1 files changed, 29 insertions, 21 deletions

diff --git a/src/backend/storage/ipc/ipci.c b/src/backend/storage/ipc/ipci.c
index 716963f4481..bf232eb8dc6 100644
--- a/src/backend/storage/ipc/ipci.c
+++ b/src/backend/storage/ipc/ipci.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/ipc/ipci.c,v 1.88 2006/10/04 00:29:57 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/ipc/ipci.c,v 1.89 2006/10/15 22:04:07 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -32,6 +32,30 @@
 #include "storage/spin.h"
 
 
+static Size total_addin_request = 0;
+static bool addin_request_allowed = true;
+
+
+/*
+ * RequestAddinShmemSpace
+ *		Request that extra shmem space be allocated for use by
+ *		a loadable module.
+ *
+ * This is only useful if called from the _PG_init hook of a library that
+ * is loaded into the postmaster via shared_preload_libraries.  Once
+ * shared memory has been allocated, calls will be ignored.  (We could
+ * raise an error, but it seems better to make it a no-op, so that
+ * libraries containing such calls can be reloaded if needed.)
+ */
+void
+RequestAddinShmemSpace(Size size)
+{
+	if (IsUnderPostmaster || !addin_request_allowed)
+		return;					/* too late */
+	total_addin_request = add_size(total_addin_request, size);
+}
+
+
 /*
  * CreateSharedMemoryAndSemaphores
  *		Creates and initializes shared memory and semaphores.
@@ -57,7 +81,6 @@ CreateSharedMemoryAndSemaphores(bool makePrivate, int port)
 	{
 		PGShmemHeader *seghdr;
 		Size		size;
-		Size		size_b4addins;
 		int			numSemas;
 
 		/*
@@ -91,16 +114,11 @@ CreateSharedMemoryAndSemaphores(bool makePrivate, int port)
 		size = add_size(size, ShmemBackendArraySize());
 #endif
 
-		/* might as well round it off to a multiple of a typical page size */
-		size = add_size(size, 8192 - (size % 8192));
+		/* freeze the addin request size and include it */
+		addin_request_allowed = false;
+		size = add_size(size, total_addin_request);
 
-		/*
-		 * The shared memory for add-ins is treated as a separate segment, but
-		 * in reality it is not.
-		 */
-		size_b4addins = size;
-		size = add_size(size, AddinShmemSize());
-		/* round it off again */
+		/* might as well round it off to a multiple of a typical page size */
 		size = add_size(size, 8192 - (size % 8192));
 
 		elog(DEBUG3, "invoking IpcMemoryCreate(size=%lu)",
@@ -111,16 +129,6 @@ CreateSharedMemoryAndSemaphores(bool makePrivate, int port)
 		 */
 		seghdr = PGSharedMemoryCreate(size, makePrivate, port);
 
-		/*
-		 * Modify hdr to show segment size before add-ins
-		 */
-		seghdr->totalsize = size_b4addins;
-
-		/*
-		 * Set up segment header sections in each Addin context
-		 */
-		InitAddinContexts((void *) ((char *) seghdr + size_b4addins));
-
 		InitShmemAccess(seghdr);
 
 		/*