Hi all,
When working on a decoder plugin, I have been pointed that it is
incorrect to write changes in an output plugin while not being in the
memory context where changes are written.
In pg_decode_change@test_decoding.c, we do the following:
old = MemoryContextSwitchTo(data->context);
OutputPluginPrepareWrite(ctx, true);
[...]
MemoryContextSwitchTo(old);
MemoryContextReset(data->context);
OutputPluginWrite(ctx, true);
Wouldn't it be better to call OutputPluginWrite before switching back
to the old context? The attached patch for test_decoding does so.
Comments welcome.
Regards,
--
Michael
From 9bd2e09433573fbfd85105fca2c6862dba383eab Mon Sep 17 00:00:00 2001
From: Michael Paquier <mich...@otacoo.com>
Date: Thu, 15 May 2014 09:01:28 +0900
Subject: [PATCH] Write changes of test_decoding while being in the data
context
OutputPluginWrite was being called after switching to the old memory
context. This seems incorrect as the changes are written in a specific
memory context.
---
contrib/test_decoding/test_decoding.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/contrib/test_decoding/test_decoding.c
b/contrib/test_decoding/test_decoding.c
index 5ce052b..903b15b 100644
--- a/contrib/test_decoding/test_decoding.c
+++ b/contrib/test_decoding/test_decoding.c
@@ -400,8 +400,10 @@ pg_decode_change(LogicalDecodingContext *ctx,
ReorderBufferTXN *txn,
Assert(false);
}
+ /* Write changes while in the context of the data */
+ OutputPluginWrite(ctx, true);
+
+ /* Switch back to old context */
MemoryContextSwitchTo(old);
MemoryContextReset(data->context);
-
- OutputPluginWrite(ctx, true);
}
--
1.9.3
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
