--- gvpe/src/iom.C	2003/03/28 05:40:54	1.7
+++ gvpe/src/iom.C	2004/04/02 14:42:45	1.20
@@ -1,5 +1,6 @@
 /*
-    iom.C -- I/O multiplexor
+    iom.C -- generic I/O multiplexor
+    Copyright (C) 2003, 2004 Marc Lehmann <pcg@goof.com>
  
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -16,185 +17,331 @@
     Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
 
-#include "config.h"
+#include <cstdio>
+#include <cstdlib>
+#include <cerrno>
 
 #include <sys/time.h>
 
-#include <algorithm>
-#include <functional>
+#include <assert.h>
+
+#if 1 // older unices need these includes for select (2)
+# include <unistd.h>
+# include <sys/types.h>
+#endif
+
+// if the BSDs would at least be marginally POSIX-compatible.. *sigh*
+// until that happens, sys/select.h must come last
+#include <sys/select.h>
+
+// for IOM_SIG
+#include <signal.h>
 
-#include "slog.h"
 #include "iom.h"
 
-inline bool lowest_first (const time_watcher *a, const time_watcher *b)
-{
-  return a->at > b->at;
-}
+// TSTAMP_MAX must still fit into a positive struct timeval
+#define TSTAMP_MAX (double)(1UL<<31)
 
-tstamp NOW;
+// this is a dummy time watcher to ensure that the first
+// time watcher is _always_ valid, this gets rid of a lot
+// of null-pointer-checks
+// (must come _before_ iom is being defined)
+static struct tw0 : time_watcher
+  {
+    void cb (time_watcher &w)
+    {
+      // should never get called
+      // reached end-of-time, or tstamp has a bogus definition,
+      // or compiler initilization order broken, or somethine else :)
+      abort ();
+    }
+
+    tw0 ()
+        : time_watcher (this, &tw0::cb)
+    { }
+  } tw0;
 
+tstamp NOW;
+static bool iom_valid;
 io_manager iom;
 
-void time_watcher::set (tstamp when)
+template<class watcher>
+void io_manager::reg (watcher *w, io_manager_vec<watcher> &queue)
 {
-  at = when;
+  if (!iom_valid)
+    abort ();
 
-  if (registered)
-    iom.reschedule_time_watchers ();
-  else
-    iom.reg (this);
+  if (!w->active)
+    {
+#if IOM_CHECK
+      queue.activity = true;
+#endif
+      queue.push_back (w);
+      w->active = queue.size ();
+    }
 }
 
-void time_watcher::trigger ()
+template<class watcher>
+void io_manager::unreg (watcher *w, io_manager_vec<watcher> &queue)
 {
-  call (at);
+  if (!iom_valid)
+    return;
 
-  if (registered)
-    iom.reschedule_time_watchers ();
-  else
-    iom.reg (this);
+  if (w->active)
+    {
+      queue [w->active - 1] = 0;
+      w->active = 0;
+    }
 }
 
-void time_watcher::start ()
+#if IOM_TIME
+void time_watcher::trigger ()
 {
-  if (!registered)
-    iom.reg (this);
+  call (*this);
+
+  iom.reg (this);
 }
 
-void io_manager::reg (int fd, short events, io_watcher *w)
-{
-  pollfd pfd;
+void io_manager::reg (time_watcher *w) { reg (w, tw); }
+void io_manager::unreg (time_watcher *w) { unreg (w, tw); }
+#endif
 
-  pfd.fd     = fd;
-  pfd.events = events;
+#if IOM_IO
+void io_manager::reg (io_watcher *w) { reg (w, iow); }
+void io_manager::unreg (io_watcher *w) { unreg (w, iow); }
+#endif
 
-  pfs.push_back (pfd);
-  iow.push_back (w);
-}
+#if IOM_CHECK
+void io_manager::reg (check_watcher *w) { reg (w, cw); }
+void io_manager::unreg (check_watcher *w) { unreg (w, cw); }
+#endif
+
+#if IOM_IDLE
+void io_manager::reg (idle_watcher *w) { reg (w, iw); }
+void io_manager::unreg (idle_watcher *w) { unreg (w, iw); }
+#endif
 
-void io_manager::unreg (io_watcher *w)
+#if IOM_TIME
+inline void set_now (void)
 {
-  unsigned int sz = iow.size ();
-  unsigned int i = find (iow.begin (), iow.end (), w) - iow.begin ();
+  struct timeval tv;
 
-  if (i != sz)
-    {
-      if (sz == 1)
-        {
-          pfs.clear ();
-          iow.clear ();
-        }
-      else if (i == sz - 1)
-        {
-          iow.pop_back ();
-          pfs.pop_back ();
-        }
-      else
-        {
-          iow[i] = iow[sz - 1]; iow.pop_back ();
-          pfs[i] = pfs[sz - 1]; pfs.pop_back ();
-        }
-    }
-}
+  gettimeofday (&tv, 0);
 
-void io_manager::reschedule_time_watchers ()
-{
-  make_heap (tw.begin (), tw.end (), lowest_first);
+  NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
 }
+#endif
 
-void io_manager::reg (time_watcher *w)
+#if IOM_SIG
+// race conditions galore
+
+void io_manager::sighandler (int signum)
 {
-  if (w->registered)
-    slog (L_CRIT, "FATAL: io_manager::reg(time_watcher) called on already-registered watcher");
+  assert (0 < signum && signum <= iom.sw.size ());
 
-  w->registered = true;
+  sig_vec &sv = *iom.sw [signum - 1];
 
-  tw.push_back (w);
-  push_heap (tw.begin (), tw.end (), lowest_first);
+  for (int i = sv.size (); i--; )
+    if (!sv[i])
+      sv.erase_unordered (i);
+    else
+      sv[i]->call (*sv[i]);
 }
 
-void io_manager::unreg (time_watcher *w)
+void io_manager::reg (sig_watcher *w)
 {
-  if (w->registered)
+  assert (0 < w->signum);
+
+  sw.reserve (w->signum);
+
+  sig_vec *&sv = sw [w->signum - 1];
+
+  if (!sv)
     {
-      unsigned int sz = tw.size ();
-      unsigned int i = find (tw.begin (), tw.end (), w) - tw.begin ();
+      sv = new sig_vec;
 
-      if (i != sz)
-        {
-          if (i != sz - 1)
-            tw[i] = tw[sz - 1];
+      struct sigaction sa;
+      sa.sa_handler = io_manager::sighandler;
+      sigfillset (&sa.sa_mask);
+      sa.sa_flags = 0;
 
-          tw.pop_back ();
-          reschedule_time_watchers ();
+      if (sigaction (w->signum, &sa, 0))
+        {
+          perror ("Error while installing signal handler");
+          abort ();
         }
-
-      w->registered = false;
     }
+
+  reg (w, *sv);
 }
 
-inline void set_now (void)
+void io_manager::unreg (sig_watcher *w)
 {
-  struct timeval tv;
-
-  gettimeofday (&tv, 0);
-
-  NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
+  assert (0 < w->signum && w->signum <= sw.size ());
+  
+  unreg (w, *sw [w->signum - 1]);
 }
 
+void sig_watcher::start (int signum)
+{
+  stop ();
+  this->signum = signum;
+  iom.reg (this);
+}
+#endif
+  
 void io_manager::loop ()
 {
+#if IOM_TIME
   set_now ();
+#endif
 
   for (;;)
     {
-      while (tw[0]->at <= NOW)
+      struct timeval *to = 0;
+      struct timeval tval;
+
+#if IOM_IDLE
+      if (iw.size ())
         {
-          // remove the first watcher
-          time_watcher *w = tw[0];
+          tval.tv_sec  = 0;
+          tval.tv_usec = 0;
+          to = &tval;
+        }
+      else
+#endif
 
-          pop_heap (tw.begin (), tw.end (), lowest_first);
-          tw.pop_back ();
+        {
+#if IOM_TIME
+          time_watcher *next;
+
+          for (;;)
+            {
+              next = tw[0]; // the first time-watcher must exist at ALL times
+
+              for (int i = tw.size (); i--; )
+                if (!tw[i])
+                  tw.erase_unordered (i);
+                else if (tw[i]->at < next->at)
+                  next = tw[i];
+
+              if (next->at > NOW)
+                {
+                  if (next != tw[0])
+                    {
+                      double diff = next->at - NOW;
+                      tval.tv_sec  = (int)diff;
+                      tval.tv_usec = (int) ((diff - tval.tv_sec) * 1000000);
+                      to = &tval;
+                    }
+                  break;
+                }
+              else
+                {
+                  unreg (next);
+                  next->call (*next);
+                }
+            }
+#endif
+
+        }
 
-          w->registered = false;
+#if IOM_CHECK
+      tw.activity = false;
 
-          // call it
-          w->call (w->at);
+      for (int i = cw.size (); i--; )
+        if (!cw[i])
+          cw.erase_unordered (i);
+        else
+          cw[i]->call (*cw[i]);
 
-          // re-add it if necessary
-          if (w->at >= 0 && !w->registered)
-            reg (w);
+      if (tw.activity)
+        {
+          tval.tv_sec  = 0;
+          tval.tv_usec = 0;
+          to = &tval;
         }
+#endif
 
-      int timeout = (int) ((tw[0]->at - NOW) * 1000);
+#if IOM_IO
+      fd_set rfd, wfd;
 
-      int fds = poll (&pfs[0], pfs.size (), timeout);
+      FD_ZERO (&rfd);
+      FD_ZERO (&wfd);
 
-      set_now ();
+      int fds = 0;
 
-      for (unsigned int i = iow.size (); fds > 0 && i--; )
-        if (pfs[i].revents)
+      for (io_manager_vec<io_watcher>::iterator i = iow.end (); i-- > iow.begin (); )
+        if (*i)
           {
-            --fds;
-            iow[i]->call (pfs[i].revents);
+            if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd);
+            if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd);
+
+            if ((*i)->fd >= fds) fds = (*i)->fd + 1;
           }
-    }
-}
 
-void io_manager::idle_cb (tstamp &ts)
-{
-  ts = NOW + 86400; // wake up every day, for no good reason
+      if (!to && !fds) //TODO: also check idle_watchers and check_watchers
+        break; // no events
+
+      fds = select (fds, &rfd, &wfd, NULL, to);
+# if IOM_TIME
+      set_now ();
+# endif
+
+      if (fds > 0)
+        for (int i = iow.size (); i--; )
+          if (!iow[i])
+            iow.erase_unordered (i);
+          else
+            {
+              short revents = iow[i]->events;
+
+              if (!FD_ISSET (iow[i]->fd, &rfd)) revents &= ~EVENT_READ;
+              if (!FD_ISSET (iow[i]->fd, &wfd)) revents &= ~EVENT_WRITE;
+
+              if (revents)
+                iow[i]->call (*iow[i], revents);
+            }
+      else if (fds < 0 && errno != EINTR)
+        {
+          perror ("Error while waiting for I/O or time event");
+          abort ();
+        }
+#if IOM_IDLE
+      else
+        for (int i = iw.size (); i--; )
+          if (!iw[i])
+            iw.erase_unordered (i);
+          else
+            iw[i]->call (*iw[i]);
+#endif
+
+#elif IOM_TIME
+      if (!to)
+        break;
+
+      select (0, 0, 0, 0, &to);
+      set_now ();
+#else
+      break;
+#endif
+
+    }
 }
 
 io_manager::io_manager ()
 {
+  iom_valid = true;
+
+#if IOM_TIME
   set_now ();
-  idle = new time_watcher (this, &io_manager::idle_cb);
-  idle->start (0);
+
+  tw0.start (TSTAMP_MAX);
+#endif
 }
 
 io_manager::~io_manager ()
 {
-  //
+  iom_valid = false;
 }