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r""" |
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This package implements abstractions found in ``torch.cuda`` |
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to facilitate writing device-agnostic code. |
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""" |
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from contextlib import AbstractContextManager |
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from typing import Any, Optional, Union |
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import torch |
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from .. import device as _device |
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from . import amp |
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__all__ = [ |
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"is_available", |
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"synchronize", |
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"current_device", |
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"current_stream", |
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"stream", |
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"set_device", |
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"device_count", |
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"Stream", |
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"StreamContext", |
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"Event", |
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] |
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_device_t = Union[_device, str, int, None] |
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def _is_cpu_support_avx2() -> bool: |
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r"""Returns a bool indicating if CPU supports AVX2.""" |
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return torch._C._cpu._is_cpu_support_avx2() |
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def _is_cpu_support_avx512() -> bool: |
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r"""Returns a bool indicating if CPU supports AVX512.""" |
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return torch._C._cpu._is_cpu_support_avx512() |
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def _is_cpu_support_vnni() -> bool: |
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r"""Returns a bool indicating if CPU supports VNNI.""" |
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return torch._C._cpu._is_cpu_support_vnni() |
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def is_available() -> bool: |
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r"""Returns a bool indicating if CPU is currently available. |
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N.B. This function only exists to facilitate device-agnostic code |
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""" |
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return True |
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def synchronize(device: _device_t = None) -> None: |
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r"""Waits for all kernels in all streams on the CPU device to complete. |
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Args: |
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device (torch.device or int, optional): ignored, there's only one CPU device. |
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N.B. This function only exists to facilitate device-agnostic code. |
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""" |
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class Stream: |
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""" |
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N.B. This class only exists to facilitate device-agnostic code |
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""" |
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def __init__(self, priority: int = -1) -> None: |
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pass |
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def wait_stream(self, stream) -> None: |
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pass |
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class Event: |
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def query(self) -> bool: |
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return True |
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def record(self, stream=None) -> None: |
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pass |
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def synchronize(self) -> None: |
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pass |
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def wait(self, stream=None) -> None: |
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pass |
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_default_cpu_stream = Stream() |
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_current_stream = _default_cpu_stream |
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def current_stream(device: _device_t = None) -> Stream: |
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r"""Returns the currently selected :class:`Stream` for a given device. |
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Args: |
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device (torch.device or int, optional): Ignored. |
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N.B. This function only exists to facilitate device-agnostic code |
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""" |
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return _current_stream |
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class StreamContext(AbstractContextManager): |
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r"""Context-manager that selects a given stream. |
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N.B. This class only exists to facilitate device-agnostic code |
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""" |
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cur_stream: Optional[Stream] |
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def __init__(self, stream): |
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self.stream = stream |
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self.prev_stream = _default_cpu_stream |
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def __enter__(self): |
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cur_stream = self.stream |
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if cur_stream is None: |
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return |
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global _current_stream |
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self.prev_stream = _current_stream |
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_current_stream = cur_stream |
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def __exit__(self, type: Any, value: Any, traceback: Any) -> None: |
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cur_stream = self.stream |
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if cur_stream is None: |
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return |
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global _current_stream |
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_current_stream = self.prev_stream |
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def stream(stream: Stream) -> AbstractContextManager: |
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r"""Wrapper around the Context-manager StreamContext that |
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selects a given stream. |
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N.B. This function only exists to facilitate device-agnostic code |
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""" |
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return StreamContext(stream) |
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def device_count() -> int: |
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r"""Returns number of CPU devices (not cores). Always 1. |
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N.B. This function only exists to facilitate device-agnostic code |
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""" |
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return 1 |
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def set_device(device: _device_t) -> None: |
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r"""Sets the current device, in CPU we do nothing. |
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N.B. This function only exists to facilitate device-agnostic code |
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""" |
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def current_device() -> str: |
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r"""Returns current device for cpu. Always 'cpu'. |
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N.B. This function only exists to facilitate device-agnostic code |
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""" |
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return "cpu" |
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