[Python-checkins] bpo-30696: Fix the REPL looping endlessly when no memory (GH-4160)
xdegaye
webhook-mailer at python.org
Sun Nov 12 10:50:52 EST 2017
https://github.com/python/cpython/commit/e0582a37c8d1776a2fd4968e9216f3a05f780276
commit: e0582a37c8d1776a2fd4968e9216f3a05f780276
branch: master
author: xdegaye <xdegaye at gmail.com>
committer: GitHub <noreply at github.com>
date: 2017-11-12T16:50:48+01:00
summary:
bpo-30696: Fix the REPL looping endlessly when no memory (GH-4160)
files:
A Lib/test/test_repl.py
A Misc/NEWS.d/next/Core and Builtins/2017-10-28-22-06-03.bpo-30696.lhC3HE.rst
M Doc/c-api/veryhigh.rst
M Python/pythonrun.c
diff --git a/Doc/c-api/veryhigh.rst b/Doc/c-api/veryhigh.rst
index 6ab5942929f..3897fdd8282 100644
--- a/Doc/c-api/veryhigh.rst
+++ b/Doc/c-api/veryhigh.rst
@@ -141,7 +141,8 @@ the same library that the Python runtime is using.
Read and execute statements from a file associated with an interactive device
until EOF is reached. The user will be prompted using ``sys.ps1`` and
``sys.ps2``. *filename* is decoded from the filesystem encoding
- (:func:`sys.getfilesystemencoding`). Returns ``0`` at EOF.
+ (:func:`sys.getfilesystemencoding`). Returns ``0`` at EOF or a negative
+ number upon failure.
.. c:var:: int (*PyOS_InputHook)(void)
diff --git a/Lib/test/test_repl.py b/Lib/test/test_repl.py
new file mode 100644
index 00000000000..9efd459a6f0
--- /dev/null
+++ b/Lib/test/test_repl.py
@@ -0,0 +1,62 @@
+"""Test the interactive interpreter."""
+
+import sys
+import os
+import unittest
+import subprocess
+from textwrap import dedent
+from test.support import cpython_only, SuppressCrashReport
+from test.support.script_helper import kill_python
+
+def spawn_repl(*args, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, **kw):
+ """Run the Python REPL with the given arguments.
+
+ kw is extra keyword args to pass to subprocess.Popen. Returns a Popen
+ object.
+ """
+
+ # To run the REPL without using a terminal, spawn python with the command
+ # line option '-i' and the process name set to '<stdin>'.
+ # The directory of argv[0] must match the directory of the Python
+ # executable for the Popen() call to python to succeed as the directory
+ # path may be used by Py_GetPath() to build the default module search
+ # path.
+ stdin_fname = os.path.join(os.path.dirname(sys.executable), "<stdin>")
+ cmd_line = [stdin_fname, '-E', '-i']
+ cmd_line.extend(args)
+
+ # Set TERM=vt100, for the rationale see the comments in spawn_python() of
+ # test.support.script_helper.
+ env = kw.setdefault('env', dict(os.environ))
+ env['TERM'] = 'vt100'
+ return subprocess.Popen(cmd_line, executable=sys.executable,
+ stdin=subprocess.PIPE,
+ stdout=stdout, stderr=stderr,
+ **kw)
+
+class TestInteractiveInterpreter(unittest.TestCase):
+
+ @cpython_only
+ def test_no_memory(self):
+ # Issue #30696: Fix the interactive interpreter looping endlessly when
+ # no memory. Check also that the fix does not break the interactive
+ # loop when an exception is raised.
+ user_input = """
+ import sys, _testcapi
+ 1/0
+ print('After the exception.')
+ _testcapi.set_nomemory(0)
+ sys.exit(0)
+ """
+ user_input = dedent(user_input)
+ user_input = user_input.encode()
+ p = spawn_repl()
+ with SuppressCrashReport():
+ p.stdin.write(user_input)
+ output = kill_python(p)
+ self.assertIn(b'After the exception.', output)
+ # Exit code 120: Py_FinalizeEx() failed to flush stdout and stderr.
+ self.assertIn(p.returncode, (1, 120))
+
+if __name__ == "__main__":
+ unittest.main()
diff --git a/Misc/NEWS.d/next/Core and Builtins/2017-10-28-22-06-03.bpo-30696.lhC3HE.rst b/Misc/NEWS.d/next/Core and Builtins/2017-10-28-22-06-03.bpo-30696.lhC3HE.rst
new file mode 100644
index 00000000000..76bc6834880
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2017-10-28-22-06-03.bpo-30696.lhC3HE.rst
@@ -0,0 +1 @@
+Fix the interactive interpreter looping endlessly when no memory.
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 3d63186a36a..90b29cb1016 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -65,6 +65,7 @@ static PyObject *run_pyc_file(FILE *, const char *, PyObject *, PyObject *,
PyCompilerFlags *);
static void err_input(perrdetail *);
static void err_free(perrdetail *);
+static int PyRun_InteractiveOneObjectEx(FILE *, PyObject *, PyCompilerFlags *);
/* Parse input from a file and execute it */
int
@@ -89,6 +90,7 @@ PyRun_InteractiveLoopFlags(FILE *fp, const char *filename_str, PyCompilerFlags *
PyObject *filename, *v;
int ret, err;
PyCompilerFlags local_flags;
+ int nomem_count = 0;
filename = PyUnicode_DecodeFSDefault(filename_str);
if (filename == NULL) {
@@ -110,22 +112,32 @@ PyRun_InteractiveLoopFlags(FILE *fp, const char *filename_str, PyCompilerFlags *
_PySys_SetObjectId(&PyId_ps2, v = PyUnicode_FromString("... "));
Py_XDECREF(v);
}
- err = -1;
- for (;;) {
- ret = PyRun_InteractiveOneObject(fp, filename, flags);
+ err = 0;
+ do {
+ ret = PyRun_InteractiveOneObjectEx(fp, filename, flags);
+ if (ret == -1 && PyErr_Occurred()) {
+ /* Prevent an endless loop after multiple consecutive MemoryErrors
+ * while still allowing an interactive command to fail with a
+ * MemoryError. */
+ if (PyErr_ExceptionMatches(PyExc_MemoryError)) {
+ if (++nomem_count > 16) {
+ PyErr_Clear();
+ err = -1;
+ break;
+ }
+ } else {
+ nomem_count = 0;
+ }
+ PyErr_Print();
+ flush_io();
+ } else {
+ nomem_count = 0;
+ }
#ifdef Py_REF_DEBUG
if (_PyDebug_XOptionShowRefCount() == Py_True)
_PyDebug_PrintTotalRefs();
#endif
- if (ret == E_EOF) {
- err = 0;
- break;
- }
- /*
- if (ret == E_NOMEM)
- break;
- */
- }
+ } while (ret != E_EOF);
Py_DECREF(filename);
return err;
}
@@ -154,8 +166,11 @@ static int PARSER_FLAGS(PyCompilerFlags *flags)
PyPARSE_WITH_IS_KEYWORD : 0)) : 0)
#endif
-int
-PyRun_InteractiveOneObject(FILE *fp, PyObject *filename, PyCompilerFlags *flags)
+/* A PyRun_InteractiveOneObject() auxiliary function that does not print the
+ * error on failure. */
+static int
+PyRun_InteractiveOneObjectEx(FILE *fp, PyObject *filename,
+ PyCompilerFlags *flags)
{
PyObject *m, *d, *v, *w, *oenc = NULL, *mod_name;
mod_ty mod;
@@ -167,7 +182,6 @@ PyRun_InteractiveOneObject(FILE *fp, PyObject *filename, PyCompilerFlags *flags)
mod_name = _PyUnicode_FromId(&PyId___main__); /* borrowed */
if (mod_name == NULL) {
- PyErr_Print();
return -1;
}
@@ -227,7 +241,6 @@ PyRun_InteractiveOneObject(FILE *fp, PyObject *filename, PyCompilerFlags *flags)
PyErr_Clear();
return E_EOF;
}
- PyErr_Print();
return -1;
}
m = PyImport_AddModuleObject(mod_name);
@@ -239,8 +252,6 @@ PyRun_InteractiveOneObject(FILE *fp, PyObject *filename, PyCompilerFlags *flags)
v = run_mod(mod, filename, d, d, flags, arena);
PyArena_Free(arena);
if (v == NULL) {
- PyErr_Print();
- flush_io();
return -1;
}
Py_DECREF(v);
@@ -249,6 +260,19 @@ PyRun_InteractiveOneObject(FILE *fp, PyObject *filename, PyCompilerFlags *flags)
}
int
+PyRun_InteractiveOneObject(FILE *fp, PyObject *filename, PyCompilerFlags *flags)
+{
+ int res;
+
+ res = PyRun_InteractiveOneObjectEx(fp, filename, flags);
+ if (res == -1) {
+ PyErr_Print();
+ flush_io();
+ }
+ return res;
+}
+
+int
PyRun_InteractiveOneFlags(FILE *fp, const char *filename_str, PyCompilerFlags *flags)
{
PyObject *filename;
More information about the Python-checkins
mailing list