From 7cd5c81437d53b3e3e4d7e4099f110281e121fc9 Mon Sep 17 00:00:00 2001 From: "benjamin.franksen" <benjamin.franksen@helmholtz-berlin.de> Date: Thu, 19 Sep 2013 14:38:48 +0000 Subject: [PATCH] docs: added the pvGet/PutComplete problem to the known problems page --- documentation/KnownProblems.txt | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/documentation/KnownProblems.txt b/documentation/KnownProblems.txt index 6f3efa01..72678696 100644 --- a/documentation/KnownProblems.txt +++ b/documentation/KnownProblems.txt @@ -12,6 +12,20 @@ see the `latest snapshot`_ or pull from the darcs repository. .. _latest snapshot: http://www-csr.bessy.de/control/SoftDist/sequencer/releases/seq-snapshot-latest.tar.gz +The pvGetComplete and pvPutComplete functions contain a serious bug +that was introduced in release 2.1.13. The effect is that sometimes +these functions return a wrong result: they can return TRUE when in +fact the callback from CA did not yet arrive, which is particularly +bad with pvGetComplete, since it can mean that if the pvGetComplete is +used in a when clause then in the code block that follows the result +is not yet available. + +Also note that non-safe mode, this can lead to a race condition +between update from the CA callback and access from the program, +possibly corrupting the variable's content. This has always been true +for monitored variables, but not when using asynchronous pvGet. + + .. _Known_Problems_2.1.12: Known Problems in Release 2.1.12 -- GitLab