With the parser rework [1] and run_kernel() rework [2], this allows the parser to print out test results incrementally.

Currently, that's held up by the fact that the LineStream eagerly pre-fetches the next line when you call pop(). This blocks parse_test_result() from returning until the line *after* the "ok 1 - test name" line is also printed.

One can see this with the following example: $ (echo -e 'TAP version 14\n1..3\nok 1 - fake test'; sleep 2; echo -e 'ok 2 - fake test 2'; sleep 3; echo -e 'ok 3 - fake test 3') | ./tools/testing/kunit/kunit.py parse

Before this patch [1]: there's a pause before 'fake test' is printed. After this patch: 'fake test' is printed out immediately.

This patch also adds * a unit test to verify LineStream's behavior directly * a test case to ensure that it's lazily calling the generator * an explicit exception for when users go beyond EOF

[1] https://lore.kernel.org/linux-kselftest/20211006170049.106852-1-dlatypov@goo... [2] https://lore.kernel.org/linux-kselftest/20211005011340.2826268-1-dlatypov@go...

Signed-off-by: Daniel Latypov dlatypov@google.com Reviewed-by: David Gow davidgow@google.com --- v1 -> v2: rebase onto v7 of parser rewrite https://lore.kernel.org/all/20211007210324.707912-1-dlatypov@google.com/ --- tools/testing/kunit/kunit_parser.py | 22 ++++++++++---- tools/testing/kunit/kunit_tool_test.py | 42 +++++++++++++++++++++++++- 2 files changed, 57 insertions(+), 7 deletions(-)

diff --git a/tools/testing/kunit/kunit_parser.py b/tools/testing/kunit/kunit_parser.py index f01fd565f978..82900a5f9ad6 100644 --- a/tools/testing/kunit/kunit_parser.py +++ b/tools/testing/kunit/kunit_parser.py @@ -172,42 +172,51 @@ class TestCounts: class LineStream: """ A class to represent the lines of kernel output. - Provides a peek()/pop() interface over an iterator of + Provides a lazy peek()/pop() interface over an iterator of (line#, text). """ _lines: Iterator[Tuple[int, str]] _next: Tuple[int, str] + _need_next: bool _done: bool

def __init__(self, lines: Iterator[Tuple[int, str]]): """Creates a new LineStream that wraps the given iterator.""" self._lines = lines self._done = False + self._need_next = True self._next = (0, '') - self._get_next()

def _get_next(self) -> None: - """Advances the LineSteam to the next line.""" + """Advances the LineSteam to the next line, if necessary.""" + if not self._need_next: + return try: self._next = next(self._lines) except StopIteration: self._done = True + finally: + self._need_next = False

def peek(self) -> str: """Returns the current line, without advancing the LineStream. """ + self._get_next() return self._next[1]

def pop(self) -> str: """Returns the current line and advances the LineStream to the next line. """ - n = self._next - self._get_next() - return n[1] + s = self.peek() + if self._done: + raise ValueError(f'LineStream: going past EOF, last line was {s}') + self._need_next = True + return s

def __bool__(self) -> bool: """Returns True if stream has more lines.""" + self._get_next() return not self._done

# Only used by kunit_tool_test.py. @@ -220,6 +229,7 @@ class LineStream:

def line_number(self) -> int: """Returns the line number of the current line.""" + self._get_next() return self._next[0]

# Parsing helper methods: diff --git a/tools/testing/kunit/kunit_tool_test.py b/tools/testing/kunit/kunit_tool_test.py index 6648de1f9ceb..77e61b0a40e8 100755 --- a/tools/testing/kunit/kunit_tool_test.py +++ b/tools/testing/kunit/kunit_tool_test.py @@ -13,9 +13,10 @@ import tempfile, shutil # Handling test_tmpdir

import itertools import json +import os import signal import subprocess -import os +from typing import Iterable

import kunit_config import kunit_parser @@ -319,6 +320,45 @@ class KUnitParserTest(unittest.TestCase): result.status) self.assertEqual('kunit-resource-test', result.test.subtests[0].name)

+def line_stream_from_strs(strs: Iterable[str]) -> kunit_parser.LineStream: + return kunit_parser.LineStream(enumerate(strs, start=1)) + +class LineStreamTest(unittest.TestCase): + + def test_basic(self): + stream = line_stream_from_strs(['hello', 'world']) + + self.assertTrue(stream, msg='Should be more input') + self.assertEqual(stream.line_number(), 1) + self.assertEqual(stream.peek(), 'hello') + self.assertEqual(stream.pop(), 'hello') + + self.assertTrue(stream, msg='Should be more input') + self.assertEqual(stream.line_number(), 2) + self.assertEqual(stream.peek(), 'world') + self.assertEqual(stream.pop(), 'world') + + self.assertFalse(stream, msg='Should be no more input') + with self.assertRaisesRegex(ValueError, 'LineStream: going past EOF'): + stream.pop() + + def test_is_lazy(self): + called_times = 0 + def generator(): + nonlocal called_times + for i in range(1,5): + called_times += 1 + yield called_times, str(called_times) + + stream = kunit_parser.LineStream(generator()) + self.assertEqual(called_times, 0) + + self.assertEqual(stream.pop(), '1') + self.assertEqual(called_times, 1) + + self.assertEqual(stream.pop(), '2') + self.assertEqual(called_times, 2) + class LinuxSourceTreeTest(unittest.TestCase):

def setUp(self):

base-commit: e3c6457b588d83b7ecd40eb4bd6d95007020fbe4