Experimental Physics and
Industrial Control System

"Mark Rivers" <[email protected]> · Thu, 21 May 2009 19:32:43 -0500

Jeff,

It looks like you only added the prototype for ca_detach_context to cadef.h on 2009-02-09, in version 1.77.2.3.  But 3.14.10 is 1.77.2.2.

Here is from the CVS log:

corvette:base-3.14.10/src/ca>cvs log cadef.h
RCS file: /net/phoebus/epicsmgr/cvsroot/epics/base/src/ca/cadef.h,v
Working file: cadef.h
head: 1.81
branch:
locks: strict
access list:
symbolic names:
        R3-14-10: 1.77.2.2

...
----------------------------
revision 1.77.2.4
date: 2009-04-27 18:31:50 +0000;  author: anj;  state: Exp;  lines: +1 -120;  commitid: Q3pBeryDyMfoxGLt;
More ANSI C conversion
----------------------------
revision 1.77.2.3
date: 2009-02-09 15:23:06 +0000;  author: jhill;  state: Exp;  lines: +1 -0;  commitid: QMXGzjgPlK56YLBt;
addred proto for ca_detach_context
----------------------------
revision 1.77.2.2
date: 2004-10-19 20:21:31 +0000;  author: jhill;  state: Exp;  lines: +1 -1;
ca_get_host_name() used to return void, but has been changed to
return the string length.
----------------------------
...

Mark

________________________________

From: [email protected] on behalf of Liyu, Andrei V
Sent: Thu 5/21/2009 6:01 PM
To: Jeff Hill; [email protected]
Subject: RE: where is ca_detach_context()?

Jeff hi,

Compiler is not a issue because header file doesn't have ca_detach_context() function.

I again have loaded baseR3.14.10.tar.gz file (date is October 27, 2008) from Epics cite

In ...\src\ca\cadeh.h

>From line 115 (you mentioned about line 119)

==========

typedef struct event_handler_args {

    void            *usr;   /* user argument supplied with request */

    chanId          chid;   /* channel id */

    long            type;   /* the type of the item returned */ 

    long            count;  /* the element count of the item returned */

    READONLY void   *dbr;   /* a pointer to the item returned */

    int             status; /* ECA_XXX status of the requested op from the server */

} evargs;

======

>From line 874

========

/*

 * used when an auxillary thread needs to join a CA client context started

 * by another thread

 */

epicsShareFunc struct ca_client_context * epicsShareAPI ca_current_context ();

epicsShareFunc int epicsShareAPI ca_attach_context ( struct ca_client_context * context );

epicsShareFunc int epicsShareAPI ca_client_status ( unsigned level );

epicsShareFunc int epicsShareAPI ca_context_status ( struct ca_client_context *, unsigned level );

=======

I don't see line with epicsShareFunc void epicsShareAPI ca_detach_context ();

Maybe somebody load baseR3.14.10.tar.gz (date is October 27, 2008)  and check also.

Thanks, Andrei.

From: Jeff Hill [mailto:[email protected]] 
Sent: Thursday, May 21, 2009 2:32 PM
To: Liyu, Andrei V; [email protected]
Subject: RE: 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 3rd 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: [email protected] [mailto:[email protected]] On Behalf Of Liyu, Andrei V
Sent: Thursday, May 21, 2009 2:56 PM
To: [email protected]
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.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System