src/bindings/python/bt2/bt2/native_bt_bt2_objects.h

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright (c) 2017 Philippe Proulx <pproulx@efficios.com>
   5  */
   6
   7 #include "logging/comp-logging.h"
   8
   9
  10 /*
  11  * Useful Python objects.
  12  */
  13
  14 static PyObject *py_mod_bt2 = NULL;
  15 static PyObject *py_mod_bt2_exc_error_type = NULL;
  16 static PyObject *py_mod_bt2_exc_memory_error = NULL;
  17 static PyObject *py_mod_bt2_exc_try_again_type = NULL;
  18 static PyObject *py_mod_bt2_exc_stop_type = NULL;
  19 static PyObject *py_mod_bt2_exc_unknown_object_type = NULL;
  20
  21 static
  22 void bt_bt2_init_from_bt2(void)
  23 {
  24         /*
  25          * This is called once the bt2 package is loaded.
  26          *
  27          * Those modules and functions are needed while the package is
  28          * used. Loading them here is safe because we know the bt2
  29          * package is imported, and we know that the user cannot use the
  30          * code here without importing bt2 first.
  31          */
  32         py_mod_bt2 = PyImport_ImportModule("bt2");
  33         BT_ASSERT(py_mod_bt2);
  34         py_mod_bt2_exc_error_type =
  35                 PyObject_GetAttrString(py_mod_bt2, "_Error");
  36         BT_ASSERT(py_mod_bt2_exc_error_type);
  37         py_mod_bt2_exc_memory_error =
  38                 PyObject_GetAttrString(py_mod_bt2, "_MemoryError");
  39         BT_ASSERT(py_mod_bt2_exc_memory_error);
  40         py_mod_bt2_exc_try_again_type =
  41                 PyObject_GetAttrString(py_mod_bt2, "TryAgain");
  42         BT_ASSERT(py_mod_bt2_exc_try_again_type);
  43         py_mod_bt2_exc_stop_type =
  44                 PyObject_GetAttrString(py_mod_bt2, "Stop");
  45         BT_ASSERT(py_mod_bt2_exc_stop_type);
  46         py_mod_bt2_exc_unknown_object_type =
  47                 PyObject_GetAttrString(py_mod_bt2, "UnknownObject");
  48         BT_ASSERT(py_mod_bt2_exc_unknown_object_type);
  49 }
  50
  51 static
  52 void bt_bt2_exit_handler(void)
  53 {
  54         /*
  55          * This is an exit handler (set by the bt2 package).
  56          *
  57          * We only give back the references that we took in
  58          * bt_bt2_init_from_bt2() here. The global variables continue
  59          * to exist for the code of this file, but they are now borrowed
  60          * references. If this code is executed, it means that somehow
  61          * the modules are still loaded, so it should be safe to use
  62          * them even without a strong reference.
  63          *
  64          * We cannot do this in the library's destructor because it
  65          * gets executed once Python is already finalized.
  66          */
  67         Py_XDECREF(py_mod_bt2);
  68         Py_XDECREF(py_mod_bt2_exc_error_type);
  69         Py_XDECREF(py_mod_bt2_exc_try_again_type);
  70         Py_XDECREF(py_mod_bt2_exc_stop_type);
  71         Py_XDECREF(py_mod_bt2_exc_unknown_object_type);
  72 }