gh-109162: libregrtest: remove WorkerJob class (#109204)

* Add attributes to Regrtest and RunTests:

  * gc_threshold
  * memory_limit
  * python_cmd
  * use_resources

* Remove WorkerJob class. Add as_json() and from_json() methods to
  RunTests. A worker process now only uses RunTests for all
  parameters.
* Add tests on support.set_memlimit() in test_support. Create
  _parse_memlimit() and also adds tests on it.
* Remove 'ns' parameter from runtest.py.

7 files changed, 126 insertions, 88 deletions

diff --git a/Lib/test/libregrtest/cmdline.py b/Lib/test/libregrtest/cmdline.py
index 71e7396..9afb132 100644
--- a/Lib/test/libregrtest/cmdline.py
+++ b/Lib/test/libregrtest/cmdline.py
@@ -177,6 +177,8 @@ class Namespace(argparse.Namespace):
         self.worker_json = None
         self.start = None
         self.timeout = None
+        self.memlimit = None
+        self.threshold = None
 
         super().__init__(**kwargs)
 
diff --git a/Lib/test/libregrtest/main.py b/Lib/test/libregrtest/main.py
index bb02101..4066d06 100644
--- a/Lib/test/libregrtest/main.py
+++ b/Lib/test/libregrtest/main.py
@@ -100,6 +100,10 @@ class Regrtest:
             self.hunt_refleak = None
         self.test_dir: str | None = ns.testdir
         self.junit_filename: str | None = ns.xmlpath
+        self.memory_limit: str | None = ns.memlimit
+        self.gc_threshold: int | None = ns.threshold
+        self.use_resources: list[str] = ns.use_resources
+        self.python_cmd: list[str] | None = ns.python
 
         # tests
         self.tests = []
@@ -363,7 +367,7 @@ class Regrtest:
         return runtests
 
     def rerun_failed_tests(self, need_rerun, runtests: RunTests):
-        if self.ns.python:
+        if self.python_cmd:
             # Temp patch for https://github.com/python/cpython/issues/94052
             self.log(
                 "Re-running failed tests is not supported with --python "
@@ -453,12 +457,12 @@ class Regrtest:
         if tracer is not None:
             # If we're tracing code coverage, then we don't exit with status
             # if on a false return value from main.
-            cmd = ('result = run_single_test(test_name, runtests, self.ns)')
+            cmd = ('result = run_single_test(test_name, runtests)')
             ns = dict(locals())
             tracer.runctx(cmd, globals=globals(), locals=ns)
             result = ns['result']
         else:
-            result = run_single_test(test_name, runtests, self.ns)
+            result = run_single_test(test_name, runtests)
 
         self.accumulate_result(result)
 
@@ -876,9 +880,14 @@ class Regrtest:
             quiet=self.quiet,
             hunt_refleak=self.hunt_refleak,
             test_dir=self.test_dir,
-            junit_filename=self.junit_filename)
-
-        setup_tests(runtests, self.ns)
+            junit_filename=self.junit_filename,
+            memory_limit=self.memory_limit,
+            gc_threshold=self.gc_threshold,
+            use_resources=self.use_resources,
+            python_cmd=self.python_cmd,
+        )
+
+        setup_tests(runtests)
 
         tracer = self.run_tests(runtests)
         self.display_result(runtests)
diff --git a/Lib/test/libregrtest/runtest.py b/Lib/test/libregrtest/runtest.py
index ab59d81..dc574ed 100644
--- a/Lib/test/libregrtest/runtest.py
+++ b/Lib/test/libregrtest/runtest.py
@@ -4,17 +4,18 @@ import faulthandler
 import gc
 import importlib
 import io
+import json
 import os
 import sys
 import time
 import traceback
 import unittest
+from typing import Any
 
 from test import support
 from test.support import TestStats
 from test.support import os_helper
 from test.support import threading_helper
-from test.libregrtest.cmdline import Namespace
 from test.libregrtest.save_env import saved_test_environment
 from test.libregrtest.utils import clear_caches, format_duration, print_warning
 
@@ -230,6 +231,10 @@ class RunTests:
     hunt_refleak: HuntRefleak | None = None
     test_dir: str | None = None
     junit_filename: str | None = None
+    memory_limit: str | None = None
+    gc_threshold: int | None = None
+    use_resources: list[str] = None
+    python_cmd: list[str] | None = None
 
     def copy(self, **override):
         state = dataclasses.asdict(self)
@@ -249,11 +254,32 @@ class RunTests:
         else:
             yield from self.tests
 
+    def as_json(self):
+        return json.dumps(self, cls=_EncodeRunTests)
+
     @staticmethod
-    def from_json_dict(json_dict):
-        if json_dict['hunt_refleak']:
-            json_dict['hunt_refleak'] = HuntRefleak(**json_dict['hunt_refleak'])
-        return RunTests(**json_dict)
+    def from_json(worker_json):
+        return json.loads(worker_json, object_hook=_decode_runtests)
+
+
+class _EncodeRunTests(json.JSONEncoder):
+    def default(self, o: Any) -> dict[str, Any]:
+        if isinstance(o, RunTests):
+            result = dataclasses.asdict(o)
+            result["__runtests__"] = True
+            return result
+        else:
+            return super().default(o)
+
+
+def _decode_runtests(data: dict[str, Any]) -> RunTests | dict[str, Any]:
+    if "__runtests__" in data:
+        data.pop('__runtests__')
+        if data['hunt_refleak']:
+            data['hunt_refleak'] = HuntRefleak(**data['hunt_refleak'])
+        return RunTests(**data)
+    else:
+        return data
 
 
 # Minimum duration of a test to display its duration or to mention that
@@ -320,7 +346,7 @@ def abs_module_name(test_name: str, test_dir: str | None) -> str:
         return 'test.' + test_name
 
 
-def setup_support(runtests: RunTests, ns: Namespace):
+def setup_support(runtests: RunTests):
     support.PGO = runtests.pgo
     support.PGO_EXTENDED = runtests.pgo_extended
     support.set_match_tests(runtests.match_tests, runtests.ignore_tests)
@@ -332,7 +358,7 @@ def setup_support(runtests: RunTests, ns: Namespace):
         support.junit_xml_list = None
 
 
-def _runtest(result: TestResult, runtests: RunTests, ns: Namespace) -> None:
+def _runtest(result: TestResult, runtests: RunTests) -> None:
     # Capture stdout and stderr, set faulthandler timeout,
     # and create JUnit XML report.
     verbose = runtests.verbose
@@ -346,7 +372,7 @@ def _runtest(result: TestResult, runtests: RunTests, ns: Namespace) -> None:
         faulthandler.dump_traceback_later(timeout, exit=True)
 
     try:
-        setup_support(runtests, ns)
+        setup_support(runtests)
 
         if output_on_failure:
             support.verbose = True
@@ -366,7 +392,7 @@ def _runtest(result: TestResult, runtests: RunTests, ns: Namespace) -> None:
                 # warnings will be written to sys.stderr below.
                 print_warning.orig_stderr = stream
 
-                _runtest_env_changed_exc(result, runtests, ns, display_failure=False)
+                _runtest_env_changed_exc(result, runtests, display_failure=False)
                 # Ignore output if the test passed successfully
                 if result.state != State.PASSED:
                     output = stream.getvalue()
@@ -381,7 +407,7 @@ def _runtest(result: TestResult, runtests: RunTests, ns: Namespace) -> None:
         else:
             # Tell tests to be moderately quiet
             support.verbose = verbose
-            _runtest_env_changed_exc(result, runtests, ns,
+            _runtest_env_changed_exc(result, runtests,
                                      display_failure=not verbose)
 
         xml_list = support.junit_xml_list
@@ -395,10 +421,9 @@ def _runtest(result: TestResult, runtests: RunTests, ns: Namespace) -> None:
         support.junit_xml_list = None
 
 
-def run_single_test(test_name: str, runtests: RunTests, ns: Namespace) -> TestResult:
+def run_single_test(test_name: str, runtests: RunTests) -> TestResult:
     """Run a single test.
 
-    ns -- regrtest namespace of options
     test_name -- the name of the test
 
     Returns a TestResult.
@@ -410,7 +435,7 @@ def run_single_test(test_name: str, runtests: RunTests, ns: Namespace) -> TestRe
     result = TestResult(test_name)
     pgo = runtests.pgo
     try:
-        _runtest(result, runtests, ns)
+        _runtest(result, runtests)
     except:
         if not pgo:
             msg = traceback.format_exc()
@@ -472,7 +497,7 @@ def regrtest_runner(result: TestResult, test_func, runtests: RunTests) -> None:
 FOUND_GARBAGE = []
 
 
-def _load_run_test(result: TestResult, runtests: RunTests, ns: Namespace) -> None:
+def _load_run_test(result: TestResult, runtests: RunTests) -> None:
     # Load the test function, run the test function.
     module_name = abs_module_name(result.test_name, runtests.test_dir)
 
@@ -513,7 +538,6 @@ def _load_run_test(result: TestResult, runtests: RunTests, ns: Namespace) -> Non
 
 
 def _runtest_env_changed_exc(result: TestResult, runtests: RunTests,
-                             ns: Namespace,
                              display_failure: bool = True) -> None:
     # Detect environment changes, handle exceptions.
 
@@ -532,7 +556,7 @@ def _runtest_env_changed_exc(result: TestResult, runtests: RunTests,
         support.gc_collect()
 
         with save_env(test_name, runtests):
-            _load_run_test(result, runtests, ns)
+            _load_run_test(result, runtests)
     except support.ResourceDenied as msg:
         if not quiet and not pgo:
             print(f"{test_name} skipped -- {msg}", flush=True)
diff --git a/Lib/test/libregrtest/runtest_mp.py b/Lib/test/libregrtest/runtest_mp.py
index 4e3148f..e4a9301 100644
--- a/Lib/test/libregrtest/runtest_mp.py
+++ b/Lib/test/libregrtest/runtest_mp.py
@@ -47,49 +47,16 @@ USE_PROCESS_GROUP = (hasattr(os, "setsid") and hasattr(os, "killpg"))
 @dataclasses.dataclass(slots=True)
 class WorkerJob:
     runtests: RunTests
-    namespace: Namespace
 
 
-class _EncodeWorkerJob(json.JSONEncoder):
-    def default(self, o: Any) -> dict[str, Any]:
-        match o:
-            case WorkerJob():
-                result = dataclasses.asdict(o)
-                result["__worker_job__"] = True
-                return result
-            case Namespace():
-                result = vars(o)
-                result["__namespace__"] = True
-                return result
-            case _:
-                return super().default(o)
-
-
-def _decode_worker_job(d: dict[str, Any]) -> WorkerJob | dict[str, Any]:
-    if "__worker_job__" in d:
-        d.pop('__worker_job__')
-        d['runtests'] = RunTests.from_json_dict(d['runtests'])
-        return WorkerJob(**d)
-    if "__namespace__" in d:
-        d.pop('__namespace__')
-        return Namespace(**d)
-    else:
-        return d
-
-
-def _parse_worker_json(worker_json: str) -> tuple[Namespace, str]:
-    return json.loads(worker_json, object_hook=_decode_worker_job)
-
-
-def create_worker_process(worker_job: WorkerJob,
+def create_worker_process(runtests: RunTests,
                           output_file: TextIO,
                           tmp_dir: str | None = None) -> subprocess.Popen:
-    ns = worker_job.namespace
-    python = ns.python
-    worker_json = json.dumps(worker_job, cls=_EncodeWorkerJob)
+    python_cmd = runtests.python_cmd
+    worker_json = runtests.as_json()
 
-    if python is not None:
-        executable = python
+    if python_cmd is not None:
+        executable = python_cmd
     else:
         executable = [sys.executable]
     cmd = [*executable, *support.args_from_interpreter_flags(),
@@ -121,14 +88,12 @@ def create_worker_process(worker_job: WorkerJob,
 
 
 def worker_process(worker_json: str) -> NoReturn:
-    worker_job = _parse_worker_json(worker_json)
-    runtests = worker_job.runtests
-    ns = worker_job.namespace
+    runtests = RunTests.from_json(worker_json)
     test_name = runtests.tests[0]
     match_tests: FilterTuple | None = runtests.match_tests
 
     setup_test_dir(runtests.test_dir)
-    setup_tests(runtests, ns)
+    setup_tests(runtests)
 
     if runtests.rerun:
         if match_tests:
@@ -137,7 +102,7 @@ def worker_process(worker_json: str) -> NoReturn:
         else:
             print(f"Re-running {test_name} in verbose mode", flush=True)
 
-    result = run_single_test(test_name, runtests, ns)
+    result = run_single_test(test_name, runtests)
     print()   # Force a newline (just in case)
 
     # Serialize TestResult as dict in JSON
@@ -330,9 +295,6 @@ class TestWorkerProcess(threading.Thread):
         if match_tests:
             kwargs['match_tests'] = match_tests
         worker_runtests = self.runtests.copy(tests=tests, **kwargs)
-        worker_job = WorkerJob(
-            worker_runtests,
-            namespace=self.ns)
 
         # gh-94026: Write stdout+stderr to a tempfile as workaround for
         # non-blocking pipes on Emscripten with NodeJS.
@@ -347,12 +309,12 @@ class TestWorkerProcess(threading.Thread):
                 tmp_dir = tempfile.mkdtemp(prefix="test_python_")
                 tmp_dir = os.path.abspath(tmp_dir)
                 try:
-                    retcode = self._run_process(worker_job, stdout_file, tmp_dir)
+                    retcode = self._run_process(worker_runtests, stdout_file, tmp_dir)
                 finally:
                     tmp_files = os.listdir(tmp_dir)
                     os_helper.rmtree(tmp_dir)
             else:
-                retcode = self._run_process(worker_job, stdout_file)
+                retcode = self._run_process(worker_runtests, stdout_file)
                 tmp_files = ()
             stdout_file.seek(0)
 
diff --git a/Lib/test/libregrtest/setup.py b/Lib/test/libregrtest/setup.py
index 59bbf2c..5944983 100644
--- a/Lib/test/libregrtest/setup.py
+++ b/Lib/test/libregrtest/setup.py
@@ -25,7 +25,7 @@ def setup_test_dir(testdir: str | None) -> None:
         sys.path.insert(0, os.path.abspath(testdir))
 
 
-def setup_tests(runtests, ns):
+def setup_tests(runtests):
     try:
         stderr_fd = sys.__stderr__.fileno()
     except (ValueError, AttributeError):
@@ -71,15 +71,15 @@ def setup_tests(runtests, ns):
     if runtests.hunt_refleak:
         unittest.BaseTestSuite._cleanup = False
 
-    if ns.memlimit is not None:
-        support.set_memlimit(ns.memlimit)
+    if runtests.memory_limit is not None:
+        support.set_memlimit(runtests.memory_limit)
 
-    if ns.threshold is not None:
-        gc.set_threshold(ns.threshold)
+    if runtests.gc_threshold is not None:
+        gc.set_threshold(runtests.gc_threshold)
 
     support.suppress_msvcrt_asserts(runtests.verbose and runtests.verbose >= 2)
 
-    support.use_resources = ns.use_resources
+    support.use_resources = runtests.use_resources
 
     if hasattr(sys, 'addaudithook'):
         # Add an auditing hook for all tests to ensure PySys_Audit is tested
diff --git a/Lib/test/support/__init__.py b/Lib/test/support/__init__.py
index f40b73b..6fc85ff 100644
--- a/Lib/test/support/__init__.py
+++ b/Lib/test/support/__init__.py
@@ -878,27 +878,31 @@ _4G = 4 * _1G
 
 MAX_Py_ssize_t = sys.maxsize
 
-def set_memlimit(limit):
-    global max_memuse
-    global real_max_memuse
+def _parse_memlimit(limit: str) -> int:
     sizes = {
         'k': 1024,
         'm': _1M,
         'g': _1G,
         't': 1024*_1G,
     }
-    m = re.match(r'(\d+(\.\d+)?) (K|M|G|T)b?$', limit,
+    m = re.match(r'(\d+(?:\.\d+)?) (K|M|G|T)b?$', limit,
                  re.IGNORECASE | re.VERBOSE)
     if m is None:
-        raise ValueError('Invalid memory limit %r' % (limit,))
-    memlimit = int(float(m.group(1)) * sizes[m.group(3).lower()])
-    real_max_memuse = memlimit
-    if memlimit > MAX_Py_ssize_t:
-        memlimit = MAX_Py_ssize_t
+        raise ValueError(f'Invalid memory limit: {limit!r}')
+    return int(float(m.group(1)) * sizes[m.group(2).lower()])
+
+def set_memlimit(limit: str) -> None:
+    global max_memuse
+    global real_max_memuse
+    memlimit = _parse_memlimit(limit)
     if memlimit < _2G - 1:
-        raise ValueError('Memory limit %r too low to be useful' % (limit,))
+        raise ValueError('Memory limit {limit!r} too low to be useful')
+
+    real_max_memuse = memlimit
+    memlimit = min(memlimit, MAX_Py_ssize_t)
     max_memuse = memlimit
 
+
 class _MemoryWatchdog:
     """An object which periodically watches the process' memory consumption
     and prints it out.
diff --git a/Lib/test/test_support.py b/Lib/test/test_support.py
index 6428073..5b57c5f 100644
--- a/Lib/test/test_support.py
+++ b/Lib/test/test_support.py
@@ -760,7 +760,45 @@ class TestSupport(unittest.TestCase):
             else:
                 self.fail("RecursionError was not raised")
 
-        #self.assertEqual(available, 2)
+    def test_parse_memlimit(self):
+        parse = support._parse_memlimit
+        KiB = 1024
+        MiB = KiB * 1024
+        GiB = MiB * 1024
+        TiB = GiB * 1024
+        self.assertEqual(parse('0k'), 0)
+        self.assertEqual(parse('3k'), 3 * KiB)
+        self.assertEqual(parse('2.4m'), int(2.4 * MiB))
+        self.assertEqual(parse('4g'), int(4 * GiB))
+        self.assertEqual(parse('1t'), TiB)
+
+        for limit in ('', '3', '3.5.10k', '10x'):
+            with self.subTest(limit=limit):
+                with self.assertRaises(ValueError):
+                    parse(limit)
+
+    def test_set_memlimit(self):
+        _4GiB = 4 * 1024 ** 3
+        TiB = 1024 ** 4
+        old_max_memuse = support.max_memuse
+        old_real_max_memuse = support.real_max_memuse
+        try:
+            if sys.maxsize > 2**32:
+                support.set_memlimit('4g')
+                self.assertEqual(support.max_memuse, _4GiB)
+                self.assertEqual(support.real_max_memuse, _4GiB)
+
+                big = 2**100 // TiB
+                support.set_memlimit(f'{big}t')
+                self.assertEqual(support.max_memuse, sys.maxsize)
+                self.assertEqual(support.real_max_memuse, big * TiB)
+            else:
+                support.set_memlimit('4g')
+                self.assertEqual(support.max_memuse, sys.maxsize)
+                self.assertEqual(support.real_max_memuse, _4GiB)
+        finally:
+            support.max_memuse = old_max_memuse
+            support.real_max_memuse = old_real_max_memuse
 
     # XXX -follows a list of untested API
     # make_legacy_pyc
@@ -773,7 +811,6 @@ class TestSupport(unittest.TestCase):
     # EnvironmentVarGuard
     # transient_internet
     # run_with_locale
-    # set_memlimit
     # bigmemtest
     # precisionbigmemtest
     # bigaddrspacetest