RE: where is ca_detach_context()?

["Jeff Hill" <johill@lanl.gov>]

Title: where is ca_detach_context()?

 

Hi Andrei,

 

You should see the function prototype, as follows, at about line number 189 in cadef.h.

 

“epicsShareFunc void epicsShareAPI ca_detach_context ();”

 

I see it also at ordinal 119 with symbol name “_ca_detach_context@0” when I run the ms depends.exe tool, and load ca.dll.

 

I am looking at the very latest version of R3.14, but I don’t expect that any of this has changed in the patch releases.

 

> I can’t use ca_detach_context () in my program because

> compiler doesn’t find this function.

 

Are you using the MS compiler? Perhaps you need to specify /MD to enable linking with multithreaded DLL runtime libraries.

Typical Windows MS Build Options

cl -c /nologo /D__STDC__=0 /Ox /GL /W3 /w44355 /MD -I. -I.. -I..\\..\\..\\include\\os\\WIN32 -I..\\..\\..\\include ..\\acctst.c

link -nologo /LTCG /incremental:no /opt:ref /release /version:3.14 -out:acctst.exe acctstMain.obj acctst.obj d:/user/R3.14.clean/epics/base/lib/WIN32-x86/ca.lib d:/user/R3.14.clean/epics/base/lib/WIN32-x86

In summary, the following code runs in the preprocess in shareLib.h when it’s a windows compilation. As I recall, _DLL is defined by windows compilers when /MD (or the equivalent with a 3^rd party compiler) is specified.

#       if defined(_DLL) /* this indicates that we are being compiled to call DLLs */

#           define epicsShareExtern __declspec(dllimport) extern

#           define epicsShareClass  __declspec(dllimport)

#           define epicsShareFunc  __declspec(dllimport)

#       else

#           define epicsShareExtern extern

#           define epicsShareClass

#           define epicsShareFunc

#       endif

Jeff

 

From: tech-talk-bounces@aps.anl.gov [mailto:tech-talk-bounces@aps.anl.gov] On Behalf Of Liyu, Andrei V
Sent: Thursday, May 21, 2009 2:56 PM
To: tech-talk@aps.anl.gov
Subject: where is ca_detach_context()?

 

Hi,

I need to write simple CA client with couple threads. Both threads use CA. So I need to use ca_attach_context() and ca_detach_context() in second thread.

…

I can’t use ca_detach_context () in my program because compiler doesn’t find this function.

I checked manually and couldn’t find “ca_detach_context” in cadef.h and ca.dll files.

I do found “ca_detach_context” in access.cpp and CAref.html have it.

What is wrong?

I try to use Epics versions 3.14.9 and 3.14.10.

Thanks, Andrei.