pygsti.tools.mpitools.write_mpi_runner_artifacts

write_mpi_runner_artifacts(protocol_obj, run_kwargs, artifact_dir, artifacts_persistent)

Serialize a protocol run into a self-contained directory for MPI workers.

Writes three files into artifact_dir:

• protocol/ — the serialized protocol (via protocol_obj.write).

• volatile_run_kwargs.pkl — pickled keyword arguments for protocol.run.

  The “volatile” prefix indicates that this file’s contents shouldn’t be treated as portable or long-lived.

• mpi_runner.py — a stand-alone Python script that each MPI worker executes. The script

  1. reads the data, protocol, and kwargs from disk, then

  2. calls protocol.run(data, comm=MPI.COMM_WORLD, **kwargs), and

  3. has rank 0 write the results back to data_dir.

Parameters:

• protocol_obj (Protocol) – The protocol to serialize. Must implement a write(dirname) method.

• run_kwargs (dict) – Keyword arguments forwarded to protocol.run. Modified in place: disable_checkpointing defaults to True if not already set.

• artifact_dir (path-like) – Directory in which to write the three artifacts. Must already exist, and must eventually contain serialization of a ProtocolData object Embedded verbatim into the runner script.

• arifacts_persistent (bool) – A flag indicating if the arifact_dir should be assumed persistent or not. If the directory is NOT persistent then we disable checkpointing, which would only slow us down. If a directory IS persistent then we log a warning about serializing with pickle.

• artifacts_persistent (bool)

Returns:

Absolute path to mpi_runner.py.

Return type:

str

Notes

See RUN_KWARGS_PICKLE_MSG for a warning about this function’s behavior when artifact_dir is persistent.