How to debug multithread program under linux system?

inspect_multithread.sh

# get processes with related threads
ps -eLf |grep "process name"

# list all opened file descriptors in a process PID and under which thread
lsof -aKp PID

# trace syscalls in a process's main thread or other thread PID
strace -p PID

# report statistics for different tasks within process
pidstat -tdru -p PID 1

# debug a process associated with PID
gdb exec_cmd PID

# list threads within process PID
info threads

# jump to thread with ID
thread ID

# print a stack trace of a running process
gstack PID