Date: Tue, 24 Jan 2023 10:42:17 -0800
From: Nathan Bossart <nathandbossart@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>,
	Amit Kapila <amit.kapila16@gmail.com>,
	Melih Mutlu <m.melihmutlu@gmail.com>,
	Thomas Munro <thomas.munro@gmail.com>,
	"Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>,
	"pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Subject: Re: wake up logical workers after ALTER SUBSCRIPTION
Message-ID: <20230124184217.GA724858@nathanxps13>
References: 
 <CAA4eK1L-N9aUpoCXhoBCiEJAGw3cmKxaxn0Fo43ja+qzAGeyhQ@mail.gmail.com>
 <20230106054017.GA786807@nathanxps13>
 <3355444.1673044286@sss.pgh.pa.us>
 <20230107004525.GB789289@nathanxps13>
 <CAA4eK1+2VbK8BCrG7xFKJQKhYhYwWwkddAN2gL2coUQnTKLJ3g@mail.gmail.com>
 <20230110174345.GA1292607@nathanxps13>
 <1353772.1674414774@sss.pgh.pa.us>
 <OS0PR01MB5716860B1454C34E5B179B6694C99@OS0PR01MB5716.jpnprd01.prod.outlook.com>
 <20230124171329.GA677220@nathanxps13>
 <2268133.1674584035@sss.pgh.pa.us>
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="lrZ03NoBR/3+SXJZ"
Content-Disposition: inline
In-Reply-To: <2268133.1674584035@sss.pgh.pa.us>
Archived-At: 
 <https://www.postgresql.org/message-id/20230124184217.GA724858%40nathanxps13>
Precedence: bulk


--lrZ03NoBR/3+SXJZ
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline

On Tue, Jan 24, 2023 at 01:13:55PM -0500, Tom Lane wrote:
> Either that comment needs to be rewritten or we need to invent some
> more macros.

Here is a first attempt at a patch.  I scanned through all the existing
uses of InvalidDsaPointer and DSM_HANDLE_INVALID and didn't notice anything
else that needed adjusting.

-- 
Nathan Bossart
Amazon Web Services: https://aws.amazon.com

--lrZ03NoBR/3+SXJZ
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment; filename="invalid_handle_values.patch"

diff --git a/src/backend/replication/logical/launcher.c b/src/backend/replication/logical/launcher.c
index 564bffe5ca..970d170e73 100644
--- a/src/backend/replication/logical/launcher.c
+++ b/src/backend/replication/logical/launcher.c
@@ -922,8 +922,8 @@ ApplyLauncherShmemInit(void)
 
 		memset(LogicalRepCtx, 0, ApplyLauncherShmemSize());
 
-		LogicalRepCtx->last_start_dsa = DSM_HANDLE_INVALID;
-		LogicalRepCtx->last_start_dsh = DSM_HANDLE_INVALID;
+		LogicalRepCtx->last_start_dsa = DSA_HANDLE_INVALID;
+		LogicalRepCtx->last_start_dsh = DSHASH_HANDLE_INVALID;
 
 		/* Initialize memory and spin locks for each worker slot. */
 		for (slot = 0; slot < max_logical_replication_workers; slot++)
@@ -947,7 +947,7 @@ logicalrep_launcher_attach_dshmem(void)
 	MemoryContext oldcontext;
 
 	/* Quick exit if we already did this. */
-	if (LogicalRepCtx->last_start_dsh != DSM_HANDLE_INVALID &&
+	if (LogicalRepCtx->last_start_dsh != DSHASH_HANDLE_INVALID &&
 		last_start_times != NULL)
 		return;
 
@@ -957,7 +957,7 @@ logicalrep_launcher_attach_dshmem(void)
 	/* Be sure any local memory allocated by DSA routines is persistent. */
 	oldcontext = MemoryContextSwitchTo(TopMemoryContext);
 
-	if (LogicalRepCtx->last_start_dsh == DSM_HANDLE_INVALID)
+	if (LogicalRepCtx->last_start_dsh == DSHASH_HANDLE_INVALID)
 	{
 		/* Initialize dynamic shared hash table for last-start times. */
 		last_start_times_dsa = dsa_create(LWTRANCHE_LAUNCHER_DSA);
diff --git a/src/include/lib/dshash.h b/src/include/lib/dshash.h
index 152927742e..c284c8489c 100644
--- a/src/include/lib/dshash.h
+++ b/src/include/lib/dshash.h
@@ -23,6 +23,9 @@ typedef struct dshash_table dshash_table;
 /* A handle for a dshash_table which can be shared with other processes. */
 typedef dsa_pointer dshash_table_handle;
 
+/* Special value for an unitinitialized dshash_table_handle */
+#define DSHASH_HANDLE_INVALID ((dshash_table_handle) InvalidDsaPointer)
+
 /* The type for hash values. */
 typedef uint32 dshash_hash;
 
diff --git a/src/include/utils/dsa.h b/src/include/utils/dsa.h
index 104386e674..ee59a76447 100644
--- a/src/include/utils/dsa.h
+++ b/src/include/utils/dsa.h
@@ -99,6 +99,9 @@ typedef pg_atomic_uint64 dsa_pointer_atomic;
  */
 typedef dsm_handle dsa_handle;
 
+/* Special value for an unitinitialized dsa_handle */
+#define DSA_HANDLE_INVALID ((dsa_handle) DSM_HANDLE_INVALID)
+
 extern dsa_area *dsa_create(int tranche_id);
 extern dsa_area *dsa_create_in_place(void *place, size_t size,
 									 int tranche_id, dsm_segment *segment);

--lrZ03NoBR/3+SXJZ--