Can I take a snapshot of the current stack for every thread in some process from outside?

[Yuri]

I have the multithreaded process, each thread has some stack state at 
each point of time. For example during the timer tick when processes are 
switched?
Is there a way to take a snapshot without disrupting a process?

I was thinking gdb, but it requires the process to exit the system call 
to attach (?).
DTrace is only activated particular sensors are crossed.

So is there such a tool/command?

Yuri