dhtlog updates
[oweals/gnunet.git] / src / util / scheduler.c
index 16f65b457bfa1096f32471534582e500ba441578..eb99414f245b0443c3b7f4a153b78551e15b40e0 100644 (file)
  */
 #include "platform.h"
 #include "gnunet_common.h"
+#include "gnunet_os_lib.h"
 #include "gnunet_scheduler_lib.h"
 #include "gnunet_signal_lib.h"
 #include "gnunet_time_lib.h"
+#include "disk.h"
+#ifdef LINUX
+#include "execinfo.h"
+
+
+/**
+ * Use lsof to generate file descriptor reports on select error?
+ * (turn off for stable releases).
+ */
+#define USE_LSOF GNUNET_YES
+
+/**
+ * Obtain trace information for all scheduler calls that schedule tasks.
+ */
+#define EXECINFO GNUNET_NO
+
+/**
+ * Depth of the traces collected via EXECINFO.
+ */
+#define MAX_TRACE_DEPTH 50
+#endif
 
 #define DEBUG_TASKS GNUNET_NO
 
+/**
+ * Should we figure out which tasks are delayed for a while
+ * before they are run? (Consider using in combination with EXECINFO).
+ */
+#define PROFILE_DELAYS GNUNET_NO
+
+/**
+ * Task that were in the queue for longer than this are reported if
+ * PROFILE_DELAYS is active.
+ */
+#define DELAY_THRESHOLD GNUNET_TIME_UNIT_SECONDS
+
 /**
  * Linked list of pending tasks.
  */
@@ -60,10 +94,9 @@ struct Task
   struct GNUNET_NETWORK_FDSet *read_set;
 
   /**
-   * Set of file descriptors this task is waiting
-   * for for writing.  Once ready, this is updated
-   * to reflect the set of file descriptors ready
-   * for operation.
+   * Set of file descriptors this task is waiting for for writing.
+   * Once ready, this is updated to reflect the set of file
+   * descriptors ready for operation.
    */
   struct GNUNET_NETWORK_FDSet *write_set;
 
@@ -83,6 +116,13 @@ struct Task
    */
   struct GNUNET_TIME_Absolute timeout;
 
+#if PROFILE_DELAYS
+  /**
+   * When was the task scheduled?
+   */
+  struct GNUNET_TIME_Absolute start_time;
+#endif
+
   /**
    * Why is the task ready?  Set after task is added to ready queue.
    * Initially set to zero.  All reasons that have already been
@@ -95,6 +135,30 @@ struct Task
    */
   enum GNUNET_SCHEDULER_Priority priority;
 
+  /**
+   * Set if we only wait for reading from a single FD, otherwise -1.
+   */
+  int read_fd;
+
+  /**
+   * Set if we only wait for writing to a single FD, otherwise -1.
+   */
+  int write_fd;
+
+#if EXECINFO
+  /**
+   * Array of strings which make up a backtrace from the point when this
+   * task was scheduled (essentially, who scheduled the task?)
+   */
+  char **backtrace_strings;
+
+  /**
+   * Size of the backtrace_strings array
+   */
+  int num_backtrace_strings;
+#endif
+
+
 };
 
 
@@ -109,6 +173,26 @@ struct GNUNET_SCHEDULER_Handle
    */
   struct Task *pending;
 
+  /**
+   * List of tasks waiting ONLY for a timeout event.
+   * Sorted by timeout (earliest first).  Used so that
+   * we do not traverse the list of these tasks when
+   * building select sets (we just look at the head
+   * to determine the respective timeout ONCE).
+   */
+  struct Task *pending_timeout;
+
+  /**
+   * Last inserted task waiting ONLY for a timeout event.
+   * Used to (heuristically) speed up insertion.
+   */
+  struct Task *pending_timeout_last;
+
+  /**
+   * ID of the task that is running right now.
+   */
+  struct Task *active_task;
+
   /**
    * List of tasks ready to run right now,
    * grouped by importance.
@@ -145,6 +229,17 @@ struct GNUNET_SCHEDULER_Handle
    */
   enum GNUNET_SCHEDULER_Priority current_priority;
 
+  /**
+   * Priority of the highest task added in the current select
+   * iteration.
+   */
+  enum GNUNET_SCHEDULER_Priority max_priority_added;
+
+  /**
+   * How 'nice' are we right now?
+   */
+  int nice_level;
+
 };
 
 
@@ -186,6 +281,15 @@ is_pending (struct GNUNET_SCHEDULER_Handle *sched,
     return GNUNET_NO;
   min = -1;                     /* maximum value */
   pos = sched->pending;
+  while (pos != NULL)
+    {
+      if (pos->id == id)
+        return GNUNET_YES;
+      if (pos->id < min)
+        min = pos->id;
+      pos = pos->next;
+    }
+  pos = sched->pending_timeout;
   while (pos != NULL)
     {
       if (pos->id == id)
@@ -226,7 +330,19 @@ update_sets (struct GNUNET_SCHEDULER_Handle *sched,
              struct GNUNET_TIME_Relative *timeout)
 {
   struct Task *pos;
+  struct GNUNET_TIME_Absolute now;
+  struct GNUNET_TIME_Relative to;
 
+  now = GNUNET_TIME_absolute_get ();
+  pos = sched->pending_timeout;
+  if (pos != NULL) 
+    {
+      to = GNUNET_TIME_absolute_get_difference (now, pos->timeout);
+      if (timeout->value > to.value)
+       *timeout = to;
+      if (pos->reason != 0)
+        *timeout = GNUNET_TIME_UNIT_ZERO;
+    }
   pos = sched->pending;
   while (pos != NULL)
     {
@@ -236,21 +352,22 @@ update_sets (struct GNUNET_SCHEDULER_Handle *sched,
           pos = pos->next;
           continue;
         }
-
       if (pos->timeout.value != GNUNET_TIME_UNIT_FOREVER_ABS.value)
         {
-          struct GNUNET_TIME_Relative to;
-
-          to = GNUNET_TIME_absolute_get_remaining (pos->timeout);
+          to = GNUNET_TIME_absolute_get_difference (now, pos->timeout);
           if (timeout->value > to.value)
             *timeout = to;
         }
+      if (pos->read_fd != -1)
+       GNUNET_NETWORK_fdset_set_native (rs, pos->read_fd);
+      if (pos->write_fd != -1)
+       GNUNET_NETWORK_fdset_set_native (ws, pos->write_fd);
       if (pos->read_set != NULL)
         GNUNET_NETWORK_fdset_add (rs, pos->read_set);
       if (pos->write_set != NULL)
         GNUNET_NETWORK_fdset_add (ws, pos->write_set);
       if (pos->reason != 0)
-       *timeout = GNUNET_TIME_UNIT_ZERO;
+        *timeout = GNUNET_TIME_UNIT_ZERO;
       pos = pos->next;
     }
 }
@@ -269,7 +386,7 @@ static int
 set_overlaps (const struct GNUNET_NETWORK_FDSet *ready,
               struct GNUNET_NETWORK_FDSet *want)
 {
-  if (NULL == want)
+  if ( (NULL == want) || (NULL == ready) )
     return GNUNET_NO;
   if (GNUNET_NETWORK_fdset_overlap (ready, want))
     {
@@ -300,22 +417,33 @@ is_ready (struct GNUNET_SCHEDULER_Handle *sched,
           const struct GNUNET_NETWORK_FDSet *rs,
           const struct GNUNET_NETWORK_FDSet *ws)
 {
-  if (now.value >= task->timeout.value) 
-    task->reason |= GNUNET_SCHEDULER_REASON_TIMEOUT;
-  if ((0 == (task->reason & GNUNET_SCHEDULER_REASON_READ_READY)) &&
-      (rs != NULL) && (set_overlaps (rs, task->read_set)))
-    task->reason |= GNUNET_SCHEDULER_REASON_READ_READY;
-  if ((0 == (task->reason & GNUNET_SCHEDULER_REASON_WRITE_READY)) &&
-      (ws != NULL) && (set_overlaps (ws, task->write_set)))
-    task->reason |= GNUNET_SCHEDULER_REASON_WRITE_READY;
-  if (task->reason == 0)
-    return GNUNET_NO;           /* not ready */
+  enum GNUNET_SCHEDULER_Reason reason;
+
+  reason = task->reason;
+  if (now.value >= task->timeout.value)
+    reason |= GNUNET_SCHEDULER_REASON_TIMEOUT;
+  if ( (0 == (reason & GNUNET_SCHEDULER_REASON_READ_READY)) &&
+       ( ( (task->read_fd != -1) &&
+          (GNUNET_YES == GNUNET_NETWORK_fdset_test_native (rs, task->read_fd)) ) ||
+        (set_overlaps (rs, task->read_set) ) ) )
+    reason |= GNUNET_SCHEDULER_REASON_READ_READY;
+  if ((0 == (reason & GNUNET_SCHEDULER_REASON_WRITE_READY)) &&
+      ( ( (task->write_fd != -1) &&
+         (GNUNET_YES == GNUNET_NETWORK_fdset_test_native (ws, task->write_fd)) ) ||
+       (set_overlaps (ws, task->write_set) ) ) )
+    reason |= GNUNET_SCHEDULER_REASON_WRITE_READY;
+  if (reason == 0)
+    return GNUNET_NO;           /* not ready */    
   if (task->prereq_id != GNUNET_SCHEDULER_NO_TASK)
     {
       if (GNUNET_YES == is_pending (sched, task->prereq_id))
-        return GNUNET_NO;       /* prereq waiting */
-      task->reason |= GNUNET_SCHEDULER_REASON_PREREQ_DONE;
+       {
+         task->reason = reason;
+         return GNUNET_NO;       /* prereq waiting */
+       }
+      reason |= GNUNET_SCHEDULER_REASON_PREREQ_DONE;
     }
+  task->reason = reason;
   return GNUNET_YES;
 }
 
@@ -327,10 +455,14 @@ is_ready (struct GNUNET_SCHEDULER_Handle *sched,
  * @param task task ready for execution
  */
 static void
-queue_ready_task (struct GNUNET_SCHEDULER_Handle *handle, struct Task *task)
+queue_ready_task (struct GNUNET_SCHEDULER_Handle *handle,
+                 struct Task *task)
 {
-  task->next = handle->ready[check_priority (task->priority)];
-  handle->ready[check_priority (task->priority)] = task;
+  enum GNUNET_SCHEDULER_Priority p = task->priority;
+  if (0 != (task->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
+    p = GNUNET_SCHEDULER_PRIORITY_SHUTDOWN;
+  task->next = handle->ready[check_priority (p)];
+  handle->ready[check_priority (p)] = task;
   handle->ready_count++;
 }
 
@@ -355,12 +487,26 @@ check_ready (struct GNUNET_SCHEDULER_Handle *handle,
 
   now = GNUNET_TIME_absolute_get ();
   prev = NULL;
+  pos = handle->pending_timeout;
+  while (pos != NULL)
+    {
+      next = pos->next;
+      if (now.value >= pos->timeout.value)
+       pos->reason |= GNUNET_SCHEDULER_REASON_TIMEOUT;
+      if (0 == pos->reason)
+       break;
+      handle->pending_timeout = next;
+      if (handle->pending_timeout_last == pos)
+       handle->pending_timeout_last = NULL;
+      queue_ready_task (handle, pos);
+      pos = next;
+    }
   pos = handle->pending;
   while (pos != NULL)
     {
 #if DEBUG_TASKS
       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                  "Checking readyness of task: %llu / %p\n",
+                  "Checking readiness of task: %llu / %p\n",
                   pos->id, pos->callback_cls);
 #endif
       next = pos->next;
@@ -393,16 +539,38 @@ void
 GNUNET_SCHEDULER_shutdown (struct GNUNET_SCHEDULER_Handle *sched)
 {
   struct Task *pos;
+  int i;
 
+  pos = sched->pending_timeout;
+  while (pos != NULL)
+    {
+      pos->reason |= GNUNET_SCHEDULER_REASON_SHUTDOWN;
+      /* we don't move the task into the ready queue yet; check_ready
+         will do that later, possibly adding additional
+         readiness-factors */
+      pos = pos->next;
+    }
   pos = sched->pending;
   while (pos != NULL)
     {
       pos->reason |= GNUNET_SCHEDULER_REASON_SHUTDOWN;
       /* we don't move the task into the ready queue yet; check_ready
-        will do that later, possibly adding additional
-        readyness-factors */
+         will do that later, possibly adding additional
+         readiness-factors */
       pos = pos->next;
     }
+  for (i=0;i<GNUNET_SCHEDULER_PRIORITY_COUNT;i++)
+    {
+      pos = sched->ready[i];
+      while (pos != NULL)
+       {
+         pos->reason |= GNUNET_SCHEDULER_REASON_SHUTDOWN;
+         /* we don't move the task into the ready queue yet; check_ready
+            will do that later, possibly adding additional
+            readiness-factors */
+         pos = pos->next;
+       }
+    }  
 }
 
 
@@ -418,6 +586,9 @@ destroy_task (struct Task *t)
     GNUNET_NETWORK_fdset_destroy (t->read_set);
   if (NULL != t->write_set)
     GNUNET_NETWORK_fdset_destroy (t->write_set);
+#if EXECINFO
+  GNUNET_free (t->backtrace_strings);
+#endif
   GNUNET_free (t);
 }
 
@@ -430,14 +601,19 @@ destroy_task (struct Task *t)
  * there are no more ready tasks, we also return.  
  *
  * @param sched the scheduler
+ * @param rs FDs ready for reading
+ * @param ws FDs ready for writing
  */
 static void
-run_ready (struct GNUNET_SCHEDULER_Handle *sched)
+run_ready (struct GNUNET_SCHEDULER_Handle *sched,
+          struct GNUNET_NETWORK_FDSet *rs,
+          struct GNUNET_NETWORK_FDSet *ws)
 {
   enum GNUNET_SCHEDULER_Priority p;
   struct Task *pos;
   struct GNUNET_SCHEDULER_TaskContext tc;
 
+  sched->max_priority_added = GNUNET_SCHEDULER_PRIORITY_KEEP;
   do
     {
       if (sched->ready_count == 0)
@@ -454,29 +630,73 @@ run_ready (struct GNUNET_SCHEDULER_Handle *sched)
       GNUNET_assert (pos != NULL);      /* ready_count wrong? */
       sched->ready[p] = pos->next;
       sched->ready_count--;
-      sched->current_priority = p;
-      GNUNET_assert (pos->priority == p);
+      if (sched->current_priority != pos->priority)
+       {
+         sched->current_priority = pos->priority;
+         (void) GNUNET_OS_set_process_priority (0, pos->priority);
+       }
+      sched->active_task = pos;
+#if PROFILE_DELAYS
+      if (GNUNET_TIME_absolute_get_duration (pos->start_time).value >
+         DELAY_THRESHOLD.value)
+       {
+         GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                     "Task %u took %llums to be scheduled\n",
+                     pos->id,
+                     (unsigned long long) GNUNET_TIME_absolute_get_duration (pos->start_time).value);
+       }
+#endif
       tc.sched = sched;
       tc.reason = pos->reason;
-      tc.read_ready = pos->read_set;
-      tc.write_ready = pos->write_set;
-      pos->callback (pos->callback_cls, &tc);
+      tc.read_ready = (pos->read_set == NULL) ? rs : pos->read_set; 
+      if ( (pos->read_fd != -1) &&
+          (0 != (pos->reason & GNUNET_SCHEDULER_REASON_READ_READY)) )
+       GNUNET_NETWORK_fdset_set_native (rs,
+                                        pos->read_fd);
+      tc.write_ready = (pos->write_set == NULL) ? ws : pos->write_set;
+      if ( (pos->write_fd != -1) &&
+          (0 != (pos->reason & GNUNET_SCHEDULER_REASON_WRITE_READY)) )
+       GNUNET_NETWORK_fdset_set_native (ws,
+                                        pos->write_fd);
+      if ( ( (tc.reason & GNUNET_SCHEDULER_REASON_WRITE_READY) != 0) &&
+          (pos->write_fd != -1) &&
+          (! GNUNET_NETWORK_fdset_test_native (ws,
+                                               pos->write_fd))) 
+       abort (); // added to ready in previous select loop!
 #if DEBUG_TASKS
       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                   "Running task: %llu / %p\n", pos->id, pos->callback_cls);
 #endif
+      pos->callback (pos->callback_cls, &tc);
+#if EXECINFO
+      int i;
+      for (i=0;i<pos->num_backtrace_strings;i++)
+        GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                    "Task %u trace %d: %s\n",
+                    pos->id,
+                    i,
+                    pos->backtrace_strings[i]);
+#endif
+      sched->active_task = NULL;
       destroy_task (pos);
       sched->tasks_run++;
     }
-  while ((sched->pending == NULL) || (p == GNUNET_SCHEDULER_PRIORITY_URGENT));
+  while ( (sched->pending == NULL) || (p >= sched->max_priority_added) );
 }
 
-#ifndef MINGW
 /**
  * Pipe used to communicate shutdown via signal.
  */
-static struct GNUNET_DISK_PipeHandle *sigpipe;
+static struct GNUNET_DISK_PipeHandle *shutdown_pipe_handle;
 
+/**
+ * Signal handler called for SIGPIPE.
+ */
+static void
+sighandler_pipe ()
+{
+  return;
+}
 
 /**
  * Signal handler called for signals that should cause us to shutdown.
@@ -487,10 +707,9 @@ sighandler_shutdown ()
   static char c;
 
   GNUNET_DISK_file_write (GNUNET_DISK_pipe_handle
-                          (sigpipe, GNUNET_DISK_PIPE_END_WRITE), &c,
+                          (shutdown_pipe_handle, GNUNET_DISK_PIPE_END_WRITE), &c,
                           sizeof (c));
 }
-#endif
 
 
 /**
@@ -519,35 +738,37 @@ GNUNET_SCHEDULER_run (GNUNET_SCHEDULER_Task task, void *task_cls)
   struct GNUNET_SIGNAL_Context *shc_term;
   struct GNUNET_SIGNAL_Context *shc_quit;
   struct GNUNET_SIGNAL_Context *shc_hup;
+  struct GNUNET_SIGNAL_Context *shc_pipe;
   unsigned long long last_tr;
   unsigned int busy_wait_warning;
-#ifndef MINGW
   const struct GNUNET_DISK_FileHandle *pr;
-#endif
   char c;
 
   rs = GNUNET_NETWORK_fdset_create ();
   ws = GNUNET_NETWORK_fdset_create ();
-#ifndef MINGW
-  GNUNET_assert (sigpipe == NULL);
-  sigpipe = GNUNET_DISK_pipe (GNUNET_NO);
-  GNUNET_assert (sigpipe != NULL);
-  pr = GNUNET_DISK_pipe_handle (sigpipe, GNUNET_DISK_PIPE_END_READ);
+  GNUNET_assert (shutdown_pipe_handle == NULL);
+  shutdown_pipe_handle = GNUNET_DISK_pipe (GNUNET_NO);
+  GNUNET_assert (shutdown_pipe_handle != NULL);
+  pr = GNUNET_DISK_pipe_handle (shutdown_pipe_handle, GNUNET_DISK_PIPE_END_READ);
   GNUNET_assert (pr != NULL);
-  shc_int  = GNUNET_SIGNAL_handler_install (SIGINT, &sighandler_shutdown);
+  shc_int = GNUNET_SIGNAL_handler_install (SIGINT, &sighandler_shutdown);
   shc_term = GNUNET_SIGNAL_handler_install (SIGTERM, &sighandler_shutdown);
+#ifndef MINGW
+  shc_pipe = GNUNET_SIGNAL_handler_install (SIGPIPE, &sighandler_pipe);
   shc_quit = GNUNET_SIGNAL_handler_install (SIGQUIT, &sighandler_shutdown);
-  shc_hup  = GNUNET_SIGNAL_handler_install (SIGHUP, &sighandler_shutdown);
+  shc_hup = GNUNET_SIGNAL_handler_install (SIGHUP, &sighandler_shutdown);
 #endif
   memset (&sched, 0, sizeof (sched));
   sched.current_priority = GNUNET_SCHEDULER_PRIORITY_DEFAULT;
   GNUNET_SCHEDULER_add_continuation (&sched,
                                      task,
-                                     task_cls, 
-                                    GNUNET_SCHEDULER_REASON_STARTUP);
+                                     task_cls,
+                                     GNUNET_SCHEDULER_REASON_STARTUP);
   last_tr = 0;
   busy_wait_warning = 0;
-  while ( (sched.pending != NULL) || (sched.ready_count > 0) )
+  while ((sched.pending != NULL) || 
+        (sched.pending_timeout != NULL) ||
+        (sched.ready_count > 0))
     {
       GNUNET_NETWORK_fdset_zero (rs);
       GNUNET_NETWORK_fdset_zero (ws);
@@ -560,23 +781,23 @@ GNUNET_SCHEDULER_run (GNUNET_SCHEDULER_Task task, void *task_cls)
           timeout = GNUNET_TIME_UNIT_ZERO;
         }
       ret = GNUNET_NETWORK_socket_select (rs, ws, NULL, timeout);
+      if (ret == GNUNET_SYSERR)
+        {
+          if (errno == EINTR)
+            continue;
+
+          GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "select");
 #ifndef MINGW
-      if (GNUNET_NETWORK_fdset_handle_isset (rs, pr))
-       {
-         /* consume the signal */
-         GNUNET_DISK_file_read (pr, &c, sizeof(c));
-         /* mark all active tasks as ready due to shutdown */
-         GNUNET_SCHEDULER_shutdown (&sched);
-       }
+#if USE_LSOF
+         char lsof[512];
+         snprintf (lsof, sizeof (lsof), "lsof -p %d", getpid());
+         close (1);
+         dup2 (2, 1);
+         system (lsof);                  
 #endif
-      if (last_tr == sched.tasks_run)
-        {
-          busy_wait_warning++;
-        }
-      else
-        {
-          last_tr = sched.tasks_run;
-          busy_wait_warning = 0;
+#endif
+          abort ();
+         break;
         }
       if ((ret == 0) && (timeout.value == 0) && (busy_wait_warning > 16))
         {
@@ -584,29 +805,53 @@ GNUNET_SCHEDULER_run (GNUNET_SCHEDULER_Task task, void *task_cls)
                       _("Looks like we're busy waiting...\n"));
           sleep (1);            /* mitigate */
         }
-      if (ret == GNUNET_SYSERR)
+      check_ready (&sched, rs, ws);
+      run_ready (&sched, rs, ws);
+      if (GNUNET_NETWORK_fdset_handle_isset (rs, pr))
         {
-          if (errno == EINTR)
-            continue;
-          GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "select");
-          break;
+          /* consume the signal */
+          GNUNET_DISK_file_read (pr, &c, sizeof (c));
+          /* mark all active tasks as ready due to shutdown */
+          GNUNET_SCHEDULER_shutdown (&sched);
+        }
+      if (last_tr == sched.tasks_run)
+        {
+          busy_wait_warning++;
+        }
+      else
+        {
+          last_tr = sched.tasks_run;
+          busy_wait_warning = 0;
         }
-      check_ready (&sched, rs, ws);
-      run_ready (&sched);
     }
-#ifndef MINGW
   GNUNET_SIGNAL_handler_uninstall (shc_int);
   GNUNET_SIGNAL_handler_uninstall (shc_term);
+#ifndef MINGW
+  GNUNET_SIGNAL_handler_uninstall (shc_pipe);
   GNUNET_SIGNAL_handler_uninstall (shc_quit);
   GNUNET_SIGNAL_handler_uninstall (shc_hup);
-  GNUNET_DISK_pipe_close (sigpipe);
-  sigpipe = NULL;
 #endif
+  GNUNET_DISK_pipe_close (shutdown_pipe_handle);
+  shutdown_pipe_handle = NULL;
   GNUNET_NETWORK_fdset_destroy (rs);
   GNUNET_NETWORK_fdset_destroy (ws);
 }
 
 
+/**
+ * Obtain the reason code for why the current task was
+ * started.  Will return the same value as 
+ * the GNUNET_SCHEDULER_TaskContext's reason field.
+ *
+ * @param sched scheduler to query
+ * @return reason(s) why the current task is run
+ */
+enum GNUNET_SCHEDULER_Reason
+GNUNET_SCHEDULER_get_reason (struct GNUNET_SCHEDULER_Handle *sched)
+{
+  return sched->active_task->reason;
+}
+
 
 /**
  * Get information about the current load of this scheduler.  Use this
@@ -630,7 +875,7 @@ GNUNET_SCHEDULER_get_load (struct GNUNET_SCHEDULER_Handle *sched,
   if (p == GNUNET_SCHEDULER_PRIORITY_KEEP)
     p = sched->current_priority;
   ret = 0;
-  pos = sched->ready[p];
+  pos = sched->ready[check_priority (p)];
   while (pos != NULL)
     {
       pos = pos->next;
@@ -655,8 +900,10 @@ GNUNET_SCHEDULER_cancel (struct GNUNET_SCHEDULER_Handle *sched,
   struct Task *t;
   struct Task *prev;
   enum GNUNET_SCHEDULER_Priority p;
+  int to;
   void *ret;
 
+  to = 0;
   prev = NULL;
   t = sched->pending;
   while (t != NULL)
@@ -666,6 +913,21 @@ GNUNET_SCHEDULER_cancel (struct GNUNET_SCHEDULER_Handle *sched,
       prev = t;
       t = t->next;
     }
+  if (t == NULL)
+    {
+      prev = NULL;
+      to = 1;
+      t = sched->pending_timeout;
+      while (t != NULL)
+       {
+         if (t->id == task)
+           break;
+         prev = t;
+         t = t->next;
+       }
+      if (sched->pending_timeout_last == t)
+       sched->pending_timeout_last = NULL;
+    }
   p = 0;
   while (t == NULL)
     {
@@ -687,12 +949,25 @@ GNUNET_SCHEDULER_cancel (struct GNUNET_SCHEDULER_Handle *sched,
   if (prev == NULL)
     {
       if (p == 0)
-        sched->pending = t->next;
+       {
+         if (to == 0)
+           {
+             sched->pending = t->next;
+           }
+         else
+           {
+             sched->pending_timeout = t->next;
+           }
+       }
       else
-        sched->ready[p] = t->next;
+       {
+         sched->ready[p] = t->next;
+       }
     }
   else
-    prev->next = t->next;
+    {
+      prev->next = t->next;
+    }
   ret = t->callback_cls;
 #if DEBUG_TASKS
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
@@ -720,11 +995,22 @@ GNUNET_SCHEDULER_add_continuation (struct GNUNET_SCHEDULER_Handle *sched,
                                    enum GNUNET_SCHEDULER_Reason reason)
 {
   struct Task *t;
-
+#if EXECINFO
+  void *backtrace_array[50];
+#endif
   t = GNUNET_malloc (sizeof (struct Task));
+#if EXECINFO
+  t->num_backtrace_strings = backtrace(backtrace_array, 50);
+  t->backtrace_strings = backtrace_symbols(backtrace_array, t->num_backtrace_strings);
+#endif
+  t->read_fd = -1;
+  t->write_fd = -1;
   t->callback = task;
   t->callback_cls = task_cls;
   t->id = ++sched->last_id;
+#if PROFILE_DELAYS
+  t->start_time = GNUNET_TIME_absolute_get ();
+#endif
   t->reason = reason;
   t->priority = sched->current_priority;
 #if DEBUG_TASKS
@@ -745,7 +1031,7 @@ GNUNET_SCHEDULER_add_continuation (struct GNUNET_SCHEDULER_Handle *sched,
  * @param sched scheduler to use
  * @param prerequisite_task run this task after the task with the given
  *        task identifier completes (and any of our other
- *        conditions, such as delay, read or write-readyness
+ *        conditions, such as delay, read or write-readiness
  *        are satisfied).  Use  GNUNET_SCHEDULER_NO_TASK to not have any dependency
  *        on completion of other tasks (this will cause the task to run as
  *        soon as possible).
@@ -757,11 +1043,10 @@ GNUNET_SCHEDULER_add_continuation (struct GNUNET_SCHEDULER_Handle *sched,
 GNUNET_SCHEDULER_TaskIdentifier
 GNUNET_SCHEDULER_add_after (struct GNUNET_SCHEDULER_Handle *sched,
                             GNUNET_SCHEDULER_TaskIdentifier prerequisite_task,
-                            GNUNET_SCHEDULER_Task task,
-                           void *task_cls)
+                            GNUNET_SCHEDULER_Task task, void *task_cls)
 {
-  return GNUNET_SCHEDULER_add_select (sched, 
-                                     GNUNET_SCHEDULER_PRIORITY_KEEP,
+  return GNUNET_SCHEDULER_add_select (sched,
+                                      GNUNET_SCHEDULER_PRIORITY_KEEP,
                                       prerequisite_task,
                                       GNUNET_TIME_UNIT_ZERO,
                                       NULL, NULL, task, task_cls);
@@ -779,13 +1064,13 @@ GNUNET_SCHEDULER_add_after (struct GNUNET_SCHEDULER_Handle *sched,
  *         only valid until "task" is started!
  */
 GNUNET_SCHEDULER_TaskIdentifier
-GNUNET_SCHEDULER_add_with_priority (struct GNUNET_SCHEDULER_Handle *sched,
-                                   enum GNUNET_SCHEDULER_Priority prio,
-                                   GNUNET_SCHEDULER_Task task,
-                                   void *task_cls)
+GNUNET_SCHEDULER_add_with_priority (struct GNUNET_SCHEDULER_Handle * sched,
+                                    enum GNUNET_SCHEDULER_Priority prio,
+                                    GNUNET_SCHEDULER_Task task,
+                                    void *task_cls)
 {
-  return GNUNET_SCHEDULER_add_select (sched, 
-                                     prio,
+  return GNUNET_SCHEDULER_add_select (sched,
+                                      prio,
                                       GNUNET_SCHEDULER_NO_TASK,
                                       GNUNET_TIME_UNIT_ZERO,
                                       NULL, NULL, task, task_cls);
@@ -807,18 +1092,196 @@ GNUNET_SCHEDULER_add_with_priority (struct GNUNET_SCHEDULER_Handle *sched,
  *         only valid until "task" is started!
  */
 GNUNET_SCHEDULER_TaskIdentifier
-GNUNET_SCHEDULER_add_delayed (struct GNUNET_SCHEDULER_Handle *sched,
+GNUNET_SCHEDULER_add_delayed (struct GNUNET_SCHEDULER_Handle * sched,
                               struct GNUNET_TIME_Relative delay,
-                              GNUNET_SCHEDULER_Task task,
-                             void *task_cls)
+                              GNUNET_SCHEDULER_Task task, void *task_cls)
 {
+#if 1
+  /* new, optimized version */
+  struct Task *t;
+  struct Task *pos;
+  struct Task *prev;
+#if EXECINFO
+  void *backtrace_array[MAX_TRACE_DEPTH];
+#endif
+
+  GNUNET_assert (NULL != task);
+  t = GNUNET_malloc (sizeof (struct Task));
+  t->callback = task;
+  t->callback_cls = task_cls;
+#if EXECINFO
+  t->num_backtrace_strings = backtrace(backtrace_array, MAX_TRACE_DEPTH);
+  t->backtrace_strings = backtrace_symbols(backtrace_array, t->num_backtrace_strings);
+#endif
+  t->read_fd = -1;
+  t->write_fd = -1;
+  t->id = ++sched->last_id;
+#if PROFILE_DELAYS
+  t->start_time = GNUNET_TIME_absolute_get ();
+#endif
+  t->timeout = GNUNET_TIME_relative_to_absolute (delay);
+  t->priority = sched->current_priority;
+  /* try tail first (optimization in case we are
+     appending to a long list of tasks with timeouts) */
+  prev = sched->pending_timeout_last;
+  if (prev != NULL) 
+    {
+      if (prev->timeout.value > t->timeout.value)
+       prev = NULL;
+      else
+       pos = prev->next; /* heuristic success! */
+    }
+  if (prev == NULL)
+    {
+      /* heuristic failed, do traversal of timeout list */
+      pos = sched->pending_timeout;
+    }
+  while ( (pos != NULL) &&
+         ( (pos->timeout.value <= t->timeout.value) ||
+           (pos->reason != 0) ) )
+    {
+      prev = pos;
+      pos = pos->next;
+    }
+  if (prev == NULL)
+    sched->pending_timeout = t;
+  else
+    prev->next = t;
+  t->next = pos;
+  /* hyper-optimization... */
+  sched->pending_timeout_last = t;
+
+#if DEBUG_TASKS
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Adding task: %llu / %p\n", t->id, t->callback_cls);
+#endif
+#if EXECINFO
+  int i;
+
+  for (i=0;i<t->num_backtrace_strings;i++)
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "Task %u trace %d: %s\n",
+                  t->id,
+                  i,
+                  t->backtrace_strings[i]);
+#endif
+  return t->id;
+
+#else
+  /* unoptimized version */
   return GNUNET_SCHEDULER_add_select (sched,
-                                     GNUNET_SCHEDULER_PRIORITY_KEEP,
+                                      GNUNET_SCHEDULER_PRIORITY_KEEP,
                                       GNUNET_SCHEDULER_NO_TASK, delay,
                                       NULL, NULL, task, task_cls);
+#endif
+}
+
+
+
+/**
+ * Schedule a new task to be run as soon as possible. The task
+ * will be run with the priority of the calling task.
+ *
+ * @param sched scheduler to use
+ * @param task main function of the task
+ * @param task_cls closure of task
+ * @return unique task identifier for the job
+ *         only valid until "task" is started!
+ */
+GNUNET_SCHEDULER_TaskIdentifier
+GNUNET_SCHEDULER_add_now (struct GNUNET_SCHEDULER_Handle *sched,
+                         GNUNET_SCHEDULER_Task task,
+                         void *task_cls)
+{
+  return GNUNET_SCHEDULER_add_select (sched,
+                                      GNUNET_SCHEDULER_PRIORITY_KEEP,
+                                      GNUNET_SCHEDULER_NO_TASK,
+                                     GNUNET_TIME_UNIT_ZERO,
+                                      NULL, NULL, task, task_cls);
 }
 
 
+
+
+/**
+ * Schedule a new task to be run with a specified delay or when any of
+ * the specified file descriptor sets is ready.  The delay can be used
+ * as a timeout on the socket(s) being ready.  The task will be
+ * scheduled for execution once either the delay has expired or any of
+ * the socket operations is ready.  This is the most general
+ * function of the "add" family.  Note that the "prerequisite_task"
+ * must be satisfied in addition to any of the other conditions.  In
+ * other words, the task will be started when
+ * <code>
+ * (prerequisite-run)
+ * && (delay-ready
+ *     || any-rs-ready
+ *     || any-ws-ready
+ *     || shutdown-active )
+ * </code>
+ *
+ * @param sched scheduler to use
+ * @param delay how long should we wait? Use GNUNET_TIME_UNIT_FOREVER_REL for "forever",
+ *        which means that the task will only be run after we receive SIGTERM
+ * @param rfd file descriptor we want to read (can be -1)
+ * @param wfd file descriptors we want to write (can be -1)
+ * @param task main function of the task
+ * @param task_cls closure of task
+ * @return unique task identifier for the job
+ *         only valid until "task" is started!
+ */
+GNUNET_SCHEDULER_TaskIdentifier
+add_without_sets (struct GNUNET_SCHEDULER_Handle * sched,
+                 struct GNUNET_TIME_Relative delay,
+                 int rfd,
+                 int wfd,
+                 GNUNET_SCHEDULER_Task task, void *task_cls)
+{
+  struct Task *t;
+#if EXECINFO
+  void *backtrace_array[MAX_TRACE_DEPTH];
+#endif
+
+  GNUNET_assert (NULL != task);
+  t = GNUNET_malloc (sizeof (struct Task));
+  t->callback = task;
+  t->callback_cls = task_cls;
+#if EXECINFO
+  t->num_backtrace_strings = backtrace(backtrace_array, MAX_TRACE_DEPTH);
+  t->backtrace_strings = backtrace_symbols(backtrace_array, t->num_backtrace_strings);
+#endif
+  t->read_fd = rfd;
+  t->write_fd = wfd;
+  t->id = ++sched->last_id;
+#if PROFILE_DELAYS
+  t->start_time = GNUNET_TIME_absolute_get ();
+#endif
+  t->prereq_id = GNUNET_SCHEDULER_NO_TASK;
+  t->timeout = GNUNET_TIME_relative_to_absolute (delay);
+  t->priority = check_priority (sched->current_priority);
+  t->next = sched->pending;
+  sched->pending = t;
+  sched->max_priority_added = GNUNET_MAX (sched->max_priority_added,
+                                         t->priority);
+#if DEBUG_TASKS
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Adding task: %llu / %p\n", t->id, t->callback_cls);
+#endif
+#if EXECINFO
+  int i;
+
+  for (i=0;i<t->num_backtrace_strings;i++)
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "Task %u trace %d: %s\n",
+                  t->id,
+                  i,
+                  t->backtrace_strings[i]);
+#endif
+  return t->id;
+}
+
+
+
 /**
  * Schedule a new task to be run with a specified delay or when the
  * specified file descriptor is ready for reading.  The delay can be
@@ -837,25 +1300,17 @@ GNUNET_SCHEDULER_add_delayed (struct GNUNET_SCHEDULER_Handle *sched,
  *         only valid until "task" is started!
  */
 GNUNET_SCHEDULER_TaskIdentifier
-GNUNET_SCHEDULER_add_read_net (struct GNUNET_SCHEDULER_Handle *sched,
-                              struct GNUNET_TIME_Relative delay,
-                              struct GNUNET_NETWORK_Handle *rfd,
-                              GNUNET_SCHEDULER_Task task,
-                              void *task_cls)
+GNUNET_SCHEDULER_add_read_net (struct GNUNET_SCHEDULER_Handle * sched,
+                               struct GNUNET_TIME_Relative delay,
+                               struct GNUNET_NETWORK_Handle * rfd,
+                               GNUNET_SCHEDULER_Task task, void *task_cls)
 {
-  struct GNUNET_NETWORK_FDSet *rs;
-  GNUNET_SCHEDULER_TaskIdentifier ret;
-
-  GNUNET_assert (rfd != NULL);
-  rs = GNUNET_NETWORK_fdset_create ();
-  GNUNET_NETWORK_fdset_set (rs, rfd);
-  ret = GNUNET_SCHEDULER_add_select (sched, 
-                                    GNUNET_SCHEDULER_PRIORITY_KEEP,
-                                     GNUNET_SCHEDULER_NO_TASK, 
-                                    delay,
-                                     rs, NULL, task, task_cls);
-  GNUNET_NETWORK_fdset_destroy (rs);
-  return ret;
+  return add_without_sets (sched,
+                          delay,
+                          GNUNET_NETWORK_get_fd (rfd),
+                          -1,
+                          task,
+                          task_cls);
 }
 
 
@@ -877,24 +1332,17 @@ GNUNET_SCHEDULER_add_read_net (struct GNUNET_SCHEDULER_Handle *sched,
  *         only valid until "task" is started!
  */
 GNUNET_SCHEDULER_TaskIdentifier
-GNUNET_SCHEDULER_add_write_net (struct GNUNET_SCHEDULER_Handle *sched,
-                               struct GNUNET_TIME_Relative delay,
-                               struct GNUNET_NETWORK_Handle *wfd, 
-                               GNUNET_SCHEDULER_Task task, 
-                               void *task_cls)
+GNUNET_SCHEDULER_add_write_net (struct GNUNET_SCHEDULER_Handle * sched,
+                                struct GNUNET_TIME_Relative delay,
+                                struct GNUNET_NETWORK_Handle * wfd,
+                                GNUNET_SCHEDULER_Task task, void *task_cls)
 {
-  struct GNUNET_NETWORK_FDSet *ws;
-  GNUNET_SCHEDULER_TaskIdentifier ret;
-
-  GNUNET_assert (wfd != NULL);
-  ws = GNUNET_NETWORK_fdset_create ();
-  GNUNET_NETWORK_fdset_set (ws, wfd);
-  ret = GNUNET_SCHEDULER_add_select (sched, 
-                                    GNUNET_SCHEDULER_PRIORITY_KEEP,
-                                     GNUNET_SCHEDULER_NO_TASK, delay,
-                                     NULL, ws, task, task_cls);
-  GNUNET_NETWORK_fdset_destroy (ws);
-  return ret;
+  return add_without_sets (sched,
+                          delay,
+                          -1,
+                          GNUNET_NETWORK_get_fd (wfd),
+                          task,
+                          task_cls);
 }
 
 
@@ -916,12 +1364,12 @@ GNUNET_SCHEDULER_add_write_net (struct GNUNET_SCHEDULER_Handle *sched,
  *         only valid until "task" is started!
  */
 GNUNET_SCHEDULER_TaskIdentifier
-GNUNET_SCHEDULER_add_read_file (struct GNUNET_SCHEDULER_Handle *sched,
-                               struct GNUNET_TIME_Relative delay,
-                               const struct GNUNET_DISK_FileHandle *rfd, 
-                               GNUNET_SCHEDULER_Task task,
-                               void *task_cls)
+GNUNET_SCHEDULER_add_read_file (struct GNUNET_SCHEDULER_Handle * sched,
+                                struct GNUNET_TIME_Relative delay,
+                                const struct GNUNET_DISK_FileHandle * rfd,
+                                GNUNET_SCHEDULER_Task task, void *task_cls)
 {
+#if MINGW
   struct GNUNET_NETWORK_FDSet *rs;
   GNUNET_SCHEDULER_TaskIdentifier ret;
 
@@ -929,11 +1377,23 @@ GNUNET_SCHEDULER_add_read_file (struct GNUNET_SCHEDULER_Handle *sched,
   rs = GNUNET_NETWORK_fdset_create ();
   GNUNET_NETWORK_fdset_handle_set (rs, rfd);
   ret = GNUNET_SCHEDULER_add_select (sched,
-                                    GNUNET_SCHEDULER_PRIORITY_KEEP,
-                                    GNUNET_SCHEDULER_NO_TASK, delay,
+                                     GNUNET_SCHEDULER_PRIORITY_KEEP,
+                                     GNUNET_SCHEDULER_NO_TASK, delay,
                                      rs, NULL, task, task_cls);
   GNUNET_NETWORK_fdset_destroy (rs);
   return ret;
+#else
+  int fd;
+
+  GNUNET_DISK_internal_file_handle_ (rfd, &fd, sizeof (int));
+  return add_without_sets (sched,
+                          delay,
+                          fd,
+                          -1,
+                          task,
+                          task_cls);
+
+#endif
 }
 
 
@@ -955,25 +1415,36 @@ GNUNET_SCHEDULER_add_read_file (struct GNUNET_SCHEDULER_Handle *sched,
  *         only valid until "task" is started!
  */
 GNUNET_SCHEDULER_TaskIdentifier
-GNUNET_SCHEDULER_add_write_file (struct GNUNET_SCHEDULER_Handle *sched,
-                                struct GNUNET_TIME_Relative delay,
-                                const struct GNUNET_DISK_FileHandle *wfd,
-                                GNUNET_SCHEDULER_Task task, 
-                                void *task_cls)
+GNUNET_SCHEDULER_add_write_file (struct GNUNET_SCHEDULER_Handle * sched,
+                                 struct GNUNET_TIME_Relative delay,
+                                 const struct GNUNET_DISK_FileHandle * wfd,
+                                 GNUNET_SCHEDULER_Task task, void *task_cls)
 {
+#if MINGW
   struct GNUNET_NETWORK_FDSet *ws;
   GNUNET_SCHEDULER_TaskIdentifier ret;
 
   GNUNET_assert (wfd != NULL);
   ws = GNUNET_NETWORK_fdset_create ();
   GNUNET_NETWORK_fdset_handle_set (ws, wfd);
-  ret = GNUNET_SCHEDULER_add_select (sched, 
-                                    GNUNET_SCHEDULER_PRIORITY_KEEP,
-                                     GNUNET_SCHEDULER_NO_TASK, 
-                                    delay,
-                                     NULL, ws, task, task_cls);
+  ret = GNUNET_SCHEDULER_add_select (sched,
+                                     GNUNET_SCHEDULER_PRIORITY_KEEP,
+                                     GNUNET_SCHEDULER_NO_TASK,
+                                     delay, NULL, ws, task, task_cls);
   GNUNET_NETWORK_fdset_destroy (ws);
   return ret;
+#else
+  int fd;
+
+  GNUNET_DISK_internal_file_handle_ (wfd, &fd, sizeof (int));
+  return add_without_sets (sched,
+                          delay,
+                          -1,
+                          fd,
+                          task,
+                          task_cls);
+
+#endif
 }
 
 
@@ -999,7 +1470,7 @@ GNUNET_SCHEDULER_add_write_file (struct GNUNET_SCHEDULER_Handle *sched,
  * @param prio how important is this task?
  * @param prerequisite_task run this task after the task with the given
  *        task identifier completes (and any of our other
- *        conditions, such as delay, read or write-readyness
+ *        conditions, such as delay, read or write-readiness
  *        are satisfied).  Use GNUNET_SCHEDULER_NO_TASK to not have any dependency
  *        on completion of other tasks.
  * @param delay how long should we wait? Use GNUNET_TIME_UNIT_FOREVER_REL for "forever",
@@ -1012,21 +1483,30 @@ GNUNET_SCHEDULER_add_write_file (struct GNUNET_SCHEDULER_Handle *sched,
  *         only valid until "task" is started!
  */
 GNUNET_SCHEDULER_TaskIdentifier
-GNUNET_SCHEDULER_add_select (struct GNUNET_SCHEDULER_Handle *sched,
+GNUNET_SCHEDULER_add_select (struct GNUNET_SCHEDULER_Handle * sched,
                              enum GNUNET_SCHEDULER_Priority prio,
                              GNUNET_SCHEDULER_TaskIdentifier
                              prerequisite_task,
                              struct GNUNET_TIME_Relative delay,
                              const struct GNUNET_NETWORK_FDSet * rs,
-                            const struct GNUNET_NETWORK_FDSet * ws,
-                             GNUNET_SCHEDULER_Task task, 
-                            void *task_cls)
+                             const struct GNUNET_NETWORK_FDSet * ws,
+                             GNUNET_SCHEDULER_Task task, void *task_cls)
 {
   struct Task *t;
+#if EXECINFO
+  void *backtrace_array[MAX_TRACE_DEPTH];
+#endif
 
+  GNUNET_assert (NULL != task);
   t = GNUNET_malloc (sizeof (struct Task));
   t->callback = task;
   t->callback_cls = task_cls;
+#if EXECINFO
+  t->num_backtrace_strings = backtrace(backtrace_array, MAX_TRACE_DEPTH);
+  t->backtrace_strings = backtrace_symbols(backtrace_array, t->num_backtrace_strings);
+#endif
+  t->read_fd = -1;
+  t->write_fd = -1;
   if (rs != NULL)
     {
       t->read_set = GNUNET_NETWORK_fdset_create ();
@@ -1038,17 +1518,32 @@ GNUNET_SCHEDULER_add_select (struct GNUNET_SCHEDULER_Handle *sched,
       GNUNET_NETWORK_fdset_copy (t->write_set, ws);
     }
   t->id = ++sched->last_id;
+#if PROFILE_DELAYS
+  t->start_time = GNUNET_TIME_absolute_get ();
+#endif
   t->prereq_id = prerequisite_task;
   t->timeout = GNUNET_TIME_relative_to_absolute (delay);
   t->priority =
     check_priority ((prio ==
                      GNUNET_SCHEDULER_PRIORITY_KEEP) ? sched->current_priority
                     : prio);
-  t->next = sched->pending;
+  t->next = sched->pending; 
   sched->pending = t;
+  sched->max_priority_added = GNUNET_MAX (sched->max_priority_added,
+                                         t->priority);
 #if DEBUG_TASKS
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
               "Adding task: %llu / %p\n", t->id, t->callback_cls);
+#endif
+#if EXECINFO
+  int i;
+
+  for (i=0;i<t->num_backtrace_strings;i++)
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "Task %u trace %d: %s\n",
+                  t->id,
+                  i,
+                  t->backtrace_strings[i]);
 #endif
   return t->id;
 }