import asyncio
  import os
  import signal
  import sys
  
  
  async def get_stdin_reader():
      loop = asyncio.get_running_loop()
      reader = asyncio.StreamReader()
      protocol = asyncio.StreamReaderProtocol(reader)
      await loop.connect_read_pipe(lambda: protocol, sys.stdin)
      return reader
  
  
  async def amain():
      print(f'pid: {os.getpid()}')
  
      sig_queue: asyncio.Queue[None] = asyncio.Queue()
      def sig_handler() -> None:
          sig_queue.put_nowait(None)
  
      loop= asyncio.get_running_loop()
      loop.add_signal_handler(signal.SIGUSR1, sig_handler)
      reader = await get_stdin_reader()
  
      task1 = loop.create_task(reader.read(1))
      task2 = loop.create_task(sig_queue.get())
      pending = {task1, task2}
      while True:
          done, pending = await asyncio.wait(pending, return_when=asyncio.FIRST_COMPLETED)
          if task1 in done:
              task1 = loop.create_task(reader.read(1))
              pending.add(task1)
              print('got char on stdin')
          if task2 in done:
              task2 = loop.create_task(sig_queue.get())
              pending.add(task2)
              print('got signal')
  
  
  asyncio.run(amain())