#!/bin/bash

# generate a backtrace for busy worker threads

PNAME=${1:-dbmail-imapd}

# only look for thread with more that MAXCPU cpu load

MAXCPU=${2:-20}

# get the imap PID

PID=`pidof $PNAME`

[ -n "$PID" ] || { echo "Error: Unable to determine main process ID for $PNAME"; exit 1; }

echo "generate backtrace for $PNAME($PID) with CPU > $MAXCPU"

# find busy threads

BUSY=`top -H -b -n1 -p $PID|grep -E "${PNAME}|pool"| awk '{if ($9 > $MAXCPU) print $1}'`

[ -n "$BUSY" ] || exit 0

# generate a gdb commandfile

tmpfile=`mktemp`

echo 'bt' > $tmpfile

for TID in $BUSY; do

# get a backtrace

gdb --batch -x $tmpfile -p $TID > \

/tmp/debug-dbmail-backtrace.$TID

echo "backtrace for $PNAME in " /tmp/debug-dbmail-backtrace.$TID

done

rm -f $tmpfile