[13/n] tensor engine, free functions implement call/broadcast/stream/etc., temp

Pull Request resolved: #478

This unifies call_on_shard_and_fetch with actor endpoints. It is now possible to issue a `.call` on a free-function remote and get a ValueMesh back. `call_on_shard_and_fetch` along with `fetch_shard` and `inspect` are implemented in terms of `call_one` now.
ghstack-source-id: 295137297
@exported-using-ghexport

Differential Revision: [D77978317](https://our.internmc.facebook.com/intern/diff/D77978317/)

Author: zdevito

python/monarch/_rust_bindings/monarch_hyperactor/shape.pyi

@@ -5,7 +5,7 @@
 # LICENSE file in the root directory of this source tree.
 
 import collections.abc
-from typing import Dict, final, Iterator, List, overload
+from typing import Dict, final, Iterator, List, overload, Sequence
 
 @final
 class Slice:
@@ -90,7 +90,7 @@ class Slice:
         ...
 
     @staticmethod
-    def new_row_major(ranks: list[int]) -> "Slice":
+    def new_row_major(ranks: Sequence[int]) -> "Slice":
         """Returns a contiguous slice composed of ranks"""
         ...
 
@@ -106,7 +106,7 @@ class Shape:
     - `labels`: A list of strings representing the labels for each dimension.
     - `slice`: An Slice object representing the shape.
     """
-    def __new__(cls, labels: List[str], slice: Slice) -> "Shape": ...
+    def __new__(cls, labels: Sequence[str], slice: Slice) -> "Shape": ...
     @property
     def ndslice(self) -> Slice: ...
     @property

python/monarch/_src/actor/actor_mesh.py

@@ -15,7 +15,10 @@
 import sys
 import traceback
 
+from abc import ABC, abstractmethod
+
 from dataclasses import dataclass
+from operator import mul
 from traceback import extract_tb, StackSummary
 from typing import (
     Any,
@@ -27,11 +30,13 @@
     Dict,
     Generic,
     Iterable,
+    Iterator,
     List,
     Literal,
     NamedTuple,
     Optional,
     ParamSpec,
+    Sequence,
     Tuple,
     Type,
     TYPE_CHECKING,
@@ -204,18 +209,32 @@ def __len__(self) -> int:
         return len(self._shape)
 
 
-class Endpoint(Generic[P, R]):
-    def __init__(
+class Extent(NamedTuple):
+    labels: Sequence[str]
+    sizes: Sequence[int]
+
+    @property
+    def nelements(self) -> int:
+        return functools.reduce(mul, self.sizes, 1)
+
+    def __str__(self) -> str:
+        return str(dict(zip(self.labels, self.sizes)))
+
+
+class Endpoint(ABC, Generic[P, R]):
+    @abstractmethod
+    def _send(
         self,
-        actor_mesh_ref: _ActorMeshRefImpl,
-        name: str,
-        impl: Callable[Concatenate[Any, P], Awaitable[R]],
-        mailbox: Mailbox,
-    ) -> None:
-        self._actor_mesh = actor_mesh_ref
-        self._name = name
-        self._signature: inspect.Signature = inspect.signature(impl)
-        self._mailbox = mailbox
+        args: Tuple[Any, ...],
+        kwargs: Dict[str, Any],
+        port: "Optional[Port]" = None,
+        selection: Selection = "all",
+    ) -> Extent:
+        pass
+
+    @abstractmethod
+    def _port(self, once: bool = False) -> "PortTuple[R]":
+        pass
 
     # the following are all 'adverbs' or different ways to handle the
     # return values of this endpoint. Adverbs should only ever take *args, **kwargs
@@ -228,46 +247,47 @@ def choose(self, *args: P.args, **kwargs: P.kwargs) -> Future[R]:
 
         Load balanced RPC-style entrypoint for request/response messaging.
         """
-        p: Port[R]
-        r: PortReceiver[R]
         p, r = port(self, once=True)
         # pyre-ignore
-        send(self, args, kwargs, port=p, selection="choose")
+        self._send(args, kwargs, port=p, selection="choose")
         return r.recv()
 
     def call_one(self, *args: P.args, **kwargs: P.kwargs) -> Future[R]:
-        if len(self._actor_mesh) != 1:
+        p, r = port(self, once=True)
+        # pyre-ignore
+        extent = self._send(args, kwargs, port=p, selection="choose")
+        if extent.nelements != 1:
             raise ValueError(
-                f"Can only use 'call_one' on a single Actor but this actor has shape {self._actor_mesh._shape}"
+                f"Can only use 'call_one' on a single Actor but this actor has shape {extent}"
             )
-        return self.choose(*args, **kwargs)
+        return r.recv()
 
     def call(self, *args: P.args, **kwargs: P.kwargs) -> "Future[ValueMesh[R]]":
         p: Port[R]
         r: RankedPortReceiver[R]
         p, r = ranked_port(self)
         # pyre-ignore
-        send(self, args, kwargs, port=p)
+        extent = self._send(args, kwargs, port=p)
 
         async def process() -> ValueMesh[R]:
-            results: List[R] = [None] * len(self._actor_mesh)  # pyre-fixme[9]
-            for _ in range(len(self._actor_mesh)):
+            results: List[R] = [None] * extent.nelements  # pyre-fixme[9]
+            for _ in range(extent.nelements):
                 rank, value = await r.recv()
                 results[rank] = value
             call_shape = Shape(
-                self._actor_mesh._shape.labels,
-                NDSlice.new_row_major(self._actor_mesh._shape.ndslice.sizes),
+                extent.labels,
+                NDSlice.new_row_major(extent.sizes),
             )
             return ValueMesh(call_shape, results)
 
         def process_blocking() -> ValueMesh[R]:
-            results: List[R] = [None] * len(self._actor_mesh)  # pyre-fixme[9]
-            for _ in range(len(self._actor_mesh)):
+            results: List[R] = [None] * extent.nelements  # pyre-fixme[9]
+            for _ in range(extent.nelements):
                 rank, value = r.recv().get()
                 results[rank] = value
             call_shape = Shape(
-                self._actor_mesh._shape.labels,
-                NDSlice.new_row_major(self._actor_mesh._shape.ndslice.sizes),
+                extent.labels,
+                NDSlice.new_row_major(extent.sizes),
             )
             return ValueMesh(call_shape, results)
 
@@ -282,8 +302,8 @@ async def stream(self, *args: P.args, **kwargs: P.kwargs) -> AsyncGenerator[R, R
         """
         p, r = port(self)
         # pyre-ignore
-        send(self, args, kwargs, port=p)
-        for _ in range(len(self._actor_mesh)):
+        extent = self._send(args, kwargs, port=p)
+        for _ in range(extent.nelements):
             yield await r.recv()
 
     def broadcast(self, *args: P.args, **kwargs: P.kwargs) -> None:
@@ -298,6 +318,46 @@ def broadcast(self, *args: P.args, **kwargs: P.kwargs) -> None:
         send(self, args, kwargs)
 
 
+class ActorEndpoint(Endpoint[P, R]):
+    def __init__(
+        self,
+        actor_mesh_ref: _ActorMeshRefImpl,
+        name: str,
+        impl: Callable[Concatenate[Any, P], Awaitable[R]],
+        mailbox: Mailbox,
+    ) -> None:
+        self._actor_mesh = actor_mesh_ref
+        self._name = name
+        self._signature: inspect.Signature = inspect.signature(impl)
+        self._mailbox = mailbox
+
+    def _send(
+        self,
+        args: Tuple[Any, ...],
+        kwargs: Dict[str, Any],
+        port: "Optional[Port]" = None,
+        selection: Selection = "all",
+    ) -> Extent:
+        """
+        Fire-and-forget broadcast invocation of the endpoint across all actors in the mesh.
+
+        This sends the message to all actors but does not wait for any result.
+        """
+        self._signature.bind(None, *args, **kwargs)
+        message = PythonMessage(
+            self._name,
+            _pickle((args, kwargs)),
+            None if port is None else port._port_ref,
+            None,
+        )
+        self._actor_mesh.cast(message, selection)
+        shape = self._actor_mesh._shape
+        return Extent(shape.labels, shape.ndslice.sizes)
+
+    def _port(self, once: bool = False) -> "PortTuple[R]":
+        return PortTuple.create(self._mailbox, once)
+
+
 class Accumulator(Generic[P, R, A]):
     def __init__(
         self, endpoint: Endpoint[P, R], identity: A, combine: Callable[[A, R], A]
@@ -337,10 +397,13 @@ def item(self, **kwargs) -> R:
 
         return self._values[self._ndslice.nditem(coordinates)]
 
-    def __iter__(self):
+    def items(self) -> Iterable[Tuple[Point, R]]:
         for rank in self._shape.ranks():
             yield Point(rank, self._shape), self._values[rank]
 
+    def __iter__(self) -> Iterator[Tuple[Point, R]]:
+        return iter(self.items())
+
     def __len__(self) -> int:
         return len(self._shape)
 
@@ -368,14 +431,7 @@ def send(
 
     This sends the message to all actors but does not wait for any result.
     """
-    endpoint._signature.bind(None, *args, **kwargs)
-    message = PythonMessage(
-        endpoint._name,
-        _pickle((args, kwargs)),
-        None if port is None else port._port_ref,
-        None,
-    )
-    endpoint._actor_mesh.cast(message, selection)
+    endpoint._send(args, kwargs, port, selection)
 
 
 class EndpointProperty(Generic[P, R]):
@@ -447,7 +503,7 @@ def create(mailbox: Mailbox, once: bool = False) -> "PortTuple[Any]":
 # not part of the Endpoint API because they way it accepts arguments
 # and handles concerns is different.
 def port(endpoint: Endpoint[P, R], once: bool = False) -> "PortTuple[R]":
-    return PortTuple.create(endpoint._mailbox, once)
+    return endpoint._port(once)
 
 
 def ranked_port(
@@ -676,7 +732,7 @@ def __init__(
                 setattr(
                     self,
                     attr_name,
-                    Endpoint(
+                    ActorEndpoint(
                         self._actor_mesh_ref,
                         attr_name,
                         attr_value._method,
@@ -695,7 +751,7 @@ def __getattr__(self, name: str) -> Any:
             attr = getattr(self._class, name)
             if isinstance(attr, EndpointProperty):
                 # Dynamically create the endpoint
-                endpoint = Endpoint(
+                endpoint = ActorEndpoint(
                     self._actor_mesh_ref,
                     name,
                     attr._method,
@@ -718,7 +774,7 @@ def _create(
         async def null_func(*_args: Iterable[Any], **_kwargs: Dict[str, Any]) -> None:
             return None
 
-        ep = Endpoint(
+        ep = ActorEndpoint(
             self._actor_mesh_ref,
             "__init__",
             null_func,

python/monarch/common/device_mesh.py

@@ -32,6 +32,7 @@
 
 from torch.utils._python_dispatch import TorchDispatchMode
 from torch.utils._pytree import tree_map
+from torch.utils.weak import weakref
 
 from ._tensor_to_table import tensor_to_table
 from .context_manager import activate_first_context_manager
@@ -170,6 +171,7 @@ def __init__(
         self.exit = lambda: None
         self.ref = None
         self._active_mesh_context = None
+        self._subset_of: Optional[weakref.ReferenceType["DeviceMesh"]] = None
 
     def define_remotely(self):
         if self.ref is None:
@@ -227,8 +229,17 @@ def _labels(self) -> Tuple[str, ...]:
     def _new_with_shape(self, shape: Shape) -> "DeviceMesh":
         mesh = DeviceMesh(self.client, shape.ndslice, tuple(shape.labels))
         mesh.exit = self.exit
+        mesh._subset_of = weakref.ref(self)
         return mesh
 
+    def _is_subset_of(self, other: "DeviceMesh") -> bool:
+        p = self
+        while p is not None:
+            if p is other:
+                return True
+            p = None if p._subset_of is None else p._subset_of()
+        return False
+
     def __call__(self, **kwargs) -> "DeviceMesh":
         """
         device_mesh(batch=3) or device_mesh(batch=slice(3, None))