py-evtregistry.c revision 1.5 
1/* Python interface to inferior thread event registries.
2
3   Copyright (C) 2009-2015 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 "defs.h"
21#include "command.h"
22#include "py-events.h"
23
24events_object gdb_py_events;
25
26extern PyTypeObject eventregistry_object_type
27    CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("eventregistry_object");
28
29/* Implementation of EventRegistry.connect () -> NULL.
30   Add FUNCTION to the list of listeners.  */
31
32static PyObject *
33evregpy_connect (PyObject *self, PyObject *function)
34{
35  PyObject *func;
36  PyObject *callback_list = (((eventregistry_object *) self)->callbacks);
37
38  if (!PyArg_ParseTuple (function, "O", &func))
39    return NULL;
40
41  if (!PyCallable_Check (func))
42    {
43      PyErr_SetString (PyExc_RuntimeError, "Function is not callable");
44      return NULL;
45    }
46
47  if (PyList_Append (callback_list, func) < 0)
48    return NULL;
49
50  Py_RETURN_NONE;
51}
52
53/* Implementation of EventRegistry.disconnect () -> NULL.
54   Remove FUNCTION from the list of listeners.  */
55
56static PyObject *
57evregpy_disconnect (PyObject *self, PyObject *function)
58{
59  PyObject *func;
60  int index;
61  PyObject *callback_list = (((eventregistry_object *) self)->callbacks);
62
63  if (!PyArg_ParseTuple (function, "O", &func))
64    return NULL;
65
66  index = PySequence_Index (callback_list, func);
67  if (index < 0)
68    Py_RETURN_NONE;
69
70  if (PySequence_DelItem (callback_list, index) < 0)
71    return NULL;
72
73  Py_RETURN_NONE;
74}
75
76/* Create a new event registry.  This function uses PyObject_New
77   and therefore returns a new reference that callers must handle.  */
78
79eventregistry_object *
80create_eventregistry_object (void)
81{
82  eventregistry_object *eventregistry_obj;
83
84  eventregistry_obj = PyObject_New (eventregistry_object,
85                                    &eventregistry_object_type);
86
87  if (!eventregistry_obj)
88    return NULL;
89
90  eventregistry_obj->callbacks = PyList_New (0);
91  if (!eventregistry_obj->callbacks)
92    {
93      Py_DECREF (eventregistry_obj);
94      return NULL;
95    }
96
97  return eventregistry_obj;
98}
99
100static void
101evregpy_dealloc (PyObject *self)
102{
103  Py_XDECREF (((eventregistry_object *) self)->callbacks);
104  Py_TYPE (self)->tp_free (self);
105}
106
107/* Initialize the Python event registry code.  */
108
109int
110gdbpy_initialize_eventregistry (void)
111{
112  if (PyType_Ready (&eventregistry_object_type) < 0)
113    return -1;
114
115  return gdb_pymodule_addobject (gdb_module, "EventRegistry",
116				 (PyObject *) &eventregistry_object_type);
117}
118
119/* Retern the number of listeners currently connected to this
120   registry.  */
121
122int
123evregpy_no_listeners_p (eventregistry_object *registry)
124{
125  return PyList_Size (registry->callbacks) == 0;
126}
127
128static PyMethodDef eventregistry_object_methods[] =
129{
130  { "connect", evregpy_connect, METH_VARARGS, "Add function" },
131  { "disconnect", evregpy_disconnect, METH_VARARGS, "Remove function" },
132  { NULL } /* Sentinel.  */
133};
134
135PyTypeObject eventregistry_object_type =
136{
137  PyVarObject_HEAD_INIT (NULL, 0)
138  "gdb.EventRegistry",                        /* tp_name */
139  sizeof (eventregistry_object),              /* tp_basicsize */
140  0,                                          /* tp_itemsize */
141  evregpy_dealloc,                            /* tp_dealloc */
142  0,                                          /* tp_print */
143  0,                                          /* tp_getattr */
144  0,                                          /* tp_setattr */
145  0,                                          /* tp_compare */
146  0,                                          /* tp_repr */
147  0,                                          /* tp_as_number */
148  0,                                          /* tp_as_sequence */
149  0,                                          /* tp_as_mapping */
150  0,                                          /* tp_hash  */
151  0,                                          /* tp_call */
152  0,                                          /* tp_str */
153  0,                                          /* tp_getattro */
154  0,                                          /* tp_setattro */
155  0,                                          /* tp_as_buffer */
156  Py_TPFLAGS_DEFAULT,                         /* tp_flags */
157  "GDB event registry object",                /* tp_doc */
158  0,                                          /* tp_traverse */
159  0,                                          /* tp_clear */
160  0,                                          /* tp_richcompare */
161  0,                                          /* tp_weaklistoffset */
162  0,                                          /* tp_iter */
163  0,                                          /* tp_iternext */
164  eventregistry_object_methods,               /* tp_methods */
165  0,                                          /* tp_members */
166  0,                                          /* tp_getset */
167  0,                                          /* tp_base */
168  0,                                          /* tp_dict */
169  0,                                          /* tp_descr_get */
170  0,                                          /* tp_descr_set */
171  0,                                          /* tp_dictoffset */
172  0,                                          /* tp_init */
173  0                                           /* tp_alloc */
174};
175