gdb/python/py-evtregistry.c

   1 /* Python interface to inferior thread event registries.
   2
   3    Copyright (C) 2009-2024 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "command.h"
  21 #include "py-events.h"
  22
  23 events_object gdb_py_events;
  24
  25 extern PyTypeObject eventregistry_object_type
  26     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("eventregistry_object");
  27
  28 /* Implementation of EventRegistry.connect () -> NULL.
  29    Add FUNCTION to the list of listeners.  */
  30
  31 static PyObject *
  32 evregpy_connect (PyObject *self, PyObject *function)
  33 {
  34   PyObject *func;
  35   PyObject *callback_list = (((eventregistry_object *) self)->callbacks);
  36
  37   if (!PyArg_ParseTuple (function, "O", &func))
  38     return NULL;
  39
  40   if (!PyCallable_Check (func))
  41     {
  42       PyErr_SetString (PyExc_RuntimeError, "Function is not callable");
  43       return NULL;
  44     }
  45
  46   if (PyList_Append (callback_list, func) < 0)
  47     return NULL;
  48
  49   Py_RETURN_NONE;
  50 }
  51
  52 /* Implementation of EventRegistry.disconnect () -> NULL.
  53    Remove FUNCTION from the list of listeners.  */
  54
  55 static PyObject *
  56 evregpy_disconnect (PyObject *self, PyObject *function)
  57 {
  58   PyObject *func;
  59   int index;
  60   PyObject *callback_list = (((eventregistry_object *) self)->callbacks);
  61
  62   if (!PyArg_ParseTuple (function, "O", &func))
  63     return NULL;
  64
  65   index = PySequence_Index (callback_list, func);
  66   if (index < 0)
  67     Py_RETURN_NONE;
  68
  69   if (PySequence_DelItem (callback_list, index) < 0)
  70     return NULL;
  71
  72   Py_RETURN_NONE;
  73 }
  74
  75 /* Create a new event registry.  This function uses PyObject_New
  76    and therefore returns a new reference that callers must handle.  */
  77
  78 eventregistry_object *
  79 create_eventregistry_object (void)
  80 {
  81   gdbpy_ref<eventregistry_object>
  82     eventregistry_obj (PyObject_New (eventregistry_object,
  83                                      &eventregistry_object_type));
  84
  85   if (eventregistry_obj == NULL)
  86     return NULL;
  87
  88   eventregistry_obj->callbacks = PyList_New (0);
  89   if (!eventregistry_obj->callbacks)
  90     return NULL;
  91
  92   return eventregistry_obj.release ();
  93 }
  94
  95 static void
  96 evregpy_dealloc (PyObject *self)
  97 {
  98   Py_XDECREF (((eventregistry_object *) self)->callbacks);
  99   Py_TYPE (self)->tp_free (self);
 100 }
 101
 102 /* Initialize the Python event registry code.  */
 103
 104 static int CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION
 105 gdbpy_initialize_eventregistry (void)
 106 {
 107   return gdbpy_type_ready (&eventregistry_object_type);
 108 }
 109
 110 /* Return the number of listeners currently connected to this
 111    registry.  */
 112
 113 bool
 114 evregpy_no_listeners_p (eventregistry_object *registry)
 115 {
 116   /* REGISTRY can be nullptr if gdb failed to find the data directory
 117      at startup.  */
 118   return registry == nullptr || PyList_Size (registry->callbacks) == 0;
 119 }
 120
 121 GDBPY_INITIALIZE_FILE (gdbpy_initialize_eventregistry);
 122
 123 static PyMethodDef eventregistry_object_methods[] =
 124 {
 125   { "connect", evregpy_connect, METH_VARARGS, "Add function" },
 126   { "disconnect", evregpy_disconnect, METH_VARARGS, "Remove function" },
 127   { NULL } /* Sentinel.  */
 128 };
 129
 130 PyTypeObject eventregistry_object_type =
 131 {
 132   PyVarObject_HEAD_INIT (NULL, 0)
 133   "gdb.EventRegistry",                        /* tp_name */
 134   sizeof (eventregistry_object),              /* tp_basicsize */
 135   0,                                          /* tp_itemsize */
 136   evregpy_dealloc,                            /* tp_dealloc */
 137   0,                                          /* tp_print */
 138   0,                                          /* tp_getattr */
 139   0,                                          /* tp_setattr */
 140   0,                                          /* tp_compare */
 141   0,                                          /* tp_repr */
 142   0,                                          /* tp_as_number */
 143   0,                                          /* tp_as_sequence */
 144   0,                                          /* tp_as_mapping */
 145   0,                                          /* tp_hash  */
 146   0,                                          /* tp_call */
 147   0,                                          /* tp_str */
 148   0,                                          /* tp_getattro */
 149   0,                                          /* tp_setattro */
 150   0,                                          /* tp_as_buffer */
 151   Py_TPFLAGS_DEFAULT,                         /* tp_flags */
 152   "GDB event registry object",                /* tp_doc */
 153   0,                                          /* tp_traverse */
 154   0,                                          /* tp_clear */
 155   0,                                          /* tp_richcompare */
 156   0,                                          /* tp_weaklistoffset */
 157   0,                                          /* tp_iter */
 158   0,                                          /* tp_iternext */
 159   eventregistry_object_methods,               /* tp_methods */
 160   0,                                          /* tp_members */
 161   0,                                          /* tp_getset */
 162   0,                                          /* tp_base */
 163   0,                                          /* tp_dict */
 164   0,                                          /* tp_descr_get */
 165   0,                                          /* tp_descr_set */
 166   0,                                          /* tp_dictoffset */
 167   0,                                          /* tp_init */
 168   0                                           /* tp_alloc */
 169 };