Supports adding Mars extensions via setup entrypoints

mars/core/entrypoints.py

@@ -0,0 +1,42 @@
+# Copyright 1999-2021 Alibaba Group Holding Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+import warnings
+import functools
+
+from pkg_resources import iter_entry_points
+
+logger = logging.getLogger(__name__)
+
+
+# from https://github.com/numba/numba/blob/master/numba/core/entrypoints.py
+# Must put this here to avoid extensions re-triggering initialization
+@functools.lru_cache(maxsize=None)
+def init_all():
+    """Execute all `mars_extensions` entry points with the name `init`
+    If extensions have already been initialized, this function does nothing.
+    """
+    for entry_point in iter_entry_points("mars_extensions", "init"):
+        logger.info("Loading extension: %s", entry_point)
+        try:
+            func = entry_point.load()
+            func()
+        except Exception as e:
+            msg = "Mars extension module '{}' failed to load due to '{}({})'."
+            warnings.warn(
+                msg.format(entry_point.module_name, type(e).__name__, str(e)),
+                stacklevel=2,
+            )
+            logger.info("Extension loading failed for: %s", entry_point)

mars/core/tests/test_entrypoints.py

@@ -0,0 +1,124 @@
+# Copyright 1999-2021 Alibaba Group Holding Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import sys
+import types
+import warnings
+import pkg_resources
+
+
+class _DummyClass(object):
+    def __init__(self, value):
+        self.value = value
+
+    def __repr__(self):
+        return "_DummyClass(%f, %f)" % self.value
+
+
+def test_init_entrypoint():
+    # FIXME: Python 2 workaround because nonlocal doesn't exist
+    counters = {"init": 0}
+
+    def init_function():
+        counters["init"] += 1
+
+    mod = types.ModuleType("_test_mars_extension")
+    mod.init_func = init_function
+
+    try:
+        # will remove this module at the end of the test
+        sys.modules[mod.__name__] = mod
+
+        # We are registering an entry point using the "mars" package
+        # ("distribution" in pkg_resources-speak) itself, though these are
+        # normally registered by other packages.
+        dist = "pymars"
+        entrypoints = pkg_resources.get_entry_map(dist)
+        my_entrypoint = pkg_resources.EntryPoint(
+            "init",  # name of entry point
+            mod.__name__,  # module with entry point object
+            attrs=["init_func"],  # name of entry point object
+            dist=pkg_resources.get_distribution(dist),
+        )
+        entrypoints.setdefault("mars_extensions", {})["init"] = my_entrypoint
+
+        from .. import entrypoints
+
+        # Allow reinitialization
+        entrypoints.init_all.cache_clear()
+
+        entrypoints.init_all()
+
+        # was our init function called?
+        assert counters["init"] == 1
+
+        # ensure we do not initialize twice
+        entrypoints.init_all()
+        assert counters["init"] == 1
+    finally:
+        # remove fake module
+        if mod.__name__ in sys.modules:
+            del sys.modules[mod.__name__]
+
+
+def test_entrypoint_tolerance():
+    # FIXME: Python 2 workaround because nonlocal doesn't exist
+    counters = {"init": 0}
+
+    def init_function():
+        counters["init"] += 1
+        raise ValueError("broken")
+
+    mod = types.ModuleType("_test_mars_bad_extension")
+    mod.init_func = init_function
+
+    try:
+        # will remove this module at the end of the test
+        sys.modules[mod.__name__] = mod
+
+        # We are registering an entry point using the "mars" package
+        # ("distribution" in pkg_resources-speak) itself, though these are
+        # normally registered by other packages.
+        dist = "pymars"
+        entrypoints = pkg_resources.get_entry_map(dist)
+        my_entrypoint = pkg_resources.EntryPoint(
+            "init",  # name of entry point
+            mod.__name__,  # module with entry point object
+            attrs=["init_func"],  # name of entry point object
+            dist=pkg_resources.get_distribution(dist),
+        )
+        entrypoints.setdefault("mars_extensions", {})["init"] = my_entrypoint
+
+        from .. import entrypoints
+
+        # Allow reinitialization
+        entrypoints.init_all.cache_clear()
+
+        with warnings.catch_warnings(record=True) as w:
+            entrypoints.init_all()
+
+        bad_str = "Mars extension module '_test_mars_bad_extension'"
+        for x in w:
+            if bad_str in str(x):
+                break
+        else:
+            raise ValueError("Expected warning message not found")
+
+        # was our init function called?
+        assert counters["init"] == 1
+
+    finally:
+        # remove fake module
+        if mod.__name__ in sys.modules:
+            del sys.modules[mod.__name__]

mars/deploy/oscar/local.py

@@ -22,6 +22,7 @@
 import numpy as np
 
 from ... import oscar as mo
+from ...core.entrypoints import init_all
 from ...lib.aio import get_isolation, stop_isolation
 from ...resource import cpu_count, cuda_count
 from ...services import NodeRole
@@ -111,6 +112,8 @@ def __init__(
         web: Union[bool, str] = "auto",
         timeout: float = None,
     ):
+        # load third party extensions.
+        init_all()
         # load config file to dict.
         if not config or isinstance(config, str):
             config = load_config(config)

mars/deploy/oscar/ray.py

@@ -20,6 +20,7 @@
 from typing import Union, Dict, List, Optional, AsyncGenerator
 
 from ... import oscar as mo
+from ...core.entrypoints import init_all
 from ...oscar.backends.ray.driver import RayActorDriver
 from ...oscar.backends.ray.utils import (
     process_placement_to_address,
@@ -371,6 +372,8 @@ def __init__(
         worker_mem: int = 32 * 1024 ** 3,
         config: Union[str, Dict] = None,
     ):
+        # load third party extensions.
+        init_all()
         self._cluster_name = cluster_name
         self._supervisor_mem = supervisor_mem
         self._worker_num = worker_num

mars/deploy/oscar/session.py

@@ -35,6 +35,7 @@
 from ... import oscar as mo
 from ...config import options
 from ...core import ChunkType, TileableType, TileableGraph, enter_mode
+from ...core.entrypoints import init_all
 from ...core.operand import Fetch
 from ...lib.aio import (
     alru_cache,
@@ -1839,6 +1840,8 @@ def new_session(
     new: bool = True,
     **kwargs,
 ) -> AbstractSession:
+    # load third party extensions.
+    init_all()
     ensure_isolation_created(kwargs)
 
     if address is None:

mars/oscar/backends/pool.py

@@ -23,6 +23,7 @@
 from abc import ABC, ABCMeta, abstractmethod
 from typing import Dict, List, Type, TypeVar, Coroutine, Callable, Union, Optional
 
+from ...core.entrypoints import init_all
 from ...utils import implements, to_binary
 from ...utils import lazy_import, register_asyncio_task_timeout_detector
 from ..api import Actor
@@ -141,6 +142,8 @@ def __init__(
         self._asyncio_task_timeout_detector_task = (
             register_asyncio_task_timeout_detector()
         )
+        # load third party extensions.
+        init_all()
 
     @property
     def router(self):