gdb/python/py-evtregistry.c

   1 /* Python interface to inferior thread event registries.
   2
   3    Copyright (C) 2009-2018 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 #include "py-ref.h"
  24
  25 events_object gdb_py_events;
  26
  27 extern PyTypeObject eventregistry_object_type
  28     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("eventregistry_object");
  29
  30 /* Implementation of EventRegistry.connect () -> NULL.
  31    Add FUNCTION to the list of listeners.  */
  32
  33 static PyObject *
  34 evregpy_connect (PyObject *self, PyObject *function)
  35 {
  36   PyObject *func;
  37   PyObject *callback_list = (((eventregistry_object *) self)->callbacks);
  38
  39   if (!PyArg_ParseTuple (function, "O", &func))
  40     return NULL;
  41
  42   if (!PyCallable_Check (func))
  43     {
  44       PyErr_SetString (PyExc_RuntimeError, "Function is not callable");
  45       return NULL;
  46     }
  47
  48   if (PyList_Append (callback_list, func) < 0)
  49     return NULL;
  50
  51   Py_RETURN_NONE;
  52 }
  53
  54 /* Implementation of EventRegistry.disconnect () -> NULL.
  55    Remove FUNCTION from the list of listeners.  */
  56
  57 static PyObject *
  58 evregpy_disconnect (PyObject *self, PyObject *function)
  59 {
  60   PyObject *func;
  61   int index;
  62   PyObject *callback_list = (((eventregistry_object *) self)->callbacks);
  63
  64   if (!PyArg_ParseTuple (function, "O", &func))
  65     return NULL;
  66
  67   index = PySequence_Index (callback_list, func);
  68   if (index < 0)
  69     Py_RETURN_NONE;
  70
  71   if (PySequence_DelItem (callback_list, index) < 0)
  72     return NULL;
  73
  74   Py_RETURN_NONE;
  75 }
  76
  77 /* Create a new event registry.  This function uses PyObject_New
  78    and therefore returns a new reference that callers must handle.  */
  79
  80 eventregistry_object *
  81 create_eventregistry_object (void)
  82 {
  83   gdbpy_ref<eventregistry_object>
  84     eventregistry_obj (PyObject_New (eventregistry_object,
  85                                      &eventregistry_object_type));
  86
  87   if (eventregistry_obj == NULL)
  88     return NULL;
  89
  90   eventregistry_obj->callbacks = PyList_New (0);
  91   if (!eventregistry_obj->callbacks)
  92     return NULL;
  93
  94   return eventregistry_obj.release ();
  95 }
  96
  97 static void
  98 evregpy_dealloc (PyObject *self)
  99 {
 100   Py_XDECREF (((eventregistry_object *) self)->callbacks);
 101   Py_TYPE (self)->tp_free (self);
 102 }
 103
 104 /* Initialize the Python event registry code.  */
 105
 106 int
 107 gdbpy_initialize_eventregistry (void)
 108 {
 109   if (PyType_Ready (&eventregistry_object_type) < 0)
 110     return -1;
 111
 112   return gdb_pymodule_addobject (gdb_module, "EventRegistry",
 113                                  (PyObject *) &eventregistry_object_type);
 114 }
 115
 116 /* Retern the number of listeners currently connected to this
 117    registry.  */
 118
 119 int
 120 evregpy_no_listeners_p (eventregistry_object *registry)
 121 {
 122   return PyList_Size (registry->callbacks) == 0;
 123 }
 124
 125 static PyMethodDef eventregistry_object_methods[] =
 126 {
 127   { "connect", evregpy_connect, METH_VARARGS, "Add function" },
 128   { "disconnect", evregpy_disconnect, METH_VARARGS, "Remove function" },
 129   { NULL } /* Sentinel.  */
 130 };
 131
 132 PyTypeObject eventregistry_object_type =
 133 {
 134   PyVarObject_HEAD_INIT (NULL, 0)
 135   "gdb.EventRegistry",                        /* tp_name */
 136   sizeof (eventregistry_object),              /* tp_basicsize */
 137   0,                                          /* tp_itemsize */
 138   evregpy_dealloc,                            /* tp_dealloc */
 139   0,                                          /* tp_print */
 140   0,                                          /* tp_getattr */
 141   0,                                          /* tp_setattr */
 142   0,                                          /* tp_compare */
 143   0,                                          /* tp_repr */
 144   0,                                          /* tp_as_number */
 145   0,                                          /* tp_as_sequence */
 146   0,                                          /* tp_as_mapping */
 147   0,                                          /* tp_hash  */
 148   0,                                          /* tp_call */
 149   0,                                          /* tp_str */
 150   0,                                          /* tp_getattro */
 151   0,                                          /* tp_setattro */
 152   0,                                          /* tp_as_buffer */
 153   Py_TPFLAGS_DEFAULT,                         /* tp_flags */
 154   "GDB event registry object",                /* tp_doc */
 155   0,                                          /* tp_traverse */
 156   0,                                          /* tp_clear */
 157   0,                                          /* tp_richcompare */
 158   0,                                          /* tp_weaklistoffset */
 159   0,                                          /* tp_iter */
 160   0,                                          /* tp_iternext */
 161   eventregistry_object_methods,               /* tp_methods */
 162   0,                                          /* tp_members */
 163   0,                                          /* tp_getset */
 164   0,                                          /* tp_base */
 165   0,                                          /* tp_dict */
 166   0,                                          /* tp_descr_get */
 167   0,                                          /* tp_descr_set */
 168   0,                                          /* tp_dictoffset */
 169   0,                                          /* tp_init */
 170   0                                           /* tp_alloc */
 171 };