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Source code for torch.cpu

# mypy: allow-untyped-defs
r"""
This package implements abstractions found in ``torch.cuda``
to facilitate writing device-agnostic code.
"""

from contextlib import AbstractContextManager
from typing import Any, Optional, Union

import torch

from .. import device as _device
from . import amp


__all__ = [
    "is_available",
    "synchronize",
    "current_device",
    "current_stream",
    "stream",
    "set_device",
    "device_count",
    "Stream",
    "StreamContext",
    "Event",
]

_device_t = Union[_device, str, int, None]


def _is_cpu_support_avx2() -> bool:
    r"""Returns a bool indicating if CPU supports AVX2."""
    return torch._C._cpu._is_cpu_support_avx2()


def _is_cpu_support_avx512() -> bool:
    r"""Returns a bool indicating if CPU supports AVX512."""
    return torch._C._cpu._is_cpu_support_avx512()


def _is_cpu_support_vnni() -> bool:
    r"""Returns a bool indicating if CPU supports VNNI."""
    return torch._C._cpu._is_cpu_support_vnni()


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

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