AReaL/arealite/workflow/rlvr.py

115 lines
4.3 KiB
Python

import asyncio
import os
import uuid
import colorama
import torch
from tensordict import TensorDict
from transformers import PreTrainedTokenizerFast
from arealite.api.cli_args import GenerationHyperparameters
from arealite.api.engine_api import InferenceEngine
from arealite.api.io_struct import LLMRequest
from arealite.api.workflow_api import RolloutWorkflow
from arealite.utils.data import concat_padded_tensors
class RLVRWorkflow(RolloutWorkflow):
def __init__(
self,
reward_fn,
gconfig: GenerationHyperparameters,
tokenizer: PreTrainedTokenizerFast,
enable_thinking: bool,
dump_dir: str | None = None,
):
self.reward_fn = reward_fn
self.gconfig = gconfig
self.tokenizer = tokenizer
self.enable_thinking = enable_thinking
self.dump_dir = dump_dir
if self.dump_dir is not None and not os.path.exists(self.dump_dir):
os.makedirs(self.dump_dir, exist_ok=True)
async def arun_episode(self, engine: InferenceEngine, data):
input_ids = self.tokenizer.apply_chat_template(
data["messages"],
tokenize=True,
add_generation_prompt=True,
enable_thinking=self.enable_thinking,
)
n_samples = self.gconfig.n_samples
req = LLMRequest(
rid=uuid.uuid4().hex,
input_ids=input_ids,
gconfig=self.gconfig.new(n_samples=1),
)
resps = await asyncio.gather(*[engine.agenerate(req) for _ in range(n_samples)])
version = engine.get_version()
prompt_strs = []
completions_strs = []
rewards = []
seqlens = []
results = []
for resp in resps:
seq = resp.input_tokens + resp.output_tokens
logprobs = [0.0] * resp.input_len + resp.output_logprobs
loss_mask = [0] * resp.input_len + [1] * resp.output_len
versions = [-1] * resp.input_len + resp.output_versions
prompt_str = self.tokenizer.decode(input_ids)
completions_str = self.tokenizer.decode(resp.output_tokens)
prompt_strs.append(prompt_str)
completions_strs.append(completions_str)
seqlens.append(len(seq))
reward = self.reward_fn(
prompt=prompt_str,
completions=completions_str,
prompt_ids=resp.input_tokens,
completion_ids=resp.output_tokens,
**data,
)
rewards.append(reward)
res = dict(
# unsqueeze to add an additional batch dimension
input_ids=torch.tensor(seq).unsqueeze(0),
loss_mask=torch.tensor(loss_mask).unsqueeze(0),
logprobs=torch.tensor(logprobs).unsqueeze(0),
versions=torch.tensor(versions).unsqueeze(0),
attention_mask=torch.ones(len(seq), dtype=torch.bool).unsqueeze(0),
# reward
rewards=torch.tensor([float(reward)]),
)
results.append(TensorDict(res, batch_size=[1]))
if self.dump_dir is not None:
os.makedirs(os.path.join(self.dump_dir, str(version)), exist_ok=True)
# Get the unique identifier for this prompt
qid = None
for key in ["query_id", "id", "qid"]:
qid = data.get(key, None)
if qid is not None:
break
qid = qid or uuid.uuid4().hex
# Dump rollout to file
with open(
os.path.join(self.dump_dir, str(version), f"{qid}.txt"), "a"
) as f:
n_samples = self.gconfig.n_samples
for i, (p, c, r, sl) in enumerate(
zip(prompt_strs, completions_strs, rewards, seqlens)
):
info = "\n".join(
[
f"idx: {i + 1} / {n_samples}, seqlen: {sl}, reward is {r}.",
f"prompt is \n{colorama.Fore.YELLOW + colorama.Style.DIM}{p}{colorama.Style.RESET_ALL}",
f"sequence is: \n{colorama.Fore.YELLOW + colorama.Style.DIM}{c}{colorama.Style.RESET_ALL}",
]
)
f.write(info + "\n")
return concat_padded_tensors(results)