message.c

   1 /*****************************************************************************\
   2 **                                                                           **
   3 ** Linux Call Route                                                          **
   4 **                                                                           **
   5 **---------------------------------------------------------------------------**
   6 ** Copyright: Andreas Eversberg                                              **
   7 **                                                                           **
   8 ** message handling                                                          **
   9 **                                                                           **
  10 \*****************************************************************************/
  11
  12 #include "main.h"
  13
  14 MESSAGES
  15
  16 struct lcr_msg *message_first = NULL;
  17 struct lcr_msg **messagepointer_end = &message_first;
  18
  19 /* creates a new message with the given attributes. the message must be filled then. after filling, the message_put must be called */
  20 struct lcr_msg *message_create(int id_from, int id_to, int flow, int type)
  21 {
  22         struct lcr_msg *message;
  23
  24         message = (struct lcr_msg *)MALLOC(sizeof(struct lcr_msg));
  25         if (!message)
  26                 FATAL("No memory for message.\n");
  27         mmemuse++;
  28
  29         message->id_from = id_from;
  30         message->id_to = id_to;
  31         message->flow = flow;
  32         message->type = type;
  33
  34         return(message);
  35 }
  36
  37 /* attaches a message to the end of the message chain */
  38 void message_put(struct lcr_msg *message)
  39 {
  40         if (message->id_to == 0)
  41         {
  42                 PDEBUG(DEBUG_MSG, "message %s not written, because destination is 0.\n", messages_txt[message->type]);
  43                 message_free(message);
  44                 return;
  45         }
  46
  47         if ((options.deb&DEBUG_MSG) && message->type != MESSAGE_DATA)
  48                 PDEBUG(DEBUG_MSG, "message %s written from %ld to %ld (memory %x)\n", messages_txt[message->type], message->id_from, message->id_to, message);
  49
  50         *messagepointer_end = message;
  51         messagepointer_end = &(message->next);
  52         /* Nullify next pointer if recycled messages */
  53         *messagepointer_end=NULL;
  54 }
  55
  56 struct lcr_msg *message_forward(int id_from, int id_to, int flow, union parameter *param)
  57 {
  58         struct lcr_msg *message;
  59
  60         /* get point to message */
  61         message = (struct lcr_msg *)((unsigned long)param - ((unsigned long)(&message->param) - (unsigned long)message));
  62
  63         /* protect, so forwarded messages are not freed after handling */
  64         message->keep = 1;
  65
  66         message->id_from = id_from;
  67         message->id_to = id_to;
  68         message->flow = flow;
  69         message_put(message);
  70
  71         return(message);
  72 }
  73
  74 /* detaches the first messages from the message chain */
  75 struct lcr_msg *message_get(void)
  76 {
  77         struct lcr_msg *message;
  78
  79         if (!message_first)
  80         {
  81                 return(0);
  82         }
  83
  84         message = message_first;
  85         message_first = message->next;
  86         if (!message_first)
  87                 messagepointer_end = &message_first;
  88
  89         message->keep = 0;
  90
  91         if ((options.deb&DEBUG_MSG) && message->type != MESSAGE_DATA)
  92
  93                 PDEBUG(DEBUG_MSG, "message %s reading from %ld to %ld (memory %x)\n", messages_txt[message->type], message->id_from, message->id_to, message);
  94
  95         return(message);
  96 }
  97
  98 /* free a message */
  99 void message_free(struct lcr_msg *message)
 100 {
 101         if (message->keep)
 102                 return;
 103         FREE(message, sizeof(struct lcr_msg));
 104         mmemuse--;
 105 }
 106
 107