common/signal.h

   1 /*
   2  * common/signal.h - Signal handling functions
   3  *
   4  * Copyright © 2009 Julien Danjou <julien@danjou.info>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  */
  21
  22 #ifndef AWESOME_COMMON_SIGNAL
  23 #define AWESOME_COMMON_SIGNAL
  24
  25 #include "common/array.h"
  26
  27 DO_ARRAY(const void *, cptr, DO_NOTHING)
  28
  29 typedef struct
  30 {
  31     unsigned long id;
  32     cptr_array_t sigfuncs;
  33 } signal_t;
  34
  35 static inline int
  36 signal_cmp(const void *a, const void *b)
  37 {
  38     const signal_t *x = a, *y = b;
  39     return x->id > y->id ? 1 : (x->id < y->id ? -1 : 0);
  40 }
  41
  42 static inline void
  43 signal_wipe(signal_t *sig)
  44 {
  45     cptr_array_wipe(&sig->sigfuncs);
  46 }
  47
  48 ARRAY_TYPE_EXTRA(signal_t, signal, struct signal_array_t *inherits_from)
  49 BARRAY_FUNCS(signal_t, signal, signal_wipe, signal_cmp)
  50
  51 static inline signal_t *
  52 signal_array_getbyid(signal_array_t *arr, unsigned long id)
  53 {
  54     signal_t sig = { .id = id };
  55     signal_t *result;
  56
  57     result = signal_array_lookup(arr, &sig);
  58     if(result)
  59         return result;
  60
  61     /* The signal doesn't exist yet. Check if some of our inherits_from have the
  62      * signal and if yes, add it.
  63      */
  64     signal_array_t *inherit = arr->inherits_from;
  65     while(inherit != NULL)
  66     {
  67         if(signal_array_lookup(inherit, &sig))
  68             break;
  69         inherit = inherit->inherits_from;
  70     }
  71     if(inherit)
  72     {
  73         /* Add the signal to this array to pretend it always existed */
  74         signal_array_insert(arr, sig);
  75         result = signal_array_lookup(arr, &sig);
  76         assert(result != NULL);
  77     }
  78     return result;
  79 }
  80
  81 /** Add a signal to a signal array.
  82  * Signals have to be added before they can be added or emitted.
  83  * \param arr The signal array.
  84  * \param name The signal name.
  85  */
  86 static inline void
  87 signal_add(signal_array_t *arr, const char *name)
  88 {
  89     unsigned long tok = a_strhash((const unsigned char *) name);
  90     signal_t *sigfound = signal_array_getbyid(arr, tok);
  91     if(!sigfound)
  92     {
  93         signal_t sig = { .id = tok };
  94         signal_array_insert(arr, sig);
  95     }
  96 }
  97
  98 /** Connect a signal inside a signal array.
  99  * You are in charge of reference counting.
 100  * \param arr The signal array.
 101  * \param name The signal name.
 102  * \param ref The reference to add.
 103  */
 104 static inline void
 105 signal_connect(signal_array_t *arr, const char *name, const void *ref)
 106 {
 107     unsigned long tok = a_strhash((const unsigned char *) name);
 108     signal_t *sigfound = signal_array_getbyid(arr, tok);
 109     if(sigfound)
 110         cptr_array_append(&sigfound->sigfuncs, ref);
 111     else
 112         warn("Trying to connect to unknown signal '%s'", name);
 113 }
 114
 115 /** Disconnect a signal inside a signal array.
 116  * You are in charge of reference counting.
 117  * \param arr The signal array.
 118  * \param name The signal name.
 119  * \param ref The reference to remove.
 120  */
 121 static inline void
 122 signal_disconnect(signal_array_t *arr, const char *name, const void *ref)
 123 {
 124     signal_t *sigfound = signal_array_getbyid(arr,
 125                                               a_strhash((const unsigned char *) name));
 126     if(sigfound)
 127     {
 128         foreach(func, sigfound->sigfuncs)
 129             if(ref == *func)
 130             {
 131                 cptr_array_remove(&sigfound->sigfuncs, func);
 132                 break;
 133             }
 134     } else
 135         warn("Trying to disconnect from unknown signal '%s'", name);
 136 }
 137
 138 #endif
 139
 140 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80