Add ability to configure domain ID

rclpy/rclpy/__init__.py

@@ -52,14 +52,20 @@
 from rclpy.utilities import ok  # noqa: F401 forwarding to this module
 from rclpy.utilities import shutdown as _shutdown
 from rclpy.utilities import try_shutdown  # noqa: F401
+from rclpy.utilities import get_default_domain_id
 
 # Avoid loading extensions on module import
 if TYPE_CHECKING:
     from rclpy.executors import Executor  # noqa: F401
     from rclpy.node import Node  # noqa: F401
 
 
-def init(*, args: Optional[List[str]] = None, context: Context = None) -> None:
+def init(
+    *,
+    args: Optional[List[str]] = None,
+    context: Context = None,
+    domain_id: int = get_default_domain_id()
+) -> None:
     """
     Initialize ROS communications for a given context.
 
@@ -68,7 +74,7 @@ def init(*, args: Optional[List[str]] = None, context: Context = None) -> None:
         (see :func:`.get_default_context`).
     """
     context = get_default_context() if context is None else context
-    return context.init(args)
+    return context.init(args, domain_id=domain_id)
 
 
 # The global spin functions need an executor to do the work

rclpy/rclpy/context.py

@@ -18,6 +18,7 @@
 from typing import List
 from typing import Optional
 import weakref
+from rclpy.impl.implementation_singleton import rclpy_implementation
 
 
 g_logging_configure_lock = threading.Lock()
@@ -46,7 +47,11 @@ def __init__(self):
     def handle(self):
         return self._handle
 
-    def init(self, args: Optional[List[str]] = None, *, initialize_logging: bool = True):
+    def init(self,
+             args: Optional[List[str]] = None,
+             *,
+             initialize_logging: bool = True,
+             domain_id: int = rclpy_implementation.rclpy_get_default_domain_id()):
         """
         Initialize ROS communications for a given context.
 
@@ -56,7 +61,10 @@ def init(self, args: Optional[List[str]] = None, *, initialize_logging: bool = T
         from rclpy.impl.implementation_singleton import rclpy_implementation
         global g_logging_ref_count
         with self._handle as capsule, self._lock:
-            rclpy_implementation.rclpy_init(args if args is not None else sys.argv, capsule)
+            rclpy_implementation.rclpy_init(
+                args if args is not None else sys.argv,
+                capsule,
+                domain_id)
             if initialize_logging and not self._logging_initialized:
                 with g_logging_configure_lock:
                     g_logging_ref_count += 1

rclpy/rclpy/utilities.py

@@ -39,6 +39,12 @@ def get_default_context(*, shutting_down=False):
         return g_default_context
 
 
+def get_default_domain_id():
+    """Return default domain id from rcl."""
+    from rclpy.impl.implementation_singleton import rclpy_implementation
+    return rclpy_implementation.rclpy_get_default_domain_id()
+
+
 def remove_ros_args(args=None):
     # imported locally to avoid loading extensions on module import
     from rclpy.impl.implementation_singleton import rclpy_implementation

rclpy/src/rclpy/_rclpy.c

@@ -26,6 +26,7 @@
 #include <rcl/remap.h>
 #include <rcl/time.h>
 #include <rcl/validate_topic_name.h>
+#include <rcl/init_options.h>
 #include <rcl_interfaces/msg/parameter_type.h>
 #include <rcl_yaml_param_parser/parser.h>
 #include <rcutils/allocator.h>
@@ -532,7 +533,9 @@ rclpy_init(PyObject * Py_UNUSED(self), PyObject * args)
   PyObject * pyargs;
   PyObject * pyseqlist;
   PyObject * pycontext;
-  if (!PyArg_ParseTuple(args, "OO", &pyargs, &pycontext)) {
+  PY_LONG_LONG domain_id;
+
+  if (!PyArg_ParseTuple(args, "OOK", &pyargs, &pycontext, &domain_id)) {
     // Exception raised
     return NULL;
   }
@@ -587,6 +590,15 @@ rclpy_init(PyObject * Py_UNUSED(self), PyObject * args)
     rcl_init_options_t init_options = rcl_get_zero_initialized_init_options();
     rcl_ret_t ret = rcl_init_options_init(&init_options, allocator);
     if (RCL_RET_OK == ret) {
+      // Set domain id
+      ret = rcl_init_options_set_domain_id(&init_options, (size_t)domain_id);
+      if (RCL_RET_OK != ret) {
+        PyErr_Format(
+          PyExc_RuntimeError,
+          "Failed to set domain id to init_options: %s",
+          rcl_get_error_string().str);
+        rcl_reset_error();
+      }
       ret = rcl_init(num_args, arg_values, &init_options, context);
       if (RCL_RET_OK == ret) {
         int unparsed_ros_args_count =
@@ -5494,6 +5506,24 @@ rclpy_publisher_get_topic_name(PyObject * Py_UNUSED(self), PyObject * args)
   return PyUnicode_FromString(topic_name);
 }
 
+
+/// Retrieves default domain id defined in rcl layer
+/**
+ *
+ * \return the defined domain id
+ */
+static PyObject *
+rclpy_get_default_domain_id(PyObject * Py_UNUSED(self), PyObject * args)
+{
+  (void)args;
+#if __WORDSIZE == 64
+  return PyLong_FromUnsignedLongLong(RCL_DEFAULT_DOMAIN_ID);
+#else
+  return PyLong_FromUnsignedLong(RCL_DEFAULT_DOMAIN_ID);
+#endif
+}
+
+
 /// Define the public methods of this module
 static PyMethodDef rclpy_methods[] = {
   {
@@ -5909,6 +5939,11 @@ static PyMethodDef rclpy_methods[] = {
     METH_VARARGS,
     "Get the resolved name(topic) of publisher"
   },
+  {
+    "rclpy_get_default_domain_id", rclpy_get_default_domain_id,
+    METH_NOARGS,
+    "Retrieve default domain ID"
+  },
 
   {NULL, NULL, 0, NULL}  /* sentinel */
 };