Catching unrecognized exception

GNU Radio
1

Hi all guys,

I have a block which is responsible to receive certain messages from
other
blocks and to write the data from the message into database. Sometimes
the
following exception occures and the block stops writing into database:

thread[thread-per-block[0]: <gr_block db_logger2 (62)>]: caught
unrecognized exception

The structure of the block is really simple:

def handle_msg(self, msg):
    message = pmt.pmt_symbol_to_string(msg)
    msg_lines = message.split('\n')
    try:
        sensor_id = msg_lines[0]
        vendor = msg_lines[2]
        sensor_type = msg_lines[3]
        time = msg_lines[1]

#try:
querry = “INSERT INTO %s.%s (id ,sens_id ,vendor,
sensor_type, det_id) VALUES (NULL , ‘%s’, ‘%s’, ‘%s’,’%s’);” %
(self._db_name, self._det_table, sensor_id, vendor, sensor_type,
self._id)

print querry

        cur = self._con.cursor()
        cur.execute(querry)
    except mdb.Error, e:
        print "Unexpected error while trying to insert into table"
        print msg_lines
        print 50*'-'
        print "Error %d: %s" % (e.args[0],e.args[1])
        sys.exit(1)

Is there any way to track this problem and find the cause?

Best regards,

2

Dear gnuradioers,

I would like to ask againi if somebody can help me understand this:
thread[thread-per-block[0]: <gr_block db_logger2 (62)>]: caught
unrecognized exception

I have two blocks of db_logger type and it looks like only one catch
this
unrecognized exception and another keeps working fine.

best and thank you

3

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Hi Nemanja,

your except syntax is wrong, most probably you wanted to use “except
ExceptionType as e” instead, refer to
http://docs.python.org/2/tutorial/errors.html

Anyway, have you tried surrounding all your handler code with a try
and catch not only the database related errors?

Greetings,
Marcus

On 20.03.2014 15:58, Nemanja S. wrote:

VALUES (NULL , ‘%s’, ‘%s’, ‘%s’,‘%s’);" % (self._db_name,
– Nemanja Savić

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4

Hi again,

so, the exception appeared again. Just to remind:
thread[thread-per-block[0]: <gr_block db_logger2 (65)>]: caught
unrecognized exception

I can’t find what (65) means.
This time complete block of code was encapsulated by try and except but
nothing was caught.

Here is my code:

def handle_msg(self, msg):
    try:
        message = pmt.pmt_symbol_to_string(msg)
        msg_lines = message.split('\n')
        sensor_id = msg_lines[0]
        vendor = msg_lines[2]
        sensor_type = msg_lines[3]
        time = msg_lines[1]
        querry = "INSERT INTO `%s`.`%s` (`id` ,`sens_id` ,`vendor`,

sensor_type, det_id) VALUES (NULL , ‘%s’, ‘%s’, ‘%s’,’%s’);" %
(self._db_name, self._det_table, sensor_id, vendor, sensor_type,
self._id)
cur = self._con.cursor()
cur.execute(querry)
except mdb.Error, e:
print “Unexpected error while trying to insert into table”
print 50*’-’
print 50*’-’
print “Error %d: %s” % (e.args[0],e.args[1])
sys.exit(1)

    except:
        print 'msg handler exception'
        print 50*'-'
        print message
        print msg_lines
        print 50*'-'

Except this function there is also constructor and additional function
for
setting the database up (it is called only in constructor). There is no
work function as this block nly receives messages and writes to
database.
Is there any idea how can I catch this?

Thanx

5

It’s commented line inside the function called only once inside
constructor, and never again :slight_smile:

6

The ‘(65)’ looks to be the line number where the error occured. Notice
that previously the line number was ‘(62)’ which probably means that the
error is coming from line 65 of one of the files you have been editing.

Mike

–
Mike J. M0MIK BSc MIET
Email: [email protected]
Web: http://scanoo.com

7

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Hi Nemanja,

Simple explanation:
You haven’t fixed your syntax for the first except clause.
Going back to my other post, it should read
“except mdb.Error as e:”, not “except mdb.Error, e”.

Because you didn’t do that, “e” is undefined in your except clause.
This raises a NameError in your except clause, which doesn’t get
handled. Fix the except syntax.

Also, don’t do system.exit() in a multithreaded application, unless
you really know what you’re doing. You’ll end up with unfinished data,
broken database commits and so on.

Greetings,
Marcus

On 15.04.2014 15:40, Nemanja S. wrote:

db_logger2 (62)>]: caught unrecognized exception

The structure of the block is really simple:
mdb.Error, e: print "Unexpected error while trying to

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8

the last message was not clear.

So, I made sql syntax error and run the program, with my old syntax, and
exception was caught, so the error should be somewhere else.

9

Hello again,

Marcus, you are right, my syntax is not any more correct but there is
backwards compatibility. I initiated error on my own and everything
works
fine, so I would say there should be rather something more serious.

10

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Hi Mike,
it’s not. It’s part of the block name ;):

gnuradio-runtime/include/gnuradio/thread/thread_body_wrapper.h:63
std::cerr << “thread[” << d_name << "]: "
<< “caught unrecognized exception\n”;

Greetings,
Marcus

On 15.04.2014 16:21, Mike J. wrote:

was encapsulated by try and except but nothing was caught.
% (self._db_name, self._det_table, sensor_id, vendor,

try and catch not only the database related errors?

I have two blocks of db_logger type and it looks like only

def handle_msg(self, msg): message =
print msg_lines print 50*‘-’ print “Error %d: %s” %

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11

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Hi Nemanja,

ah that’s interesting, I’ve tried and for me, it fails. Strange. I’m
going to investigate that.

However, if that syntax is ok, then I’m out of ideas. You’re not
giving out all too much details, though. When excatly does this
exception occur? Does your block work at all? Does it work when
commenting out functionality? How about print “done this and that”
debugging? Do your two blocks share the same database connection (if
that’s the case, are you doing multithreading correctly?)?

My only guess would still be that one of your except clauses throws an
Exception. Maybe “print message”, if message = pmt.symbol_to_string()
failed?

By the way, “caught unrecognized exception” comes from the C++ domain,
it happens when there is an uncaught C++ exception, which might have
nothing to do with your executed python.

What you can do is run your program in a debugger, i.e.

$ gdb --args python your_python_flowgraph.py
…
(gdb)run
…
interrupt (ctrl-z), try to set a breakpoint at
gnuradio-runtime/include/gnuradio/thread/thread_body_wrapper.h:61 ,
then continue running your program
(gdb)cont
…
and see what happened prior to that call:
(gdb)bt

Greetings,
Marcus

On 16.04.2014 10:45, Nemanja S. wrote:

Also, don’t do system.exit() in a multithreaded application,

caught unrecognized exception
msg_lines[2] sensor_type = msg_lines[3] time = msg_lines[1]
message print msg_lines print 50*‘-’

a try and catch not only the database related errors?

I have two blocks of db_logger type and it looks like

mdb.Error, e: print "Unexpected error while trying

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