kernel/system/do_exit.c

   1 /* The kernel call implemented in this file:
   2  *   m_type:    SYS_EXIT
   3  *
   4  * The parameters for this kernel call are:
   5  *    m1_i1:    PR_ENDPT                (slot number of exiting process)
   6  */
   7
   8 #include "../system.h"
   9
  10 #include <minix/endpoint.h>
  11
  12 #if USE_EXIT
  13
  14 FORWARD _PROTOTYPE( void clear_proc, (register struct proc *rc));
  15
  16 /*===========================================================================*
  17  *                              do_exit                                      *
  18  *===========================================================================*/
  19 PUBLIC int do_exit(m_ptr)
  20 message *m_ptr;                 /* pointer to request message */
  21 {
  22 /* Handle sys_exit. A user process has exited or a system process requests
  23  * to exit. Only the PM can request other process slots to be cleared.
  24  * The routine to clean up a process table slot cancels outstanding timers,
  25  * possibly removes the process from the message queues, and resets certain
  26  * process table fields to the default values.
  27  */
  28   int exit_e;
  29
  30   /* Determine what process exited. User processes are handled here. */
  31   if (PM_PROC_NR == who_p) {
  32       if (m_ptr->PR_ENDPT != SELF) {            /* PM tries to exit self */
  33           if(!isokendpt(m_ptr->PR_ENDPT, &exit_e)) /* get exiting process */
  34              return EINVAL;
  35           clear_proc(proc_addr(exit_e));        /* exit a user process */
  36           return(OK);                           /* report back to PM */
  37       }
  38   }
  39
  40   /* The PM or some other system process requested to be exited. */
  41   clear_proc(proc_addr(who_p));
  42   return(EDONTREPLY);
  43 }
  44
  45 /*===========================================================================*
  46  *                               clear_proc                                  *
  47  *===========================================================================*/
  48 PRIVATE void clear_proc(rc)
  49 register struct proc *rc;               /* slot of process to clean up */
  50 {
  51   register struct proc *rp;             /* iterate over process table */
  52   register struct proc **xpp;           /* iterate over caller queue */
  53   int i;
  54   int sys_id;
  55
  56   /* Don't clear if already cleared. */
  57   if(isemptyp(rc)) return;
  58
  59   /* Remove the process' ability to send and receive messages */
  60   clear_endpoint(rc);
  61
  62   /* Turn off any alarm timers at the clock. */
  63   reset_timer(&priv(rc)->s_alarm_timer);
  64
  65   /* Make sure that the exiting process is no longer scheduled,
  66    * and mark slot as FREE.
  67    */
  68   RTS_LOCK_SETFLAGS(rc, SLOT_FREE);
  69
  70   /* Check the table with IRQ hooks to see if hooks should be released. */
  71   for (i=0; i < NR_IRQ_HOOKS; i++) {
  72       int proc;
  73       if (rc->p_endpoint == irq_hooks[i].proc_nr_e) {
  74         rm_irq_handler(&irq_hooks[i]);  /* remove interrupt handler */
  75         irq_hooks[i].proc_nr_e = NONE;  /* mark hook as free */
  76       }
  77   }
  78
  79   /* Release the process table slot. If this is a system process, also
  80    * release its privilege structure.  Further cleanup is not needed at
  81    * this point. All important fields are reinitialized when the
  82    * slots are assigned to another, new process.
  83    */
  84   if (priv(rc)->s_flags & SYS_PROC) priv(rc)->s_proc_nr = NONE;
  85
  86   /* Clean up virtual memory */
  87   if (rc->p_misc_flags & MF_VM)
  88         vm_map_default(rc);
  89 }
  90
  91 #endif /* USE_EXIT */
  92