Kernel/messages.c

   1 /*
   2  * AcessOS Microkernel Version
   3  * messages.c
   4  */
   5 #include <common.h>
   6 #include <proc.h>
   7 #include <errno.h>
   8
   9 // === CODE ===
  10 /**
  11  * \fn int Proc_SendMessage(Uint *Err, Uint Dest, int Length, void *Data)
  12  * \brief Send an IPC message
  13  * \param Err   Pointer to the errno variable
  14  * \param Dest  Destination Thread
  15  */
  16 int Proc_SendMessage(Uint *Err, Uint Dest, int Length, void *Data)
  17 {
  18         tThread *thread;
  19         tMsg    *msg;
  20
  21         Log("Proc_SendMessage: (Err=%p, Dest=%i, Length=%i, Data=%p)", Err, Dest, Length, Data);
  22
  23         if(Length <= 0 || !Data) {
  24                 *Err = -EINVAL;
  25                 return -1;
  26         }
  27
  28         // Get thread
  29         thread = Proc_GetThread( Dest );
  30
  31         // Error check
  32         if(!thread) {   return -1;      }
  33
  34         // Get Spinlock
  35         LOCK( &thread->IsLocked );
  36
  37         // Check if thread is still alive
  38         if(thread->Status == THREAD_STAT_DEAD)  return -1;
  39
  40         // Create message
  41         msg = malloc( sizeof(tMsg)+Length );
  42         msg->Next = NULL;
  43         msg->Source = gCurrentThread->TID;
  44         msg->Length = Length;
  45         memcpy(msg->Data, Data, Length);
  46
  47         // If there are already messages
  48         if(thread->LastMessage) {
  49                 thread->LastMessage->Next = msg;
  50                 thread->LastMessage = msg;
  51         } else {
  52                 thread->Messages = msg;
  53                 thread->LastMessage = msg;
  54         }
  55
  56         RELEASE(&thread->IsLocked);
  57
  58         Thread_Wake( thread );
  59
  60         return 0;
  61 }
  62
  63 /**
  64  * \fn int Proc_GetMessage(Uint *Err, Uint *Source, void *Buffer)
  65  * \brief Gets a message
  66  */
  67 int Proc_GetMessage(Uint *Err, Uint *Source, void *Buffer)
  68 {
  69          int    ret;
  70         void *tmp;
  71
  72         // Check if queue has any items
  73         if(!gCurrentThread->Messages) {
  74                 return 0;
  75         }
  76
  77         LOCK( &gCurrentThread->IsLocked );
  78
  79         if(Source)
  80                 *Source = gCurrentThread->Messages->Source;
  81
  82         // Get message length
  83         if( !Buffer ) {
  84                 ret = gCurrentThread->Messages->Length;
  85                 RELEASE( &gCurrentThread->IsLocked );
  86                 return ret;
  87         }
  88
  89         // Get message
  90         if(Buffer != GETMSG_IGNORE)
  91                 memcpy(Buffer, gCurrentThread->Messages->Data, gCurrentThread->Messages->Length);
  92         ret = gCurrentThread->Messages->Length;
  93
  94         // Remove from list
  95         tmp = gCurrentThread->Messages->Next;
  96         free(gCurrentThread->Messages);
  97         gCurrentThread->Messages = tmp;
  98
  99         RELEASE( &gCurrentThread->IsLocked );
 100
 101         return ret;
 102 }