process; multiple fixes

- put the process into ready state if it tries to sleep on a signal
  (we need to address this better in chksigs instead see issues)
- remember to wake init if we reparent it something
- fix various nready corner cases that causes weird hangs and behavuour

diff --git a/Kernel/process.c b/Kernel/process.c
index 9fafe08..1995034 100644 (file)
--- a/Kernel/process.c
+++ b/Kernel/process.c
@@ -82,14 +82,14 @@ void wakeup(void *event)
 void pwake(ptptr p)
 {
        if (p->p_status > P_RUNNING && p->p_status < P_STOPPED) {
-               p->p_status = P_READY;
+               if (p->p_status != P_READY) {
+                       nready++;
+                       p->p_status = P_READY;
+               }
                p->p_wait = NULL;
-               nready++;
        }
 }
 
-
-
 /* Getproc returns the process table pointer of a runnable process.
  * It is actually the scheduler.  If there are none, it loops.
  * This is the only time-wasting loop in the system.
@@ -492,6 +492,7 @@ rescan:
                        if (m & stopper) {
                                /* Don't allow us to race SIGCONT */
                                irqflags_t irq = di();
+                               /* FIXME: can we ever end up here not in READY/RUNNING ? */
                                nready--;
                                udata.u_ptab->p_status = P_STOPPED;
                                udata.u_ptab->p_event = j;
@@ -515,6 +516,14 @@ rescan:
 #ifdef DEBUG
                        kprintf("process terminated by signal %d\n", j);
 #endif
+                       /* We may have marked ourselves as asleep and
+                          then been caught by the chksigs when we tried
+                          to task switch into bed. In that case we need
+                          to put the process back in running state */
+                       if (udata.u_ptab->p_status == P_SLEEP) {
+                               udata.u_ptab->p_status = P_RUNNING;
+                               nready++;
+                       }
                        doexit(dump_core(j));
                } else if (*svec != SIG_IGN) {
                        /* Arrange to call the user routine at return */
@@ -681,8 +690,12 @@ void doexit(uint16_t val)
                        p->p_pptr = ptab;       /* ptab is always init */
                        /* Suppose our child is a zombie and init has
                           SIGCLD blocked */
-                       if (ptab[0].p_ignored & (1UL << SIGCHLD))
+                       if (ptab[0].p_ignored & (1UL << SIGCHLD)) {
                                p->p_status = P_EMPTY;
+                       } else {
+                               ssig(&ptab[0], SIGCHLD);
+                               wakeup(&ptab[0]);
+                       }
                }
                /* Send SIGHUP to any pgrp members and remove
                   them from our pgrp */