I redid the tests from Konstantin for our MEG experiment at PSI. The event structure is different, so it
is interesting how the two different experiments compare. We have an event size of 2.4 MB and a trigger
rate of ~10 Hz, so we produce a raw data rate of 24 MB/sec. A typical run contains 2000 events, so has a 
size of 5 GB. Here are the results:


cat                 : time   7.8s, size   4960156030   4960156030, comp   0%, rate 639M/s 639M/s

gzip -1             : time 147.2s, size   4960156030   2468073901, comp  50%, rate  33M/s  16M/s

pbzip2 -p1          : time 679.6s, size   4960156030   1738127829, comp  65%, rate   7M/s   2M/s (1 CPU)
pbzip2 -p8          : time  96.1s, size   4960156030   1738127829, comp  65%, rate  51M/s  18M/s (8 CPU)


As one can see, our compression ratio is poorer (due to the quasi random noise in our waveforms), but the
difference between gzip -1 and pbzip2 is larger (15% instead 10% for DEAP). The single CPU version of
pbzip cannot sustain our DAQ rate of 24 MB, but the parallel version can. Actually we have a somehow old
dual-core dual-CPU board 2.5 GHz Xenon box, and make 8 hyper-threading CPUs out of the total 4 cores.
Interestingly the compression rate scales with 7.3 for 8 virtual cores, so hyper-threading does its job.
So we take all our data with the pbzip2 compression. The additional 15% as compared with gzip does 
not sound much, but we produce raw 250 TB/year. So gzip gives us 132 TB/year and pbzip2 gives 
us 98 TB/year, and we save quite some disks.

Note that you can run bzip2 (as all the other methods) already now with the current logger, if you specify
an external compression program in the ODB using the pipe functionality:


local:MEG:S]/>cd Logger/Channels/0/Settings/
[local:MEG:S]Settings>ls
Active                          y
Type                            Disk
Filename                        |pbzip2>/megdata/run%06d.mid.bz2
Format                          MIDAS
Compression                     0
ODB dump                        y
Log messages                    0
Buffer                          SYSTEM
Event ID                        -1
Trigger mask                    -1
Event limit                     0
Byte limit                      0
Subrun Byte limit               0
Tape capacity                   0
Subdir format                   
Current filename                /megdata/run197090.mid.bz2
</pre>

> The simplest thing is probably to delete all files .[A-Z]*.SHM in the odb directory (the
> one you specified in /etc/exptab).
> This wipes the ODB, shared memory and all the other obscure stuff, giving you a clean,
> fresh start.
> 
> Of course it wipes all the valuable stuff, too. That's why it's handy to sometimes open
> odbedit and "save odb_<yyyymmdd>.odb". You can reload the thing after such a fatal 
> "rm .[A-Z]*.SHM" 

Thanks Randolf for helping out, I was not in the office this week.

In addition of deleting the *SHM files, it's sometimes necessary to delete the shared memory. You do this with the 
command line tools

ipcs -m
ipcrm -m <shmid>


/Stefan

The simplest thing is probably to delete all files .[A-Z]*.SHM in the odb directory (the
one you specified in /etc/exptab).
This wipes the ODB, shared memory and all the other obscure stuff, giving you a clean,
fresh start.

Of course it wipes all the valuable stuff, too. That's why it's handy to sometimes open
odbedit and "save odb_<yyyymmdd>.odb". You can reload the thing after such a fatal 
"rm .[A-Z]*.SHM" 

I've managed to put the analyzer into state where it cannot connect to the 
statistics database.  The error message suggests another analyzer is connected.  
I've recompiled MIDAS and the user code, restarted the computer etc..., and the 
analyzer cannot connect.  If I run "odbedit -c clean", I can start the analyzer, 
but get the same error when exiting or starting a run.  I've commented out all the
user code in the analyzer.c and its associated analyzer module's, and read event
code in the frontend and nothing resolves this issue.  Any suggestion?

The output from attempting to run the analyzer is:

Connect to experiment nnbarxwnr...[odb.c:1013:db_open_database,ERROR] Removed ODB
client 'Analyzer', index 0 because process pid 31982 does not exists
Deleted entry '/System/Clients/31982' for client 'Analyzer' because it is not
connected to ODB
OK
Root server listening on port 9090...
Loading previous online histos from ./data/last.root
ss_mutex_wait_for: pthread_mutex_lock() returned errno 22 (Invalid argument),
aborting...


When attempting to clean up the Analyzer tree in the ODB I receive the message
:"deletion of key not allowed."  

It appears that running the analyzer sets the permissions of the Statistics tree of
my analyzer module into RWDE.  

Adding the following lines to my start up script eliminate the above problem:
odbedit -c clean
odbedit -c "chmod 7 Analyzer/"
odbedit -c "rm /Analyzer/fADCs/Statistics"

Now when starting a run the analyzer crashes with this error:analyzer:
src/midas.c:11443: rpc_execute: Assertion `return_buffer' failed.
Aborted (core dumped)

and the messages in the odb are :

[system.c:4295:recv_tcp,ERROR] header: recv returned 0, n_received = 0, unexpected
connection closure
[midas.c:10042:rpc_client_call,ERROR] recv_tcp() failed, routine = "rc_transition",
host = "LANL-FADC-DAQ"
[midas.c:4130:cm_transition,ERROR] Could not start a run: cm_transition() status 503,
message 'Unknown error 503 from client 'Analyzer' on host LANL-FADC-DAQ'
Deleted entry '/System/Clients/1001' for client 'Analyzer' because process pid 1001
does not exists
[midas.c:8893:rpc_client_check,ERROR] Connection broken to "Analyzer" on host
LANL-FADC-DAQ
Run #180 start aborted
Error: Unknown error 503 from client 'Analyzer' on host LANL-FADC-DAQ

20:05:02 [Logger,INFO] Deleting previous file "./data/run00180.mid"

20:05:02 [ODBEdit,ERROR] [system.c:4295:recv_tcp,ERROR] header: recv returned 0,
n_received = 0, unexpected connection closure

20:05:02 [ODBEdit,ERROR] [midas.c:10042:rpc_client_call,ERROR] recv_tcp() failed,
routine = "rc_transition", host = "LANL-FADC-DAQ"

20:05:02 [ODBEdit,ERROR] [midas.c:4130:cm_transition,ERROR] Could not start a run:
cm_transition() status 503, message 'Unknown error 503 from client 'Analyzer' on host
LANL-FADC-DAQ'

20:05:02 [ODBEdit,INFO] Deleted entry '/System/Clients/1001' for client 'Analyzer'
because process pid 1001 does not exists

20:05:02 [ODBEdit,ERROR] [midas.c:8893:rpc_client_check,ERROR] Connection broken to
"Analyzer" on host LANL-FADC-DAQ

20:05:02 [ODBEdit,INFO] Run #180 start aborted
20:05:03 [mdump,INFO] Client 'Analyzer' on buffer 'SYSTEM' removed by cm_watchdog
because process pid 1001 does not exist
20:05:11 [mhttpd,INFO] Client 'Analyzer' (PID 1001) on database 'ODB' removed by
cm_watchdog (idle 10.1s,TO 10s)


Thanks,
Robert Pattie

In the DEAP experiment, the normal MIDAS mlogger gzip compression  is not fast enough for some data 
taking modes, so I am doing tests of other compression programs. Here is the results.

Executive summary:

fastest compression is no compression (cat at 1800 Mbytes/sec - memcpy speed), next best are:
"lzf" at 300 Mbytes/sec and  "lzop" at 250 Mbytes/sec with 50% compression
"gzip -1" at around 70 Mbytes/sec with around 70% compression
"bzip2" at around 12 Mbytes/sec with around 80% compression
"pbzip2", as advertised, scales bzip2 compression linearly with the number of CPUs to 46 Mbytes/sec (4 
real CPUs), then slower to a maximum 60 Mbytes/sec (8 hyper-threaded CPUs).

This confirms that our original choice of "gzip -1" method for compression using zlib inside mlogger is 
still a good choice. bzip2 can gain an additional 10% compression at the cost of 6 times more CPU 
utilization. lzo/lzf can do 50% compression at GigE network speed and at "normal" disk speed.

I think these numbers make a good case for adding lzo/lzf compression to mlogger.

Comments about the data:

- time measured is the "elapsed" time of the compression program. it excludes the time spent flushing 
the compressed output file to disk.
- the relevant number is the first rate number (input data rate)
- test machine has 32GB of RAM, so all I/O is cached, disk speed does not affect these results
- "cat" gives a measure of overall machine "speed" (but test file is too small to give precise measurement)
- "gzip -1" is the recommended MIDAS mlogger compression setting
- "pbzip2 -p8" uses 8 "hyper-threaded" CPUs, but machine only has 4 "real" CPU cores

<pre>
cat                 : time   0.2s, size    431379371    431379371, comp   0%, rate 1797M/s 1797M/s
cat                 : time   0.6s, size   1013573981   1013573981, comp   0%, rate 1809M/s 1809M/s
cat                 : time   1.1s, size   2027241617   2027241617, comp   0%, rate 1826M/s 1826M/s

gzip -1             : time   6.4s, size    431379371    141008293, comp  67%, rate  67M/s  22M/s
gzip                : time  30.3s, size    431379371    131017324, comp  70%, rate  14M/s   4M/s
gzip -9             : time  94.2s, size    431379371    133071189, comp  69%, rate   4M/s   1M/s

gzip -1             : time  15.2s, size   1013573981    347820209, comp  66%, rate  66M/s  22M/s
gzip -1             : time  29.4s, size   2027241617    638495283, comp  69%, rate  68M/s  21M/s

bzip2 -1            : time  34.4s, size    431379371     91905771, comp  79%, rate  12M/s   2M/s
bzip2               : time  33.9s, size    431379371     86144682, comp  80%, rate  12M/s   2M/s
bzip2 -9            : time  34.2s, size    431379371     86144682, comp  80%, rate  12M/s   2M/s

pbzip2 -p1          : time  34.9s, size    431379371     86152857, comp  80%, rate  12M/s   2M/s (1 CPU)
pbzip2 -p1 -1       : time  34.6s, size    431379371     91935441, comp  79%, rate  12M/s   2M/s
pbzip2 -p1 -9       : time  34.8s, size    431379371     86152857, comp  80%, rate  12M/s   2M/s

pbzip2 -p2          : time  17.6s, size    431379371     86152857, comp  80%, rate  24M/s   4M/s (2 CPU)
pbzip2 -p3          : time  11.9s, size    431379371     86152857, comp  80%, rate  36M/s   7M/s (3 CPU)
pbzip2 -p4          : time   9.3s, size    431379371     86152857, comp  80%, rate  46M/s   9M/s (4 CPU)
pbzip2 -p4          : time  45.3s, size   2027241617    384406870, comp  81%, rate  44M/s   8M/s
pbzip2 -p8          : time  33.3s, size   2027241617    384406870, comp  81%, rate  60M/s  11M/s

lzop -1             : time   1.6s, size    431379371    213416336, comp  51%, rate 261M/s 129M/s
lzop                : time   1.7s, size    431379371    213328371, comp  51%, rate 249M/s 123M/s
lzop                : time   4.3s, size   1013573981    515317099, comp  49%, rate 234M/s 119M/s
lzop                : time   7.3s, size   2027241617    978374154, comp  52%, rate 277M/s 133M/s
lzop -9             : time 176.6s, size    431379371    157985635, comp  63%, rate   2M/s   0M/s

lzf                 : time   1.4s, size    431379371    210789363, comp  51%, rate 299M/s 146M/s
lzf                 : time   3.6s, size   1013573981    523007102, comp  48%, rate 282M/s 145M/s
lzf                 : time   6.7s, size   2027241617    972953255, comp  52%, rate 303M/s 145M/s

lzma -0             : time  27s, size    431379371    112406964, comp  74%, rate  15M/s   4M/s
lzma -1             : time  35s, size    431379371    111235594, comp  74%, rate  12M/s   3M/s
lzma: > 5 min, killed

xz -0               : time  28s, size    431379371    112424452, comp  74%, rate  15M/s   4M/s
xz -1               : time  35s, size    431379371    111252916, comp  74%, rate  12M/s   3M/s
xz: > 5 min, killed
</pre>

Columns are:
compression program
time: elapsed time of the compression program (excludes the time to flush output file to disk)
size: size of input file, size of output file
comp: compression ration (0%=no compression, 100%=file compresses into nothing)
rate: input data rate (size of input file divided by elapsed time), output data rate (size of output file 
divided by elapsed time)

Machine used for testing (from /proc/cpuinfo):
Intel(R) Core(TM) i7-3820 CPU @ 3.60GHz
quad core cpu with hyper-threading (8 CPU total)
32 GB quad-channel DDR3-1600.

Script used for testing:

#!/usr/bin/perl -w

my $x = join(" ", @ARGV);

my $in  = "test.mid";
my $out = "test.mid.out";
my $tout = "test.time";

my $cmd = "/usr/bin/time -o $tout -f \"%e\" /usr/bin/time $x < test.mid > test.mid.out";

print $cmd,"\n";

my $t0 = time();
system $cmd;
my $t1 = time();

my $c = `cat $tout`;
print "Elapsed time: $c";

my $t = $c;

#system "/bin/ls -l $in $out";

my $sin  = -s $in;
my $sout = -s $out;

my $xt = $t1-$t0;
$xt = 1 if $xt<1;

print "Total time: $xt\n";

print sprintf("%-20s: time %5.1fs, size %12d %12d, comp %3.0f%%, rate %3dM/s %3dM/s", $x, $t, $sin, 
$sout, 100*($sin-$sout)/$sin, ($sin/$t)/1e6, ($sout/$t)/1e6), "\n";

exit 0;
# end

Typical output:

[deap@deap00 pet]$ ./r.perl lzf    
/usr/bin/time -o test.time -f "%e" /usr/bin/time lzf < test.mid > test.mid.out
1.27user 0.15system 0:01.44elapsed 99%CPU (0avgtext+0avgdata 2800maxresident)k
0inputs+411704outputs (0major+268minor)pagefaults 0swaps
Elapsed time: 1.44
Total time: 3
lzf                 : time   1.4s, size    431379371    210789363, comp  51%, rate 299M/s 146M/s

K.O.

Dear Bill,

the Midas analyzer "mana.c" is currently not maintained. At PSI we use the ROME framework (which might be too complicated for a 
small experiment) and at TRIUMF the ROOTANA framework is used:

http://ladd00.triumf.ca/~olchansk/rootana/

You might be better off switching to that one.

Best regards,
Stefan

Dear Midas Experts

I am Wenliang Li, a graduate student from University of Regina. Our group have
encountered some difficulty on outputting ADC and TDC data into ROOT tree with
the MIDAS SVN Revision: 5347.

Our Linux Distribution: Scientific Linux release 6.0 (Carbon)
ROOT Version:           ROOT 5.28
gcc version:            g++ (GCC) 4.4.4 20100726 (Red Hat 4.4.4-13)
kernel version:         2.6.32-279.19.1.el6.i686


I am using the given example $MIDASSYS/examples/experiment to generate some
data, and the issue is that the analyzer refuses to turn on the  ADC0 and TDC0
back switches. 

If the ADC and TDC banks are switched off, the analyzer will successfully output
the histograms but not the ROOT tree, and the Trigger and Scaler root trees are
completely empty.

With the same example experiment: $MIDASSYS/examples/experiment, this issue does
not occur on MIDAS SVN Revision: 4309.


The output error messages in the analyzer window are shown if the ADC and TDC
banks are switched to 1:

*************************
Connect to experiment ...OK
Root server listening on port 9090...
Loading previous online histos from /home/billlee/experiment/test_exp/last.root
Running analyzer online. Stop with "!"
Error in <TTree::Branch>: The pointer specified for ADC0 is not of a class known
to ROOT and (null) is not a known class
ROOT TTree rebooked
Error in <TTree::Branch>: The pointer specified for ADC0 is not of a class known
to ROOT and (null) is not a known class
Error in <TTree::Branch>: The pointer specified for TDC0 is not of a class known
to ROOT and (null) is not a known class
ROOT TTree rebooked
***********************
***************************



If I analyze the data with TDC and ADC bank switched set to be 1 :
$ analyzer -i runXXXXX.mid -o runXXXXX.root

I get the following error messages:


************************************************************************
************************************************************************


Root server listening on port 9090...
Running analyzer offline. Stop with "!"
Error in <TTree::Branch>: The pointer specified for ADC0 is not of a class known
to ROOT and (null) is not a known class
Error in <TTree::Branch>: The pointer specified for TDC0 is not of a class known
to ROOT and (null) is not a known class
Set run number 1 in ODB
Load ODB from run 1...OK

 *** Break *** segmentation violation



===========================================================
There was a crash.
This is the entire stack trace of all threads:
===========================================================

Thread 2 (Thread 0x7f46c6853700 (LWP 10808)):
#0  0x0000003b63a0e84d in accept () from /lib64/libpthread.so.0
#1  0x0000003b64e370f4 in TUnixSystem::AcceptConnection(int) () from
/usr/lib64/root/libCore.so.5.28
#2  0x0000003b6647849c in TServerSocket::Accept(unsigned char) () from
/usr/lib64/root/libNet.so.5.28
#3  0x000000000040c50e in root_socket_server (arg=<value optimized out>) at
src/mana.c:5275
#4  0x00007f46c8dc513a in TThread::Function(void*) () from
/usr/lib64/root/libThread.so.5.28
#5  0x0000003b63a07851 in start_thread () from /lib64/libpthread.so.0
#6  0x0000003b62ee811d in clone () from /lib64/libc.so.6

Thread 1 (Thread 0x7f46c8b94720 (LWP 10800)):
#0  0x0000003b62eabfdd in waitpid () from /lib64/libc.so.6
#1  0x0000003b62e3e899 in do_system () from /lib64/libc.so.6
#2  0x0000003b62e3ebd0 in system () from /lib64/libc.so.6
#3  0x0000003b64e3da31 in TUnixSystem::StackTrace() () from
/usr/lib64/root/libCore.so.5.28
#4  0x0000003b64e3d3f3 in TUnixSystem::DispatchSignals(ESignals) () from
/usr/lib64/root/libCore.so.5.28
#5  <signal handler called>
#6  0x000000000041245f in TIter (file=<value optimized out>,
pevent=0x7f46c5281010, par=0x665180) at /usr/include/root/TCollection.h:148
#7  write_event_ttree (file=<value optimized out>, pevent=0x7f46c5281010,
par=0x665180) at src/mana.c:2872
#8  0x0000000000412a4c in process_event (par=0x665180, pevent=0x7f46c5281010) at
src/mana.c:3195
#9  0x0000000000412e42 in analyze_run (run_number=1,
input_file_name=0x7fff4d738340 "run00001.mid", output_file_name=<value optimized
out>) at src/mana.c:4178
#10 0x0000000000413372 in loop_runs_offline () at src/mana.c:4366
#11 0x0000000000413ba5 in main (argc=<value optimized out>, argv=<value
optimized out>) at src/mana.c:5579
===========================================================


The lines below might hint at the cause of the crash.
If they do not help you then please submit a bug report at
http://root.cern.ch/bugs. Please post the ENTIRE stack trace
from above as an attachment in addition to anything else
that might help us fixing this issue.
===========================================================
#6  0x000000000041245f in TIter (file=<value optimized out>,
pevent=0x7f46c5281010, par=0x665180) at /usr/include/root/TCollection.h:148
#7  write_event_ttree (file=<value optimized out>, pevent=0x7f46c5281010,
par=0x665180) at src/mana.c:2872
#8  0x0000000000412a4c in process_event (par=0x665180, pevent=0x7f46c5281010) at
src/mana.c:3195
#9  0x0000000000412e42 in analyze_run (run_number=1,
input_file_name=0x7fff4d738340 "run00001.mid", output_file_name=<value optimized
out>) at src/mana.c:4178
#10 0x0000000000413372 in loop_runs_offline () at src/mana.c:4366
#11 0x0000000000413ba5 in main (argc=<value optimized out>, argv=<value
optimized out>) at src/mana.c:5579
===========================================================


[midas.c:1973:,ERROR] cm_disconnect_experiment not called at end of program

**********************************************************************************************
**********************************************************************************************







I wonder if there is any program syntax change between MIDAS Version 4309 and
5347, and are there any simple working setup example which can output root tree
with the newest version of MIDAS?
 
In the end, I would like to thank the continuous effort from Triumf and PSI on
developing MIDAS, it is a pleasure to work with.

Many thanks
Bill 

Please, tell me how to choose a value of a "key" like DCM, pulser period,
presamples, upper thresholds to run a experiment? where can I find the related
informations? 

If is not so easy to get out of zlib how many bytes have been written actually. I used an undocumented function, 
which breaks down on 64-bit systems.

I now rewrote the code in mlogger.cxx to use lseek() to "measure" actually the output file and set the values 
correctly. I tried on a few systems but am not 100% sure if it works everywhere. Can you please double check?

The fix is in SVN revision 5347.

/Stefan

I try to do make in zlib folder and got  this
cc -O -o example example.o -L. -lz
/usr/bin/ld: errno: TLS definition in /lib/libc.so.6 section .tbss mismatches
non-TLS reference in ./libz.a(gzio.o)
/lib/libc.so.6: could not read symbols: Bad value
collect2: ld returned 1 exit status
make: *** [example] Error 1

Do I miss any package to be installed?
Thanks in advance,
Xelap

> > I've been trying to set up midas to create an automatic elog entry at the end of
> > each run and I've run into a problem. I've setup an elog on our server which
> > uses SSL and it seems that the melog provided by midas to create logbook entries
> > doesn't know any SSL.
> > 
> > My solution to this was to copy the crypt.c from the elog package to the
> > computer running midas and changed melog.c and the makefile to use SSL if a flag
> > -s is used. Does this seem like a sensible solution or did I oversee the obvious
> > and/or right way to do this?
> 
> Indeed melog.c is an old version of the elog.c utility in the elog package, which has not been maintained since a 
> long time. Can't you just use the recent elog.c utility from the elog package?

Well, that's essentially what I did, I just didn't want to install the whole elog package on the midas server. Whether
the utility is called elog or melog doesn't really matter. I just wanted to make sure that this is the right way to do
it. 

Thanks!

> I've been trying to set up midas to create an automatic elog entry at the end of
> each run and I've run into a problem. I've setup an elog on our server which
> uses SSL and it seems that the melog provided by midas to create logbook entries
> doesn't know any SSL.
> 
> My solution to this was to copy the crypt.c from the elog package to the
> computer running midas and changed melog.c and the makefile to use SSL if a flag
> -s is used. Does this seem like a sensible solution or did I oversee the obvious
> and/or right way to do this?

Indeed melog.c is an old version of the elog.c utility in the elog package, which has not been maintained since a 
long time. Can't you just use the recent elog.c utility from the elog package?

I've been trying to set up midas to create an automatic elog entry at the end of
each run and I've run into a problem. I've setup an elog on our server which
uses SSL and it seems that the melog provided by midas to create logbook entries
doesn't know any SSL.

My solution to this was to copy the crypt.c from the elog package to the
computer running midas and changed melog.c and the makefile to use SSL if a flag
-s is used. Does this seem like a sensible solution or did I oversee the obvious
and/or right way to do this?

When building MIDAS on Fedora 17 64-bit, the default zlib 1.2.5 shared library
is linked to.  When recording data, the "/Logger/Channels/*/Statistics/Bytes
written" value does not get set correctly beyond the first few seconds of the
run.  Occasionally, it appears to not get set at all, and mlogger aborts the run.

Installing zlib 1.2.3 in static form to /usr/local/lib (the default location),
and changing the NEED_ZLIB section of the MIDAS Makefile to the following seems
to function as a workaround:

ifdef NEED_ZLIB
CFLAGS   += -DHAVE-ZLIB
LIBS     += /usr/local/lib/libz.a
endif

Several Fedora 17 libraries expect zlib 1.2.5 specifically, so it seems safest
to not replace the default zlib shared library.

Some extra details are that the VME CPU is an XVB602, and the most recent GE-IP
drivers are being used for VME communication.  Fedora 17 was chosen to avoid a
bug with the VGA output in Fedora 13-16.

> > Hi, I'm having some trouble getting ss_thread_kill() to work properly. It seems 
> > to kill the entire program instead of just the thread.
> 
> You cannot kill a thread. It's not a well defined operation. Most OSes do have the 
> technical possibility to kill threads, but if you use them, you will not like the 
> results. For a taste of small trouble, if a thread is holding a lock and you kill 
> it, who's job is it to release the lock?
> 
> The best you can do is to ask the thread to gracefully shutdown itself. (I.e. by 
> using global variable flags).
> 
> P.S. I did not implement the ss_thread stuff, I do not know what ss_thread_kill() 
> does, but I recommend that you do not use it.
> 
> P.P.S. Programming using threads is complicated, I recommend that you read at least 
> some literature on the topic before using threads. At the least you must understand 
> the common pitfalls and mistakes. At the least, you must know about deadlocks, 
> livelocks, race conditions and semaphore priority inversions.
> 
> K.O.

Yes, but unfortunately what I was attempting to do was use a library function that I
can't alter. It sometimes gets stuck and I wanted a way to kill it. Anyway I ended up
not doing this at all in c++; I was able to do what I needed in python.

Shaun

> Hi, I'm having some trouble getting ss_thread_kill() to work properly. It seems 
> to kill the entire program instead of just the thread.

You cannot kill a thread. It's not a well defined operation. Most OSes do have the 
technical possibility to kill threads, but if you use them, you will not like the 
results. For a taste of small trouble, if a thread is holding a lock and you kill 
it, who's job is it to release the lock?

The best you can do is to ask the thread to gracefully shutdown itself. (I.e. by 
using global variable flags).

P.S. I did not implement the ss_thread stuff, I do not know what ss_thread_kill() 
does, but I recommend that you do not use it.

P.P.S. Programming using threads is complicated, I recommend that you read at least 
some literature on the topic before using threads. At the least you must understand 
the common pitfalls and mistakes. At the least, you must know about deadlocks, 
livelocks, race conditions and semaphore priority inversions.

K.O.

The Linux thread functionality was introduced by Konstantin, so he might have a better idea about that.

What I usually do is a graceful thread shutdown just by a flag. Like

int stop_thread = 0;

INT f(void *param)
{
  for (int x = 0; x < 100; x++) {
    sleep(1);
    if (stop_thread) {
      // clean up things here...
      return 0;
    }
  }
  return 0;
}

int main()
{
 printf("creating thread\n");
 midas_thread_t thr = ss_thread_create(f, NULL);
 sleep(2);
 printf("killing thread\n");
 stop_thread = 1;
 sleep(2);
 printf("success\n");
 return 0;
}


This way I have a chance to clean up things in the thread, which otherwise I would not be able to.

Hi, I'm having some trouble getting ss_thread_kill() to work properly. It seems 
to kill the entire program instead 
of just the thread. Here is a test program to show the error:

_________________________________
#include <stdio.h>
#include <stdlib.h>
#include "midas.h"
#include "msystem.h"

INT f(void *param)
{
  for (int x = 0; x < 100; x++)
    sleep(1);
  return 0;
}

int main()
{
  printf("creating thread\n");
  midas_thread_t thr = ss_thread_create(f, NULL);
  sleep(2);
  printf("killing thread\n");
  ss_thread_kill(thr);
  printf("success\n");
  return 0;
}
_________________________________

Makefile:
_________________________________
FLAGS=-g -Wall -DLINUX -DOS_LINUX -I/home/deap/packages/midas/include 
LIBS=-L/home/deap/packages/midas/linux-m64/lib -lmidas -lpthread -lrt -lutil

main.exe: main.cpp 
	g++ $(FLAGS) -o $@ $^ $(LIBS)

_________________________________

Output when run:

_________________________________

[deap@deap04 multithread]$ ./main.exe 
creating thread
killing thread
Killed
[deap@deap04 multithread]$ 
_________________________________

The last "Killed" indicated the whole program got killed, when it should 
actually just kill the thread and then 
print "success".

I noticed the function in system.c uses pthread_kill(). Some google searches 
show me that it may be better to use 
pthread_cancel() (ie http://stackoverflow.com/questions/3438536/when-to-use-
pthread-cancel-and-not-pthread-kill ).


Shaun

Hi Pierre-André, 

sorry for the long delay, another things keep me out of this computer.
Thanks a lot for correcting makefile.nt and the other applications!

Now I have try, downloading the MIDAS packages from the tarball mechanism, as
before,
and now it seems that the previous problems are solved. It remains only one small
problem, it is related to the odbedit.

I attach here the figure with the error that is reported by the computer. Is it
possible that is another file that needs to be updated? Can you help me with that?

Thanks a lot in advance!!!!



> Hi Raquel,
> 
> The makefile.nt has been corrected.
> Obviously Midas on Windows has not been updated for quite a while.
> mhttpd.c has been converted to c++ (mhttpd.cxx) as well as a couple of other 
> applications.
> 
> Please give a try,  PAA
> 
> > Hi,
> > 
> > I need to install MIDAS on a Windows system (Microsoft Windows Server 2003). 
> > The computer has the Microsoft Visual C++ 2010 Express version.
> > I have downloaded the MIDAS packages using the tarball mechanism. I have create 
> > the environment variables without problems and I have create the file           
> > %SystemRoot%\system32\exptab 
> > But when I try to build MIDAS and I do 
> > nmake -f makefile.nt
> > I have the following problem:
> > Microsoft (R) Program Maintenance Utility Version 10.00.30319.01
> > Copyright (C) Microsoft Corporation.  All rights reserved.
> > 
> > NMAKE : fatal error U1073: don't know how to make 'src/mhttpd.c'
> > Stop.
> > 
> > I don't understand this problem. Can anybody help me, please?
> > 
> > Thanks in advance!!!

> Hi,
> 
> I had to apply the attached patch to convince SuSE Linux 12.2 to compile mana.c
> gcc version is "(SUSE Linux) 4.6.2"
> 
> Problem is that gz{write,close, etc.} expect a 1st argument of type gzFile (see
> zlib.h), whereas out_file is FILE*. In fact, out_file is a cast to FILE*, even
> in the case when we work on a gzfile (HAVE_ZLIB).
> 
> Could you please confirm that the patch is correct, and possibly apply it to trunk?
> 
> I haven't checked if mana works as advertised now.
> 
> Cheers,
> 
> 
> Randolf

I applied your patch to the trunk.

Best,
Stefan