Files
sglang/python/sglang/multimodal_gen/runtime/layers/utils.py

248 lines
8.9 KiB
Python

# Copied and adapted from: https://github.com/hao-ai-lab/FastVideo
# SPDX-License-Identifier: Apache-2.0
# Adapted from vllm: https://github.com/vllm-project/vllm/blob/v0.7.3/vllm/model_executor/layers/utils.py
"""Utility methods for model layers."""
import inspect
from typing import Any, Callable, List, Optional
import torch
from torch.library import Library
from sglang.multimodal_gen.runtime.platforms import current_platform
def get_token_bin_counts_and_mask(
tokens: torch.Tensor,
vocab_size: int,
num_seqs: int,
) -> tuple[torch.Tensor, torch.Tensor]:
# Compute the bin counts for the tokens.
# vocab_size + 1 for padding.
bin_counts = torch.zeros(
(num_seqs, vocab_size + 1), dtype=torch.long, device=tokens.device
)
bin_counts.scatter_add_(1, tokens, torch.ones_like(tokens))
bin_counts = bin_counts[:, :vocab_size]
mask = bin_counts > 0
return bin_counts, mask
sglang_lib = Library("sglang", "FRAGMENT") # noqa
def direct_register_custom_op(
op_name: str,
op_func: Callable,
mutates_args: List[str],
fake_impl: Optional[Callable] = None,
target_lib: Optional[Library] = None,
):
"""
`torch.library.custom_op` can have significant overhead because it
needs to consider complicated dispatching logic. This function
directly registers a custom op and dispatches it to the CUDA backend.
See https://gist.github.com/youkaichao/ecbea9ec9fc79a45d2adce1784d7a9a5
for more details.
By default, the custom op is registered to the vLLM library. If you
want to register it to a different library, you can pass the library
object to the `target_lib` argument.
IMPORTANT: the lifetime of the operator is tied to the lifetime of the
library object. If you want to bind the operator to a different library,
make sure the library object is alive when the operator is used.
Note: This function will silently skip registration if the operator
with the same name is already registered to avoid RuntimeError in
multi-engine scenarios (e.g., VERL framework).
"""
import torch.library
my_lib = target_lib or sglang_lib
# Check if operator is already registered to avoid duplicate registration
# This is important for scenarios where multiple SGLang engines run in the same process
try:
# Try to access the operator to see if it's already registered
lib_name = my_lib.m.name if hasattr(my_lib.m, "name") else "sglang"
if hasattr(torch.ops, lib_name) and hasattr(
getattr(torch.ops, lib_name), op_name
):
# Operator already exists, skip registration
return
except (AttributeError, RuntimeError):
# Operator doesn't exist, proceed with registration
pass
if hasattr(torch.library, "infer_schema"):
schema_str = torch.library.infer_schema(op_func, mutates_args=mutates_args)
else:
# for pytorch 2.4
import torch._custom_op.impl
schema_str = torch._custom_op.impl.infer_schema(op_func, mutates_args)
try:
my_lib.define(op_name + schema_str)
my_lib.impl(
op_name, op_func, "CUDA" if not current_platform.is_npu() else "PrivateUse1"
)
if fake_impl is not None:
my_lib._register_fake(op_name, fake_impl)
except RuntimeError as error:
if "Tried to register an operator" in str(error) and "multiple times" in str(
error
):
# Silently ignore duplicate registration errors
# This can happen in multi-engine scenarios
pass
else:
# Re-raise other RuntimeErrors
raise error
except AttributeError as error:
# Always re-raise AttributeError as it indicates missing dependencies
raise error
class CustomOpWrapper:
def __init__(
self,
op_name: str,
op_func: Callable,
mutates_args: List[str],
**extra_kwargs,
):
self.op_name = op_name
self.op_func = op_func
self.mutates_args = mutates_args
self.extra_kwargs = extra_kwargs
self._impl: Optional[Callable] = None
def __call__(self, *args, **kwargs):
return self.real_impl(*args, **kwargs)
@property
def real_impl(self) -> Callable:
if self._impl is None:
if not hasattr(torch.ops.sglang, self.op_name):
# NOTE(dark): if torch compile fail here, mark the decorator as eager
# lazy registration does not work with torch compile
direct_register_custom_op(
op_name=self.op_name,
op_func=self.op_func,
mutates_args=self.mutates_args,
fake_impl=self.fake_impl,
)
self._impl = getattr(torch.ops.sglang, self.op_name)
assert self._impl is not None
return self._impl
@property
def fake_impl(self) -> Callable:
if "fake_impl" in self.extra_kwargs:
return self.extra_kwargs["fake_impl"]
assert "out_shape" in self.extra_kwargs
signature = inspect.signature(self.op_func)
out_shape = self.extra_kwargs["out_shape"]
# check out_shape in signature
def fake_impl(*args, **kwargs):
if out_shape is None:
return None
bound = signature.bind(*args, **kwargs)
bound.apply_defaults()
try:
return torch.empty_like(
bound.args[out_shape]
if isinstance(out_shape, int)
else bound.arguments[out_shape]
)
except (IndexError, KeyError):
raise RuntimeError(
f"Cannot find output argument at position `{out_shape}` for "
f"custom operator `{self.op_name}` with signature `{signature}`."
)
return fake_impl
# Real implementation
def register_custom_op(
fn: Optional[Callable] = None,
*,
op_name: Optional[str] = None,
mutates_args: Optional[List[str]] = None,
eager: bool = True,
**extra_kwargs,
) -> Any:
"""
A decorator to register a custom operator.
Example usage:
```python
# inplace operator, out_shape is None by default
@register_custom_op(mutates_args=["x"])
def add_1_(x: torch.Tensor) -> None:
x.add_(1)
# operator with output, out_shape indicates the position of output
@register_custom_op(mutates_args=["x"], out_shape=0)
def add(x: torch.Tensor, y: torch.Tensor) -> torch.Tensor:
return x.add_(y)
```
:param fn: The function to be registered as a custom operator.
If None, return a decorator.
:type fn: Callable
:param op_name: The name of the operator. If None, use the function name
:type op_name: Optional[str]
:param mutates_args: A list of argument names that are mutated in-place.
:type mutates_args: List[str]
:param out_shape: The position (int for positional, str for keyword) of the output-shape tensor.
It is used to generate a fake implementation for torch.compile compatibility.
If the operator is inplace and has no output, set to None.
:type out_shape: Optional[List[Union[int, str]]]
:param fake_impl: A fake implementation for the operator.
Only one of `out_shape` or `fake_impl` should be provided.
:type fake_impl: Optional[Callable]
:param eager: Whether to register the operator eagerly.
If False, the registration will be deferred until the first call.
If you met any issue with torch.compile, try to set eager=True.
Currently, to avoid misuse, we set eager=True by default.
:type eager: bool
:return: The registered JIT custom operator, or a decorator.
NOTE: the real register will occur at the first call of the function.
:rtype: Callable
"""
extra_kwarg_keys = set(extra_kwargs.keys())
expected_kwarg_keys = set({"out_shape", "fake_impl"})
assert (
expected_kwarg_keys >= extra_kwarg_keys
), f"Unexpected extra kwargs: {extra_kwarg_keys - expected_kwarg_keys}"
has_out_shape = "out_shape" in extra_kwargs
has_fake_impl = "fake_impl" in extra_kwargs
assert not (
has_out_shape and has_fake_impl
), "Only one of `out_shape` or `fake_impl` should be provided."
# Assume inplace if neither out_shape nor fake_impl is provided
if not (has_out_shape or has_fake_impl):
extra_kwargs["out_shape"] = None
def decorator(op_func: Callable) -> Callable:
wrapper = CustomOpWrapper(
op_name=op_name or op_func.__name__,
op_func=op_func,
mutates_args=mutates_args or [],
**extra_kwargs,
)
return wrapper.real_impl if eager else wrapper
if fn is not None:
return decorator(fn)
return decorator