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3d4ac1a2c2
Concurrent accesses from multiple threads to the same `cell` object did not scale well in the free-threaded build. Use `_PyStackRef` and optimistically avoid locking to improve scaling. With the locks around cell reads gone, some of the free threading tests were prone to starvation: the readers were able to run in a tight loop and the writer threads weren't scheduled frequently enough to make timely progress. Adjust the tests to avoid this. Co-authored-by: Donghee Na <donghee.na@python.org>
96 lines
2.4 KiB
Python
96 lines
2.4 KiB
Python
import unittest
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from threading import Thread, Barrier
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from unittest import TestCase
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from test.support import threading_helper
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NTHREAD = 10
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OBJECT_COUNT = 5_000
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class C:
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def __init__(self, v):
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self.v = v
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@threading_helper.requires_working_threading()
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class TestList(TestCase):
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def test_racing_iter_append(self):
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l = []
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barrier = Barrier(NTHREAD + 1)
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def writer_func(l):
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barrier.wait()
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for i in range(OBJECT_COUNT):
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l.append(C(i + OBJECT_COUNT))
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def reader_func(l):
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barrier.wait()
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while True:
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count = len(l)
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for i, x in enumerate(l):
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self.assertEqual(x.v, i + OBJECT_COUNT)
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if count == OBJECT_COUNT:
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break
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writer = Thread(target=writer_func, args=(l,))
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readers = []
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for x in range(NTHREAD):
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reader = Thread(target=reader_func, args=(l,))
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readers.append(reader)
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reader.start()
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writer.start()
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writer.join()
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for reader in readers:
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reader.join()
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def test_racing_iter_extend(self):
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l = []
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barrier = Barrier(NTHREAD + 1)
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def writer_func():
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barrier.wait()
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for i in range(OBJECT_COUNT):
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l.extend([C(i + OBJECT_COUNT)])
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def reader_func():
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barrier.wait()
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while True:
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count = len(l)
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for i, x in enumerate(l):
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self.assertEqual(x.v, i + OBJECT_COUNT)
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if count == OBJECT_COUNT:
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break
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writer = Thread(target=writer_func)
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readers = []
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for x in range(NTHREAD):
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reader = Thread(target=reader_func)
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readers.append(reader)
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reader.start()
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writer.start()
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writer.join()
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for reader in readers:
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reader.join()
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def test_store_list_int(self):
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def copy_back_and_forth(b, l):
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b.wait()
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for _ in range(100):
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l[0] = l[1]
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l[1] = l[0]
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l = [0, 1]
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barrier = Barrier(NTHREAD)
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threads = [Thread(target=copy_back_and_forth, args=(barrier, l))
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for _ in range(NTHREAD)]
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with threading_helper.start_threads(threads):
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pass
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if __name__ == "__main__":
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unittest.main()
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