WUT_Computer_Science/Programming/PORR/code/threads_too_simple.py
Krzysztof kuhy Rudnicki 8798105aa1 Grade against 3.14 too, not just run on it
The pre-commit workflow already installs `python-version: "3.x"`, but ruff was
still grading the archive against py310 -- so it kept withholding the pyupgrade
and type-checking fixes that only become safe at the newer target.
`pin_ci_python.py` rewrites the knob.

The 17 findings that appeared are what the stale target was hiding:
`datetime.timezone.utc` where `datetime.UTC` is now correct (UP017), and 14
imports used only in annotations that belong under `TYPE_CHECKING` (TC002,
TC003) -- safe here precisely because 3.14's PEP 649 defers annotation
evaluation, which is the same reason ruff would not offer them at py310.

`ruff check` and `ruff format --check` are clean again, so the zero-findings
state this repo reached earlier today holds at the new target.

Still contradictory and deliberately untouched: the four
`Programming/ERSMS-project/*/Dockerfile` files say `FROM python:3.10-slim`.
They build an archived coursework service against its own era's pinned
dependencies, and nothing in this repo runs them; bumping the base image would
be a rewrite of that project, not a lint-target change.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SfnJmxxsZ534AKk16rC2Gr
2026-08-29 11:55:43 +02:00

103 lines
2.9 KiB
Python
Executable File

#!/usr/bin/env python3
"""Threaded Richardson, the first attempt (one thread per slice)."""
import gc
import logging
import multiprocessing
import sys
import threading
import time
from typing import TYPE_CHECKING
import numpy as np
from time_measurement import (
longest_time_accumulator,
tests_time,
time_measurement_longest,
)
if TYPE_CHECKING:
from richardson_problem import Problem, Settings
logger = logging.getLogger(__name__)
# Called with numpy arrays here and with plain lists in the sequential
# backend; the aliases name both.
Matrix = np.ndarray | list[list[float]]
Vector = np.ndarray | list[float]
@time_measurement_longest(longest_time_accumulator)
def richardson_thread(
matrix: Matrix,
b: Vector,
vectors: tuple[Vector, Vector],
omega: float,
span: tuple[int, int],
) -> None:
"""Run one thread's slice of a Richardson iteration.
``vectors`` is (x, next_x) and ``span`` is the half-open row range this
thread owns.
"""
x, _x = vectors
start, end = span
for i in range(start, end):
sigma = np.dot(matrix[i, :], _x) - matrix[i, i] * _x[i]
x[i] = (1 - omega) * _x[i] + omega * (b[i] - sigma) / matrix[i, i]
def richardson_method_threads(
problem: Problem, settings: Settings
) -> tuple[Vector, str | None]:
"""Run Richardson with one thread per chunk."""
matrix = problem.matrix
b = problem.rhs
max_iterations = settings.max_iterations
x0 = settings.x0
longest_time_accumulator.total_time = 0
longest_time_accumulator.start = sys.float_info.max
longest_time_accumulator.end = 0
gc.disable()
start_time = time.perf_counter()
n = len(b)
x0 = x0 if x0 is not None else [0.0] * len(b)
x = x0[:]
omega = 0.05 # 2 / (lambda_min + lambda_max)
num_threads = multiprocessing.cpu_count()
threads = []
chunk_size = n // num_threads
max_iterations = 1000
for _ in range(max_iterations):
_x = x[:]
for i in range(num_threads):
# start is an index into A: each thread gets the next multiple of
# the per-thread chunk size as its starting point.
start = i * chunk_size
end = n if i == num_threads - 1 else (i + 1) * chunk_size
thread = threading.Thread(
target=richardson_thread, args=(matrix, b, (x, _x), omega, (start, end))
)
threads.append(thread)
thread.start()
for thread in threads:
thread.join()
end_time = time.perf_counter()
gc.enable()
total_time = end_time - start_time
sequential_time = total_time - longest_time_accumulator.total_time
logger.info(
"Total: %ss, Seq: %ss, Parallel (threads): %ss, Tests time: %ss",
total_time,
sequential_time,
longest_time_accumulator.total_time,
tests_time.total_time,
)
return x, 0