# This test ensures that the scheduler doesn't trigger any assertions
# while dealing with concurrent access from multiple threads.

import _thread
import utime
import micropython
import gc

try:
 micropython.schedule
except AttributeError:
 print("SKIP")
 raise SystemExit

gc.disable()

_NUM_TASKS = 10000
_TIMEOUT_MS = 10000

n = 0 # How many times the task successfully ran.
t = None # Start time of test, assigned here to preallocate entry in globals dict.


def task(x):
 global n
 n += 1


def thread():
 while True:
 try:
 micropython.schedule(task, None)
 except RuntimeError:
 # Queue full, back off.
 utime.sleep_ms(10)


for i in range(8):
 _thread.start_new_thread(thread, ())

# Wait up to 10 seconds for 10000 tasks to be scheduled.
t = utime.ticks_ms()
while n < _NUM_TASKS and utime.ticks_diff(utime.ticks_ms(), t) < _TIMEOUT_MS:
 pass

if n < _NUM_TASKS:
 # Not all the tasks were scheduled, likely the scheduler stopped working.
 print(n)
else:
 print("PASS")