add pdeathsigger

[slicklash]

Problem

Sometimes gprofilter hangs

Causes

sometimes start_process (Popen) hangs because of preexec_fn

Caution

The preexec_fn parameter is NOT SAFE to use in the presence of threads in your application. The child process could deadlock before exec is called. https://docs.python.org/3/library/subprocess.html#popen-constructor

Solution

replace preexec_fn with start_new_session flag and introduce pdeathsigger

[d3dave]

So this will try to snapshot() every 100ms? I don't think we can do snapshots that fast, it is a very heavy operation. If the issue is that pids do not appear fast enough in snapshots (what is the underlying reason 🤔 ? I see it's independent of runtime) then I'd be more comfortable sticking a sleep(2) before profiler.snapshot() instead of calling snapshot multiple times in a row.