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authorPetr Viktorin <pviktori@redhat.com>2015-05-26 13:25:12 +0200
committerAndrew Bartlett <abartlet@samba.org>2015-06-10 06:06:19 +0200
commit560576217f11b132f9c32de6e41c623dbc152137 (patch)
tree00ea621614defa31c8cbf2a1a3becb7388fa453b /lib
parent4399dc582fa06b04e1cec1d3aa59cd332e4b5ba2 (diff)
downloadsamba-560576217f11b132f9c32de6e41c623dbc152137.tar.gz
pytalloc: Improve timer wrapper, and test it
Using Context.add_timer resulted in crashes due to missing type object and bad reference handling. Add a TeventTimer_Type struct, and introduce a clear ownership/lifetime model. Add a "add_timer_offset" to allow adding timers from Python. (add_timer requires passing struct timeval as a Python integer, which can't really be done portably). Add tests. Signed-off-by: Petr Viktorin <pviktori@redhat.com> Reviewed-by: Andrew Bartlett <abartlet@samba.org> Reviewed-by: Jelmer Vernooij <jelmer@samba.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/tevent/bindings.py52
-rw-r--r--lib/tevent/pytevent.c147
-rwxr-xr-xlib/tevent/wscript5
3 files changed, 185 insertions, 19 deletions
diff --git a/lib/tevent/bindings.py b/lib/tevent/bindings.py
index 1060caf28df..55aafbb64a6 100644
--- a/lib/tevent/bindings.py
+++ b/lib/tevent/bindings.py
@@ -22,8 +22,10 @@
# License along with this library; if not, see <http://www.gnu.org/licenses/>.
import signal
+from unittest import TestCase, TestProgram
+import gc
+
import _tevent
-from unittest import TestCase
class BackendListTests(TestCase):
@@ -60,3 +62,51 @@ class ContextTests(TestCase):
def test_add_signal(self):
sig = self.ctx.add_signal(signal.SIGINT, 0, lambda callback: None)
self.assertTrue(isinstance(sig, _tevent.Signal))
+
+ def test_timer(self):
+ """Test a timer is can be scheduled"""
+ collecting_list = []
+ # time "0" has already passed, callback will be scheduled immediately
+ timer = self.ctx.add_timer(0, lambda t: collecting_list.append(True))
+ self.assertTrue(timer.active)
+ self.assertEqual(collecting_list, [])
+ self.ctx.loop_once()
+ self.assertFalse(timer.active)
+ self.assertEqual(collecting_list, [True])
+
+ def test_timer_deallocate_timer(self):
+ """Test timer is scheduled even if reference to it isn't held"""
+ collecting_list = []
+ def callback(t):
+ collecting_list.append(True)
+ timer = self.ctx.add_timer(0, lambda t: collecting_list.append(True))
+ gc.collect()
+ self.assertEqual(collecting_list, [])
+ self.ctx.loop_once()
+ self.assertEqual(collecting_list, [True])
+
+ def test_timer_deallocate_context(self):
+ """Test timer is unscheduled when context is freed"""
+ collecting_list = []
+ def callback(t):
+ collecting_list.append(True)
+ timer = self.ctx.add_timer(0, lambda t: collecting_list.append(True))
+ self.assertTrue(timer.active)
+ del self.ctx
+ gc.collect()
+ self.assertEqual(collecting_list, [])
+ self.assertFalse(timer.active)
+
+ def test_timer_offset(self):
+ """Test scheduling timer with an offset"""
+ collecting_list = []
+ self.ctx.add_timer_offset(0.2, lambda t: collecting_list.append(2))
+ self.ctx.add_timer_offset(0.1, lambda t: collecting_list.append(1))
+ self.assertEqual(collecting_list, [])
+ self.ctx.loop_once()
+ self.assertEqual(collecting_list, [1])
+ self.ctx.loop_once()
+ self.assertEqual(collecting_list, [1, 2])
+
+if __name__ == '__main__':
+ TestProgram()
diff --git a/lib/tevent/pytevent.c b/lib/tevent/pytevent.c
index a495da5385d..a04d5657b0d 100644
--- a/lib/tevent/pytevent.c
+++ b/lib/tevent/pytevent.c
@@ -50,6 +50,7 @@ typedef struct {
typedef struct {
PyObject_HEAD
struct tevent_timer *timer;
+ PyObject *callback;
} TeventTimer_Object;
typedef struct {
@@ -372,38 +373,148 @@ static void py_timer_handler(struct tevent_context *ev,
struct timeval current_time,
void *private_data)
{
- PyObject *callback = private_data, *ret;
- ret = PyObject_CallFunction(callback, "l", te);
+ TeventTimer_Object *self = private_data;
+ PyObject *ret;
+
+ ret = PyObject_CallFunction(self->callback, "l", te);
+ if (ret == NULL) {
+ /* No Python stack to propagate exception to; just print traceback */
+ PyErr_PrintEx(0);
+ }
Py_XDECREF(ret);
}
-static PyObject *py_tevent_context_add_timer(TeventContext_Object *self, PyObject *args)
+static void py_tevent_timer_dealloc(TeventTimer_Object *self)
{
- TeventTimer_Object *ret;
- struct timeval next_event;
- struct tevent_timer *timer;
- PyObject *handler;
- if (!PyArg_ParseTuple(args, "lO", &next_event, &handler))
- return NULL;
-
- timer = tevent_add_timer(self->ev, NULL, next_event, py_timer_handler,
- handler);
- if (timer == NULL) {
- PyErr_SetNone(PyExc_RuntimeError);
- return NULL;
+ if (self->timer) {
+ talloc_free(self->timer);
}
+ Py_DECREF(self->callback);
+ PyObject_Del(self);
+}
+
+static int py_tevent_timer_traverse(TeventTimer_Object *self, visitproc visit, void *arg)
+{
+ Py_VISIT(self->callback);
+ return 0;
+}
+
+static PyObject* py_tevent_timer_get_active(TeventTimer_Object *self) {
+ return PyBool_FromLong(self->timer != NULL);
+}
+
+struct PyGetSetDef py_tevent_timer_getset[] = {
+ {
+ .name = "active",
+ .get = (getter)py_tevent_timer_get_active,
+ .doc = "true if the timer is scheduled to run",
+ },
+ {NULL},
+};
+
+static PyTypeObject TeventTimer_Type = {
+ .tp_name = "tevent.Timer",
+ .tp_basicsize = sizeof(TeventTimer_Object),
+ .tp_dealloc = (destructor)py_tevent_timer_dealloc,
+ .tp_traverse = (traverseproc)py_tevent_timer_traverse,
+ .tp_getset = py_tevent_timer_getset,
+ .tp_flags = Py_TPFLAGS_DEFAULT,
+};
+
+static int timer_destructor(void* ptr)
+{
+ TeventTimer_Object *obj = *(TeventTimer_Object **)ptr;
+ obj->timer = NULL;
+ Py_DECREF(obj);
+ return 0;
+}
+
+static PyObject *py_tevent_context_add_timer_internal(TeventContext_Object *self,
+ struct timeval next_event,
+ PyObject *callback)
+{
+ /* Ownership notes:
+ *
+ * There are 5 pieces in play; two tevent contexts and 3 Python objects:
+ * - The tevent timer
+ * - The tevent context
+ * - The Python context -- "self"
+ * - The Python timer (TeventTimer_Object) -- "ret"
+ * - The Python callback function -- "callback"
+ *
+ * We only use the Python context for getting the tevent context,
+ * afterwards it can be destroyed.
+ *
+ * The tevent context owns the tevent timer.
+ *
+ * The tevent timer holds a reference to the Python timer, so the Python
+ * timer must always outlive the tevent timer.
+ * The Python timer has a pointer to the tevent timer; a destructor is
+ * used to set this to NULL when the tevent timer is deallocated.
+ *
+ * The tevent timer can be deallocated in these cases:
+ * 1) when the context is destroyed
+ * 2) after the event fires
+ * Posssibly, API might be added to cancel (free the tevent timer).
+ *
+ * The Python timer holds a reference to the callback.
+ */
+ TeventTimer_Object *ret;
+ TeventTimer_Object **tmp_context;
ret = PyObject_New(TeventTimer_Object, &TeventTimer_Type);
if (ret == NULL) {
PyErr_NoMemory();
- talloc_free(timer);
return NULL;
}
- ret->timer = timer;
+ Py_INCREF(callback);
+ ret->callback = callback;
+ ret->timer = tevent_add_timer(self->ev, NULL, next_event, py_timer_handler,
+ ret);
+ if (ret->timer == NULL) {
+ Py_DECREF(ret);
+ PyErr_SetString(PyExc_RuntimeError, "Could not initialize timer");
+ return NULL;
+ }
+ tmp_context = talloc(ret->timer, TeventTimer_Object*);
+ if (tmp_context == NULL) {
+ talloc_free(ret->timer);
+ Py_DECREF(ret);
+ PyErr_SetString(PyExc_RuntimeError, "Could not initialize timer");
+ return NULL;
+ }
+ Py_INCREF(ret);
+ *tmp_context = ret;
+ talloc_set_destructor(tmp_context, timer_destructor);
return (PyObject *)ret;
}
+static PyObject *py_tevent_context_add_timer(TeventContext_Object *self, PyObject *args)
+{
+ struct timeval next_event;
+ PyObject *callback;
+ if (!PyArg_ParseTuple(args, "lO", &next_event, &callback))
+ return NULL;
+
+ return py_tevent_context_add_timer_internal(self, next_event, callback);
+}
+
+static PyObject *py_tevent_context_add_timer_offset(TeventContext_Object *self, PyObject *args)
+{
+ struct timeval next_event;
+ double offset;
+ int seconds;
+ PyObject *callback;
+ if (!PyArg_ParseTuple(args, "dO", &offset, &callback))
+ return NULL;
+
+ seconds = offset;
+ offset -= seconds;
+ next_event = tevent_timeval_current_ofs(seconds, (int)(offset*1000000));
+ return py_tevent_context_add_timer_internal(self, next_event, callback);
+}
+
static void py_fd_handler(struct tevent_context *ev,
struct tevent_fd *fde,
uint16_t flags,
@@ -479,6 +590,8 @@ static PyMethodDef py_tevent_context_methods[] = {
METH_VARARGS, "S.add_signal(signum, sa_flags, handler) -> signal" },
{ "add_timer", (PyCFunction)py_tevent_context_add_timer,
METH_VARARGS, "S.add_timer(next_event, handler) -> timer" },
+ { "add_timer_offset", (PyCFunction)py_tevent_context_add_timer_offset,
+ METH_VARARGS, "S.add_timer(offset_seconds, handler) -> timer" },
{ "add_fd", (PyCFunction)py_tevent_context_add_fd,
METH_VARARGS, "S.add_fd(fd, flags, handler) -> fd" },
#ifdef TEVENT_DEPRECATED
diff --git a/lib/tevent/wscript b/lib/tevent/wscript
index 026cd9a1c1b..d0f1ac18366 100755
--- a/lib/tevent/wscript
+++ b/lib/tevent/wscript
@@ -13,7 +13,7 @@ while not os.path.exists(srcdir+'/buildtools') and len(srcdir.split('/')) < 5:
srcdir = srcdir + '/..'
sys.path.insert(0, srcdir + '/buildtools/wafsamba')
-import wafsamba, samba_dist, Options, Logs
+import wafsamba, samba_dist, samba_utils, Options, Logs
samba_dist.DIST_DIRS('lib/tevent:. lib/replace:lib/replace lib/talloc:lib/talloc buildtools:buildtools third_party/waf:third_party/waf')
@@ -130,6 +130,9 @@ def test(ctx):
'''test tevent'''
print("The tevent testsuite is part of smbtorture in samba4")
+ pyret = samba_utils.RUN_PYTHON_TESTS(['bindings.py'])
+ sys.exit(pyret)
+
def dist():
'''makes a tarball for distribution'''