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_PROC_NR (slot number of exiting process)
6 */
7
8 #include "../system.h"
9
10 #if USE_EXIT
11
12 FORWARD _PROTOTYPE( void clear_proc, (register struct proc *rc));
13
14 /*===========================================================================*
15 * do_exit *
16 *===========================================================================*/
17 PUBLIC int do_exit(m_ptr)
18 message *m_ptr; /* pointer to request message */
19 {
20 /* Handle sys_exit. A user process has exited or a system process requests
21 * to exit. Only the PM can request other process slots to be cleared.
22 * The routine to clean up a process table slot cancels outstanding timers,
23 * possibly removes the process from the message queues, and resets certain
24 * process table fields to the default values.
25 */
26 int exit_proc_nr;
27
28 /* Determine what process exited. User processes are handled here. */
29 if (PM_PROC_NR == m_ptr->m_source) {
30 exit_proc_nr = m_ptr->PR_PROC_NR; /* get exiting process */
31 if (exit_proc_nr != SELF) { /* PM tries to exit self */
32 if (! isokprocn(exit_proc_nr)) return(EINVAL);
33 clear_proc(proc_addr(exit_proc_nr)); /* exit a user process */
34 return(OK); /* report back to PM */
35 }
36 }
37
38 /* The PM or some other system process requested to be exited. */
39 clear_proc(proc_addr(m_ptr->m_source));
40 return(EDONTREPLY);
41 }
42
43 /*===========================================================================*
44 * clear_proc *
45 *===========================================================================*/
46 PRIVATE void clear_proc(rc)
47 register struct proc *rc; /* slot of process to clean up */
48 {
49 register struct proc *rp; /* iterate over process table */
50 register struct proc **xpp; /* iterate over caller queue */
51 int i;
52 int sys_id;
53 char saved_rts_flags;
54
55 /* Don't clear if already cleared. */
56 if(isemptyp(rc)) return;
57
58 /* Turn off any alarm timers at the clock. */
59 reset_timer(&priv(rc)->s_alarm_timer);
60
61 /* Make sure that the exiting process is no longer scheduled. */
62 if (rc->p_rts_flags == 0) lock_dequeue(rc);
63
64 /* Release the process table slot. If this is a system process, also
65 * release its privilege structure. Further cleanup is not needed at
66 * this point. All important fields are reinitialized when the
67 * slots are assigned to another, new process.
68 */
69 saved_rts_flags = rc->p_rts_flags;
70 rc->p_rts_flags = SLOT_FREE;
71 if (priv(rc)->s_flags & SYS_PROC) priv(rc)->s_proc_nr = NONE;
72
73 /* If the process being terminated happens to be queued trying to send a
74 * message (e.g., the process was killed by a signal, rather than it doing
75 * a normal exit), then it must be removed from the message queues.
76 */
77 if (saved_rts_flags & SENDING) {
78 xpp = &proc[rc->p_sendto].p_caller_q; /* destination's queue */
79 while (*xpp != NIL_PROC) { /* check entire queue */
80 if (*xpp == rc) { /* process is on the queue */
81 *xpp = (*xpp)->p_q_link; /* replace by next process */
82 #if DEBUG_ENABLE_IPC_WARNINGS
83 kprintf("Proc %d removed from queue at %d\n",
84 proc_nr(rc), rc->p_sendto);
85 #endif
86 break; /* can only be queued once */
87 }
88 xpp = &(*xpp)->p_q_link; /* proceed to next queued */
89 }
90 }
91
92 /* Likewise, if another process was sending or receive a message to or from
93 * the exiting process, it must be alerted that process no longer is alive.
94 * Check all processes.
95 */
96 for (rp = BEG_PROC_ADDR; rp < END_PROC_ADDR; rp++) {
97 if(isemptyp(rp))
98 continue;
99
100 /* Unset pending notification bits. */
101 unset_sys_bit(priv(rp)->s_notify_pending, priv(rc)->s_id);
102
103 /* Check if process is receiving from exiting process. */
104 if ((rp->p_rts_flags & RECEIVING) && rp->p_getfrom == proc_nr(rc)) {
105 rp->p_reg.retreg = ESRCDIED; /* report source died */
106 rp->p_rts_flags &= ~RECEIVING; /* no longer receiving */
107 #if DEBUG_ENABLE_IPC_WARNINGS
108 kprintf("Proc %d receive dead src %d\n", proc_nr(rp), proc_nr(rc));
109 #endif
110 if (rp->p_rts_flags == 0) lock_enqueue(rp);/* let process run again */
111 }
112 if ((rp->p_rts_flags & SENDING) && rp->p_sendto == proc_nr(rc)) {
113 rp->p_reg.retreg = EDSTDIED; /* report destination died */
114 rp->p_rts_flags &= ~SENDING; /* no longer sending */
115 #if DEBUG_ENABLE_IPC_WARNINGS
116 kprintf("Proc %d send dead dst %d\n", proc_nr(rp), proc_nr(rc));
117 #endif
118 if (rp->p_rts_flags == 0) lock_enqueue(rp);/* let process run again */
119 }
120 }
121
122 /* Check the table with IRQ hooks to see if hooks should be released. */
123 for (i=0; i < NR_IRQ_HOOKS; i++) {
124 if (irq_hooks[i].proc_nr == proc_nr(rc)) {
125 rm_irq_handler(&irq_hooks[i]); /* remove interrupt handler */
126 irq_hooks[i].proc_nr = NONE; /* mark hook as free */
127 }
128 }
129 }
130
131 #endif /* USE_EXIT */
132
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