Add Cancellable.get_pollfd()

Useful for integrating with an existing event loop.

frida/core.py

@@ -448,6 +448,9 @@ class Cancellable(object):
     def raise_if_cancelled(self):
         self._impl.raise_if_cancelled()
 
+    def get_pollfd(self):
+        return CancellablePollFD(self._impl)
+
     @classmethod
     def get_current(cls):
         return _Cancellable.get_current()
@@ -468,6 +471,30 @@ class Cancellable(object):
         self._impl.cancel()
 
 
+class CancellablePollFD(object):
+    def __init__(self, cancellable):
+        self.handle = cancellable.get_fd()
+        self._cancellable = cancellable
+
+    def __del__(self):
+        self.release()
+
+    def release(self):
+        if self._cancellable is not None:
+            self._cancellable.release_fd()
+            self._cancellable = None
+            self.handle = -1
+
+    def __repr__(self):
+        return repr(self.handle)
+
+    def __enter__(self):
+        return self.handle
+
+    def __exit__(self, *args):
+        self.release()
+
+
 def _to_camel_case(name):
     result = ""
     uppercase_next = False

src/_frida.c

@@ -375,6 +375,8 @@ static int PyCancellable_init (PyCancellable * self, PyObject * args, PyObject *
 static PyObject * PyCancellable_repr (PyCancellable * self);
 static PyObject * PyCancellable_is_cancelled (PyCancellable * self);
 static PyObject * PyCancellable_raise_if_cancelled (PyCancellable * self);
+static PyObject * PyCancellable_get_fd (PyCancellable * self);
+static PyObject * PyCancellable_release_fd (PyCancellable * self);
 static PyObject * PyCancellable_get_current (PyCancellable * self);
 static PyObject * PyCancellable_push_current (PyCancellable * self);
 static PyObject * PyCancellable_pop_current (PyCancellable * self);
@@ -553,6 +555,8 @@ static PyMethodDef PyCancellable_methods[] =
 {
   { "is_cancelled", (PyCFunction) PyCancellable_is_cancelled, METH_NOARGS, "Query whether cancellable has been cancelled." },
   { "raise_if_cancelled", (PyCFunction) PyCancellable_raise_if_cancelled, METH_NOARGS, "Raise an exception if cancelled." },
+  { "get_fd", (PyCFunction) PyCancellable_get_fd, METH_NOARGS, "Get file descriptor for integrating with an event loop." },
+  { "release_fd", (PyCFunction) PyCancellable_release_fd, METH_NOARGS, "Release a resource previously allocated by get_fd()." },
   { "get_current", (PyCFunction) PyCancellable_get_current, METH_CLASS | METH_NOARGS, "Get the top cancellable from the stack." },
   { "push_current", (PyCFunction) PyCancellable_push_current, METH_NOARGS, "Push cancellable onto the cancellable stack." },
   { "pop_current", (PyCFunction) PyCancellable_pop_current, METH_NOARGS, "Pop cancellable off the cancellable stack." },
@@ -3695,6 +3699,20 @@ PyCancellable_raise_if_cancelled (PyCancellable * self)
   Py_RETURN_NONE;
 }
 
+static PyObject *
+PyCancellable_get_fd (PyCancellable * self)
+{
+  return PyLong_FromLong (g_cancellable_get_fd (PY_GOBJECT_HANDLE (self)));
+}
+
+static PyObject *
+PyCancellable_release_fd (PyCancellable * self)
+{
+  g_cancellable_release_fd (PY_GOBJECT_HANDLE (self));
+
+  Py_RETURN_NONE;
+}
+
 static PyObject *
 PyCancellable_get_current (PyCancellable * self)
 {