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/lualib.h"
  26 #include "common/array.h"
  27
  28 DO_ARRAY(const void *, cptr, DO_NOTHING)
  29
  30 typedef struct
  31 {
  32     unsigned long id;
  33     cptr_array_t sigfuncs;
  34 } signal_t;
  35
  36 static inline int
  37 signal_cmp(const void *a, const void *b)
  38 {
  39     const signal_t *x = a, *y = b;
  40     return x->id > y->id ? 1 : (x->id < y->id ? -1 : 0);
  41 }
  42
  43 static inline void
  44 signal_wipe(signal_t *sig)
  45 {
  46     cptr_array_wipe(&sig->sigfuncs);
  47 }
  48
  49 ARRAY_TYPE_EXTRA(signal_t, signal, struct signal_array_t *inherits_from)
  50 BARRAY_FUNCS(signal_t, signal, signal_wipe, signal_cmp)
  51
  52 static inline signal_t *
  53 signal_array_getbyid(signal_array_t *arr, unsigned long id)
  54 {
  55     signal_t sig = { .id = id };
  56     signal_t *result;
  57
  58     result = signal_array_lookup(arr, &sig);
  59     if(result)
  60         return result;
  61
  62     /* The signal doesn't exist yet. Check if some of our inherits_from have the
  63      * signal and if yes, add it.
  64      */
  65     signal_array_t *inherit = arr->inherits_from;
  66     while(inherit != NULL)
  67     {
  68         if(signal_array_lookup(inherit, &sig))
  69             break;
  70         inherit = inherit->inherits_from;
  71     }
  72     if(inherit)
  73     {
  74         /* Add the signal to this array to pretend it always existed */
  75         signal_array_insert(arr, sig);
  76         result = signal_array_lookup(arr, &sig);
  77         assert(result != NULL);
  78     }
  79     return result;
  80 }
  81
  82 /** Add a signal to a signal array.
  83  * Signals have to be added before they can be added or emitted.
  84  * \param arr The signal array.
  85  * \param name The signal name.
  86  */
  87 static inline void
  88 signal_add(signal_array_t *arr, const char *name)
  89 {
  90     unsigned long tok = a_strhash((const unsigned char *) name);
  91     signal_t *sigfound = signal_array_getbyid(arr, tok);
  92     if(!sigfound)
  93     {
  94         signal_t sig = { .id = tok };
  95         signal_array_insert(arr, sig);
  96     }
  97 }
  98
  99 /** Connect a signal inside a signal array.
 100  * You are in charge of reference counting.
 101  * \param arr The signal array.
 102  * \param name The signal name.
 103  * \param ref The reference to add.
 104  */
 105 static inline void
 106 signal_connect(signal_array_t *arr, const char *name, const void *ref)
 107 {
 108     unsigned long tok = a_strhash((const unsigned char *) name);
 109     signal_t *sigfound = signal_array_getbyid(arr, tok);
 110     if(sigfound)
 111         cptr_array_append(&sigfound->sigfuncs, ref);
 112     else
 113         warn("Trying to connect to unknown signal '%s'", name);
 114 }
 115
 116 /** Disconnect a signal inside a signal array.
 117  * You are in charge of reference counting.
 118  * \param arr The signal array.
 119  * \param name The signal name.
 120  * \param ref The reference to remove.
 121  */
 122 static inline void
 123 signal_disconnect(signal_array_t *arr, const char *name, const void *ref)
 124 {
 125     signal_t *sigfound = signal_array_getbyid(arr,
 126                                               a_strhash((const unsigned char *) name));
 127     if(sigfound)
 128     {
 129         foreach(func, sigfound->sigfuncs)
 130             if(ref == *func)
 131             {
 132                 cptr_array_remove(&sigfound->sigfuncs, func);
 133                 break;
 134             }
 135     } else
 136         warn("Trying to disconnect from unknown signal '%s'", name);
 137 }
 138
 139 #endif
 140
 141 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80