mirror of
https://github.com/python/cpython.git
synced 2024-12-01 11:15:56 +01:00
303 lines
8.3 KiB
C
303 lines
8.3 KiB
C
/*
|
|
* C Extension module to test pycore_critical_section.h API.
|
|
*/
|
|
|
|
#include "parts.h"
|
|
|
|
#include "pycore_critical_section.h"
|
|
|
|
#ifdef Py_GIL_DISABLED
|
|
#define assert_nogil assert
|
|
#define assert_gil(x)
|
|
#else
|
|
#define assert_gil assert
|
|
#define assert_nogil(x)
|
|
#endif
|
|
|
|
|
|
static PyObject *
|
|
test_critical_sections(PyObject *self, PyObject *Py_UNUSED(args))
|
|
{
|
|
PyObject *d1 = PyDict_New();
|
|
assert(d1 != NULL);
|
|
|
|
PyObject *d2 = PyDict_New();
|
|
assert(d2 != NULL);
|
|
|
|
// Beginning a critical section should lock the associated object and
|
|
// push the critical section onto the thread's stack (in Py_GIL_DISABLED builds).
|
|
Py_BEGIN_CRITICAL_SECTION(d1);
|
|
assert_nogil(PyMutex_IsLocked(&d1->ob_mutex));
|
|
assert_nogil(_PyCriticalSection_IsActive(PyThreadState_GET()->critical_section));
|
|
assert_gil(PyThreadState_GET()->critical_section == 0);
|
|
Py_END_CRITICAL_SECTION();
|
|
assert_nogil(!PyMutex_IsLocked(&d1->ob_mutex));
|
|
|
|
assert_nogil(!PyMutex_IsLocked(&d1->ob_mutex));
|
|
assert_nogil(!PyMutex_IsLocked(&d2->ob_mutex));
|
|
Py_BEGIN_CRITICAL_SECTION2(d1, d2);
|
|
assert_nogil(PyMutex_IsLocked(&d1->ob_mutex));
|
|
assert_nogil(PyMutex_IsLocked(&d2->ob_mutex));
|
|
Py_END_CRITICAL_SECTION2();
|
|
assert_nogil(!PyMutex_IsLocked(&d1->ob_mutex));
|
|
assert_nogil(!PyMutex_IsLocked(&d2->ob_mutex));
|
|
|
|
// Passing the same object twice should work (and not deadlock).
|
|
assert_nogil(!PyMutex_IsLocked(&d2->ob_mutex));
|
|
Py_BEGIN_CRITICAL_SECTION2(d2, d2);
|
|
assert_nogil(PyMutex_IsLocked(&d2->ob_mutex));
|
|
Py_END_CRITICAL_SECTION2();
|
|
assert_nogil(!PyMutex_IsLocked(&d2->ob_mutex));
|
|
|
|
Py_DECREF(d2);
|
|
Py_DECREF(d1);
|
|
Py_RETURN_NONE;
|
|
}
|
|
|
|
static void
|
|
lock_unlock_object(PyObject *obj, int recurse_depth)
|
|
{
|
|
Py_BEGIN_CRITICAL_SECTION(obj);
|
|
if (recurse_depth > 0) {
|
|
lock_unlock_object(obj, recurse_depth - 1);
|
|
}
|
|
Py_END_CRITICAL_SECTION();
|
|
}
|
|
|
|
static void
|
|
lock_unlock_two_objects(PyObject *a, PyObject *b, int recurse_depth)
|
|
{
|
|
Py_BEGIN_CRITICAL_SECTION2(a, b);
|
|
if (recurse_depth > 0) {
|
|
lock_unlock_two_objects(a, b, recurse_depth - 1);
|
|
}
|
|
Py_END_CRITICAL_SECTION2();
|
|
}
|
|
|
|
|
|
// Test that nested critical sections do not deadlock if they attempt to lock
|
|
// the same object.
|
|
static PyObject *
|
|
test_critical_sections_nest(PyObject *self, PyObject *Py_UNUSED(args))
|
|
{
|
|
PyObject *a = PyDict_New();
|
|
assert(a != NULL);
|
|
PyObject *b = PyDict_New();
|
|
assert(b != NULL);
|
|
|
|
// Locking an object recursively with this API should not deadlock.
|
|
assert_nogil(!PyMutex_IsLocked(&a->ob_mutex));
|
|
Py_BEGIN_CRITICAL_SECTION(a);
|
|
assert_nogil(PyMutex_IsLocked(&a->ob_mutex));
|
|
lock_unlock_object(a, 10);
|
|
assert_nogil(PyMutex_IsLocked(&a->ob_mutex));
|
|
Py_END_CRITICAL_SECTION();
|
|
assert_nogil(!PyMutex_IsLocked(&a->ob_mutex));
|
|
|
|
// Same test but with two objects.
|
|
Py_BEGIN_CRITICAL_SECTION2(b, a);
|
|
lock_unlock_two_objects(a, b, 10);
|
|
assert_nogil(PyMutex_IsLocked(&a->ob_mutex));
|
|
assert_nogil(PyMutex_IsLocked(&b->ob_mutex));
|
|
Py_END_CRITICAL_SECTION2();
|
|
|
|
Py_DECREF(b);
|
|
Py_DECREF(a);
|
|
Py_RETURN_NONE;
|
|
}
|
|
|
|
// Test that a critical section is suspended by a Py_BEGIN_ALLOW_THREADS and
|
|
// resumed by a Py_END_ALLOW_THREADS.
|
|
static PyObject *
|
|
test_critical_sections_suspend(PyObject *self, PyObject *Py_UNUSED(args))
|
|
{
|
|
PyObject *a = PyDict_New();
|
|
assert(a != NULL);
|
|
|
|
Py_BEGIN_CRITICAL_SECTION(a);
|
|
assert_nogil(PyMutex_IsLocked(&a->ob_mutex));
|
|
|
|
// Py_BEGIN_ALLOW_THREADS should suspend the active critical section
|
|
Py_BEGIN_ALLOW_THREADS
|
|
assert_nogil(!PyMutex_IsLocked(&a->ob_mutex));
|
|
Py_END_ALLOW_THREADS;
|
|
|
|
// After Py_END_ALLOW_THREADS the critical section should be resumed.
|
|
assert_nogil(PyMutex_IsLocked(&a->ob_mutex));
|
|
Py_END_CRITICAL_SECTION();
|
|
|
|
Py_DECREF(a);
|
|
Py_RETURN_NONE;
|
|
}
|
|
|
|
#ifdef Py_CAN_START_THREADS
|
|
struct test_data {
|
|
PyObject *obj1;
|
|
PyObject *obj2;
|
|
PyObject *obj3;
|
|
Py_ssize_t countdown;
|
|
PyEvent done_event;
|
|
};
|
|
|
|
static void
|
|
thread_critical_sections(void *arg)
|
|
{
|
|
const Py_ssize_t NUM_ITERS = 200;
|
|
struct test_data *test_data = arg;
|
|
PyGILState_STATE gil = PyGILState_Ensure();
|
|
|
|
for (Py_ssize_t i = 0; i < NUM_ITERS; i++) {
|
|
Py_BEGIN_CRITICAL_SECTION(test_data->obj1);
|
|
Py_END_CRITICAL_SECTION();
|
|
|
|
Py_BEGIN_CRITICAL_SECTION(test_data->obj2);
|
|
lock_unlock_object(test_data->obj1, 1);
|
|
Py_END_CRITICAL_SECTION();
|
|
|
|
Py_BEGIN_CRITICAL_SECTION2(test_data->obj3, test_data->obj1);
|
|
lock_unlock_object(test_data->obj2, 2);
|
|
Py_END_CRITICAL_SECTION2();
|
|
|
|
Py_BEGIN_CRITICAL_SECTION(test_data->obj3);
|
|
Py_BEGIN_ALLOW_THREADS
|
|
Py_END_ALLOW_THREADS
|
|
Py_END_CRITICAL_SECTION();
|
|
}
|
|
|
|
PyGILState_Release(gil);
|
|
if (_Py_atomic_add_ssize(&test_data->countdown, -1) == 1) {
|
|
// last thread to finish sets done_event
|
|
_PyEvent_Notify(&test_data->done_event);
|
|
}
|
|
}
|
|
|
|
static PyObject *
|
|
test_critical_sections_threads(PyObject *self, PyObject *Py_UNUSED(args))
|
|
{
|
|
const Py_ssize_t NUM_THREADS = 4;
|
|
struct test_data test_data = {
|
|
.obj1 = PyDict_New(),
|
|
.obj2 = PyDict_New(),
|
|
.obj3 = PyDict_New(),
|
|
.countdown = NUM_THREADS,
|
|
};
|
|
assert(test_data.obj1 != NULL);
|
|
assert(test_data.obj2 != NULL);
|
|
assert(test_data.obj3 != NULL);
|
|
|
|
for (Py_ssize_t i = 0; i < NUM_THREADS; i++) {
|
|
PyThread_start_new_thread(&thread_critical_sections, &test_data);
|
|
}
|
|
PyEvent_Wait(&test_data.done_event);
|
|
|
|
Py_DECREF(test_data.obj3);
|
|
Py_DECREF(test_data.obj2);
|
|
Py_DECREF(test_data.obj1);
|
|
Py_RETURN_NONE;
|
|
}
|
|
|
|
static void
|
|
pysleep(int ms)
|
|
{
|
|
#ifdef MS_WINDOWS
|
|
Sleep(ms);
|
|
#else
|
|
usleep(ms * 1000);
|
|
#endif
|
|
}
|
|
|
|
struct test_data_gc {
|
|
PyObject *obj;
|
|
Py_ssize_t num_threads;
|
|
Py_ssize_t id;
|
|
Py_ssize_t countdown;
|
|
PyEvent done_event;
|
|
PyEvent ready;
|
|
};
|
|
|
|
static void
|
|
thread_gc(void *arg)
|
|
{
|
|
struct test_data_gc *test_data = arg;
|
|
PyGILState_STATE gil = PyGILState_Ensure();
|
|
|
|
Py_ssize_t id = _Py_atomic_add_ssize(&test_data->id, 1);
|
|
if (id == test_data->num_threads - 1) {
|
|
_PyEvent_Notify(&test_data->ready);
|
|
}
|
|
else {
|
|
// wait for all test threads to more reliably reproduce the issue.
|
|
PyEvent_Wait(&test_data->ready);
|
|
}
|
|
|
|
if (id == 0) {
|
|
Py_BEGIN_CRITICAL_SECTION(test_data->obj);
|
|
// pause long enough that the lock would be handed off directly to
|
|
// a waiting thread.
|
|
pysleep(5);
|
|
PyGC_Collect();
|
|
Py_END_CRITICAL_SECTION();
|
|
}
|
|
else if (id == 1) {
|
|
pysleep(1);
|
|
Py_BEGIN_CRITICAL_SECTION(test_data->obj);
|
|
pysleep(1);
|
|
Py_END_CRITICAL_SECTION();
|
|
}
|
|
else if (id == 2) {
|
|
// sleep long enough so that thread 0 is waiting to stop the world
|
|
pysleep(6);
|
|
Py_BEGIN_CRITICAL_SECTION(test_data->obj);
|
|
pysleep(1);
|
|
Py_END_CRITICAL_SECTION();
|
|
}
|
|
|
|
PyGILState_Release(gil);
|
|
if (_Py_atomic_add_ssize(&test_data->countdown, -1) == 1) {
|
|
// last thread to finish sets done_event
|
|
_PyEvent_Notify(&test_data->done_event);
|
|
}
|
|
}
|
|
|
|
static PyObject *
|
|
test_critical_sections_gc(PyObject *self, PyObject *Py_UNUSED(args))
|
|
{
|
|
// gh-118332: Contended critical sections should not deadlock with GC
|
|
const Py_ssize_t NUM_THREADS = 3;
|
|
struct test_data_gc test_data = {
|
|
.obj = PyDict_New(),
|
|
.countdown = NUM_THREADS,
|
|
.num_threads = NUM_THREADS,
|
|
};
|
|
assert(test_data.obj != NULL);
|
|
|
|
for (Py_ssize_t i = 0; i < NUM_THREADS; i++) {
|
|
PyThread_start_new_thread(&thread_gc, &test_data);
|
|
}
|
|
PyEvent_Wait(&test_data.done_event);
|
|
Py_DECREF(test_data.obj);
|
|
Py_RETURN_NONE;
|
|
}
|
|
|
|
#endif
|
|
|
|
static PyMethodDef test_methods[] = {
|
|
{"test_critical_sections", test_critical_sections, METH_NOARGS},
|
|
{"test_critical_sections_nest", test_critical_sections_nest, METH_NOARGS},
|
|
{"test_critical_sections_suspend", test_critical_sections_suspend, METH_NOARGS},
|
|
#ifdef Py_CAN_START_THREADS
|
|
{"test_critical_sections_threads", test_critical_sections_threads, METH_NOARGS},
|
|
{"test_critical_sections_gc", test_critical_sections_gc, METH_NOARGS},
|
|
#endif
|
|
{NULL, NULL} /* sentinel */
|
|
};
|
|
|
|
int
|
|
_PyTestInternalCapi_Init_CriticalSection(PyObject *mod)
|
|
{
|
|
if (PyModule_AddFunctions(mod, test_methods) < 0) {
|
|
return -1;
|
|
}
|
|
return 0;
|
|
}
|