pygsti.tools.sharedmemtools

Utility functions for working with shared memory

Module Contents

Classes

LocalNumpyArray

Numpy array with metadata for referencing how this "local" array is part

Functions

shared_mem_is_enabled()	Whether shared memory functionality is available (Python 3.8+)
create_shared_ndarray(resource_alloc, shape, dtype[, ...])	Creates a numpy.ndarray that is potentially shared between processors.
cleanup_shared_ndarray(shm)	De-allocates a (potentially) shared numpy array, created by create_shared_ndarray().

class pygsti.tools.sharedmemtools.LocalNumpyArray(shape, dtype=float, buffer=None, offset=0, strides=None, order=None)

Bases: numpy.ndarray

Numpy array with metadata for referencing how this “local” array is part of a larger shared memory array.

pygsti.tools.sharedmemtools.shared_mem_is_enabled()

Whether shared memory functionality is available (Python 3.8+)

Returns

bool

pygsti.tools.sharedmemtools.create_shared_ndarray(resource_alloc, shape, dtype, zero_out=False, memory_tracker=None)

Creates a numpy.ndarray that is potentially shared between processors.

A shared memory array is created when resource_alloc.host_comm is not None, in which case it indicates which processors belong to the same host and have access to the same shared memory.

Parameters

resource_allocResourceAllocation

The resource allocation object containing information about whether or not to create shared memory arrays and how to do so (see above).

shapetuple

The shape of the returned array

dtypenumpy.dtype

The numpy data type of the returned array.

zero_outbool, optional

Whether to initialize the array to all zeros. When True, this function behaves as numpy.zeros; when False as numpy.empty.

memory_trackerResourceAllocation, optional

If not none, callc memory_tracker.add_tracked_memory to track the size of the allocated array.

Returns

arnumpy.ndarray

The potentially shared-memory array.

shmmultiprocessing.shared_memory.SharedMemory

A shared memory object needed to cleanup the shared memory. If a normal array is created, this is None. Provide this to cleanup_shared_ndarray() to ensure ar is deallocated properly.

pygsti.tools.sharedmemtools.cleanup_shared_ndarray(shm)

De-allocates a (potentially) shared numpy array, created by create_shared_ndarray().

Parameters

shmmultiprocessing.shared_memory.SharedMemory or None

The shared memory object to deallocate. If None, no deallocation is is performed.

Returns

None