process: make signal_parent reusable, and document

diff --git a/Kernel/process.c b/Kernel/process.c
index 92164ca..adda2c4 100644 (file)
--- a/Kernel/process.c
+++ b/Kernel/process.c
@@ -749,12 +749,19 @@ void acctexit(ptptr p)
 }
 #endif
 
-/* Perform the terminal process signalling */
-/* FIXME: why return a value - we don't use it */
-/* FIXME: pass the process id not parent in then can reuse in doexit
-   special cases */
-static int signal_parent(ptptr p)
+/*
+ *     Perform the terminal process signalling for process c
+ *
+ *     POSIX requires
+ *     1. If SIGCHLD is ignored - the process dies
+ *     2. Otherwise it becomes a zombie and we signal the parent
+ *
+ *     This gets called both when a process dies and when it gets reparented
+ *     to init (parent dies), because init is entitled to ignore SIGCHLD too
+ */
+static int signal_parent(ptptr c)
 {
+       ptptr p = c->p_pptr;
         if (p->p_sig[1].s_ignored & (1UL << SIGCHLD)) {
                /* POSIX.1 says that SIG_IGN for SIGCHLD means don't go
                   zombie, just clean up as we go */
@@ -825,14 +832,9 @@ void doexit(uint16_t val)
                /* Set any child's parents to init */
                if (p->p_pptr == udata.u_ptab) {
                        p->p_pptr = ptab;       /* ptab is always init */
-                       /* Suppose our child is a zombie and init has
-                          SIGCLD blocked */
-                       if (ptab[0].p_sig[1].s_ignored & SIGBIT(SIGCHLD)) {
-                               p->p_status = P_EMPTY;
-                       } else {
-                               ssig(&ptab[0], SIGCHLD);
-                               wakeup(&ptab[0]);
-                       }
+                       /* Figure out if we are signalling init or just
+                          blowing the slot away */
+                       signal_parent(p);
                }
                /* Send SIGHUP to any pgrp members and remove
                   them from our pgrp */
@@ -854,7 +856,7 @@ void doexit(uint16_t val)
 #endif
         udata.u_page = 0xFFFFU;
         udata.u_page2 = 0xFFFFU;
-        signal_parent(udata.u_ptab->p_pptr);
+        signal_parent(udata.u_ptab);
        nready--;
        nproc--;