[Make Scheme hooks and timers threadsafe
clinton@unknownlamer.org**20081113222011
 * Timers are now maintained as a sorted list
 * Timer callbacks and other threads can call bot:[add|del]timer
 * Running hooks presently *cannot* call bot:addhook.
] {
hunk ./source/BotInterp.C 24
+#include <algorithm>
+
hunk ./source/BotInterp.C 39
-  : bot(b), counter(0)
+  : bot(b), counter(0), timer_mutex (true)
hunk ./source/BotInterp.C 75
-		   String name) {
+		   String name) 
+{
hunk ./source/BotInterp.C 86
+
+  BotLock hook_lock (hook_mutex);
+
hunk ./source/BotInterp.C 114
+  BotLock hook_lock (hook_mutex);
+
hunk ./source/BotInterp.C 117
+
hunk ./source/BotInterp.C 122
+
hunk ./source/BotInterp.C 125
+
hunk ./source/BotInterp.C 140
+
hunk ./source/BotInterp.C 147
+  BotLock timer_lock (timer_mutex);  
hunk ./source/BotInterp.C 149
-  int c = ++counter;
+
hunk ./source/BotInterp.C 151
-  Timer *t = new Timer(c, when, function);
-  timersList.push_back(t);
-  return scm_from_int (c);
+
+  Timer *timer = new Timer (++counter, when, function);
+  TimerList::iterator it = std::find_if (timers.begin (), timers.end (),
+					 std::bind1st (timer_sort_p, timer));
+  
+  if (it != timers.end ())
+    timers.insert (it, timer);
+  else
+    timers.push_back (timer);
+
+  return scm_from_int (counter);
+
hunk ./source/BotInterp.C 168
+  BotLock timer_lock (timer_mutex);
+
hunk ./source/BotInterp.C 171
-  std::list<Timer *>::iterator it = timersList.begin();
-  std::list<Timer *>::iterator it2 = timersList.end();
+  TimerList::iterator it = timers.begin();
+  TimerList::iterator end = timers.end();
hunk ./source/BotInterp.C 174
-  for ( ; it != it2; ++it) {
-    if ((*it)->count == count) {
-      scm_gc_unprotect_object((*it)->function);
-      delete (*it);
-      timersList.erase(it);
-      return true;
+  for ( ; it != end; ++it) 
+    {
+      if ((*it)->count == count) 
+	{
+	  scm_gc_unprotect_object((*it)->function);
+	  delete (*it);
+	  timers.erase(it);
+
+	  return true;
+	}
hunk ./source/BotInterp.C 185
-  }
+
hunk ./source/BotInterp.C 192
-  std::list<Timer *>::iterator it = timersList.begin();
-  std::list<Timer *>::iterator it2 = timersList.end();
-  std::list<Timer *>::iterator it3;
-
+  BotLock timer_lock (timer_mutex);
hunk ./source/BotInterp.C 196
-  while (it != it2) {
-    if ((*it)->when <= now) {
-      wd.func = (*it)->function;
-      scm_internal_catch(SCM_BOOL_T,
-		     (scm_t_catch_body) Interp::LazyApplyWrapper, (void *)&wd,
-		     (scm_t_catch_handler) Interp::EmptyHandler, 0);
-      scm_gc_unprotect_object(wd.func);
-      it3 = it;
-      ++it3;
-      delete (*it);
-      timersList.erase(it);
-      it = it3;
-    } else {
-      ++it;
+  while (!timers.empty ())
+    {
+      // Keep a stack allocated copy of the front of the timer queue
+      // just in case the timer is deleted while being executed (which
+      // is very unlikely as the only place this could occur is if the
+      // timer deleted itself)
+      Timer current_timer = *timers.front () ; 
+
+      if (current_timer.when <= now) 
+	{
+	  wd.func = current_timer.function;
+
+	  scm_internal_catch (SCM_BOOL_T,
+			      (scm_t_catch_body) Interp::LazyApplyWrapper,
+			      (void *)&wd,
+			      (scm_t_catch_handler) Interp::EmptyHandler, 
+			      0);
+
+	  // The timer list may have been modified by the timer
+	  // callback; if it has in such a way that the first queue
+	  // item has changed (adding a timer in the past) then we
+	  // switch the slow path for deleting a timer
+	  if (current_timer.count == timers.front()->count)
+	    {
+	      scm_gc_unprotect_object (current_timer.function);
+	      delete timers.front ();
+	      timers.pop_front ();
+	    }
+	  else
+	    {
+	      DelTimer (scm_from_int (current_timer.count));
+	    }
+	} 
+      else 
+	{
+	  break;
+	}
hunk ./source/BotInterp.C 234
-  }
+
hunk ./source/BotInterp.H 3
-// Copyright (C) 2002,2005 Clinton Ebadi
+// Copyright (C) 2002,2005,2008 Clinton Ebadi
hunk ./source/BotInterp.H 30
+#include <map>
+#include <list>
+#include <functional>
+
hunk ./source/BotInterp.H 35
+
+#include "BotThreading.H"
hunk ./source/BotInterp.H 38
+#include "Utils.H"
hunk ./source/BotInterp.H 105
+
+  bool operator< (const Timer & other) const
+  { return when < other.when; }
hunk ./source/BotInterp.H 111
+  typedef std::list<Timer *> TimerList;
+  
hunk ./source/BotInterp.H 116
-  std::list<Timer *> timersList;
+  TimerList timers;
+  Utils::IndirectPred<Timer, std::less<Timer> > timer_sort_p;
hunk ./source/BotInterp.H 119
+  BotMutex hook_mutex;
+  BotMutex timer_mutex; // NOTE: recursive lock
}