Subprocess leaking

[ttill]

• uvloop version: 0.11.0
• Python version: 3.6.6
• Platform: Linux (Archlinux)
• Can you reproduce the bug with PYTHONASYNCIODEBUG in env?: yes

A lot of subsequent failing calls to asyncio.create_subprocess_exec cause a Too many open files OS error. Using the standard event loop, I do not get an error thrown.

Here is a minimal example:

import asyncio
import uvloop

async def m():
    for i in range(0, 10000):
        try:
            await asyncio.create_subprocess_exec('nonexistant')
        except FileNotFoundError:
            print(i)
        await asyncio.sleep(.001)

asyncio.set_event_loop_policy(uvloop.EventLoopPolicy())
asyncio.get_event_loop().run_until_complete(m())

Output:

[…]
333
334
335
Traceback (most recent call last):
  File "uvseg.py", line 13, in <module>
    asyncio.get_event_loop().run_until_complete(m())
  File "uvloop/loop.pyx", line 1448, in uvloop.loop.Loop.run_until_complete
  File "uvseg.py", line 7, in m
    await asyncio.create_subprocess_exec('nonexistant')
  File "/usr/lib64/python3.6/asyncio/coroutines.py", line 110, in __next__
    return self.gen.send(None)
  File "/usr/lib64/python3.6/asyncio/subprocess.py", line 225, in create_subprocess_exec
    stderr=stderr, **kwds)
  File "uvloop/loop.pyx", line 2603, in subprocess_exec
  File "uvloop/loop.pyx", line 2563, in __subprocess_run
  File "uvloop/handles/process.pyx", line 580, in uvloop.loop.UVProcessTransport.new
  File "uvloop/handles/process.pyx", line 87, in uvloop.loop.UVProcess._init
OSError: [Errno 24] Too many open files

The same code runs until the end when removing asyncio.set_event_loop_policy(uvloop.EventLoopPolicy()).

[1st1]

Fixed in uvloop 0.11.1

[1st1]

Thanks for submitting this bug!

[ttill]

Thank you!