Use uvloop (winloop) as default loop, if available.

.travis.yml

@@ -4,17 +4,18 @@ jobs:
  - python: 3.9
  env:
  - MPYC_NOPRSS=1
- install: pip install numpy==1.23.* gmpy2
+ install: pip install numpy==1.23.* gmpy2 uvloop
  - python: pypy3.9-7.3.9
  install: pip install numpy==1.24.*
  - python: 3.10
  env:
  - MPYC_NONUMPY=1
  - MPYC_NOGMPY=1
+ - MPYC_NOUVLOOP=1
  - python: 3.11
  install: pip install numpy==1.25.* gmpy2
  - python: 3.12
- install: pip install numpy
+ install: pip install numpy uvloop
 before_install:
  - pip install --upgrade pip
  - pip install coverage

README.md

@@ -34,6 +34,8 @@ Use `pip install numpy` to enable support for secure NumPy arrays in MPyC, along
 
 Use `pip install gmpy2` to run MPyC with the package [gmpy2](https://pypi.org/project/gmpy2/) for considerably better performance.
 
+Use `pip install uvloop` (or `pip install winloop` on Windows) to replace Python's default asyncio event loop in MPyC for generally improved performance.
+
 ### Some Tips
 
 - Try `run-all.sh` or `run-all.bat` in the `demos` directory to have a quick look at all pure Python demos.

mpyc/__init__.py

@@ -29,7 +29,7 @@
 and statistics (securely mimicking Python’s statistics module).
 """
 
-__version__ = '0.9.7'
+__version__ = '0.9.8'
 __license__ = 'MIT License'
 
 import os
@@ -69,8 +69,6 @@ def get_arg_parser():
  help='enable SSL connections')
  group.add_argument('-W', '--workers', type=int, metavar='w',
  help='maximum number of worker threads per party')
- group.add_argument('-E', '--event-loop', type=int, metavar='e',
- help='0=asyncio_default 1=uvloop/winloop 2=WindowsSelector')
 
  group = parser.add_argument_group('MPyC parameters')
  group.add_argument('-L', '--bit-length', type=int, metavar='l',
@@ -89,6 +87,8 @@ def get_arg_parser():
  help='disable use of gmpy2 package')
  group.add_argument('--no-numpy', action='store_true',
  help='disable use of numpy package')
+ group.add_argument('--no-uvloop', action='store_true',
+ help='disable use of uvloop (winloop) package')
  group.add_argument('--no-prss', action='store_true',
  help='disable use of PRSS (pseudorandom secret sharing)')
  group.add_argument('--mix32-64bit', action='store_true',
@@ -164,16 +164,27 @@ def get_arg_parser():
  if not env_no_gmpy2:
  os.environ['MPYC_NOGMPY'] = '1' # NB: MPYC_NOGMPY also set for subprocesses
 
- # Set event loop policy early (e.g., before mpyc.__main__.py is imported).
- if options.event_loop == 1:
- if sys.platform.startswith('win32'):
+ # Load uvloop (winloop) if available and not disabled.
+ env_no_uvloop = int(os.getenv('MPYC_NOUVLOOP', '0'))
+ EventLoopPolicy = None
+ if importlib.util.find_spec('winloop' if sys.platform.startswith('win32') else 'uvloop'):
+ # uvloop (winloop) package available
+ if options.no_uvloop or env_no_uvloop:
+ logging.info(f'Use of package uvloop (winloop) inside MPyC disabled.')
+ elif sys.platform.startswith('win32'):
  from winloop import EventLoopPolicy
+ logging.debug(f'Load winloop')
  else:
- from uvloop import EventLoopPolicy
- asyncio.set_event_loop_policy(EventLoopPolicy())
- elif options.event_loop == 2 and sys.platform.startswith('win32'):
+ from uvloop import EventLoopPolicy, _version
+ logging.debug(f'Load uvloop version {_version.__version__}')
+ del _version
+ # Hidden feature to set selector loop on Windows (only via MPYC_NOUVLOOP).
+ if env_no_uvloop == 2 and sys.platform.startswith('win32'):
  # override default asyncio.WindowsProactorEventLoopPolicy
- asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())
+ EventLoopPolicy = asyncio.WindowsSelectorEventLoopPolicy
+ if EventLoopPolicy:
+ # set event loop policy early (e.g., before mpyc.__main__.py is imported)
+ asyncio.set_event_loop_policy(EventLoopPolicy())
  logging.debug(f'Event loop policy: {type(asyncio.get_event_loop_policy())}')
 
- del options, env_max_workers, env_no_numpy, env_no_gmpy2
+ del options, env_max_workers, env_no_numpy, env_no_gmpy2, env_no_uvloop, EventLoopPolicy

mpyc/asyncoro.py

@@ -50,24 +50,6 @@ def connection_made(self, transport):
  to the peer as well as any PRSS keys.
  """
  self.transport = transport
- if 'winloop' in str(self.runtime._loop):
- # Workaround to avoid problems with handling of high/low watermarks when
- # running MPyC demos with large communication complexity.
- # For example, "python np_lpsolver.py -i5 -M3 -E1"
- # gives "OSError: [Errno 4088] Unknown error" (4088 stands for UV_EAGAIN).
- # Winloop 0.1.0 default setting, with FLOW_CONTROL_HIGH_WATER = 64:
- # high = 65536 = FLOW_CONTROL_HIGH_WATER * 1024
- # low = 16 = FLOW_CONTROL_HIGH_WATER // 4
- # Workaround:
- self.transport.set_write_buffer_limits(high=2**18)
- # With high=2**18, problem still present for cases with even larger communication
- # complexity, like "python np_lpsolver.py -i5 -M3 -E1", and setting
- # high=2**22 resolves this case as well.
- # Alternative workaround: set high=0 to disable use of high/low watermarks.
- # NB: these workarounds do not work with SSL,
- # for example, "python np_lpsolver.py -i5 -M3 -E1 --ssl"
- # keeps giving "OSError: [Errno 4088] Unknown error" whatever we set for high and low.
- print(f'workaround for Winloop: {self.transport.get_write_buffer_limits()=}')
  if self.peer_pid is not None: # this party is client (peer is server)
  rt = self.runtime
  pid_keys = [rt.pid.to_bytes(2, 'little')] # send pid
@@ -158,18 +140,7 @@ def connection_lost(self, exc):
  Otherwise, if the connection is lost unexpectedly, exc may indicate the cause.
  """
  if exc:
- if 'winloop' in str(self.runtime._loop):
- # Workaround to suppress seemingly spurious UV_EOF (4095) exception from winloop.
- # For example, "python helloworld.py -M2 --output-file -E1"
- # creates a file "party2_1.log" with the error present.
- # Does not happen over SSL, which makes sense as for SSL
- # self.transport.can_write_eof() == False.
- if exc.errno == 4095: # NB: exc is an OSError in Winloop 0.1.0
- print(f'suppressed UV_EOF error in connection_lost(): {type(exc)=} {exc=}')
- else:
- raise exc
- else:
- raise exc
+ raise exc
 
  rt = self.runtime
  rt.parties[self.peer_pid].protocol = None