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v0.5.1
https://github.com/python/cpython
Revision f4d644f36ffb6cb11b34bfcf533c14cfaebf709a authored by Gregory P. Smith on 30 January 2018, 05:27:39 UTC, committed by GitHub on 30 January 2018, 05:27:39 UTC
Do not allow receiving a SIGINT to cause the subprocess module to trigger an
immediate SIGKILL of the child process.  SIGINT is normally sent to all child
processes by the OS at the same time already as was the established normal
behavior in 2.7 and 3.2.  This behavior change was introduced during the fix to https://bugs.python.org/issue12494 and is generally surprising to command line
tool users who expect other tools launched in child processes to get their own
SIGINT and do their own cleanup.

In Python 3.3-3.6 subprocess.call and subprocess.run would immediately
SIGKILL the child process upon receiving a SIGINT (which raises a
KeyboardInterrupt).  We now give the child a small amount of time to
exit gracefully before resorting to a SIGKILL.

This is also the case for subprocess.Popen.__exit__ which would
previously block indefinitely waiting for the child to die.  This was
hidden from many users by virtue of subprocess.call and subprocess.run
sending the signal immediately.

Behavior change: subprocess.Popen.__exit__ will not block indefinitely
when the exiting exception is a KeyboardInterrupt.  This is done for
user friendliness as people expect their ^C to actually happen.  This
could cause occasional orphaned Popen objects when not using `call` or
`run` with a child process that hasn't exited.

Refactoring involved: The Popen.wait method deals with the
KeyboardInterrupt second chance, existing platform specific internals
have been renamed to _wait().
Also fixes comment typos.
1 parent 83e64c8
Raw File
Tip revision: f4d644f36ffb6cb11b34bfcf533c14cfaebf709a authored by Gregory P. Smith on 30 January 2018, 05:27:39 UTC
bpo-25942: make subprocess more graceful on ^C (GH-5026)
Tip revision: f4d644f
_testconsole.c

/* Testing module for multi-phase initialization of extension modules (PEP 489)
 */

#include "Python.h"

#ifdef MS_WINDOWS

#include "..\modules\_io\_iomodule.h"

#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <fcntl.h>

 /* The full definition is in iomodule. We reproduce
 enough here to get the handle, which is all we want. */
typedef struct {
    PyObject_HEAD
    HANDLE handle;
} winconsoleio;


static int execfunc(PyObject *m)
{
    return 0;
}

PyModuleDef_Slot testconsole_slots[] = {
    {Py_mod_exec, execfunc},
    {0, NULL},
};

/*[clinic input]
module _testconsole

_testconsole.write_input
    file: object
    s: PyBytesObject

Writes UTF-16-LE encoded bytes to the console as if typed by a user.
[clinic start generated code]*/

static PyObject *
_testconsole_write_input_impl(PyObject *module, PyObject *file,
                              PyBytesObject *s)
/*[clinic end generated code: output=48f9563db34aedb3 input=4c774f2d05770bc6]*/
{
    INPUT_RECORD *rec = NULL;

    if (!PyWindowsConsoleIO_Check(file)) {
        PyErr_SetString(PyExc_TypeError, "expected raw console object");
        return NULL;
    }

    const wchar_t *p = (const wchar_t *)PyBytes_AS_STRING(s);
    DWORD size = (DWORD)PyBytes_GET_SIZE(s) / sizeof(wchar_t);

    rec = (INPUT_RECORD*)PyMem_Malloc(sizeof(INPUT_RECORD) * size);
    if (!rec)
        goto error;
    memset(rec, 0, sizeof(INPUT_RECORD) * size);

    INPUT_RECORD *prec = rec;
    for (DWORD i = 0; i < size; ++i, ++p, ++prec) {
        prec->EventType = KEY_EVENT;
        prec->Event.KeyEvent.bKeyDown = TRUE;
        prec->Event.KeyEvent.wRepeatCount = 10;
        prec->Event.KeyEvent.uChar.UnicodeChar = *p;
    }

    HANDLE hInput = ((winconsoleio*)file)->handle;
    DWORD total = 0;
    while (total < size) {
        DWORD wrote;
        if (!WriteConsoleInputW(hInput, &rec[total], (size - total), &wrote)) {
            PyErr_SetFromWindowsErr(0);
            goto error;
        }
        total += wrote;
    }

    PyMem_Free((void*)rec);

    Py_RETURN_NONE;
error:
    if (rec)
        PyMem_Free((void*)rec);
    return NULL;
}

/*[clinic input]
_testconsole.read_output
    file: object

Reads a str from the console as written to stdout.
[clinic start generated code]*/

static PyObject *
_testconsole_read_output_impl(PyObject *module, PyObject *file)
/*[clinic end generated code: output=876310d81a73e6d2 input=b3521f64b1b558e3]*/
{
    Py_RETURN_NONE;
}

#include "clinic\_testconsole.c.h"

PyMethodDef testconsole_methods[] = {
    _TESTCONSOLE_WRITE_INPUT_METHODDEF
    _TESTCONSOLE_READ_OUTPUT_METHODDEF
    {NULL, NULL}
};

static PyModuleDef testconsole_def = {
    PyModuleDef_HEAD_INIT,                      /* m_base */
    "_testconsole",                             /* m_name */
    PyDoc_STR("Test module for the Windows console"), /* m_doc */
    0,                                          /* m_size */
    testconsole_methods,                        /* m_methods */
    testconsole_slots,                          /* m_slots */
    NULL,                                       /* m_traverse */
    NULL,                                       /* m_clear */
    NULL,                                       /* m_free */
};

PyMODINIT_FUNC
PyInit__testconsole(PyObject *spec)
{
    return PyModuleDef_Init(&testconsole_def);
}

#endif /* MS_WINDOWS */
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