chore: import upstream snapshot with attribution

python/paddle/distributed/fleet/base/strategy_group.py

@@ -0,0 +1,271 @@
+# Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
+#
+# 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 paddle.distributed as dist
+from paddle.distributed.fleet.layers.mpu import RNGStatesTracker
+
+
+class StrategyGroupBase:
+    """
+    The base class of communication group with distributed strategy.
+
+    Args:
+        list_of_ranks: A 2D-array, such as `[[0, 1, 2, 3], [4, 5, 6, 7]]`. Ranks in sublist represents
+    they are in the same communication group.
+
+    Returns:
+        The instance of strategy group.
+
+    Examples:
+        .. code-block:: pycon
+
+            >>> # doctest: +REQUIRES(env: DISTRIBUTED)
+            >>> import paddle.distributed as dist
+            >>> from paddle.distributed.fleet.base.strategy_group import StrategyGroupBase
+
+            >>> dist.init_parallel_env()
+            >>> strategy_group = dist.fleet.base.strategy_group.StrategyGroupBase([[0, 1], [2, 3]])
+            >>> print(strategy_group.world_size)
+            2
+
+
+    """
+
+    def __init__(self, list_of_ranks):
+        """
+        Initialize the communication group.
+        """
+        assert dist.is_initialized(), (
+            "The global communication group need to be initialized."
+        )
+        assert len(list_of_ranks), "The list_of_ranks can not be empty."
+        self._rank = dist.get_rank()
+        self._list_of_ranks = list_of_ranks
+        self._group = self._create_group()
+        self.random_states_tracker = RNGStatesTracker()
+
+    def add_random_seed(self, name, seed):
+        """
+        Add random seed for current rank.
+        """
+        self.random_states_tracker.add(name, seed)
+
+    def get_random_states_tracker(self):
+        """
+        Get the random states tracker.
+        """
+        return self.random_states_tracker
+
+    @property
+    def world_size(self):
+        """
+        The world size of communication group.
+
+        Returns:
+            Integer if the world_size of each group are equal, or a list of world_size if they are not equal.
+        """
+        world_size_list = []
+        for ranks in self._list_of_ranks:
+            world_size_list.append(len(ranks))
+        is_value = all(
+            world_size == world_size_list[0] for world_size in world_size_list
+        )
+        return world_size_list[0] if is_value else world_size_list
+
+    @property
+    def group(self):
+        """
+        The communication group which current rank belongs to.
+
+        Returns:
+            Group if current rank only belong to single communication group, or a list of Group if it belongs many.
+        """
+        return self._group
+
+    def _create_group(self):
+        self.list_of_group = []
+        for ranks in self._list_of_ranks:
+            group = dist.new_group(ranks=ranks)
+            if self._rank in ranks:
+                self.list_of_group.append(group)
+
+        if not self.list_of_group:
+            return None
+        else:
+            return (
+                self.list_of_group[0]
+                if len(self.list_of_group) == 1
+                else self.list_of_group
+            )
+
+    def __repr__(self):
+        debug_str = f"seed: {self._seed}; "
+        if not self.list_of_group:
+            return debug_str + "No group."
+        for i in range(len(self.list_of_group)):
+            debug_str += f"Group[{i}]: {self.list_of_group[i]}; "
+        return debug_str
+
+
+class DPGroup(StrategyGroupBase):
+    """
+    The communication group strategy for data parallel.
+
+    Args:
+        list_of_ranks: A 2D-array, such as `[[0, 1, 2, 3], [4, 5, 6, 7]]`. Ranks in sublist represents
+    they are in the same communication group.
+
+    Returns:
+        The instance of data parallel strategy group.
+    """
+
+    def __init__(self, list_of_ranks):
+        super().__init__(list_of_ranks)
+        assert not isinstance(self.group, list), (
+            f"Rank {self._rank} belongs to multi dp groups"
+        )
+
+
+class MPGroup(StrategyGroupBase):
+    """
+    The communication group strategy for model parallel.
+
+    Args:
+        list_of_ranks: A 2D-array, such as `[[0, 1, 2, 3], [4, 5, 6, 7]]`. Ranks in sublist represents
+    they are in the same communication group.
+
+    Returns:
+        The instance of model parallel strategy group.
+    """
+
+    def __init__(self, list_of_ranks):
+        super().__init__(list_of_ranks)
+        assert not isinstance(self.group, list), (
+            f"Rank {self._rank} belongs to multi mp groups"
+        )
+
+
+class ShardingGroup(StrategyGroupBase):
+    """
+    The communication group strategy for sharding parallel.
+
+    Args:
+        list_of_ranks: A 2D-array, such as `[[0, 1, 2, 3], [4, 5, 6, 7]]`. Ranks in sublist represents
+    they are in the same communication group.
+
+    Returns:
+        The instance of sharding parallel strategy group.
+    """
+
+    def __init__(self, list_of_ranks):
+        super().__init__(list_of_ranks)
+        assert not isinstance(self.group, list), (
+            f"Rank {self._rank} belongs to multi sharding groups"
+        )
+
+
+class PPGroup(StrategyGroupBase):
+    """
+    The communication group strategy for pipeline parallel.
+
+    Args:
+        list_of_ranks: A 2D-array, such as `[[0, 1, 2, 3], [4, 5, 6, 7]]`. Ranks in sublist represents
+    they are in the same communication group.
+
+    Returns:
+        The instance of pipeline parallel strategy group.
+    """
+
+    def __init__(self, list_of_ranks):
+        super().__init__(list_of_ranks)
+        assert not isinstance(self.group, list), (
+            f"Rank {self._rank} belongs to multi pp groups"
+        )
+
+        self._send_next_group = None
+        self._send_prev_group = None
+        self._recv_next_group = None
+        self._recv_prev_group = None
+        self._rank_of_next_stage = None
+        self._rank_of_prev_stage = None
+
+        if self.world_size > 1:
+            self._create_p2p_group()
+
+    @property
+    def rank_of_prev_stage(self):
+        """
+        Rank of the previous pp stage.
+
+        Returns:
+            The global rank of previous pp stage. `None` if without previous.
+        """
+        return self._rank_of_prev_stage
+
+    @property
+    def rank_of_next_stage(self):
+        """
+        Rank of the next pp stage.
+
+        Returns:
+            The global rank of next pp stage. `None` if without next.
+        """
+        return self._rank_of_next_stage
+
+    @property
+    def p2p_groups(self):
+        """
+        Communication subgroup in order to switch data with previous and next stage.
+
+        Returns:
+            Four subgroups including send/recv to/from prev/next.
+        """
+        return (
+            self._send_next_group,
+            self._send_prev_group,
+            self._recv_next_group,
+            self._recv_prev_group,
+        )
+
+    def _create_p2p_group(self):
+        degree = self.world_size
+        for ranks in self._list_of_ranks:
+            for idx, rank in enumerate(ranks):
+                next_rank = ranks[(idx + 1) % degree]
+                prev_rank = ranks[(idx - 1) % degree]
+
+                if self._rank == rank:
+                    self._rank_of_next_stage = next_rank
+                    self._rank_of_prev_stage = prev_rank
+
+                next_group = dist.new_group(ranks=[rank, next_rank])
+
+                if self._rank == rank:
+                    self._send_next_group = next_group
+                elif self._rank == next_rank:
+                    self._recv_prev_group = next_group
+
+                prev_group = dist.new_group(ranks=[prev_rank, rank])
+                if self._rank == rank:
+                    self._send_prev_group = prev_group
+                elif self._rank == prev_rank:
+                    self._recv_next_group = prev_group
+
+        assert (
+            self._send_next_group
+            and self._send_prev_group
+            and self._recv_next_group
+            and self._recv_prev_group
+        ), f"Error occurs while creating p2p group for rank {self._rank}."