ColossalAI/applications/Chat/coati/trainer/strategies/base.py

138 lines
5.3 KiB
Python

from abc import ABC, abstractmethod
from contextlib import nullcontext
from typing import Callable, Dict, List, Optional, Tuple, Union
import torch
import torch.nn as nn
from coati.experience_buffer import ExperienceBuffer
from torch.optim import Optimizer
from torch.utils.data import DataLoader
from transformers.tokenization_utils_base import PreTrainedTokenizerBase
from colossalai.booster import Booster
from colossalai.booster.plugin import Plugin
from .sampler import DistributedSampler
_BoostArgSpec = Union[nn.Module, Tuple[nn.Module, Optimizer], Dict]
class Strategy(ABC):
"""
Base class for training strategies.
"""
def __init__(self, plugin_initializer: Callable[..., Optional[Plugin]] = lambda: None) -> None:
super().__init__()
# NOTE: dist must be initialized before Booster
self.setup_distributed()
self.plugin = plugin_initializer()
self.booster = Booster(plugin=self.plugin)
self._post_init()
@abstractmethod
def _post_init(self) -> None:
pass
def backward(self, loss: torch.Tensor, model: nn.Module, optimizer: Optimizer, **kwargs) -> None:
self.booster.backward(loss, optimizer)
def optimizer_step(self, optimizer: Optimizer, **kwargs) -> None:
optimizer.step()
@abstractmethod
def setup_distributed(self) -> None:
pass
@abstractmethod
def setup_dataloader(self, data_buffer: ExperienceBuffer, pin_memory: bool = False) -> DataLoader:
pass
def model_init_context(self):
return nullcontext()
def prepare(self, *boost_args: _BoostArgSpec) -> Union[List[_BoostArgSpec], _BoostArgSpec]:
"""Prepare [model | (model, optimizer) | Dict] based on each strategy.
NOTE: the keys of Dict must be a subset of `self.booster.boost`'s arguments.
Example::
>>> # e.g., include lr_scheduler
>>> result_dict = strategy.prepare(dict(model=model, lr_scheduler=lr_scheduler))
>>> # when fine-tuning actor and critic
>>> (actor, actor_optim), (critic, critic_optim), reward_model, initial_model = strategy.prepare((actor, actor_optim), (critic, critic_optim), reward_model, initial_model)
>>> # or when training reward model
>>> (reward_model, reward_model_optim) = strategy.prepare((reward_model, reward_model_optim))
>>> # or just inference
>>> actor, critic = strategy.prepare(actor, critic)
Returns:
Union[List[_BoostArgSpec], _BoostArgSpec]: [model | (model, optimizer) | Dict] in the original order.
"""
rets = []
for arg in boost_args:
if isinstance(arg, nn.Module):
model, *_ = self.booster.boost(arg)
rets.append(model)
elif isinstance(arg, tuple):
try:
model, optimizer = arg
except ValueError:
raise RuntimeError(f'Expect (model, optimizer) pair, got a tuple with size "{len(arg)}"')
model, optimizer, *_ = self.booster.boost(model=model, optimizer=optimizer)
rets.append((model, optimizer))
elif isinstance(arg, Dict):
model, optimizer, criterion, dataloader, lr_scheduler = self.booster.boost(**arg)
boost_result = dict(model=model,
optimizer=optimizer,
criterion=criterion,
dataloader=dataloader,
lr_scheduler=lr_scheduler)
# remove None values
boost_result = {key: value for key, value in boost_result.items() if value is not None}
rets.append(boost_result)
else:
raise RuntimeError(f'Type {type(arg)} is not supported')
return rets[0] if len(rets) == 1 else rets
@staticmethod
def unwrap_model(model: nn.Module) -> nn.Module:
"""Get the unwrapped model from a wrapped model made by Strategy.prepare.
Args:
model (nn.Module): the model to unwrap
Returns:
nn.Module: the original model
"""
return model
def save_model(self, model: nn.Module, path: str, only_rank0: bool = True, **kwargs) -> None:
self.booster.save_model(model, path, shard=not only_rank0, **kwargs)
def load_model(self, model: nn.Module, path: str, strict: bool = True) -> None:
self.booster.load_model(model, path, strict)
def save_optimizer(self, optimizer: Optimizer, path: str, only_rank0: bool = False, **kwargs) -> None:
self.booster.save_optimizer(optimizer, path, shard=not only_rank0, **kwargs)
def load_optimizer(self, optimizer: Optimizer, path: str) -> None:
self.booster.load_optimizer(optimizer, path)
def setup_sampler(self, dataset) -> DistributedSampler:
# FIXME(cwher): this is only invoked in train_on_ray, not tested after adapt Boost API.
return DistributedSampler(dataset, 1, 0)
@abstractmethod
def save_pretrained(self,
model: nn.Module,
path: str,
only_rank0: bool = True,
tokenizer: Optional[PreTrainedTokenizerBase] = None) -> None:
pass
@abstractmethod
def get_model_state_dict_shard(self, model: nn.Module, **config):
pass