Experimental Physics and
Industrial Control System

Mark Rivers <[email protected]> · Fri, 13 Dec 2013 03:27:57 +0000

Hi Peter,

OK, we're making progress.  It is crashing when drvPM304.cc::motor_init is called from device support.  That function attempts to figure out what model controller it is talking to, whether it is servo or stepper, etc. by querying the controller.  It calls send_recv_mess to talk to the device, and that in turn calls epicsStrtok_r, which is crashing.

Since it is crashing when the driver itself is intializing all controllers, it will crash before you can run dbior, as you discovered.

The next step is to turn on debugging in the PM304 driver.  You need to edit the motor/motorApp/MclennanSrc/Makefile and uncomment this line:

#USR_CXXFLAGS += -DDEBUG

Then rebuild that directory and your application.

In your startup script add the following line:

var drvPM304Debug 10

before the call to PM304Setup(1, 10)

Then we should get some debugging information when the driver initializes.

I see you are running on linux-arm.  Perhaps there is a problem with epicsStrtok_r (which I wrote a long time ago) on that architecture.  But let's hope it's something simpler!

Mark

________________________________________
From: Peter Linardakis [[email protected]]
Sent: Thursday, December 12, 2013 8:54 PM
To: Mark Rivers; [email protected]; [email protected]
Subject: RE: Mclennan PM600 motor controller

Hi Mark

By including asynSetTraceMask("test-se1-1",0,255) in st.cmd, between boot and seg fault we get:

        ...
        2013/12/13 01:56:21.420 test-se1-1 asynManager::queueLockPort locking port
        2013/12/13 01:56:21.423 test-se1-1 asynManager::queueLockPort created queueLockPortPvt=0x289718
        2013/12/13 01:56:21.426 test-se1-1 asynManager::queueLockPort created queueLockPortPvt=0x289718, event=0x28ee98, mutex=0x28ef10
        2013/12/13 01:56:21.428 test-se1-1 asynManager::queueLockPort taking mutex 0x28ef10
        2013/12/13 01:56:21.430 test-se1-1 asynManager::queueLockPort queueing request
        2013/12/13 01:56:21.431 test-se1-1 addr -1 queueRequest priority 0 not lockHolder
        2013/12/13 01:56:21.432 asynManager::portThread port=test-se1-1 callback
        2013/12/13 01:56:21.434 test-se1-1 asynManager::queueLockPortCallback signaling begin event
        2013/12/13 01:56:21.435 test-se1-1 asynManager::queueLockPortCallback waiting for mutex from queueUnlockPort
        2013/12/13 01:56:21.436 test-se1-1 asynManager::queueLockPort waiting for event
        2013/12/13 01:56:21.437 test-se1-1 asynManager::queueLockPort got event from callback
        2013/12/13 01:56:21.438 test-se1-1 flush
        2013/12/13 01:56:21.439 172.16.0.108:5300 flush
        2013/12/13 01:56:21.440 asynOctetSyncIO flush
        2013/12/13 01:56:21.441 test-se1-1 queueUnlockPort
        2013/12/13 01:56:21.442 test-se1-1 asynManager::queueUnlockPort waiting for event
        2013/12/13 01:56:21.443 test-se1-1 queueUnlockPort unlock mutex 0x28ef10 complete.
        2013/12/13 01:56:21.445 test-se1-1 asynManager::queueLockPort locking port
        2013/12/13 01:56:21.445 test-se1-1 asynManager::queueLockPort taking mutex 0x28ef10
        2013/12/13 01:56:21.446 test-se1-1 asynManager::queueLockPort queueing request
        2013/12/13 01:56:21.447 test-se1-1 addr -1 queueRequest priority 0 not lockHolder
        2013/12/13 01:56:21.448 asynManager::portThread port=test-se1-1 callback
        2013/12/13 01:56:21.449 test-se1-1 asynManager::queueLockPortCallback signaling begin event
        2013/12/13 01:56:21.450 test-se1-1 asynManager::queueLockPortCallback waiting for mutex from queueUnlockPort
        2013/12/13 01:56:21.451 test-se1-1 asynManager::queueLockPort waiting for event
        2013/12/13 01:56:21.452 test-se1-1 asynManager::queueLockPort got event from callback
        2013/12/13 01:56:21.453 172.16.0.108:5300 read.
        2013/12/13 01:56:21.455 test-se1-1 queueUnlockPort
        2013/12/13 01:56:21.456 test-se1-1 asynManager::queueUnlockPort waiting for event
        2013/12/13 01:56:21.458 test-se1-1 queueUnlockPort unlock mutex 0x28ef10 complete.

and the gdb backtrace is:

        ...
        Core was generated by `../../bin/linux-arm/pitest st.cmd'.
        Program terminated with signal 11, Segmentation fault.
        #0  0xb6d649d4 in epicsStrtok_r () from /opt/epics/base/lib/linux-arm/libCom.so
        (gdb) backtrace
        #0  0xb6d649d4 in epicsStrtok_r () from /opt/epics/base/lib/linux-arm/libCom.so
        #1  0xb6eb4bb0 in send_recv_mess(int, char const*, char*) () from /opt/epics/modules/motorR6-8/lib/linux-arm/libMclennan.so
        #2  0xb6eb5218 in motor_init() () from /opt/epics/modules/motorR6-8/lib/linux-arm/libMclennan.so
        #3  0xb6eb49dc in PM304_init(void*) () from /opt/epics/modules/motorR6-8/lib/linux-arm/libMclennan.so
        #4  0xb6de26d0 in dbInitDevSup () from /opt/epics/base/lib/linux-arm/libdbStaticIoc.so
        #5  0xb6e7af8c in iocBuild () from /opt/epics/base/lib/linux-arm/libmiscIoc.so
        #6  0xb6e7b52c in iocInit () from /opt/epics/base/lib/linux-arm/libmiscIoc.so
        #7  0xb6d5ef78 in iocshBody () from /opt/epics/base/lib/linux-arm/libCom.so
        #8  0x0000bcc4 in main ()

As far as the dbior command goes, I assume you meant commenting out the database that contains the motor record?  If that's the case, the it seg faults before I get to a prompt, as it normally does and the backtrace is the same as above.

Regards
Peter

-----Original Message-----
From: Mark Rivers [mailto:[email protected]]
Sent: Friday, 13 December 2013 11:14 AM
To: Peter Linardakis; [email protected]; [email protected]
Subject: RE: Mclennan PM600 motor controller

Hi Peter,

> I had this nagging suspicion that I should indeed be basing my record
> on motor.db, but was confused from the motorR6-8 README file saying that serial devices needed asyn4-2.  Live and learn I guess.

Your confusion is understandable.  There are actually 2 layers in the motor software that use asyn.

1) The interface between the motor driver and message based interfaces like RS-232, GPIB, and TCP/IP.  The motor drivers always use asyn for this layer, even the old Model 1 drivers.

2) The interface between motor record device support and the motor driver.  Only Model 2 and Model 3 drivers use asyn in this layer.

> I changed the PM304Config(0, "test-se1-1", 1) line from PM304Config(1,
> "test-se1-1", 1), since I assumed from the "#C0 S0" syntax that if I only have one card, then it must be card 0.
> In this case, the IOC seg faults immediately after boot.

The correct command is card 0, as you did.

These are the command in my startup script:
##############################
# PM304 driver setup parameters:
#     (1) maximum # of controllers,
#     (2) motor task polling rate (min=1Hz, max=60Hz)
PM304Setup(1, 10)
# PM304 driver configuration parameters:
#     (1) controller
#     (2) asyn port
#     (3) MAX axes
# Example:
#   PM304Config(0, "serial1", 1)
PM304Config(0, "serial9", 1)
##############################

So now we need to figure out why it is segfaulting for you.

Your startup script has these lines:

drvAsynIPPortConfigure("test-se1-1", "172.16.0.108:5300") # Add these lines for asynTrace debugging
asynSetTraceIOMask("test-se1-1",0,2)
asynSetTraceMask("test-se1-1",0,9)

The last line is turning on ASYN_TRACEIO_DRIVER for the TCP driver.  So you should see messages for every write and read operation to the device.  Do you see any such I/O before it crashes?  You could change the last line to:

asynSetTraceMask("test-se1-1",0,255)

to turn on all possible messages.

See if you get any messages before it seg faults.

You should also run gdb to figure out where it is crashing.  Here's how to do that:

- Enable core dumps.  With the csh this is done with

limit core 1000000

With bash it is

ulimit -c 1000000

Now run your application so it seqfaults.  You will get a core file, core.XXXXX, where XXXXX is a number.

Now run gdb on your application with that core file:

gdb PATH_TO_YOUR_APPLICATION core.XXXXX

When you get the gdb prompt type the command

backtrace

That should show what function was executing when it crashed.

Here is something else to do.  Load your application, but comment out the line to load the motor database.  At the IOC prompt type this command

dbior "drvPM304",10

That should give you a report like the following:

Driver: drvPM304
    PM304 controller 0, id: Mclennan Servo Supplies Ltd  PM304  V6.17

Mark

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System