedef struct MemoryStatsContextId
 
 extern PGDLLIMPORT MemoryStatsBackendState *memCxtState;
 extern PGDLLIMPORT MemoryStatsCtl *memCxtArea;
+extern PGDLLIMPORT dsa_area *MemoryStatsDsaArea;
 extern void ProcessGetMemoryContextInterrupt(void);
 extern const char *ContextTypeToString(NodeTag type);
 extern void HandleGetMemoryContextInterrupt(void);
 extern Size MemoryContextReportingShmemSize(void);
 extern void MemoryContextReportingShmemInit(void);
 extern void AtProcExit_memstats_cleanup(int code, Datum arg);
-extern dsa_area *area;
 #endif							/* MEMUTILS_H */
