wsutil/wmem/wmem_user_cb.c

   1 /* wmem_user_cb.c
   2  * Wireshark Memory Manager User Callbacks
   3  * Copyright 2012, Evan Huus <eapache@gmail.com>
   4  *
   5  * Wireshark - Network traffic analyzer
   6  * By Gerald Combs <gerald@wireshark.org>
   7  * Copyright 1998 Gerald Combs
   8  *
   9  * SPDX-License-Identifier: GPL-2.0-or-later
  10  */
  11
  12 #include "wmem_core.h"
  13 #include "wmem_allocator.h"
  14
  15 #include "wmem_user_cb.h"
  16 #include "wmem_user_cb_int.h"
  17
  18 typedef struct _wmem_user_cb_container_t {
  19     wmem_user_cb_t                    cb;
  20     void                             *user_data;
  21     struct _wmem_user_cb_container_t *next;
  22     unsigned                          id;
  23 } wmem_user_cb_container_t;
  24
  25 void
  26 wmem_call_callbacks(wmem_allocator_t *allocator, wmem_cb_event_t event)
  27 {
  28     wmem_user_cb_container_t **prev, *cur;
  29     bool again;
  30
  31     prev = &(allocator->callbacks);
  32     cur  = allocator->callbacks;
  33
  34     while (cur) {
  35
  36         /* call it */
  37         again = cur->cb(allocator, event, cur->user_data);
  38
  39         /* if the callback requested deregistration, or this is being triggered
  40          * by the final destruction of the allocator, remove the callback */
  41         if (! again || event == WMEM_CB_DESTROY_EVENT) {
  42             *prev = cur->next;
  43             wmem_free(NULL, cur);
  44             cur = *prev;
  45         }
  46         else {
  47             prev = &(cur->next);
  48             cur  = cur->next;
  49         }
  50     }
  51 }
  52
  53 unsigned
  54 wmem_register_callback(wmem_allocator_t *allocator,
  55         wmem_user_cb_t callback, void *user_data)
  56 {
  57     wmem_user_cb_container_t *container;
  58     static unsigned next_id = 1;
  59
  60     container = wmem_new(NULL, wmem_user_cb_container_t);
  61
  62     container->cb        = callback;
  63     container->user_data = user_data;
  64     container->next      = allocator->callbacks;
  65     container->id        = next_id++;
  66
  67     allocator->callbacks = container;
  68
  69     return container->id;
  70 }
  71
  72 void
  73 wmem_unregister_callback(wmem_allocator_t *allocator, unsigned id)
  74 {
  75     wmem_user_cb_container_t **prev, *cur;
  76
  77     prev = &(allocator->callbacks);
  78     cur  = allocator->callbacks;
  79
  80     while (cur) {
  81
  82         if (cur->id == id) {
  83             *prev = cur->next;
  84             wmem_free(NULL, cur);
  85             return;
  86         }
  87
  88         prev = &(cur->next);
  89         cur  = cur->next;
  90     }
  91 }
  92
  93 /*
  94  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
  95  *
  96  * Local variables:
  97  * c-basic-offset: 4
  98  * tab-width: 8
  99  * indent-tabs-mode: nil
 100  * End:
 101  *
 102  * vi: set shiftwidth=4 tabstop=8 expandtab:
 103  * :indentSize=4:tabSize=8:noTabs=true:
 104  */