> midas currently does not compile on linux
> 
> /usr/include/x86_64-linux-gnu/bits/fcntl2.h:50:24: error: call to ‘__open_missing_mode’ declared with attribute error: open with O_CREAT or O_TMPFILE in second argument needs 3 arguments
>    50 |    __open_missing_mode ();
> 
> giving the mode is mandatory: https://man7.org/linux/man-pages/man2/open.2.html
> 
> fix is to give open in midas/examples/lowlevel/split.cxx a default mode, e.g. 006600

Thanks. Fixed.

Stefan

> > midas currently does not compile on linux
> > fix is to give open in midas/examples/lowlevel/split.cxx a default mode, e.g. 006600

I got more warnings from split.cxx, looked at the code and see so many problems that it is easier
to delete it than it is to fix it.

Check for end of file is done incorrectly (check for read() return 0, -1 or short read),
memory overrun if given file name is longer than 80 bytes, no check for valid event length
read from the file, and so on and so on.

A better example for reading and writing midas files is in midasio/test_midasio.cxx. Proper c++ coding, and can read compressed files.

K.O.

> > serious (but rare) bug was fixed in the history reader.
> previous fix was incomplete. please update to git commit
> https://bitbucket.org/tmidas/midas/commits/b343c3c98e4e6fd00a00cf686c74c7ccc6da0c63

a race condition between reading history file in mhttpd and writing history file in 
mlogger was accidentally introduced. mhttpd would file spurious errors about "timestamp 
is after last timestamp".

fixed, please update to git commit
https://bitbucket.org/tmidas/midas/commits/7a9f6e0c58ffddcacb9ee19934ce3e2033a805ef

fix race condition in history file reader - a race condition was added accidentally - 
first the reader remembers the history file size and the time of the last entry, then it 
goes to read the file and bombs if at the same time mlogger added more entries - their 
time is after the remembered time of last entry and error "timestamp is after last 
timestamp" is triggered.

K.O.

This is an important improvement, should have a post of it's own. K.O.

> > > RFE filed:
> > > https://bitbucket.org/tmidas/midas/issues/367/odb-should-be-saved-to-disk-
periodically
> > 
> > Implemented and closed: https://bitbucket.org/tmidas/midas/issues/367/odb-
should-be-saved-to-disk-periodically
> > 
> > Stefan
> 
> Stefan's comments from the closed bug report:
> 
> Ok I implemented some periodic flushing. Here is what I did:
> 
> Created
> 
> /System/Flush/Flush period : TID_UINT32 /System/Flush/Last flush : TID_UINT32
> 
> which control the flushing to disk. The default value for “Flush period” is 60 
seconds or one minute.
> 
> All clients call db_flush_database() through their cm_yield() function
> db_flush_database() checks the “Last flush” and only flushes the ODB when the 
period has expired. This test is 
> done inside the ODB semaphore so that we don’t get a race condigiton
> If the period has expired, db_flush_database() calls ss_shm_flush()
> ss_shm_flush() tries to allocate a buffer of the shared memory. If the 
allocation is not successful (out of 
> memory), ss_shm_flush() writes directly to the binary file as before.
> If the allocation is successful, ss_shm_flush() copies the share memory to a 
buffer and passes this buffer to a 
> dedicated thread which writes the buffer to the binary file. This causes 
ss_shm_flush() to return immediately and 
> not block the calling program during the disk write operation.
> Added back the “if (destroy_flag) ss_shm_flush()” so that the ODB is flushed 
for sure before the shared memory 
> gets deleted.
> This means now that under normal circumstances, exiting programs like odbedit 
do NOT flush the ODB. This allows to 
> call many “odbedit -c” in a row without the flush penalty. Nevertheless, the 
ODB then gets flushed by other 
> clients latest 60 seconds (or whatever the flush period is) after odbedit 
exits.
> 
> Please note that ODB flushing has two purposes:
> 
> When all programs exit, we need a persistent storage for the ODB. In most 
experiments this only happens very 
> seldom. Maybe at the end of a beam time period.
> If the computer crashes, a recent version of the ODB is kept on disk to 
simplify recovery after the crash.
> Since crashes are not so often (during production periods we have maybe one 
hardware failure every few years) the 
> flushing of the ODB too often does not make sense and just consumes resources. 
Flushing does also not help from 
> corrupted ODBs, since the binary image will also get corrupted. So the only 
reason for periodic flushes is to ease 
> recovery after a total crash. I put the default to 60 seconds, but if people 
are really paranoid they can decrease 
> it to 10 seconds or so. Or increase it to 600 seconds if their system does not 
crash every week and disks are 
> slow.
> 
> I made a dedicated branch feature/periodic_odb_flush so people can test the 
new functionality. If there are no 
> complaints within the next few days, I will merge that into develop.
> 
> Stefan

both the xml and the json decoders have a bug (fix pending). loading saved odb 
from xml and json file did not truncate arrays in odb to the size of arrays in 
the file. for example, if /example/double_array has size 20 in odb, but size 5 
in xml or json file, after loading the file, array size is still 20.

this is unexpected: after loading an odb save file we expect odb to return to 
same state as when odb save file was created. we do not expect some arrays to 
have half of their elements restored from file and half their elements left 
unchanged.

save and restore from .odb file does not have this problem.

I think this is a bug and I committed (but did not yet push) a fix for both xml 
and json odb decoder.

I have run this problem while writing the new history panel editor, where 
deleting variables did not work because json rpc db_paste() was not truncating 
any arrays.

I am still finishing up the last few bits of the new history panel editor, and 
there is a bit of time to discuss and comment this odb change before I push it 
to midas.

K.O.

> The symptoms are consistent with a string --> int64 conversion not happening 
> where it is needed. 

Thanks for the report Pasha. Indeed I was missing a conversion in one place. Fixed now!

Ben

> > The symptoms are consistent with a string --> int64 conversion not happening 
> > where it is needed. 
> 
> Thanks for the report Pasha. Indeed I was missing a conversion in one place. Fixed now!
> 

Are we running these tests as part of the nightly build on bitbucket? They would be part of 
the "make test" target. Correct python dependancies may need to be added to the bitbucket OS 
image in bitbucket-pipelines.yml. (This is a PITA to get right).

K.O.

> Are we running these tests as part of the nightly build on bitbucket? They would be part of 
> the "make test" target. Correct python dependancies may need to be added to the bitbucket OS 
> image in bitbucket-pipelines.yml. (This is a PITA to get right).

I added ubuntu-22 to the nightly builds.

but I notice the build says "no python" and I am not sure what packages I need to install for 
midas python to work.

Ben, can you help me with this?

https://bitbucket.org/tmidas/midas/pipelines/results/1106/steps/%7B9ef2cf97-bd9f-4fd3-9ca2-9c6aa5e20828%7D

K.O.

Dear Midas users,

As you certainly aware, ELOG (Electronic Logbook) has been written
by Stefan Ritt and its functionality is part of the Midas package too.
This web site using Elog is replacing the W-Agora Forum previously setup.

You will need to register to this forum in order to gain Write access and 
possible Email notification.

We would like to encourage you to post your questions or comments at
this Midas Elog site instead of using private Email to the authors as your 
remarks are surely of interest to the other users too.

 
 

- remove ss_tape_get_blockn from lazylogger.c
- add ss_tape_get_blockn to system.c
- add ss_tape_get_blockn prototype into midas.h
- fix buffer size for "dir" in mtape.c
- add block# for "dir" in mtape if command successful.
- handle TID_STRUCT bank type by display as 8bit in ybos.c (mdump)

I have added ROOT support to midas\examples\experiment\makefile.nt. To 
compile the example experiment under Windows, one needs

1) Installed version of ROOT
2) Having ROOTSYS environment variable defined
3) Invoke "nmake -f makefile.nt" in the midas\examples\experiment directory

Please note that in the current release 3.05 of ROOT, sockets are not yet 
working under Windows, so the histogram server built into the analyzer 
cannot be accessed. It is however possible to output the analyzed data into 
a .root file and visualize it with the root browser like

analyzer -i run00001.mid -o run00001.root

Added ss_create_thread support for Linux in system.c
Added pthread library in main make file

The current and future situation of the Midas analyzer is summarized in the
attachment below.

Box explanation:
================
Front end:
---------
Midas code for accessing/gathering the hardware information into the Midas
format.

Midas SHM:
---------
Midas back end shared memory where the front end data are sent to.

mlogger:
-------
Data logger collecting the midas events and storing them on a physical
logging device (Disk, Tape)

Midas Analyzer:
--------------
Midas client for event-by-event analysis. Incoming data can be either online
or offline.

mserver:
-------
Subprocess interfacing external (remote) midas client to the centralized
data collection and database system.

PAW:
---
Standalone physics data analyzer (CERN).

ROOT:
----
Standalone Physics data analyser (CERN).


This diagram represents the data path from the Frontend to the analyzer in
online and offline mode. Each data path is annoted with a circled number
discussed below. In all cases, the data will flow from the front end
application to the midas back end data buffers which reside in a specific
share memory for a given experiment.

Path:
(1): From the shared memory, the midas analyzer can request events directly
and process them for output to divers destination.

(2): The data logger is a specific application which stores all the data to
 a storage media such as a disk or tape. This path is specific to the
creation of file.mid file format. The actual storage file in this .mid
format can be readout later on by the midas analyzer.

(3): The Midas analyzer has been developed originally for interfacing to the
PAW analyzer which uses its own shared memory segment for online display.
The analyzer can also save the data into a specific data format consistent
with PAW (HBOOK and Ntuples, extension .rz).

(4): Presently the data logger support a creation of the ROOT file format.
This file contains in the form of a Tree the midas event-by-event data. This
file is fully compatible with ROOT and therefore can be read out by the
standard ROOT application.

(5): Equivalent to the data logger, the analyzer receiving from the data
buffer or reading from a .mid file data can apply an event-by-event analysis
and on request produce a compliant ROOT file for further analysis. This
.root file can be composed of Trees as well as histograms.

(6): The possibility of ONLINE ROOT analysis has been implemented in a first
stage through the TMapFile (ROOT shared memory). While this configuration is
still in use an experiment, the intention is to deprecate it and replace it
with the data path (7).

(7): This path uses the network socket channel to transfer data out of the
analyzer to the ROOT environment. The current analyzer has a limited support
for ROOT analysis by only publishing on request the Midas analysis built in
histograms. No mean is yet implemented for Tree passing mechanism.

(8): The pass has not been yet investigated, but ROOT does provide
accessibility to external function calls which makes this option possible.
The ROOT framework will then perform dedicated event call to the main midas
data buffer using the standard midas communication scheme. The data format
translation from Midas banks to ROOT format will have to be taken care at
the user level in the ROOT environment.


Discussion:
==========
Presently the Socket communication between Midas and ROOT (7) is under
revision by Stefan Ritt and René Brun. This revision will simplify the
remote access of an object such as an histogram. For the Tree itself, the
requirement would be to implement a "ring buffer" mechanism for remote tree
request. This is currently under discussion.

The path (8) has been suggested by Triumf to address small experiment setup
where only a single analyzer is required. This path minimize the DAQ
requirements by moving all the data analysis handling to the user.
The same ROOT analysis code would be applicable to a ONLINE as well as
OFFLINE analysis.

Cons:
- Necessity of publishing raw data through the network for every instance of
the remote analyzer.
- Result sharing of the analysis cannot be done yet in real time.

Pros:
- No need of extra task for data translation (midas/root).
- Unique data unpacking code part of the user code.
- Less CPU requirement.

Other issues:
============
- The current necessity of the Midas shared memory for the midas analyzer to
run is a concern in particular for offline analysis where a priori no midas
is available. 

- The handling of the run/analyzer parameters. Possible parameter extraction
from file.odb.

Add more checks to db_validate_key() for pkey->total_size, item_size and
num_values. Automatically correct total_size to be item_size*num_values (we
saw this corruption and tested this fix).

K.O.

For your enjoyment, here is the diff:

RCS file: /usr/local/cvsroot/midas/src/odb.c,v
retrieving revision 1.64
diff -r1.64 odb.c
718a719,744
>   /* check key sizes */
>   if ((pkey->total_size < 0)||(pkey->total_size > pheader->key_size))
>     {
>     cm_msg(MERROR, "db_validate_key", "Warning: invalid key \"%s\"
total_size: %d", path, pkey->total_size);
>     return 0;
>     }
> 
>   if ((pkey->item_size < 0)||(pkey->item_size > pheader->key_size))
>     {
>     cm_msg(MERROR, "db_validate_key", "Warning: invalid key \"%s\"
item_size: %d", path, pkey->item_size);
>     return 0;
>     }
> 
>   if ((pkey->num_values < 0)||(pkey->num_values > pheader->key_size))
>     {
>     cm_msg(MERROR, "db_validate_key", "Warning: invalid key \"%s\"
num_values: %d", path, pkey->num_values);
>     return 0;
>     }
> 
>   /* check and correct key size */
>   if (pkey->total_size != pkey->item_size*pkey->num_values)
>     {
>     cm_msg(MINFO,  "db_validate_key", "Warning: corrected key \"%s\" size:
total_size=%d, should be %d*%d=%d", path, pkey->total_size, pkey->item_size,
pkey->num_values, pkey
->item_size*pkey->num_values);
>     pkey->total_size = pkey->item_size*pkey->num_values;
>     }
> 

Add switch "-C" to odbedit to allow it to connect to corrupted ODB. Then,
depending on corruption, the user can manually remove or correct the
corrupted entries. Also, some corruption is automatically fixed by "odbedit"
itself. I use this functionality to debug and fix broken ODBs.

K.O.

For your enjoyment, here is the diff:

diff -r1.64 odbedit.c
3058a3059
> BOOL          corrupted;
3063c3064
<   debug = cmd_mode = FALSE;
---
>   debug = corrupted = cmd_mode = FALSE;
3077a3079,3080
>     else if (argv[i][0] == '-' && argv[i][1] == 'C')
>       corrupted = TRUE;
3104c3107,3108
<         printf("               [-c Command] [-c @CommandFile] [-s size]
[-g (debug)]\n\n");
---
>         printf("               [-c Command] [-c @CommandFile] [-s size]\n");
>         printf("               [-g (debug)] [-C (connect to corrupted
ODB)]\n\n");
3123c3127,3133
<   if (status != CM_SUCCESS)
---
>   else if ((status == DB_INVALID_HANDLE)&&corrupted)
>     {
>     cm_get_error(status, str);
>     puts(str);
>     printf("ODB is corrupted, connecting anyway...\n");
>     }
>   else if (status != CM_SUCCESS)

It appears that all midas applications are now required to link with the
pthreads library even if they do not use threads. This is caused by a
pthread_create() call from ss_thread_create() in system.c.

Is this the intended behaviour?

K.O.

The change is required to support implementation of pthreads in the Linux
compile of Midas. This was added recently. I believe pthreads is also needed
for ROOT based compiles.

David

> It appears that all midas applications are now required to link with the
> pthreads library even if they do not use threads. This is caused by a
> pthread_create() call from ss_thread_create() in system.c.
> 
> Is this the intended behaviour?
> 
> K.O.

Invalid values of ODB /RunInfo/State cause mhttpd crash in
show_status_page() because of an out of bounds access to the array of state
names. Suggest this fix: remove array of state names, use existing ladder of
if/else statements to explicitely set state name. Verified the fix works for
TWIST. Will commit this into MIDAS CVS unless get feedback.

src/mhttpd.c:show_status_page() {
  ...
  rsprintf("<tr align=center><td>Run #%d", runinfo.run_number);

  if (runinfo.state == STATE_STOPPED)
    rsprintf("<td colspan=1 bgcolor=#FF0000>Stopped");
  else if (runinfo.state == STATE_PAUSED)
    rsprintf("<td colspan=1 bgcolor=#FFFF00>Paused");
  else if (runinfo.state == STATE_RUNNING)
    rsprintf("<td colspan=1 bgcolor=#00FF00>Running");
  else
    rsprintf("<td colspan=1 bgcolor=#FFFFFF>Unknown");

  if (runinfo.requested_transition)
  ...

K.O.

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.

- add pthread lib to examples/... makefile
- fix ybos_simfe.c for max_event_size
- fix camacnul.c for cam_inhibit_test(), cam_interrupt_test()
- update documentation (1.9.3)
- made midas-1.9.3-1.tar.gz on Triumf site