multi_interface_roam: multi_interface_roam: sigblock.c Source File

00001 /*
00002  * GPLv2 License. Modified from sigmask.c in qmtest.
00003  */
00004 
00005 /******************************************************************
00006  *
00007  * File: sigblock.c
00008  * Author: Nathaniel Smith
00009  * Date: 2004-05-01
00010  *
00011  * Contents:
00012  *   Simple Python support for saving and restoring the signal mask.
00013  *
00014  * Copyright (c) 2004 by CodeSourcery, LLC.  All rights reserved.
00015  *
00016  * For license terms see the file COPYING.
00017  *
00018  ******************************************************************/
00019 
00020 #include <Python.h>
00021 #include <signal.h>
00022 
00023 static PyObject* SigblockError;
00024 
00025 static int the_mask_is_set;
00026 static sigset_t the_mask;
00027 
00028 static PyObject *
00029 save_mask(PyObject* self, PyObject* args)
00030 {
00031     /* We take no arguments. */
00032     if (!PyArg_ParseTuple(args, "")) return NULL;
00033 
00034     if (sigprocmask(SIG_BLOCK, NULL, &the_mask) == -1)
00035     {
00036         PyErr_SetString(SigblockError, "Error fetching mask");
00037         return NULL;
00038     }
00039 
00040     the_mask_is_set = 1;
00041     
00042     Py_INCREF(Py_None);
00043     return Py_None;
00044 }
00045 
00046 
00047 static PyObject *
00048 restore_mask(PyObject* self, PyObject* args)
00049 {
00050     /* We take no arguments. */
00051     if (!PyArg_ParseTuple(args, "")) return NULL;
00052 
00053     if (!the_mask_is_set)
00054     {
00055         PyErr_SetString(SigblockError,
00056                         "Must call save_mask before restore_mask");
00057         return NULL;
00058     }
00059     
00060     if (sigprocmask(SIG_SETMASK, &the_mask, NULL) == -1)
00061     {
00062         PyErr_SetString(SigblockError, "Error setting mask");
00063         return NULL;
00064     }
00065 
00066     Py_INCREF(Py_None);
00067     return Py_None;
00068 }
00069 
00070 
00071 static PyObject *
00072 block_signal(PyObject* self, PyObject* args)
00073 {
00074     int sig;
00075    
00076     /* We take no arguments. */
00077     if (!PyArg_ParseTuple(args, "i", &sig))
00078       return NULL;
00079 
00080     sigset_t mask;
00081     sigemptyset (&mask);
00082     sigaddset(&mask, sig);
00083 
00084     if (sigprocmask(SIG_BLOCK, &mask, NULL) == -1)
00085     {
00086         PyErr_SetString(SigblockError, "Error setting mask");
00087         return NULL;
00088     }
00089 
00090     Py_INCREF(Py_None);
00091     return Py_None;
00092 }
00093 
00094 
00095 static PyMethodDef module_methods[] = 
00096 {
00097     {"save_mask", save_mask, METH_VARARGS,
00098      "Saves the current signal mask internally."},
00099     {"restore_mask", restore_mask, METH_VARARGS,
00100      "Sets the current signal mask to match that of the last call to save_mask."},
00101     {"block_signal", block_signal, METH_VARARGS,
00102      "Remove specified signal from the signal mask."},
00103     {NULL, NULL, 0, NULL}  /* Sentinel */
00104 };
00105 
00106 
00107 #ifndef PyMODINIT_FUNC  /* Declarations for DLL import/export */
00108 #define PyMODINIT_FUNC void
00109 #endif
00110 PyMODINIT_FUNC
00111 initsigblock(void)
00112 {
00113     PyObject* m;
00114     
00115     m = Py_InitModule3("sigblock", module_methods,
00116                        "Module to save/restore signal mask.");
00117 
00118     the_mask_is_set = 0;
00119 
00120     SigblockError = PyErr_NewException("sigblock.SigblockError", NULL, NULL);
00121     PyModule_AddObject(m, "SigblockError", SigblockError);
00122 }
00123