# SPDX-FileCopyrightText: 2026 John C. Travers and contributors
#
# SPDX-License-Identifier: GPL-3.0-or-later
"""Calibrating automatically on first use (SEP 46 sections 5 and 6.10).
Under ``SOLPROP_CALIBRATION=auto``, the default, the first native workspace built in
an allocation with no row in its machine's profile first runs the quick calibration,
about 20 s, after a :class:`~solprop.exceptions.CalibrationNotice`. A process that
had not loaded the native extension yet then takes the whole new profile when it does;
one that had applies the new workspace settings that hold under the process settings
it started with, and the rest from its next process. Importing the native backend
never calibrates.
A scan calibrates its workers' allocation at the standard level before it starts
them (:func:`for_workers`), unless a standard or thorough row already matches; a
worker never calibrates. Concurrent first runs on one host wait for the one that holds
the calibration claim, up to its deadline, then use its profile. A busy machine's
inconclusive calibration publishes nothing, and ``auto`` tries again after a day.
"""
from __future__ import annotations
import logging
import os
import sys
import time
import warnings
from collections.abc import Mapping, Sequence
from typing import TYPE_CHECKING
from solprop import _process
from solprop.calibration import _native
from solprop.exceptions import BackendError, CalibrationNotice
if TYPE_CHECKING:
from solprop_native._allocation import ( # pyright: ignore[reportMissingImports]
AllocationClass,
)
from solprop_native._profile import ( # pyright: ignore[reportMissingImports]
Choice,
)
from solprop_native._store import ( # pyright: ignore[reportMissingImports]
Store,
)
from solprop.calibration.controller import CalibrationReport
__all__ = ["RETRY_SECONDS", "ROLE", "ensure", "for_workers"]
logger = logging.getLogger(__name__)
ROLE = "SOLPROP_CALIBRATION_ROLE"
"""Set to ``worker`` in a scan's workers, which never calibrate."""
RETRY_SECONDS = 86400.0
"""How long ``auto`` waits after an inconclusive calibration before trying again."""
_DONE: set[tuple[str, ...]] = set()
def _notice(level: str, seconds: float, store: object, cores: int) -> None:
"""Issue the first-use notice as a warning and a log record.
Parameters
----------
level : str
The level about to run.
seconds : float
Its budget.
store : object
The store's directory.
cores : int
The allocation's cores.
"""
message = (
f"solprop is calibrating the native backend to this machine ({level}, about "
f"{seconds:.0f} s on {cores} cores; once per machine, allocation and release). "
f"The profile is kept in {store}. Run `solprop calibrate` for a fuller "
"calibration, or set SOLPROP_CALIBRATION=use to never measure, or =off to "
"ignore profiles."
)
logger.info(message)
warnings.warn(message, CalibrationNotice, stacklevel=4)
def _device_build() -> bool:
"""Return whether the installed native build runs on a device (phase 6's).
Returns
-------
bool
Whether its build record names a device backend.
"""
import json # noqa: PLC0415
for directory in _native.packages():
try:
record = json.loads((directory / "_build.json").read_text(encoding="utf-8"))
except OSError, ValueError:
continue
return isinstance(record, dict) and record.get("device_backend") not in (
None,
"none",
)
return False
def _wait_for(store: Store, digest: str, key: str) -> bool:
"""Wait for another process on this host calibrating this class; say if one was.
Parameters
----------
store : solprop_native._store.Store
The user's store.
digest : str
The machine and build's key.
key : str
The allocation class's key.
Returns
-------
bool
Whether a claim was held, here or elsewhere: then this process does not
calibrate.
"""
import socket # noqa: PLC0415
holder = store.holder(digest, key)
if holder is None:
return False
if holder.host != socket.gethostname():
return True
while store.holder(digest, key) is not None:
time.sleep(0.25)
return True
def _allowed(environ: Mapping[str, str]) -> bool:
"""Return whether this process may measure implicitly.
Parameters
----------
environ : Mapping[str, str]
The environment.
Returns
-------
bool
``SOLPROP_CALIBRATION=auto``, not a scan's worker, and a CPU build.
"""
return (
_native.store.mode(environ) == "auto"
and environ.get(ROLE) != "worker"
and not _device_build()
)
def _covered(found: Choice, allocation: AllocationClass, need: str) -> bool:
"""Return whether the profile already has the row an allocation needs.
Parameters
----------
found : solprop_native._profile.Choice
What the stores hold for this machine and build.
allocation : solprop_native._allocation.AllocationClass
The allocation's class.
need : str
``"any"``: any row it takes, its own or a nearer one's; ``"standard"``: its own
at the standard or thorough level.
Returns
-------
bool
Whether nothing needs measuring.
"""
from solprop.calibration.controller import ORDER # noqa: PLC0415
if need == "any" and found.found is not None:
return True
for row in () if found.generation is None else found.generation.rows:
try:
same = _native.allocation.AllocationClass.read(row.allocation) == allocation
except ValueError:
continue
if same and (need == "any" or ORDER.get(row.level, -1) >= ORDER["standard"]):
return True
return False
def _calibrate(
level: str, cpus: Sequence[int], environ: Mapping[str, str], *, need: str
) -> CalibrationReport | None:
"""Calibrate `cpus`' allocation at `level` unless a row it needs exists.
Parameters
----------
level : str
``"quick"`` or ``"standard"``.
cpus : sequence of int
The allocation's CPUs.
environ : Mapping[str, str]
The environment.
need : str
``"any"`` or ``"standard"`` (:func:`_covered`).
Returns
-------
CalibrationReport or None
The report, or ``None`` when nothing was measured.
"""
if len(cpus) < 2:
# One CPU has no team, waiting or grain to choose: a single-threaded scan's
# workers run on the built-in table without measuring (SEP 46 Part II).
return None
try:
_native.packages()
_native.store.mode(environ)
except BackendError, ImportError:
# No native backend, or one without the calibration's modules: selecting it
# fails, or runs on its own table, on its own terms.
return None
if not _allowed(environ):
return None
from solprop import calibration # noqa: PLC0415 - imports this module's package
from solprop.calibration.controller import LEVELS, calibrate # noqa: PLC0415
machine = _native.topology.read_topology()
allocation = _native.allocation.classify(machine, cpus, _process.cgroup_cpus())
found = calibration.choice(environ)
assert found.fingerprint is not None # "auto" always fingerprints
digest = found.fingerprint.digest
store = _native.store.Store(calibration.store_directory(environ))
key = (digest, allocation.key(), level)
try:
since = store.inconclusive_since(digest, allocation.key())
if (
key in _DONE
or _covered(found, allocation, need)
or (since is not None and time.time() - since < RETRY_SECONDS)
or _wait_for(store, digest, allocation.key())
):
return None
_DONE.add(key)
_notice(level, LEVELS[level].budget, store.root, allocation.cores)
return calibrate(level, environ=environ, cpus=cpus)
except OSError as error:
# The calibration is optional: a store that cannot be written (read-only,
# missing, full) leaves runs on the built-in table, with one warning.
_DONE.add(key)
message = (
f"solprop could not use its calibration store at {store.root} ({error}); "
"the native backend runs on its built-in settings"
)
logger.warning(message)
warnings.warn(message, CalibrationNotice, stacklevel=4)
return None
[docs]
def ensure(environ: Mapping[str, str] | None = None) -> CalibrationReport | None:
"""Calibrate quickly before a first native workspace, if this allocation needs it.
A no-op unless ``SOLPROP_CALIBRATION=auto``, in a process that is not a scan's
worker, on a CPU build, with no row for its allocation, no inconclusive attempt in
the last day and nobody else calibrating it; once per process. A process that has
already loaded the native extension then refreshes its profile.
Parameters
----------
environ : Mapping[str, str] or None, optional
The environment; the process's when ``None``.
Returns
-------
solprop.calibration.controller.CalibrationReport or None
The quick calibration's report, or ``None`` when none ran.
"""
environ = os.environ if environ is None else environ
report = _calibrate("quick", _process.allowed_cpus(), environ, need="any")
if report is not None and "solprop_native" in sys.modules:
sys.modules["solprop_native"].refresh_profile()
return report
[docs]
def for_workers(
cpus: Sequence[int], environ: Mapping[str, str] | None = None
) -> CalibrationReport | None:
"""Calibrate a scan's workers' allocation at the standard level, if it needs it.
Run by the scan's parent before its workers start, in children pinned like one
worker; the other partitions stay idle meanwhile, so caches and memory bandwidth
are less loaded than in the scan, which the row's evidence records.
Parameters
----------
cpus : sequence of int
One worker's CPUs.
environ : Mapping[str, str] or None, optional
The environment; the process's when ``None``.
Returns
-------
solprop.calibration.controller.CalibrationReport or None
The report, or ``None`` when a standard or thorough row already matches or
nothing may be measured.
"""
environ = os.environ if environ is None else environ
return _calibrate("standard", cpus, environ, need="standard")