bindings: python: add support for controlled execution

Provide __enter__ and __exit__ callbacks for Chip so that it can be
used with the 'with' statement.

Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>

diff --git a/bindings/python/examples/gpiod_tests.py b/bindings/python/examples/gpiod_tests.py
index 3fd3cb2babf31d74d0ce448ff18f9a985c669336..91ea9612bdf98d87aab848aef61e0b0057869a44 100755 (executable)
--- a/bindings/python/examples/gpiod_tests.py
+++ b/bindings/python/examples/gpiod_tests.py
@@ -102,6 +102,14 @@ def chip_use_after_close():
 
 add_test('Use a GPIO chip after closing it', chip_use_after_close)
 
+def chip_with_statement():
+    with gpiod.Chip('gpiochip0') as chip:
+        print('Chip name in controlled execution: {}'.format(chip.name()))
+        line = chip.get_line(3)
+        print('Got line from chip in controlled execution: {}'.format(line.name()))
+
+add_test('Use a GPIO chip in controlled execution', chip_with_statement)
+
 def chip_info():
     chip = gpiod.Chip('gpiochip0')
     print('name: {}'.format(chip.name()))

diff --git a/bindings/python/gpiodmodule.c b/bindings/python/gpiodmodule.c
index 1bf8de7befab5ac830b900cd58de0ade5373797e..86760450900b049caf0a402a930518d28f1fd5fa 100644 (file)
--- a/bindings/python/gpiodmodule.c
+++ b/bindings/python/gpiodmodule.c
@@ -1315,6 +1315,23 @@ static PyObject *gpiod_Chip_close(gpiod_ChipObject *self)
        Py_RETURN_NONE;
 }
 
+PyDoc_STRVAR(gpiod_Chip_enter_doc,
+"Controlled execution enter callback.");
+
+static PyObject *gpiod_Chip_enter(gpiod_ChipObject *chip)
+{
+       Py_INCREF(chip);
+       return (PyObject *)chip;
+}
+
+PyDoc_STRVAR(gpiod_Chip_exit_doc,
+"Controlled execution exit callback.");
+
+static PyObject *gpiod_Chip_exit(gpiod_ChipObject *chip)
+{
+       return PyObject_CallMethod((PyObject *)chip, "close", "");
+}
+
 static bool gpiod_ChipIsClosed(gpiod_ChipObject *chip)
 {
        if (!chip->chip) {
@@ -1664,6 +1681,18 @@ static PyMethodDef gpiod_Chip_methods[] = {
                .ml_flags = METH_NOARGS,
                .ml_doc = gpiod_Chip_close_doc,
        },
+       {
+               .ml_name = "__enter__",
+               .ml_meth = (PyCFunction)gpiod_Chip_enter,
+               .ml_flags = METH_NOARGS,
+               .ml_doc = gpiod_Chip_enter_doc,
+       },
+       {
+               .ml_name = "__exit__",
+               .ml_meth = (PyCFunction)gpiod_Chip_exit,
+               .ml_flags = METH_VARARGS,
+               .ml_doc = gpiod_Chip_exit_doc,
+       },
        {
                .ml_name = "name",
                .ml_meth = (PyCFunction)gpiod_Chip_name,