xinu: Desktop/xinu_mips-1.0.2.tar/xinu_mips-1.0.2/system/send.c Source File

00001 
00007 /* Embedded XINU, Copyright (C) 2007.  All rights reserved. */
00008 
00009 #include <kernel.h>
00010 #include <proc.h>
00011 
00019 syscall send(ushort pid, long msg, bool block)
00020 {
00021         irqmask ps;    
00022         pcb *ppcb;
00023 
00024         ppcb = &proctab[pid];                 /* acquire pcb from process table */
00025         ps = disable();                       /* disable interrupts             */
00026         if (isbadpid(pid) || (ppcb->state == PRFREE) || ppcb->hasmsg != FALSE) 
00027         {
00028                 restore(ps);
00029                 return SYSERR;
00030         }
00031         ppcb->msg = msg;                      /* deliver message                */
00032         ppcb->hasmsg = TRUE;                  /* raise mailbox flag             */
00033         if (ppcb->state == PRRECV) { ready(pid, RESCHED_NO); }
00034         restore(ps);                          /* restore interrupts             */
00035         if (BLOCK == block) { resched(); }
00036         return OK;
00037 }