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                 PDEBUG(DEBUG_MSG, "message %s not written, because destination is 0.\n", messages_txt[message->type]);
  42                 message_free(message);
  43                 return;
  44         }
  45
  46         if ((options.deb&DEBUG_MSG) && message->type != MESSAGE_DATA)
  47                 PDEBUG(DEBUG_MSG, "message %s written from %ld to %ld (memory %x)\n", messages_txt[message->type], message->id_from, message->id_to, message);
  48
  49         *messagepointer_end = message;
  50         messagepointer_end = &(message->next);
  51         /* Nullify next pointer if recycled messages */
  52         *messagepointer_end=NULL;
  53 }
  54
  55 struct lcr_msg *message_forward(int id_from, int id_to, int flow, union parameter *param)
  56 {
  57         struct lcr_msg *message;
  58
  59         /* get point to message */
  60         message = (struct lcr_msg *)((unsigned long)param - ((unsigned long)(&message->param) - (unsigned long)message));
  61
  62         /* protect, so forwarded messages are not freed after handling */
  63         message->keep = 1;
  64
  65         message->id_from = id_from;
  66         message->id_to = id_to;
  67         message->flow = flow;
  68         message_put(message);
  69
  70         return(message);
  71 }
  72
  73 /* detaches the first messages from the message chain */
  74 struct lcr_msg *message_get(void)
  75 {
  76         struct lcr_msg *message;
  77
  78         if (!message_first)
  79                 return(0);
  80
  81         message = message_first;
  82         message_first = message->next;
  83         if (!message_first)
  84                 messagepointer_end = &message_first;
  85
  86         message->keep = 0;
  87
  88         if ((options.deb&DEBUG_MSG) && message->type != MESSAGE_DATA)
  89
  90                 PDEBUG(DEBUG_MSG, "message %s reading from %ld to %ld (memory %x)\n", messages_txt[message->type], message->id_from, message->id_to, message);
  91
  92         return(message);
  93 }
  94
  95 /* free a message */
  96 void message_free(struct lcr_msg *message)
  97 {
  98         if (message->keep)
  99                 return;
 100         FREE(message, sizeof(struct lcr_msg));
 101         mmemuse--;
 102 }
 103
 104