check-stack.py

import sys
import trio

def dump_stack(where):
    print("-- {} --".format(where))
    frame = sys._getframe(1)
    while frame:
        print(frame.f_code.co_name)
        frame = frame.f_back

async def f():
    dump_stack("f before yielding")
    await g()
    dump_stack("f after yielding")

async def g():
    dump_stack("g before yielding")
    await h()
    dump_stack("g after yielding")

async def h():
    dump_stack("h before yielding")
    await trio.sleep(0)
    dump_stack("h after yielding")

trio.run(f)

output.txt

~/trio$ python check-stack.py
-- f before yielding --
f
send
run_impl
run
<module>
-- g before yielding --
g
f
send
run_impl
run
<module>
-- h before yielding --
h
g
f
send
run_impl
run
<module>
-- h after yielding --
h
send
run_impl
run
<module>
-- g after yielding --
g
send
run_impl
run
<module>
-- f after yielding --
f
send
run_impl
run
<module>