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[PATCH 1/5] bootstrap: convert Typ to a List*
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* [PATCH 1/5] bootstrap: convert Typ to a List*
@ 2020-11-20 02:48  Justin Pryzby <[email protected]>
  0 siblings, 0 replies; 2+ messages in thread

From: Justin Pryzby @ 2020-11-20 02:48 UTC (permalink / raw)

---
 src/backend/bootstrap/bootstrap.c | 69 ++++++++++++++-----------------
 1 file changed, 31 insertions(+), 38 deletions(-)

diff --git a/src/backend/bootstrap/bootstrap.c b/src/backend/bootstrap/bootstrap.c
index 6f615e6622..18eb62ca47 100644
--- a/src/backend/bootstrap/bootstrap.c
+++ b/src/backend/bootstrap/bootstrap.c
@@ -159,7 +159,7 @@ struct typmap
 	FormData_pg_type am_typ;
 };
 
-static struct typmap **Typ = NULL;
+static List *Typ = NIL; /* List of struct typmap* */
 static struct typmap *Ap = NULL;
 
 static Datum values[MAXATTR];	/* current row's attribute values */
@@ -597,7 +597,7 @@ boot_openrel(char *relname)
 	 * pg_type must be filled before any OPEN command is executed, hence we
 	 * can now populate the Typ array if we haven't yet.
 	 */
-	if (Typ == NULL)
+	if (Typ == NIL)
 		populate_typ_array();
 
 	if (boot_reldesc != NULL)
@@ -688,7 +688,7 @@ DefineAttr(char *name, char *type, int attnum, int nullness)
 
 	typeoid = gettype(type);
 
-	if (Typ != NULL)
+	if (Typ != NIL)
 	{
 		attrtypes[attnum]->atttypid = Ap->am_oid;
 		attrtypes[attnum]->attlen = Ap->am_typ.typlen;
@@ -877,36 +877,25 @@ populate_typ_array(void)
 	Relation	rel;
 	TableScanDesc scan;
 	HeapTuple	tup;
-	int			nalloc;
-	int			i;
-
-	Assert(Typ == NULL);
 
-	nalloc = 512;
-	Typ = (struct typmap **)
-		MemoryContextAlloc(TopMemoryContext, nalloc * sizeof(struct typmap *));
+	Assert(Typ == NIL);
 
 	rel = table_open(TypeRelationId, NoLock);
 	scan = table_beginscan_catalog(rel, 0, NULL);
-	i = 0;
 	while ((tup = heap_getnext(scan, ForwardScanDirection)) != NULL)
 	{
 		Form_pg_type typForm = (Form_pg_type) GETSTRUCT(tup);
+		struct typmap *newtyp;
+		MemoryContext old;
 
-		/* make sure there will be room for a trailing NULL pointer */
-		if (i >= nalloc - 1)
-		{
-			nalloc *= 2;
-			Typ = (struct typmap **)
-				repalloc(Typ, nalloc * sizeof(struct typmap *));
-		}
-		Typ[i] = (struct typmap *)
-			MemoryContextAlloc(TopMemoryContext, sizeof(struct typmap));
-		Typ[i]->am_oid = typForm->oid;
-		memcpy(&(Typ[i]->am_typ), typForm, sizeof(Typ[i]->am_typ));
-		i++;
+		old = MemoryContextSwitchTo(TopMemoryContext);
+		newtyp = (struct typmap *) palloc(sizeof(struct typmap));
+		Typ = lappend(Typ, newtyp);
+		MemoryContextSwitchTo(old);
+
+		newtyp->am_oid = typForm->oid;
+		memcpy(&newtyp->am_typ, typForm, sizeof(newtyp->am_typ));
 	}
-	Typ[i] = NULL;				/* Fill trailing NULL pointer */
 	table_endscan(scan);
 	table_close(rel, NoLock);
 }
@@ -925,16 +914,17 @@ populate_typ_array(void)
 static Oid
 gettype(char *type)
 {
-	if (Typ != NULL)
+	if (Typ != NIL)
 	{
-		struct typmap **app;
+		ListCell *lc;
 
-		for (app = Typ; *app != NULL; app++)
+		foreach (lc, Typ)
 		{
-			if (strncmp(NameStr((*app)->am_typ.typname), type, NAMEDATALEN) == 0)
+			struct typmap *app = lfirst(lc);
+			if (strncmp(NameStr(app->am_typ.typname), type, NAMEDATALEN) == 0)
 			{
-				Ap = *app;
-				return (*app)->am_oid;
+				Ap = app;
+				return app->am_oid;
 			}
 		}
 	}
@@ -980,14 +970,17 @@ boot_get_type_io_data(Oid typid,
 	if (Typ != NULL)
 	{
 		/* We have the boot-time contents of pg_type, so use it */
-		struct typmap **app;
-		struct typmap *ap;
-
-		app = Typ;
-		while (*app && (*app)->am_oid != typid)
-			++app;
-		ap = *app;
-		if (ap == NULL)
+		struct typmap *ap = NULL;
+		ListCell *lc;
+
+		foreach (lc, Typ)
+		{
+			ap = lfirst(lc);
+			if (ap->am_oid == typid)
+				break;
+		}
+
+		if (!ap || ap->am_oid != typid)
 			elog(ERROR, "type OID %u not found in Typ list", typid);
 
 		*typlen = ap->am_typ.typlen;
-- 
2.26.2


--------------614DDB87AFFED893713AC0E9
Content-Type: text/x-patch; charset=UTF-8;
 name="0002-Allow-composite-types-in-bootstrap-20210304.patch"
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
 filename="0002-Allow-composite-types-in-bootstrap-20210304.patch"



^ permalink  raw  reply  [nested|flat] 2+ messages in thread

* Re: Does a cancelled REINDEX CONCURRENTLY need to be messy?
@ 2023-06-29 11:04  Andreas Karlsson <[email protected]>
  0 siblings, 0 replies; 2+ messages in thread

From: Andreas Karlsson @ 2023-06-29 11:04 UTC (permalink / raw)
  To: Thom Brown <[email protected]>; PostgreSQL Hackers <[email protected]>

On 6/29/23 11:13, Thom Brown wrote:
> I get the feeling that this is deliberate, and perhaps an attempt to
> mitigate locking issues, or some other explanation, but the rationale
> isn't immediately apparent to me if this is the case.

I have always assumed the reason is that there might be other 
transactions using the index so if we are going to drop it on rollback 
we might get stuck forever waiting for an exclusive lock on the index. 
How do you get around that? Rollback being stuck waiting forever is 
certainly not a nice behavior.

Andreas







^ permalink  raw  reply  [nested|flat] 2+ messages in thread


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2020-11-20 02:48 [PATCH 1/5] bootstrap: convert Typ to a List* Justin Pryzby <[email protected]>
2023-06-29 11:04 Re: Does a cancelled REINDEX CONCURRENTLY need to be messy? Andreas Karlsson <[email protected]>

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