Hi Paul,

sorry my late reply, I had to find some time for debugging your problem. 
Thank you very much for the detailed description of the problem, I wish all 
bug reports would be such elaborate!

You were right that there was a bug in the RPC system. The function 
db_remove_open_record() got a new parameter recently, which was not changed 
in the RPC call, and caused the mserver side to crash on any 
db_close_record() call.

I fixed it and the update is under CVS (http://midas.psi.ch/cgi-
bin/cvsweb/midas/src/). Since you need to update many files, I wonder if I 
should enable anonymous CVS read access. Does anybody know how to set this 
up using "ssh" as the protocol (via CVS_RSH=ssh)?

Please note that db_close_record() is not necessary as 
cm_disconnect_experiment() takes care of this, but having it there does not 
hurt.

I committed several small fixes and changes:

- install.txt which mentions explicitly ROOT
- mana.c and the main Makefile which fixes all HBOOK compiler warnings
- mana.c to write an explicit warning if the experiment directoy contains 
uppercase letters in the path (HBOOK does not like this and refuses to 
read/write histos)
- mserver.c, mrpc.c, odb.c to fix a wrong parameter in 
db_remove_open_record() (see previous entry from Paul)
- added experim.h into the dependency of the hbookexpt Makefile

Dear all,

there are continuing requests about the C indent style we use in midas. As 
you know, the current style does not comply with any standard. It is even 
a mixture of styles since code comes from different people. To fix this 
once and forever, I am considering using the "indent" program which comes 
with every linux installation. Running indent regularly on all our code 
ensures a consistent look. So I propose (actually the idea came from Paul 
Knowles) to put a new section in the midas makefile:

indent:
        find . -name "*.[hc]" -exec indent <flags> {} \;

so one can easily do a "make indent". The question is now how the <flags> 
should look like. The standard is GNU style, but this deviates from the 
original K&R style such that the opening "{" is put on a new line, which I 
use but most of you do not. The "-kr" style does the standard K&R style, 
but used tabs (which is not good), and does a 4-column indention which is 
I think too much. So I would propose following flags:

indent -kr -nut -i2 -di8 -bad <filename.c>

Please take some of your source code, and format it this way, and let me 
know if these flags are a good combination or if you would like to have 
anything changed. It should also be checked (->PAA) that this style 
complies with the DOC++ system. Once we all agree, I can put it into the 
makefile, execute it and commit the newly formatted code for the whole 
source tree.

The current Triumf DAQ standard (Midas) since the second quarter of this
year (2003) has the capability to deal with ROOT histograms. The internal
midas logger can save data files in ROOT format and the analyzer can book
and fill ROOT histograms. These features triggered a new project started
during summer 2003 for building a Triumf GUI ROOT/Midas display utility.

The initial requirements for this utility are:
1) Solely based on ROOT (VirtualX, no Qt)
2) Similar overall functionality than PAW.
   - Open concurrent ROOT files.
   - Open connection to a single Midas Online experiment (requires analyzer
                                                          as server)
   - Optional Auto-update in ONLINE mode.
   - Zoning, Zooming option display.
   - Simple Historgram gaphic manipulation. (based on current ROOT
                                             implementation)
   - Tree manipulation ( use of TBrowser())
   - Simple user script invocation.
   - Optional experiment specific customization.
3) Session configuration save/restore option.

An initial version has been developed and currently is under evaluation.
Improvement and further development will based on the local experimenters
responses. 

This utility will be available for external use around the second quarter of
the 2004 at the latest.

.

> I want midas alarms to go off when I cannot ping arbitrary remote hosts. Is
> there is easy/preferred way to do this? K.O.

There are "internal alarms" with type AT_EVALUATED. Just find a program 
where you can put some code which gets periodically executed (like the idle 
loop in the frontend), and so something like:

DWORD last = 0;

  if (ss_time() > last+60)
    {
    last = ss_time();

    /* do a ping via socket(), bind() and connect() */
    ...

    if (status != CM_SUCCESS)
      al_trigger_alarm("XYZ Ping", str, "Warning", 
                       "Host is dead", AT_INTERNAL);
    }

Pierre does the same thing in lazylogger.c, just have a look. I don't know 
how to do a ping correctly in C, I guess you have to send an UDP packet 
somewhere, but I never did it. If you find it out, please post it.


 

Hi Stefan,

> once and forever, I am considering using the "indent" program which comes 
> with every linux installation. Running indent regularly on all our code 
> ensures a consistent look.

I think this can be called a Good Thing.

> The "-kr" style does the standard K&R style, 
> but used tabs (which is not good), and does a 4-column 
> indention which is I think too much. So I would propose 
> following flags:
>        indent -kr -nut -i2 -di8 -bad <filename.c>

(some of this is a repeat from an earlier mail to SR):
You might also want a -l90 for a longer line length than 75
characters.  K&R style with indentation from 5 to 8 spaces
is a good indicator of complexity: as soon as 40 characters
of code wind up unreadably squashed to the right of the
screen, you have to refactor to have less indentation
levels.  This means you wind up rolling up the inner parts
of deeply nested conditionals or loops as separate
functions, making the whole code easier to understand.

I think that setting -i2 is ``going around the problem'' 
of deep nesting.  If you really need to keep the indentation 
tabs less than 4 (8 is ideal) because your code is falling off the 
right edge of the screen, you are indented too deeply.  Why do 
I say that?  There is the famous ``7+-1'' idea that you can hold
in you head only 7 ideas (give or take one) at any time.  I'm not 
that smart and I top out at about 5:  So for example, a conditional 
in a loop  in a conditional in a switch is about as deep a level 
of nesting as  I can easily understand (remember that I also have 
to hold the line i'm working on as well): that's 4 levels, plus one for the
function itself and we are at 40 characters away from the right edge
of the screen using -i8 and have some 40 characters available for writing code
(how often is a line of code really longer than about 40 characters?).
On top of that, the indentation is easily seen so you know immediately 
wheather you are at the upper conditional, or inner conditional.  A -i2
just doesn't make the difference big enough.  -i5 is a happy balance 
with enough visual clue as to the indentation level, but leaves you 50
to 60 characters for the code line itself.

However, if you are indenting very deeply, then the poor reader can't hold
on to the context: there are more than 6 or 7 things to keep in mind.
In those cases, roll up the inner levels as a separate function and 
call it that way. The inner complexity of the nested statements gets 
nicely abstracted and then dumb people like me can understand what 
you are doing.

So, in brief: indent is a good idea, and -in with n>=4 will be best.
I don't think -i2 will lend itself to making the code so much easier 
to read.

thanks for listening.
.p.

Hi Paul,

I agree with you that a nesting level of more than 4-5 is a bad thing, but I 
believe that throughout the midas code, this level is not exceeded (my poor 
mind also does not hold more than 5 things (;-) ). An indent level of 8 columns 
alone does hot force you too much in not extending the nesting level. I have 
seen code which does that, so there are nesting levels of 8 and more, which 
ends up that the code is smashed to the right side of the screen, where each 
statement is broken into many line since each line only holds 10 or 20 
characters. All the nice real estate on the left side of the scree is lost.

So having said that, I don't feel a strong need of giving up a "-i2", since the 
midas code does not contain deep nesting levels and hopefully will never have. 
In my opinion, a small indent level makes more use of your screen space, since 
you do not have a large white area at the left. A typical nesting level is 3-4, 
which causes already 32 blank charactes at the left, or 1/3 of your screen, 
just for nothing. It will lead to more lines (even with -l90), so people have 
to scroll more.

What do others think (Pierre, Konstantin, Renee) ?

> I don't feel a strong need of giving up a "-i2"...

I am comfortable with the current MIDAS styling convention and I would rather not
have yet another private religious war over the right location for the curley braces.

If we are to consider changing the MIDAS coding convention, I urge all and sundry
to read the ROOT coding convention, as written by Rene Brun and Fons Rademakers at
http://root.cern.ch/root/Conventions.html. The ROOT people did their homework, they
did read the literature and they produced a well considered and well argumented style.

Also, while there, do read the Taligent documentation- by far, one of the most
coherent manuals to C++ programming style.

K.O.

Ok, taking all comments so far into account, I conclude adopting the ROOT 
coding style would be best for us. So I put

indent:
	find . -name "*.[hc]" -exec indent -kr -nut -i3 {} \;

Into the makefile. Hope everybody is happy now (;-)))

While watching "The Wizard of Oz", the greatest movie ever made, I took a shot at building 
midas on my macosx computer. After stumbling on a few small and on a few hard problems, I 
built almost everything. However, odb does not work- some further debugging is in order.

Anyway, the easy problems are:
- a few missing header files: pty.h, sys/vfs.h, malloc.h
- a few missing features in system.c (stime(), "get tape position")
- /usr/include/string.h already has strlcpy() & co.
- dbg_malloc() has inconsistent prototypes (size_t vs unsigned int)
- for reasons unknown, PVM is #defined. This flushed a bug in mana.c

A few hard problems:
- namespace pollution by Apple- they #define ALIGN in system headers, colliding with ALIGN 
in midas.h. I was amazed that the two are almost identical, but MIDAS ALIGN aligns to 8 
bytes, while Apple does 4 bytes. ALIGN is used all over the place and I am not sure how to 
reconcile this.
- "timezone" in mhttpd.c. On linux, it's an "int", on darwin, it's a function. What gives?
- building libmidas.a requires running ranlib
- building libmidas.so requires unknown macosx specific magic.

For your enjoyment, the "cvs diff" is attached. The resulting code is known to not work.

K.O.

Great, I got already questions about MacOSX support...

Once it's working, you should commit the changes. But take into account that using "//" for 
comments might cause problems for the VxWorks compiler (talk to Pierre about that!).

> A few hard problems:
> - namespace pollution by Apple- they #define ALIGN in system headers, colliding with ALIGN 
> in midas.h. I was amazed that the two are almost identical, but MIDAS ALIGN aligns to 8 
> bytes, while Apple does 4 bytes. ALIGN is used all over the place and I am not sure how to 
> reconcile this.

You can rename ALIGN to ALIGN8 all over the place.

> - "timezone" in mhttpd.c. On linux, it's an "int", on darwin, it's a function. What gives?

Wrap it into a function get_timezone(). Under linux, just return "timezone", under OSX, 
return timezone() via conditional compiling.

> - building libmidas.a requires running ranlib
> - building libmidas.so requires unknown macosx specific magic.

I guess we should foget for now about the shared libraries (Mac people anyhow have too much 
money so they can affort additional RAM (;-) ), but building the static library is mandatory. 

I am just starting to explore MIDAS, i.e. reading the manual and trying 
some examples. For the moment I would like to make a simple frontend that 
access a portable multimeter through RS-232 port. I think this could help 
me understand how to access hardare inside MIDAS framework. Initially I've 
started from the MiniFE.c example and tried to initialize the serial port 
on run start transition and build a readout loop in the main function. I 
know that this is not a full frontend but I was just interested in getting 
some experience with the drivers available in the distribution, in this 
case RS-232. The portable multimeter is very simple in principle, one just 
has to configure the port settings and then send character 'R' and read 14 
ASCII characters from the device. Unfortunately I could not understand how 
to invoke the driver services so I changed and started again with the 
slowcont/frontend.c example. From this example and after reading the "Slow 
Control System" section in the MIDAS manual I think that all I need to do 
is to define my own equipment structure based on the multi.c class driver 
with a single input channel (and replace the null driver with the RS-232).

Here I got stuck. I see from the code source that there is a relationship 
between drivers at all levels (even bus) and the ODB but I don't yet fully 
understand how they work. Actually for a couple of days now I am in a loop 
going from class to device to bus and then back again to class drivers 
trying to see how to create my own device driver and especially how to call 
the bus driver. It could be that the framework is invoking the drivers and 
the user just has to configure things ... up to now I didn't dare to look 
at the mfe.c.

Is there a more detailed documentation about slow control and drivers then 
the MIDAS manual? What is the data flow through the three layers system for 
drivers? What is the role of the framework and what is left to the user 
choice?

Thanks

There is some information at

http://midas.triumf.ca/doc/html/Internal.html#Slow_Control_system

and at

http://midas/download/course/course_rt03.zip , file "part1.ppt", expecially 
page 59 and page 62 "writing your own device driver".

So what you are missing for your application is a "device driver" for your 
multimeter. The only function it has to implement is the function CMD_INIT 
where you initialize the RS232 port, and the funciton CMD_GET, which sends 
a "R" and reads the value. Now you have two options:

1) You implement RS232 calls directly in your device driver

You link against rs232.c and directly call rs232_init() at the inizialization, 
then call rs232_write() and rs232_read() where you read your 14 ASCII 
characters.

2) You call a "bus driver" in your device driver

This method makes the device driver independent of the underlying transport 
interface. So if your next multimeter accepts the same "R" command over 
Ethernet, you can just replace the RS232 bus driver by the TCPIP bus driver 
without having to change your device driver. But I guess that method 2) is not 
worth for such a simple device like your multimeter.

So take nulldev.c or dastemp.c as your starting point, put some RS232 
initialization into the init routine and the communication via "R" into 
the "get" routine. The slow control frontend, driven by mfe.c, should then 
regularly read your multimeter and the value should appear in the ODB. Take 
the examples/slowcont/frontend.c as an example, and adjust the multi_driver[] 
list to use your new device driver (instead of the nulldev).

I would like to mention that the usage of midas only makes sense for some 
experiemnts which require event based readout, using VME or CAMAC crates. If 
your only task is to read out some devices which are called "slow control 
equipment" in the midas language, then you might be better of with labview or 
something.

The multimeter device is indeed to simple to use MIDAS but I am just trying 
it as a learning experience. The DAQ system to develop involves VME crates 
and general purpose I/O boards. The slow control part, especially accessing 
the I/O boards seem to me more complex then the VME access. I want to 
understand very well the "correct" way of using the MIDAS slow control 
framework before starting the project.

I chose the second method and created a meterdev.c driver (essentially a 
copy of the nulldev.c) where I changed the init. function and the get 
function. I am not sending a "INIT ..." string because for this device it 
is useless. In the get function I send a "D" and read my string. I changed 
the frontend of the example to have a new driver list (in the first try I 
eliminated the Output device but the ODB got corrupted, I guess the class 
multi needs to have defined output channels). The output channel is linked 
with nulldev and null (I guess this is like if they would not be present).

The result is strange because the get function is called all the time very 
fast (much faster then the 9 seconds as set in the equipment) and even 
before starting the run (I just put the flag RO_RUNNING).

Thanks for any help

> Great, I got already questions about MacOSX support...
> Once it's working, you should commit the changes.

With the ALIGN8() change ODB works, mhttpd works. ALIGN8 change now commited to cvs, verified that "make all" builds 
on Linux.

ROOT stuff still blows up because of more namespace pollution (/usr/include/sys/something does #define Free(x) 
free(blah...)). Arguably, it is not Apple's fault- portable programs should not include any <sys/foo.h> header files. I 
think I can fix it by moving "#include <sys/mount.h>" from midasinc.h to system.h.

Also figured out why PVM is defined- more pollution from "#include <sys/blah...>". This is only in mana.c and I will 
repace every "#ifdef PVM" with "#ifdef HAVE_PVM". Is there documentation that should be updated as well? Alternatively I 
can try to play games with header files...


> But take into account that using "//" for comments might cause problems for the VxWorks compiler (talk to Pierre 
about that!).

Yes, "// comments" stay out of midas. I used them to make the modification more visible.

> You can rename ALIGN to ALIGN8 all over the place.

Done, commited.

> > - "timezone" in mhttpd.c. On linux, it's an "int", on darwin, it's a function. What gives?
> Wrap it into a function get_timezone(). Under linux, just return "timezone", under OSX, 
> return timezone() via conditional compiling.

Right. Still on the todo list.

> > - building libmidas.a requires running ranlib

I still have to cleanup the Makefile. Not commiting it yet.

Then, a new problem- on MacOSX, pthread_t is not an "INT" and system.c:ss_thread_create() whines about it. I want to 
introduce a system dependant THREAD_T (or whatever) and make ss_thread_create() return that, rather than INT.

ROOT stuff is still not fully tested- it takes a little while to build ROOT on a 600MHz laptop.

Attached is my current CVS diff.

K.O.

> With the ALIGN8() change ODB works, mhttpd works. ALIGN8 change now commited to cvs, verified that "make all" builds 
> on Linux.

Verified that "make all" still works under Windows.

> ROOT stuff still blows up because of more namespace pollution (/usr/include/sys/something does #define Free(x) 
> free(blah...)). Arguably, it is not Apple's fault- portable programs should not include any <sys/foo.h> header files. I 
> think I can fix it by moving "#include <sys/mount.h>" from midasinc.h to system.h.

I would like to keep all OS specific #includes in midasinc.h. In worst case put another section there for OSX, like

in midas.h:

#if !defined(OS_MACOSX)
#if defined ( __????__ ) <- put the proper thing here
#define OS_MACOSX
#endif
#endif

then make a new seciton in midasinc.h

#ifdef OS_MACOSX
#include <...>
#endif

> Also figured out why PVM is defined- more pollution from "#include <sys/blah...>". This is only in mana.c and I will 
> repace every "#ifdef PVM" with "#ifdef HAVE_PVM". Is there documentation that should be updated as well? Alternatively I 
> can try to play games with header files...

Right, PVM should be replaced by HAVE_PVM. This is only for the analyzer. I planned at some point to run the analyzer in 
parallel on a linux cluster, but it was never really used. Going to ROOT, that facility should be replaces by PROOF.

> Then, a new problem- on MacOSX, pthread_t is not an "INT" and system.c:ss_thread_create() whines about it. I want to 
> introduce a system dependant THREAD_T (or whatever) and make ss_thread_create() return that, rather than INT.

Good. If you have a OS_MACOSX, that should help you there.

-SR

> The result is strange because the get function is called all the time very 
> fast (much faster then the 9 seconds as set in the equipment) and even 
> before starting the run (I just put the flag RO_RUNNING).

This is on purpose. When the frontend is idle, it loops over the slow control 
equipment as fast as possible. This way, you see changes in your hardware very 
quickly. I see no reason to waste CPU cycles in the frontend when there are 
better things to do like reading slow control equipment. Presume you have the 
alarm system running, which turns off some equipment in case of an over 
current. You better do this as quickly as possible, not wasting up to 9 
seconds each time.

The 9 seconds you mention are for reading *EVENTS*. You have double 
functionality: First, reading the slow control system, writing updated values 
to the ODB, where someone else can display or evaluate them (in the alarm 
system for example). Second, assemble events and sending them with the other 
data to disk or tape. Only the second one gets controlled by RO_RUNNING and 
the 9 seconds. You can see this by the updating event statists on your 
frontend display, which increments only when running and then every 9 seconds.

> I would like to keep all OS specific #includes in midasinc.h

No go. Here is the problem:

midasinc.h includes sys/mount.h, which #defines Free(x) to be something else
mana.c includes msystem.h, which includes midasinc.h
mana.c includes ROOT header files, which blow up because Free(x) is redefined.

I want this:

mana.c does *not* include sys/mount.h
system.c does include sys/mount.h

Simplest solution is to take sys/mount.h out of midasinc.h and include it in system.c

> Right, PVM should be replaced by HAVE_PVM.

Commited.

> > Then, a new problem- on MacOSX, pthread_t is not an "INT" and system.c:ss_thread_create() whines about it. I want to 
> > introduce a system dependant THREAD_T (or whatever) and make ss_thread_create() return that, rather than INT.
> Good. If you have a OS_MACOSX, that should help you there.

Okey. In Darwin, pthread_t is not an int. It is a pointer to a struct. In midas.c I typedef midas_pthread_t to HANDLE on Windows and to pthread_t n OS_UNIX.

This uncovered a problem with ss_getthandle(). What is it supposed to do? On Windows it returns a handle to the current thread, on OS_UNIX, it returns getpid(). 
What gives? I am leaving it alone for now.

Attached is the current diff. Most changes are in system.c: ss_timezone() and midas_pthread_t. The Makefile part is already commited. Building the shared 
library was made dependant on NEED_SHLIB. Now, building static midas applications is very simple, use "make SHLIB="

K.O.

> I want this:
> 
> mana.c does *not* include sys/mount.h
> system.c does include sys/mount.h
> 
> Simplest solution is to take sys/mount.h out of midasinc.h and include it in system.c

Agree.

> This uncovered a problem with ss_getthandle(). What is it supposed to do? On Windows it returns a handle to the current thread, on OS_UNIX, it returns getpid(). 
> What gives? I am leaving it alone for now.

The Unix version of ss_getthandle() returns the pid since at the time when I wrote that function (many years ago) there were no threads under Unix. It should now 
be replaces with a function which returns the real thread id (at least under Linux).

> > Simplest solution is to take sys/mount.h out of midasinc.h and include it in system.c
> Agree.

Done.

With this, I commited the rest of my changes: midas_thread_t in midas.h, change ss_thread_xxx() prototypes in msystem.h
, implementation in system.c

My cvs diff is now empty.

Midas should compile on Darwin aka macosx, I tested "odbedit" and "mhttpd"- they seem to work.
 
> > This uncovered a problem with ss_getthandle(). 
> The Unix version of ss_getthandle() returns the pid since at the time when I wrote that function (many years ago) there were no threads under Unix. It should now 
> be replaces with a function which returns the real thread id (at least under Linux).

I do not want to touch this. Sorry.

K.O.