Function ceph_dispatch_remote

src/mgr/BaseMgrModule.cc:851–956

static PyObject *
ceph_dispatch_remote(BaseMgrModule *self, PyObject *args)
{
  // PyArgs_ParseTuple doesn't give us refcounts here
  char *other_module = nullptr;
  char *method = nullptr;
  PyObject *remote_args = nullptr;
  PyObject *remote_kwargs = nullptr;
  if (!PyArg_ParseTuple(args, "ssOO:ceph_dispatch_remote",
        &other_module, &method, &remote_args, &remote_kwargs)) {
    return nullptr;
  }

  // Early error handling, because if the module doesn't exist then we
  // won't be able to use its thread state to set python error state
  // inside dispatch_remote().
  if (!self->py_modules->module_exists(other_module)) {
    derr << "no module '" << other_module << "'" << dendl;
    PyErr_SetString(PyExc_ImportError, "Module not found");
    return nullptr;
  }

  auto pmodule = self->this_module->py_module->pPickleModule;
  auto pickled_args = PyObject_CallMethodObjArgs(
    pmodule,
    PyUnicode_FromString("dumps"),
    remote_args,
    nullptr);
  if (pickled_args == nullptr) {
    std::string caller = "ceph_dispatch_remote "s + " " + method;
    std::string err = handle_pyerror(true, other_module, caller);
    PyErr_SetString(PyExc_RuntimeError, err.c_str());
    derr << err << dendl;
    return nullptr;
  }
  std::span<std::byte const> pickled_args_span = py_bytes_as_span(pickled_args);

  auto pickled_kwargs = PyObject_CallMethodObjArgs(
    pmodule,
    PyUnicode_FromString("dumps"),
    remote_kwargs,
    nullptr);
  if (pickled_kwargs == nullptr) {
    std::string caller = "ceph_dispatch_remote "s + " " + method;
    std::string err = handle_pyerror(true, other_module, caller);
    PyErr_SetString(PyExc_RuntimeError, err.c_str());
    derr << err << dendl;

    Py_DECREF(pickled_args);
    return nullptr;
  }
  std::span<std::byte const> pickled_kwargs_span =
    py_bytes_as_span(pickled_kwargs);

  // Drop GIL from calling python thread state, it will be taken
  // both for checking for method existence and for executing method.
  PyThreadState *tstate = PyEval_SaveThread();