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from typing import Any
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import warnings
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+ from jax ._src .api import device_put
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from jax import numpy as jnp
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from jax ._src import array
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from jax ._src import xla_bridge
@@ -82,16 +83,107 @@ def to_dlpack(x: Array, take_ownership: bool = False,
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x .addressable_data (0 ), stream = stream
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) # type: ignore
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+ def _place_array (_arr , device , dlpack_device , copy ):
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+ if device and dlpack_device != device :
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+ if copy == False :
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+ raise ValueError (
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+ f"Specified { device = } which requires a copy since the source device "
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+ f"is { repr (dlpack_device )} , however copy=False. Set copy=True or "
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+ "copy=None to perform the requested operation."
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+ )
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+ else :
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+ return device_put (_arr , device )
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+ if copy :
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+ return jnp .array (_arr , copy = True )
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+ return _arr
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+
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+ def _legacy_from_dlpack (dlpack , device : xla_client .Device | None = None , copy : bool | None = None ):
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+ preferred_platform = getattr (device , "platform" , None )
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+ if device and preferred_platform == "gpu" :
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+ preferred_platform = "cuda" if "cuda" in device .client .platform_version else "rocm"
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+
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+ cpu_backend = xla_bridge .get_backend ("cpu" )
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+ gpu_backend = None
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+
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+ if preferred_platform in {"cuda" , "rocm" }:
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+ try :
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+ gpu_backend = xla_bridge .get_backend (preferred_platform )
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+ except RuntimeError :
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+ raise TypeError (
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+ f"A { str .upper (preferred_platform )} device was specified, however no "
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+ f"{ str .upper (preferred_platform )} backend was found."
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+ )
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- def from_dlpack (external_array ):
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+ if preferred_platform is None :
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+ try :
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+ gpu_backend = xla_bridge .get_backend ("cuda" )
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+ except RuntimeError :
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+ pass
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+ # Try ROCm if CUDA backend not found
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+ if gpu_backend is None :
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+ try :
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+ gpu_backend = xla_bridge .get_backend ("rocm" )
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+ except RuntimeError :
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+ pass
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+
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+ _arr = jnp .asarray (xla_client ._xla .dlpack_managed_tensor_to_buffer (
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+ dlpack , cpu_backend , gpu_backend ))
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+
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+ return _place_array (_arr , device , _arr .devices ().pop (), copy )
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+
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+ def _from_dlpack (external_array , device : xla_client .Device | None = None , copy : bool | None = None ):
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+ dl_device_type , device_id = external_array .__dlpack_device__ ()
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+ try :
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+ dl_device_platform = {
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+ DLDeviceType .kDLCPU : "cpu" ,
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+ DLDeviceType .kDLCUDA : "cuda" ,
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+ DLDeviceType .kDLROCM : "rocm" ,
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+ }[dl_device_type ]
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+ except TypeError :
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+ # https://dmlc.github.io/dlpack/latest/python_spec.html recommends using
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+ # TypeError.
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+ raise TypeError (
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+ "Array passed to from_dlpack is on unsupported device type "
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+ f"(DLDeviceType: { dl_device_type } , array: { external_array } " )
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+
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+ backend = xla_bridge .get_backend (dl_device_platform )
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+ dlpack_device = backend .device_from_local_hardware_id (device_id )
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+ try :
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+ stream = dlpack_device .get_stream_for_external_ready_events ()
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+ except xla_client .XlaRuntimeError as err : # type: ignore
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+ if "UNIMPLEMENTED" in str (err ):
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+ stream = None
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+ else :
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+ raise
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+ dlpack = external_array .__dlpack__ (stream = stream )
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+
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+ _arr = jnp .asarray (xla_client ._xla .dlpack_managed_tensor_to_buffer (
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+ dlpack , dlpack_device , stream ))
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+
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+ return _place_array (_arr , device , dlpack_device , copy )
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+
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+ def from_dlpack (external_array , device : xla_client .Device | None = None , copy : bool | None = None ):
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"""Returns a :class:`~jax.Array` representation of a DLPack tensor.
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The returned :class:`~jax.Array` shares memory with ``external_array``.
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Args:
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- external_array: an array object that has __dlpack__ and __dlpack_device__
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+ external_array: An array object that has __dlpack__ and __dlpack_device__
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methods, or a DLPack tensor on either CPU or GPU (legacy API).
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+ device: The (optional) :py:class:`Device`, representing the device on which
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+ the returned array should be placed. If given, then the result is committed
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+ to the device. If unspecified, the resulting array will be unpacked onto the
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+ same device it originated from. Setting ``device`` to a device different from
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+ the source of ``external_array`` will require a copy, meaning ``copy`` must be
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+ set to either ``True`` or ``None``.
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+
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+ copy: An (optional) boolean, controlling whether or not to a copy is performed.
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+ If ``copy=True`` then a copy is always performed, even if unpacked onto the
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+ same device. If ``copy=False`` then the copy is never peformed and will raise
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+ an error if necessary. When ``copy=None`` then a copy may be performed if
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+ needed for a device transfer.
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+
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Returns:
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A jax.Array
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@@ -103,48 +195,7 @@ def from_dlpack(external_array):
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the associated JAX array.
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"""
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if hasattr (external_array , "__dlpack__" ):
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- dl_device_type , device_id = external_array .__dlpack_device__ ()
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- try :
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- device_platform = {
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- DLDeviceType .kDLCPU : "cpu" ,
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- DLDeviceType .kDLCUDA : "cuda" ,
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- DLDeviceType .kDLROCM : "rocm" ,
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- }[dl_device_type ]
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- except TypeError :
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- # https://dmlc.github.io/dlpack/latest/python_spec.html recommends using
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- # TypeError.
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- raise TypeError (
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- "Array passed to from_dlpack is on unsupported device type "
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- f"(DLDeviceType: { dl_device_type } , array: { external_array } " )
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-
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- backend = xla_bridge .get_backend (device_platform )
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- device = backend .device_from_local_hardware_id (device_id )
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- try :
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- stream = device .get_stream_for_external_ready_events ()
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- except xla_client .XlaRuntimeError as err : # type: ignore
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- if "UNIMPLEMENTED" in str (err ):
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- stream = None
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- else :
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- raise
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- dlpack = external_array .__dlpack__ (stream = stream )
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-
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- return jnp .asarray (xla_client ._xla .dlpack_managed_tensor_to_buffer (
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- dlpack , device , stream ))
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- else :
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- # Legacy path
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- dlpack = external_array
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- cpu_backend = xla_bridge .get_backend ("cpu" )
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- try :
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- gpu_backend = xla_bridge .get_backend ("cuda" )
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- except RuntimeError :
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- gpu_backend = None
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-
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- # Try ROCm if CUDA backend not found
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- if gpu_backend is None :
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- try :
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- gpu_backend = xla_bridge .get_backend ("rocm" )
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- except RuntimeError :
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- gpu_backend = None
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+ return _from_dlpack (external_array , device , copy )
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- return jnp . asarray ( xla_client . _xla . dlpack_managed_tensor_to_buffer (
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- dlpack , cpu_backend , gpu_backend ) )
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+ # Legacy path
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+ return _legacy_from_dlpack ( external_array , device , copy )
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