gh-76785: Add More Tests to test_interpreters.test_api (gh-117662)

In addition to the increase test coverage, this is a precursor to sorting out how we handle interpreters created directly via the C-API.

Lib/test/test_interpreters/utils.py

@@ -1,30 +1,344 @@
+from collections import namedtuple
 import contextlib
+import json
+import io
 import os
 import os.path
+import pickle
+import queue
+#import select
 import subprocess
 import sys
 import tempfile
-from textwrap import dedent
+from textwrap import dedent, indent
 import threading
 import types
 import unittest
+import warnings
 
 from test import support
 from test.support import os_helper
+from test.support import import_helper
 
+_interpreters = import_helper.import_module('_xxsubinterpreters')
 from test.support import interpreters
 
 
-def _captured_script(script):
-    r, w = os.pipe()
-    indented = script.replace('\n', '\n                ')
-    wrapped = dedent(f"""
-        import contextlib
-        with open({w}, 'w', encoding='utf-8') as spipe:
-            with contextlib.redirect_stdout(spipe):
+try:
+    import _testinternalcapi
+    import _testcapi
+except ImportError:
+    _testinternalcapi = None
+    _testcapi = None
+
+def requires_test_modules(func):
+    return unittest.skipIf(_testinternalcapi is None, "test requires _testinternalcapi module")(func)
+
+
+def _dump_script(text):
+    lines = text.splitlines()
+    print()
+    print('-' * 20)
+    for i, line in enumerate(lines, 1):
+        print(f' {i:>{len(str(len(lines)))}}  {line}')
+    print('-' * 20)
+
+
+def _close_file(file):
+    try:
+        if hasattr(file, 'close'):
+            file.close()
+        else:
+            os.close(file)
+    except OSError as exc:
+        if exc.errno != 9:
+            raise  # re-raise
+        # It was closed already.
+
+
+def pack_exception(exc=None):
+    captured = _interpreters.capture_exception(exc)
+    data = dict(captured.__dict__)
+    data['type'] = dict(captured.type.__dict__)
+    return json.dumps(data)
+
+
+def unpack_exception(packed):
+    try:
+        data = json.loads(packed)
+    except json.decoder.JSONDecodeError:
+        warnings.warn('incomplete exception data', RuntimeWarning)
+        print(packed if isinstance(packed, str) else packed.decode('utf-8'))
+        return None
+    exc = types.SimpleNamespace(**data)
+    exc.type = types.SimpleNamespace(**exc.type)
+    return exc;
+
+
+class CapturingResults:
+
+    STDIO = dedent("""\
+        with open({w_pipe}, 'wb', buffering=0) as _spipe_{stream}:
+            _captured_std{stream} = io.StringIO()
+            with contextlib.redirect_std{stream}(_captured_std{stream}):
+                #########################
+                # begin wrapped script
+
                 {indented}
-        """)
-    return wrapped, open(r, encoding='utf-8')
+
+                # end wrapped script
+                #########################
+            text = _captured_std{stream}.getvalue()
+            _spipe_{stream}.write(text.encode('utf-8'))
+        """)[:-1]
+    EXC = dedent("""\
+        with open({w_pipe}, 'wb', buffering=0) as _spipe_exc:
+            try:
+                #########################
+                # begin wrapped script
+
+                {indented}
+
+                # end wrapped script
+                #########################
+            except Exception as exc:
+                text = _interp_utils.pack_exception(exc)
+                _spipe_exc.write(text.encode('utf-8'))
+        """)[:-1]
+
+    @classmethod
+    def wrap_script(cls, script, *, stdout=True, stderr=False, exc=False):
+        script = dedent(script).strip(os.linesep)
+        imports = [
+            f'import {__name__} as _interp_utils',
+        ]
+        wrapped = script
+
+        # Handle exc.
+        if exc:
+            exc = os.pipe()
+            r_exc, w_exc = exc
+            indented = wrapped.replace('\n', '\n        ')
+            wrapped = cls.EXC.format(
+                w_pipe=w_exc,
+                indented=indented,
+            )
+        else:
+            exc = None
+
+        # Handle stdout.
+        if stdout:
+            imports.extend([
+                'import contextlib, io',
+            ])
+            stdout = os.pipe()
+            r_out, w_out = stdout
+            indented = wrapped.replace('\n', '\n        ')
+            wrapped = cls.STDIO.format(
+                w_pipe=w_out,
+                indented=indented,
+                stream='out',
+            )
+        else:
+            stdout = None
+
+        # Handle stderr.
+        if stderr == 'stdout':
+            stderr = None
+        elif stderr:
+            if not stdout:
+                imports.extend([
+                    'import contextlib, io',
+                ])
+            stderr = os.pipe()
+            r_err, w_err = stderr
+            indented = wrapped.replace('\n', '\n        ')
+            wrapped = cls.STDIO.format(
+                w_pipe=w_err,
+                indented=indented,
+                stream='err',
+            )
+        else:
+            stderr = None
+
+        if wrapped == script:
+            raise NotImplementedError
+        else:
+            for line in imports:
+                wrapped = f'{line}{os.linesep}{wrapped}'
+
+        results = cls(stdout, stderr, exc)
+        return wrapped, results
+
+    def __init__(self, out, err, exc):
+        self._rf_out = None
+        self._rf_err = None
+        self._rf_exc = None
+        self._w_out = None
+        self._w_err = None
+        self._w_exc = None
+
+        if out is not None:
+            r_out, w_out = out
+            self._rf_out = open(r_out, 'rb', buffering=0)
+            self._w_out = w_out
+
+        if err is not None:
+            r_err, w_err = err
+            self._rf_err = open(r_err, 'rb', buffering=0)
+            self._w_err = w_err
+
+        if exc is not None:
+            r_exc, w_exc = exc
+            self._rf_exc = open(r_exc, 'rb', buffering=0)
+            self._w_exc = w_exc
+
+        self._buf_out = b''
+        self._buf_err = b''
+        self._buf_exc = b''
+        self._exc = None
+
+        self._closed = False
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        self.close()
+
+    @property
+    def closed(self):
+        return self._closed
+
+    def close(self):
+        if self._closed:
+            return
+        self._closed = True
+
+        if self._w_out is not None:
+            _close_file(self._w_out)
+            self._w_out = None
+        if self._w_err is not None:
+            _close_file(self._w_err)
+            self._w_err = None
+        if self._w_exc is not None:
+            _close_file(self._w_exc)
+            self._w_exc = None
+
+        self._capture()
+
+        if self._rf_out is not None:
+            _close_file(self._rf_out)
+            self._rf_out = None
+        if self._rf_err is not None:
+            _close_file(self._rf_err)
+            self._rf_err = None
+        if self._rf_exc is not None:
+            _close_file(self._rf_exc)
+            self._rf_exc = None
+
+    def _capture(self):
+        # Ideally this is called only after the script finishes
+        # (and thus has closed the write end of the pipe.
+        if self._rf_out is not None:
+            chunk = self._rf_out.read(100)
+            while chunk:
+                self._buf_out += chunk
+                chunk = self._rf_out.read(100)
+        if self._rf_err is not None:
+            chunk = self._rf_err.read(100)
+            while chunk:
+                self._buf_err += chunk
+                chunk = self._rf_err.read(100)
+        if self._rf_exc is not None:
+            chunk = self._rf_exc.read(100)
+            while chunk:
+                self._buf_exc += chunk
+                chunk = self._rf_exc.read(100)
+
+    def _unpack_stdout(self):
+        return self._buf_out.decode('utf-8')
+
+    def _unpack_stderr(self):
+        return self._buf_err.decode('utf-8')
+
+    def _unpack_exc(self):
+        if self._exc is not None:
+            return self._exc
+        if not self._buf_exc:
+            return None
+        self._exc = unpack_exception(self._buf_exc)
+        return self._exc
+
+    def stdout(self):
+        if self.closed:
+            return self.final().stdout
+        self._capture()
+        return self._unpack_stdout()
+
+    def stderr(self):
+        if self.closed:
+            return self.final().stderr
+        self._capture()
+        return self._unpack_stderr()
+
+    def exc(self):
+        if self.closed:
+            return self.final().exc
+        self._capture()
+        return self._unpack_exc()
+
+    def final(self, *, force=False):
+        try:
+            return self._final
+        except AttributeError:
+            if not self._closed:
+                if not force:
+                    raise Exception('no final results available yet')
+                else:
+                    return CapturedResults.Proxy(self)
+            self._final = CapturedResults(
+                self._unpack_stdout(),
+                self._unpack_stderr(),
+                self._unpack_exc(),
+            )
+            return self._final
+
+
+class CapturedResults(namedtuple('CapturedResults', 'stdout stderr exc')):
+
+    class Proxy:
+        def __init__(self, capturing):
+            self._capturing = capturing
+        def _finish(self):
+            if self._capturing is None:
+                return
+            self._final = self._capturing.final()
+            self._capturing = None
+        def __iter__(self):
+            self._finish()
+            yield from self._final
+        def __len__(self):
+            self._finish()
+            return len(self._final)
+        def __getattr__(self, name):
+            self._finish()
+            if name.startswith('_'):
+                raise AttributeError(name)
+            return getattr(self._final, name)
+
+    def raise_if_failed(self):
+        if self.exc is not None:
+            raise interpreters.ExecutionFailed(self.exc)
+
+
+def _captured_script(script, *, stdout=True, stderr=False, exc=False):
+    return CapturingResults.wrap_script(
+        script,
+        stdout=stdout,
+        stderr=stderr,
+        exc=exc,
+    )
 
 
 def clean_up_interpreters():
@@ -33,17 +347,17 @@ def clean_up_interpreters():
             continue
         try:
             interp.close()
-        except RuntimeError:
+        except _interpreters.InterpreterError:
             pass  # already destroyed
 
 
 def _run_output(interp, request, init=None):
-    script, rpipe = _captured_script(request)
-    with rpipe:
+    script, results = _captured_script(request)
+    with results:
         if init:
             interp.prepare_main(init)
         interp.exec(script)
-        return rpipe.read()
+    return results.stdout()
 
 
 @contextlib.contextmanager
@@ -175,3 +489,184 @@ def assert_ns_equal(self, ns1, ns2, msg=None):
         diff = f'namespace({diff})'
         standardMsg = self._truncateMessage(standardMsg, diff)
         self.fail(self._formatMessage(msg, standardMsg))
+
+    def _run_string(self, interp, script):
+        wrapped, results = _captured_script(script, exc=False)
+        #_dump_script(wrapped)
+        with results:
+            if isinstance(interp, interpreters.Interpreter):
+                interp.exec(script)
+            else:
+                err = _interpreters.run_string(interp, wrapped)
+                if err is not None:
+                    return None, err
+        return results.stdout(), None
+
+    def run_and_capture(self, interp, script):
+        text, err = self._run_string(interp, script)
+        if err is not None:
+            raise interpreters.ExecutionFailed(err)
+        else:
+            return text
+
+    @requires_test_modules
+    @contextlib.contextmanager
+    def interpreter_from_capi(self, config=None, whence=None):
+        if config is False:
+            if whence is None:
+                whence = _interpreters.WHENCE_LEGACY_CAPI
+            else:
+                assert whence in (_interpreters.WHENCE_LEGACY_CAPI,
+                                  _interpreters.WHENCE_UNKNOWN), repr(whence)
+            config = None
+        elif config is True:
+            config = _interpreters.new_config('default')
+        elif config is None:
+            if whence not in (
+                _interpreters.WHENCE_LEGACY_CAPI,
+                _interpreters.WHENCE_UNKNOWN,
+            ):
+                config = _interpreters.new_config('legacy')
+        elif isinstance(config, str):
+            config = _interpreters.new_config(config)
+
+        if whence is None:
+            whence = _interpreters.WHENCE_XI
+
+        interpid = _testinternalcapi.create_interpreter(config, whence=whence)
+        try:
+            yield interpid
+        finally:
+            try:
+                _testinternalcapi.destroy_interpreter(interpid)
+            except _interpreters.InterpreterNotFoundError:
+                pass
+
+    @contextlib.contextmanager
+    def interpreter_obj_from_capi(self, config='legacy'):
+        with self.interpreter_from_capi(config) as interpid:
+            yield interpreters.Interpreter(interpid), interpid
+
+    @contextlib.contextmanager
+    def capturing(self, script):
+        wrapped, capturing = _captured_script(script, stdout=True, exc=True)
+        #_dump_script(wrapped)
+        with capturing:
+            yield wrapped, capturing.final(force=True)
+
+    @requires_test_modules
+    def run_from_capi(self, interpid, script, *, main=False):
+        with self.capturing(script) as (wrapped, results):
+            rc = _testinternalcapi.exec_interpreter(interpid, wrapped, main=main)
+            assert rc == 0, rc
+        results.raise_if_failed()
+        return results.stdout
+
+    @contextlib.contextmanager
+    def _running(self, run_interp, exec_interp):
+        token = b'\0'
+        r_in, w_in = self.pipe()
+        r_out, w_out = self.pipe()
+
+        def close():
+            _close_file(r_in)
+            _close_file(w_in)
+            _close_file(r_out)
+            _close_file(w_out)
+
+        # Start running (and wait).
+        script = dedent(f"""
+            import os
+            try:
+                # handshake
+                token = os.read({r_in}, 1)
+                os.write({w_out}, token)
+                # Wait for the "done" message.
+                os.read({r_in}, 1)
+            except BrokenPipeError:
+                pass
+            except OSError as exc:
+                if exc.errno != 9:
+                    raise  # re-raise
+                # It was closed already.
+            """)
+        failed = None
+        def run():
+            nonlocal failed
+            try:
+                run_interp(script)
+            except Exception as exc:
+                failed = exc
+                close()
+        t = threading.Thread(target=run)
+        t.start()
+
+        # handshake
+        try:
+            os.write(w_in, token)
+            token2 = os.read(r_out, 1)
+            assert token2 == token, (token2, token)
+        except OSError:
+            t.join()
+            if failed is not None:
+                raise failed
+
+        # CM __exit__()
+        try:
+            try:
+                yield
+            finally:
+                # Send "done".
+                os.write(w_in, b'\0')
+        finally:
+            close()
+            t.join()
+            if failed is not None:
+                raise failed
+
+    @contextlib.contextmanager
+    def running(self, interp):
+        if isinstance(interp, int):
+            interpid = interp
+            def exec_interp(script):
+                exc = _interpreters.exec(interpid, script)
+                assert exc is None, exc
+            run_interp = exec_interp
+        else:
+            def run_interp(script):
+                text = self.run_and_capture(interp, script)
+                assert text == '', repr(text)
+            def exec_interp(script):
+                interp.exec(script)
+        with self._running(run_interp, exec_interp):
+            yield
+
+    @requires_test_modules
+    @contextlib.contextmanager
+    def running_from_capi(self, interpid, *, main=False):
+        def run_interp(script):
+            text = self.run_from_capi(interpid, script, main=main)
+            assert text == '', repr(text)
+        def exec_interp(script):
+            rc = _testinternalcapi.exec_interpreter(interpid, script)
+            assert rc == 0, rc
+        with self._running(run_interp, exec_interp):
+            yield
+
+    @requires_test_modules
+    def run_temp_from_capi(self, script, config='legacy'):
+        if config is False:
+            # Force using Py_NewInterpreter().
+            run_in_interp = (lambda s, c: _testcapi.run_in_subinterp(s))
+            config = None
+        else:
+            run_in_interp = _testinternalcapi.run_in_subinterp_with_config
+            if config is True:
+                config = 'default'
+            if isinstance(config, str):
+                config = _interpreters.new_config(config)
+        with self.capturing(script) as (wrapped, results):
+            rc = run_in_interp(wrapped, config)
+            assert rc == 0, rc
+        results.raise_if_failed()
+        return results.stdout