> > Could you give more info on your setup:
> > - CAMAC controller model
> Jorway 73A, we have three in hand and the problem doesn't depend on which controller
> we were using.

Dawei sent me a copy of his jorway73a.c scsi-camac driver. It is quite different from the
file in the MIDAS distribution. Dawei tells me that the file from the MIDAS distribution
does not compile. Stack traces from Dawei indicate a hang in this modified jorway73a.c
scsi-camac driver.

K.O.

> uint32_t mvme_read_value(MVME_INTERFACE * vme, mvme_addr_t vme_addr);
> Question: How to distinguish the status and value returned?

On VME interfaces using the Universe and tsi148 PCI-VME bridges, your question has no meaning.

The VME address space is directly mapped into the PCI address space, then mmap()ed into your 
program address space. Internally mvme_read_value() is "return *(uint32_t*)(mmap_base + vme_addr);" 
and there is no such thing as "status".

Physically on the VME bus, for single-word VME cycles (mvme_read_value), there are only 2 error 
conditions, an AS or a DS timeout, and these bridges return the bit pattern 0xFFFFFFFF for either error, 
the same as the traditional VME bus always worked (i.e. before PCI, before ISA, back when the VME bus 
*was* the main CPU-memory-IO bus).

So the answer to your question is "yes". If mvme_read_value() returned 0xFFFFFFFF, there was a VME 
bus timeout because the board you are trying to address a) is not installed, b) was unplugged, c) does 
not decode the address you tried to access (maybe you used the wrong AM code or the wrong data 
width).

With Universe and tsi148 PCI-VME bridges, the mvme_read() call runs the DMA interface that can issue 
block transfer cycles on the VME bus. These DMA interfaces have interesting error handling, but 
basically, they only tell you the estimated VME address at which the AS or DS timeout or BERR has 
occurred. For sane VME boards, DMA errors mean very basic breakage of the VME crate and VME board.

With non-directly attached VME interfaces, i.e. the SIS3100, you can also have communication errors. I 
do not know how those are reported by the SIS3100 Linux drivers, and I do not know how the MIDAS 
driver reports them. But I do know that if you see those errors, your interface is very broken and VME 
bus errors are the least of your worries.

P.S. There also exist PCI bus errors, they also return the bit pattern 0xFFFFFFFF and mean basic 
breakage inside your computer. PCI-PCI and PCI-host bridges have special registers you can read to 
find out the exact cause of the error ("your computer is broken").

K.O.

FYI - committed the last changes from TRIUMF DAQ systems for PIENU and T2K/ND280 FGD and TPC 
tests:

- mhttpd: add <odb xxx format="%d">xxx</odb>, similar to AJAX ODBget() method
- alarm.c: if alarm stops the run, log a message (sometimes it is hard to tell "why did this run stop?!?") 
use DETACH transition (was ASYNC - does not follow requested transition sequencing, now calls 
mtransition helper). Also verified that alarm handler always runs on the main computer - for remote 
clients, alarms are processed inside the corresponding mserver process.
- midas.c: event buffer fixes:
-- mserver 100% cpu busy loop if event buffer is full
-- consolidate event buffer cleanup into one routine. do things similar to odb cleanup - check for client 
pid, etc.
-- do not kill clients that have the watchdog timeout set to zero.

svn rev 4541
K.O.

> FYI - committed the last changes from TRIUMF DAQ systems for PIENU and T2K/ND280 FGD and TPC 
> tests:
> svn rev 4541

Also:

- add traps to event buffer code to catch event buffer (shared memory) corruption observed in PIENU
- dynamically allocate some RPC network data buffers to permit better communication between MIDAS clients built with different values of 
MAX_EVENT_SIZE (in T2K/ND280 the default 4 Mbytes is too small for some users, while other users use the default size - this change permits all 
these programs to talk to each other).

K.O.

> If you compile each source into an object, you may encounter a link error ...

Also camac rpc did not work at all last time we tried to use it at triumf, maybe 4 month ago in the Dragon 
experiment (upgrade from older version of midas). Never got around to trace down why. YMMV.

K.O.

> I encountered many warning while building MIDAS (svn r4556). Please see the
> attached log file. Most of them are caused by type conversion from string to
> "char*".
> Though I can ignore all the warning without any problem, I still hate to see
> them. :-)

There is no "type conversions". The compiler is whining about code like this:

/* data type names */
static char *tid_name[] = {
   "NULL",
   "BYTE",
   ...

I guess we should keep the compiler happy and make them "static const char*".

BTW, my compiler is SL5.2 gcc-4.1.2 and it does not complain. What's your compiler?

K.O.

> $ odbedit -e expcvadc
> odbedit: /opt/DAQ/repos/bot/midas/src/odb.c:651: db_validate_sizes: Assertion 
`sizeof(EQUIPMENT_INFO) == 400' failed.

Yes, this is now fixed, svn rev 4571 should be okey. Sorry about causing this problem - Stefan added 
some useful additional data to EQUIPMENT_INFO and my check for binary compatibility caught it and 
complained. Unfortunately on Saturday Stefan had to abruptly go back to PSI and things have been a little 
bit chaotic because we did not complete the testing of all the new changes and additions.

K.O.

> Linking CXX executable bin/mh2sql
> CMakeFiles/mh2sql.dir/utils/mh2sql.cxx.o: In function `main':
> /opt/DAQ/repos/bot/midas/utils/mh2sql.cxx:150: undefined reference to `MakeMidasHistoryODBC()'

Yes, I am in the process of changing the midas history interface and accidentally committed a version of 
mh2sql (utility for converting MIDAS history .hst files to SQL database) that uses the new interface.

This is now fixed in svn rev 4571.

The new C++ interface to the MIDAS history is in include/history.h and implementations for data storage 
using both midas .hst files and SQL (ODBC/MySQL) database are also committed (history_midas.cxx
and history_sql.cxx). The file history_odbc.cxx will be removed after some more testing of the new 
interface.

(All the new code is not activated yet, pending more testing).

K.O.

> --- Makefile
> < 	ld -shared -o $@ $^ $(LIBS) -lc
> ---
> > 	$(CXX) -shared -o $@ $^ $(LIBS) -lc

Will do. We also have a long standing request to change shared library name from lidmidas.so to libmidas-shared.so.

Different name for the .so file will permit us to build the shared library by default, but still link all MIDAS executables
with the static libmidas.a.

(there is no benefit from linking MIDAS executables - mlogger, mhttpd, etc - with the shared library,
and there is a significant cost in confusion from version skew between the executables and shared
libraries - I have had enough midnight calls "why did odbedit stop working? Oh, who changed LD_LIBRARY_PATH
and why is it now binding against this obsolete libmidas.so left over from 2 years ago?").

For user applications you can do whatever, but for MIDAS core applications I strongly suggest that they
be linked to the midas static library.

K.O.

> Linking CXX shared library lib/libmidas.so
/usr/bin/c++  ... -o lib/libmidas.so ... CMakeFiles/midas-shared.dir/src/history_odbc.cxx.o 
CMakeFiles/midas-shared.dir/src/history_sql.cxx.o 
CMakeFiles/midas-shared.dir/src/history_sql.cxx.o: In function `SqlODBC':
/opt/DAQ/repos/bot/midas/src/history_sql.cxx:200: multiple definition of `SqlODBC::SqlODBC()'
CMakeFiles/midas-
shared.dir/src/history_odbc.cxx.o:/opt/DAQ/repos/bot/midas/src/history_odbc.cxx:315: first defined 
here
> Why is the class "SqlODBC" duplicated?

This is interesting. I do not think my C++ book spells it out that I cannot have class A in foo.cxx
and a class A in bar.cxx. In fact I already discovered that the two classes A will collide (duplicate default 
constructor A::A, even if all other member functions are different) if I link an executable that uses both 
foo.o and bar.o.

Is there a way around this problem? In C, I can declare functions and variables "static" to "hide" them
from the linker.

What is the C++ equivalent for classes? (Any C++ experts here?)

In this specific case, the file history_odbc.cxx will disappear with the next commit of mhttpd, hopefully 
today. mlogger and mh2sql already do not use it.

And I will commit the Makefile change renaming libmidas.so to libmidas-shared.so, so we can build it 
by default but still link midas core executables to the normal midas library.

This will catch such a problem if it happens again.

K.O.

>  The "g++" is whining while compiling history_midas.cxx. Please see the attached log file.

Fixed. svn 4594. K.O.

> > > 	$(CXX) -shared -o $@ $^ $(LIBS) -lc

Done.
MIDAS shared library renamed from libmidas.so to libmidas-shared.so and always build on Linux (.so) and MacOS (.dylib and .so bundle).

Users who wish to link their applications to the shared library should change their Makefile from "gcc ... -lmidas" to "gcc ... -lmidas-shared".

MIDAS core applications (mhttpd, mlogger, etc) are linked to the static library to permit multiple versions of midas to be used
at the same time (LD_LIBRARY_PATH should point to the shared library for *which* midas?!?), avoid problems with wrong setting
of LD_LIBRARY_PATH and to avoid problems with version skew (which we found unavoidable once a midas daq is used for a year or
more - main reason we gave up on using the midas shared library in the first place).

svn rev 4594
K.O.

> > Why is the class "SqlODBC" duplicated?
> 
> This is interesting. I do not think my C++ book spells it out that I cannot have class A in foo.cxx
> and a class A in bar.cxx.

I guess nobody knows the answer to this C++ puzzle. In any case history_odbc.cxx is not used anymore removing duplication of class SqlODBC.

svn rev 4594
K.O.

> Documentation for writing midas history data to SQL (mysql) is now documented in midas doxygen files 
> (make dox; firefox doxfiles/html/index.html). The corresponding logger and mhttpd code has been 
> committed for some time now and it is used in production environment by the t2k/nd280 slow controls 
> daq system at TRIUMF.
> svn rev 4487


An updated version of the SQL history code is now committed to midas svn.

The new code is in history_sql.cxx. It implements a C++ interface to the MIDAS history (history.h),
and improves on the old code history_odbc.cxx by adding:
- an index table for remembering MIDAS names of SQL tables and columns (our midas users like to use funny characters in history 
names that are not permitted in SQL table and column names),
- caching of database schema (event names, etc) with a noticeable speedup of mhttpd (there is a new button on the history panel editor 
"clear history cache" to make mhttpd reload the database schema.

The updated documentation for using SQL history is committed to midas svn doxfiles/internal.dox (svn up; make dox; firefox 
doxfiles/html/index.html), or see my copy on the web at
http://ladd00.triumf.ca/~olchansk/midas/Internal.html#History_sql_internal

svn rev 4595
K.O.

I committed an updated lazylogger with updated documentation. The new version supports subruns and 
can save to external storage arbitrary files (i.e. odb dump files). It also moves most book keeping out of 
odb to permit handling more files on bigger storage disks.

Example lazylogger scripts for castor (CERN) and dcache (TRIUMF) are in the directory "utils".

The lazylogger documentation was updated to remove obsolete information and to describe the new 
functions. As usual "make dox; cd doxfiles/html; firefox index.html" or see my copy at:

http://ladd00.triumf.ca/~olchansk/midas/Utilities.html#lazylogger_task

svn rev 4615, 4616.
K.O.

odb.c rev 4622 fixes ODB corruption by db_connect_database() if client_name is
too long. Also fixed is potential ODB corruption by too long key names in
db_create_key(). Problem kindly reported by Tim Nichols of T2K/ND280 experiment.
K.O.

> odb.c rev 4622 fixes ODB corruption by db_connect_database() if client_name is
> too long. Also fixed is potential ODB corruption by too long key names in
> db_create_key(). Problem kindly reported by Tim Nichols of T2K/ND280 experiment.


Related bug fix - db_connect_database() should not permit client names that contain
the slash (/) character. Names like "aaa/bbb" create entries /Programs/aaa/bbb (aaa
is a subdirectory) and names like "../aaa" create entries in the ODB root directory.

svn rev 4623.
K.O.

> When using remote midas clients with mserver, you may have noticed the zero-size .RPC.SHM files 
> these clients create in the directory where you run them.

Well, RPC.SHM bites. Please reread the parent message for full details, but in the nutshell, it is a global
semaphore that permits only one midas rpc client to talk to midas at a time (it was intended for local
locking between threads inside one midas application).

I have about 10 remote midas frontends started by ssh all in the same directory, so they all share the same
.RPC.SHM semaphore and do not live through the night - die from ODB timeouts because of RPC semaphore contention.

In a test version of MIDAS, I disabled the RPC.SHM semaphore, and now my clients live through the night, very
good.

Long term, we should fix this by using application-local mutexes (i.e. pthread_mutex, also works on MacOS, do
Windows have pthreads yet?).

This will also cleanup some of the ODB locking, which currently confuses pid's, tid's etc and is completely
broken on MacOS because some of these values are 64-bit and do not fit into the 32-bit data fields in MIDAS
shared memories.

Short term, I can add a flag for enabling and disabling the RPC semaphore from the user application: enabled
by default, but user can disable it if they do not use threads.

Alternatively, I can disable it by default, then enable it automatically if multiple threads are detected or
if ss_thread_create() is called.

Could also make it an environment variable.

Any preferences?

K.O.

Please be aware of mlogger.c update rev 4566 on Sept 23rd 2009, when Stefan
fixed a buglet in the subrun file size computations. Before this fix, the first
subrun could be of a short length. If you use subruns, please update your
mlogger to at least rev 4566 (or newer, Stefan added the run and subrun time
limits just recently).
K.O.

We were debugging a strange problem in the event builder, where out of 14
fragments, two fragments were always getting serial number mismatches and the
serial numbers were not sequentially increasing (the other 12 fragments were
just fine).

Then we noticed in the event builder debug output that these 2 fragments were
getting assigned the same buffer handle number, despite having different names -
BUF09 and BUFTPC.

Then we looked at "ipcs", counted the buffers, and there are only 13 buffers for
14 frontends.

Aha, we went, maybe we have unlucky buffer names, renamed BUFTPC to BUFAAA and
everything started to work just fine.

It turns out that the MIDAS ss_shm_open() function uses "ftok" to convert buffer
names to SystemV shared memory keys. This "ftok" function promises to create
unique keys, but I guess, just not today.

Using a short test program, I confirmed that indeed we have unlucky buffer names
and ftok() returns duplicate keys, see below.

Apparently ftok() uses the low 16 bits of the file inode number, but in our
case, the files are NFS mounted and inode numbers are faked inside NFS. When I
run my test program on a different computer, I get non-duplicate keys. So I
guess we are double unlucky.

Test program:

#include <stdio.h>
#include <sys/types.h>
#include <sys/ipc.h>

int main(int argc, char* argv[])
{
  //key_t ftok(const char *pathname, int proj_id);
  
  int k1 = ftok("/home/t2kdaq/midas/nd280/backend/.BUF09.SHM", 'M');
  int k2 = ftok("/home/t2kdaq/midas/nd280/backend/.BUFTPC.SHM", 'M');
  int k3 = ftok("/home/t2kdaq/midas/nd280/backend/.BUFFGD.SHM", 'M');

  printf("key1: 0x%08x, key2: 0x%08x, key3: 0x%08x\n", k1, k2, k3);
  return 0;
}

[t2kfgd@t2knd280logger ~/xxx]$ g++ -o ftok -Wall ftok.cxx
[t2kfgd@t2knd280logger ~/xxx]$ ./ftok
key1: 0x4d138154, key2: 0x4d138154, key3: 0x4d138152

Also:

[t2kfgd@t2knd280logger ~/xxx]$ ls -li ...
14385492 -rw-r--r-- 1 t2kdaq t2kdaq  8405052 Nov 24 17:42
/home/t2kdaq/midas/nd280/backend/.BUF09.SHM
36077906 -rw-r--r-- 1 t2kdaq t2kdaq 67125308 Nov 26 10:19
/home/t2kdaq/midas/nd280/backend/.BUFFGD.SHM
36077908 -rw-r--r-- 1 t2kdaq t2kdaq  8405052 Nov 25 15:53
/home/t2kdaq/midas/nd280/backend/.BUFTPC.SHM

(hint: print the inode numbers in hex and compare to shm keys printed by the
program)

K.O.