From 9294197a50b16053776c39471120c9660c115460 Mon Sep 17 00:00:00 2001
From: Thomas Munro <thomas.munro@enterprisedb.com>
Date: Tue, 25 Sep 2018 15:51:13 +1200
Subject: [PATCH 2/2] Remove dsm_resize() and dsm_remap().

An earlier commit disabled them in a way that is friendly to client
code (if there is any), for back-branches.  This commit removes them
completely from future releases.

Author: Thomas Munro
Reviewed-by:
Discussion: https://postgr.es/m/CAA4eK1%2B%3DyAFUvpFoHXFi_gm8YqmXN-TtkFH%2BVYjvDLS6-SFq-Q%40mail.gmail.com
---
 src/backend/storage/ipc/dsm.c      | 20 --------------------
 src/backend/storage/ipc/dsm_impl.c | 13 -------------
 src/include/storage/dsm.h          |  4 +---
 src/include/storage/dsm_impl.h     |  3 ---
 4 files changed, 1 insertion(+), 39 deletions(-)

diff --git a/src/backend/storage/ipc/dsm.c b/src/backend/storage/ipc/dsm.c
index af1162c6e8..a81e4db435 100644
--- a/src/backend/storage/ipc/dsm.c
+++ b/src/backend/storage/ipc/dsm.c
@@ -653,26 +653,6 @@ dsm_detach_all(void)
 					&dsm_control_mapped_size, ERROR);
 }
 
-/*
- * Resize an existing shared memory segment.
- */
-void *
-dsm_resize(dsm_segment *seg, Size size)
-{
-	elog(ERROR, "dsm_resize not supported");
-	return NULL;
-}
-
-/*
- * Remap an existing shared memory segment.
- */
-void *
-dsm_remap(dsm_segment *seg)
-{
-	elog(ERROR, "dsm_remap not supported");
-	return NULL;
-}
-
 /*
  * Detach from a shared memory segment, destroying the segment if we
  * remove the last reference.
diff --git a/src/backend/storage/ipc/dsm_impl.c b/src/backend/storage/ipc/dsm_impl.c
index fe581afffb..78154010aa 100644
--- a/src/backend/storage/ipc/dsm_impl.c
+++ b/src/backend/storage/ipc/dsm_impl.c
@@ -192,19 +192,6 @@ dsm_impl_op(dsm_op op, dsm_handle handle, Size request_size,
 	}
 }
 
-/*
- * Previously we supported resizing DSM segments on some platforms.  Since
- * the work was never extended to all platforms so that it couldn't be relied
- * on in general, and potential bugs were discovered on one one platform
- * where we did support it, we decided to remove this.  The interface will
- * disappear completely in a later release.
- */
-bool
-dsm_impl_can_resize(void)
-{
-	return false;
-}
-
 #ifdef USE_DSM_POSIX
 /*
  * Operating system primitives to support POSIX shared memory.
diff --git a/src/include/storage/dsm.h b/src/include/storage/dsm.h
index 169de946f7..b4654cb5ca 100644
--- a/src/include/storage/dsm.h
+++ b/src/include/storage/dsm.h
@@ -33,11 +33,9 @@ extern void dsm_detach_all(void);
 extern void dsm_set_control_handle(dsm_handle h);
 #endif
 
-/* Functions that create, update, or remove mappings. */
+/* Functions that create or remove mappings. */
 extern dsm_segment *dsm_create(Size size, int flags);
 extern dsm_segment *dsm_attach(dsm_handle h);
-extern void *dsm_resize(dsm_segment *seg, Size size);
-extern void *dsm_remap(dsm_segment *seg);
 extern void dsm_detach(dsm_segment *seg);
 
 /* Resource management functions. */
diff --git a/src/include/storage/dsm_impl.h b/src/include/storage/dsm_impl.h
index c8adc425fd..9485446c91 100644
--- a/src/include/storage/dsm_impl.h
+++ b/src/include/storage/dsm_impl.h
@@ -67,9 +67,6 @@ extern bool dsm_impl_op(dsm_op op, dsm_handle handle, Size request_size,
 			void **impl_private, void **mapped_address, Size *mapped_size,
 			int elevel);
 
-/* Some implementations cannot resize segments.  Can this one? */
-extern bool dsm_impl_can_resize(void);
-
 /* Implementation-dependent actions required to keep segment until shutdown. */
 extern void dsm_impl_pin_segment(dsm_handle handle, void *impl_private,
 					 void **impl_private_pm_handle);
-- 
2.17.0