buf: Fix two embarassing bugs found while writing Lisp bindings.

[mLib] / sel.c

diff --git a/sel.c b/sel.c
index a9dd4cfbda814bb26f82e3a085772113bcd595ac..5dede9bb268060df86787326e01221faac4c391f 100644 (file)
--- a/sel.c
+++ b/sel.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: sel.c,v 1.5 1999/08/31 17:42:22 mdw Exp $
+ * $Id: sel.c,v 1.13 2004/04/08 01:36:13 mdw Exp $
  *
  * I/O multiplexing support
  *
@@ -27,29 +27,9 @@
  * MA 02111-1307, USA.
  */
 
-/*----- Revision history --------------------------------------------------* 
- *
- * $Log: sel.c,v $
- * Revision 1.5  1999/08/31 17:42:22  mdw
- * New function `sel_force' to force a descriptor to be `selected'.
- *
- * Revision 1.4  1999/08/19 18:30:26  mdw
- * Implement hooks for foreign select-using systems (currently not well
- * tested).
- *
- * Revision 1.3  1999/05/21 22:13:59  mdw
- * Use new `tv' macros.  Fix ordering bug for timeout selectors.
- *
- * Revision 1.2  1999/05/15 10:33:32  mdw
- * Fix copyright notices.
- *
- * Revision 1.1  1999/05/14 21:01:14  mdw
- * Integrated `select' handling bits from the background resolver project.
- *
- */
-
 /*----- Header files ------------------------------------------------------*/
 
+#include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -59,8 +39,21 @@
 #include <unistd.h>
 
 #include "sel.h"
+#include "sub.h"
 #include "tv.h"
 
+/*----- Data structures ---------------------------------------------------*/
+
+typedef struct sel_pendfile {
+  struct sel_pendfile *next;
+  sel_file *f;
+} pfile;
+
+typedef struct sel_pendtimer {
+  struct sel_pendtimer *next;
+  sel_timer *t;
+} ptimer;
+
 /*----- Main code ---------------------------------------------------------*/
 
 /* --- @sel_init@ --- *
@@ -111,6 +104,7 @@ void sel_initfile(sel_state *s, sel_file *f,
   f->mode = mode;
   f->func = func;
   f->p = p;
+  f->pend = 0;
 }
 
 /* --- @sel_addfile@ --- *
@@ -131,9 +125,9 @@ void sel_addfile(sel_file *f)
   while (*ff && (*ff)->fd > f->fd)
     ff = &(*ff)->next;
   f->next = *ff;
-  f->prev = (sel_file *)ff;
+  f->prev = ff;
   if (*ff)
-    (*ff)->prev = f;
+    (*ff)->prev = &f->next;
   *ff = f;
   FD_SET(f->fd, f->s->fd + f->mode);
 }
@@ -167,10 +161,14 @@ void sel_force(sel_file *f)
 
 void sel_rmfile(sel_file *f)
 {
-  f->prev->next = f->next;
+  *f->prev = f->next;
   if (f->next)
     f->next->prev = f->prev;
   FD_CLR(f->fd, f->s->fd + f->mode);
+  if (f->pend) {
+    f->pend->f = 0;
+    f->pend = 0;
+  }
 }
 
 /* --- @sel_addtimer@ --- *
@@ -192,21 +190,23 @@ void sel_addtimer(sel_state *s, sel_timer *t,
                  void *p)
 {
   sel_timer **tt = &s->timers;
+  { sel_timer *q; for (q = s->timers; q; q = q->next) assert(q != t); }
 
   /* --- Set up the timer block --- */
 
   t->tv = *tv;
   t->func = func;
   t->p = p;
+  t->pend = 0;
 
   /* --- More line noise --- */
   
   while (*tt && TV_CMP(&(*tt)->tv, <, tv))
     tt = &(*tt)->next;
   t->next = *tt;
-  t->prev = (sel_timer *)tt;
+  t->prev = tt;
   if (*tt)
-    (*tt)->prev = t;
+    (*tt)->prev = &t->next;
   *tt = t;
 }
 
@@ -221,9 +221,14 @@ void sel_addtimer(sel_state *s, sel_timer *t,
 
 void sel_rmtimer(sel_timer *t)
 {
-  t->prev->next = t->next;
-  if (t->next)
-    t->next->prev = t->prev;
+  if (t->pend) {
+    t->pend->t = 0;
+    t->pend = 0;
+  } else {
+    *t->prev = t->next;
+    if (t->next)
+      t->next->prev = t->prev;
+  }
 }
 
 /* --- @sel_addhook@ --- *
@@ -246,9 +251,9 @@ void sel_addhook(sel_state *s, sel_hook *h,
   h->after = after;
   h->p = p;
   h->next = s->hooks;
-  h->prev = (sel_hook *)&s->hooks;
+  h->prev = &s->hooks;
   if (s->hooks)
-    s->hooks->prev = h;
+    s->hooks->prev = &h->next;
   s->hooks = h;
 }
 
@@ -265,11 +270,11 @@ void sel_rmhook(sel_hook *h)
 {
   if (h->next)
     h->next->prev = h->prev;
-  h->prev->next = h->next;
+  *h->prev = h->next;
 }
 
 /* --- @sel_fdmerge@ --- *
-    *
+ *
  * Arguments:   @fd_set *dest@ = destination FD set
  *              @fd_set *fd@ = pointer to set to merge
  *              @int maxfd@ = highest numbered descriptor in @fd@ + 1
@@ -325,7 +330,12 @@ int sel_select(sel_state *s)
   if (!s->timers)
     a.tvp = 0;
   else {
-    TV_SUB(&a.tv, &s->timers->tv, &a.now);
+    if (TV_CMP(&s->timers->tv, >, &a.now))
+      TV_SUB(&a.tv, &s->timers->tv, &a.now);
+    else {
+      a.tv.tv_sec = 0;
+      a.tv.tv_usec = 0;
+    }
     a.tvp = &a.tv;
   }
   s->args = &a;
@@ -368,16 +378,35 @@ int sel_select(sel_state *s)
 
   /* --- Run through the timers --- */
 
-  {
-    sel_timer *t, *tt;
-    for (t = s->timers; t && TV_CMP(&t->tv, <=, &a.now); t = tt) {
-      tt = t->next;
-      t->next = t->prev = t;
-      t->func(&a.now, t->p);
+  if (s->timers) {
+    ptimer *pthead, *pt, **ptt = &pthead;
+    sel_timer *t;
+
+    for (t = s->timers; t && TV_CMP(&t->tv, <=, &a.now); t = t->next) {
+      pt = CREATE(ptimer);
+      pt->t = t;
+      t->pend = pt;
+      *ptt = pt;
+      ptt = &pt->next;
+    }
+    *ptt = 0;
+    if (t) {
+      *t->prev = 0;
+      t->prev = &s->timers;
     }
     s->timers = t;
-    if (t)
-      t->prev = (sel_timer *)&s->timers;
+    while (pthead) {
+      pt = pthead;
+      pthead = pt->next;
+      t = pt->t;
+      if (t) {
+       t->pend = 0;
+       t->next = 0;
+       t->prev = &t->next;
+       t->func(&a.now, t->p);
+      }
+      DESTROY(pt);
+    }
   }
 
   /* --- And finally run through the files --- *
@@ -391,11 +420,28 @@ int sel_select(sel_state *s)
     int i;
 
     for (i = 0; i < SEL_MODES; i++) {
-      sel_file *f, *ff;
-      for (f = s->files[i]; f; f = ff) {
-       ff = f->next;
-       if (FD_ISSET(f->fd, a.fd + f->mode))
-         f->func(f->fd, f->mode, f->p);
+      pfile *pfhead, *pf, **pff = &pfhead;
+      sel_file *f;
+
+      for (f = s->files[i]; f; f = f->next) {
+       if (!FD_ISSET(f->fd, &a.fd[i]))
+         continue;
+       pf = CREATE(pfile);
+       pf->f = f;
+       f->pend = pf;
+       *pff = pf;
+       pff = &pf->next;
+      }
+      *pff = 0;
+      while (pfhead) {
+       pf = pfhead;
+       pfhead = pf->next;
+       f = pf->f;
+       if (f) {
+         f->pend = 0;
+         f->func(f->fd, i, f->p);
+       }
+       DESTROY(pf);
       }
     }
   }