From 42df6a2e7a56e7250145d507fbd2654383443848 Mon Sep 17 00:00:00 2001
From: Andreas Kloeckner <inform@tiker.net>
Date: Mon, 29 Nov 2021 17:05:23 -0600
Subject: [PATCH] Prototype DistributedExecutionContext

---
 arraycontext/distributed/__init__.py | 134 +++++++++++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 arraycontext/distributed/__init__.py

diff --git a/arraycontext/distributed/__init__.py b/arraycontext/distributed/__init__.py
new file mode 100644
index 00000000..abb2ddfd
--- /dev/null
+++ b/arraycontext/distributed/__init__.py
@@ -0,0 +1,134 @@
+"""
+.. autoclass:: DistributedExecutionContext
+"""
+
+__copyright__ = """
+Copyright (C) 2020-1 University of Illinois Board of Trustees
+"""
+
+__license__ = """
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+"""
+
+from typing import Any, Hashable, Tuple, TYPE_CHECKING
+import numpy as np
+
+from abc import ABC, abstractmethod
+
+if TYPE_CHECKING:
+    from mpi4py import MPI
+
+
+CommTag = Hashable
+
+
+# {{{ abstract
+
+class Request(ABC):
+    @abstractmethod
+    def complete_before(self, req: "Request"):
+        pass
+
+    @abstractmethod
+    def complete(self) -> None:
+        pass
+
+
+class RecvRequest(Request):
+    @abstractmethod
+    def complete(self) -> Any:
+        pass
+
+
+class DistributedExecutionContext:
+    @property
+    @abstractmethod
+    def rank(self):
+        pass
+
+    @property
+    @abstractmethod
+    def size(self):
+        pass
+
+    @abstractmethod
+    def compile(self, f):
+        pass
+
+    @abstractmethod
+    def initiate_send(self, remote_rank: int, comm_tag: CommTag,
+            array: Any) -> Request:
+        pass
+
+    @abstractmethod
+    def initiate_recv(self, remote_rank: int, comm_tag: CommTag,
+            shape: Tuple[int, ...], dtype: np.dtype) -> RecvRequest:
+        pass
+
+# }}}
+
+
+# {{{
+
+class _MPIRequest(ABC):
+    @abstractmethod
+    def complete_before(self, req: "Request"):
+        pass
+
+    @abstractmethod
+    def complete(self) -> None:
+        pass
+
+
+class _MPIRecvRequest(Request):
+    @abstractmethod
+    def complete(self) -> Any:
+        pass
+
+
+class MPIDistributedExecutionContext:
+    def __init__(self, mpi_communicator: "MPI.Comm") -> None:
+        self.mpi_communicator = mpi_communicator
+
+    @property
+    @abstractmethod
+    def rank(self):
+        return self.mpi_communicator.rank
+
+    @property
+    @abstractmethod
+    def size(self):
+        return self.mpi_communicator.size
+
+    def compile(self, f):
+        1/0
+
+    @abstractmethod
+    def initiate_send(self, remote_rank: int, comm_tag: CommTag,
+            array: Any) -> Request:
+        pass
+
+    @abstractmethod
+    def initiate_recv(self, remote_rank: int, comm_tag: CommTag,
+            shape: Tuple[int, ...], dtype: np.dtype) -> RecvRequest:
+        pass
+
+# }}}
+
+# vim: foldmethod=marker