ArrayList FindHook (Hook[] hooks, HookType hookType, HookAction action, Type type, string member)
{
ArrayList foundHooks = new ArrayList ();
if (hooks == null) return foundHooks;
foreach (Hook hook in hooks)
{
if (action == HookAction.InsertBefore && (hook.InsertBefore == null || hook.InsertBefore == ""))
continue;
else if (action == HookAction.InsertAfter && (hook.InsertAfter == null || hook.InsertAfter == ""))
continue;
else if (action == HookAction.Replace && (hook.Replace == null || hook.Replace == ""))
continue;
if (hook.HookType != hookType)
continue;
if (hook.Select != null)
{
if (hook.Select.TypeName != null && hook.Select.TypeName != "")
if (hook.Select.TypeName != type.FullName) continue;
if (hook.Select.TypeMember != null && hook.Select.TypeMember != "")
if (hook.Select.TypeMember != member) continue;
if (hook.Select.TypeAttributes != null && hook.Select.TypeAttributes.Length > 0)
{
object[] ats = type.GetCustomAttributes (true);
bool found = false;
foreach (object at in ats)
if (Array.IndexOf (hook.Select.TypeAttributes, at.GetType().FullName) != -1) { found = true; break; }
if (!found) continue;
}
}
foundHooks.Add (hook);
}
return foundHooks;
}
private void Worker ()
{
DateTime end_time_of_previous_task = DateTime.MinValue;
double duration_of_previous_task = 0.0;
Hook pre_hook = null;
Hook post_hook = null;
ArrayList to_be_executed = new ArrayList ();
Hashtable max_priority_by_source = new Hashtable ();
int executed_task_count = 0;
StringBuilder status_builder = new StringBuilder ();
while (running) {
status_str = "Finding next task to execute";
lock (big_lock) {
// If there are no pending tasks, wait
// on our lock and then re-start our
// while loop
if (tasks_by_tag.Count == 0) {
if (EmptyQueueEvent != null)
EmptyQueueEvent ();
status_str = "Waiting on empty queue";
Monitor.Wait (big_lock);
executed_task_count = 0;
continue;
}
if (Debug)
Log.Debug ("Running Scheduler inner loop. Pending tasks: {0}", tasks_by_tag.Count);
// Walk across our list of tasks and find
// the next one to execute.
DateTime now = DateTime.Now;
DateTime next_trigger_time = DateTime.MaxValue;
// Make a first pass over our tasks, finding the
// highest-priority item per source.
max_priority_by_source.Clear ();
foreach (Task task in tasks_by_tag.Values) {
if (task.Blocked || task.TriggerTime >= now)
continue;
if (max_priority_by_source.Contains (task.Source)) {
Priority p = (Priority) max_priority_by_source [task.Source];
if (p < task.Priority)
max_priority_by_source [task.Source] = task.Priority;
} else {
max_priority_by_source [task.Source] = task.Priority;
}
}
// Now make a second pass over the tasks and find
// the highest-priority item. We use the information
// from the first pass to correctly prioritize maintenance tasks.
Task next_task = null;
foreach (Task task in tasks_by_tag.Values) {
if (task.Blocked)
continue;
if (task.TriggerTime >= now) {
if (task.TriggerTime < next_trigger_time)
next_trigger_time = task.TriggerTime;
continue;
}
// If this is a maintenance task and there is a high-priority
// task from the same source, skip it.
if (task.Priority == Priority.Maintenance) {
Priority p = (Priority) max_priority_by_source [task.Source];
if (p > task.Priority)
continue;
}
if (task.TriggerTime < now) {
if (next_task == null || next_task.CompareTo (task) < 0)
next_task = task;
}
}
// If we didn't find a task, wait for the next trigger-time
// and then re-start our while loop.
if (next_task == null) {
if (next_trigger_time == DateTime.MaxValue) {
status_str = "Waiting for an unblocked task";
Monitor.Wait (big_lock);
} else {
status_str = "Waiting for the next trigger time";
Monitor.Wait (big_lock, next_trigger_time - now);
}
executed_task_count = 0;
continue;
}
// If we did find a task, do we want to execute it right now?
// Or should we wait a bit?
// How should we space things out?
double delay = 0;
delay = ComputeDelay (next_task.Priority, duration_of_previous_task, executed_task_count);
delay = Math.Min (delay, (next_trigger_time - now).TotalSeconds);
if (Debug)
Log.Debug ("Computed a delay of {0:.00}s for next task ({1}: {2})", delay, next_task.Tag, next_task.Priority);
// Adjust by the time that has actually elapsed since the
// last task.
delay -= (now - end_time_of_previous_task).TotalSeconds;
// If we still need to wait a bit longer, wait for the appropriate
// amount of time and then re-start our while loop.
if (delay > 0.001) {
TimeSpan span = TimeSpanFromSeconds (delay);
if (Debug)
Log.Debug ("Waiting {0:.00}s until the next task at {1}", span.TotalSeconds, now + span);
status_str = String.Format ("Waiting for next task at {0}", now + span);
Monitor.Wait (big_lock, span);
executed_task_count = 0;
continue;
}
//
// If we've made it to this point, it is time to start
// executing our selected task.
//
to_be_executed.Clear ();
if (next_task.Collector == null) {
to_be_executed.Add (next_task);
} else {
pre_hook = new Hook (next_task.Collector.PreTaskHook);
post_hook = new Hook (next_task.Collector.PostTaskHook);
// Find all eligible tasks with the same collector,
// and add them to the collection list.
now = DateTime.Now;
foreach (Task task in tasks_by_tag.Values)
if (task != next_task
&& task.Collector == next_task.Collector
&& !task.Blocked
&& task.TriggerTime < now)
to_be_executed.Add (task);
// Order the tasks from highest to lowest priority.
// Our original task will always be the first item
// in the resulting array.
to_be_executed.Sort ();
to_be_executed.Add (next_task);
to_be_executed.Reverse ();
// Now find how many tasks can be executed before we
// exceed the collector's maximum weight. If necessary,
// prune the list of tasks.
double remaining_weight;
remaining_weight = next_task.Collector.GetMaximumWeight ();
int i = 0;
while (i < to_be_executed.Count && remaining_weight > 0) {
Task task;
task = to_be_executed [i] as Task;
remaining_weight -= task.Weight;
++i;
}
if (i < to_be_executed.Count)
to_be_executed.RemoveRange (i, to_be_executed.Count - i);
}
// Remove the tasks we are about to execute from our
// master list.
foreach (Task task in to_be_executed)
tasks_by_tag.Remove (task.Tag);
// Pulse our lock, in case anyone is waiting for it.
Monitor.Pulse (big_lock);
}
// Now actually execute the set of tasks we found.
status_builder.Length = 0;
status_builder.Append ("Executing task");
if (to_be_executed.Count > 1)
status_builder.Append ('s');
status_builder.Append ('\n');
foreach (Task task in to_be_executed) {
task.AppendToStringBuilder (status_builder);
status_builder.Append ('\n');
}
status_str = status_builder.ToString ();
DateTime start_time = DateTime.Now;
if (pre_hook != null) {
try {
pre_hook ();
} catch (Exception ex) {
Logger.Log.Error (ex, "Caught exception in pre_hook '{0}'", pre_hook);
}
}
foreach (Task task in to_be_executed) {
task.DoTask ();
++total_executed_task_count;
++executed_task_count;
}
if (post_hook != null) {
try {
post_hook ();
} catch (Exception ex) {
Logger.Log.Error (ex, "Caught exception in post_hook '{0}'", post_hook);
}
}
end_time_of_previous_task = DateTime.Now;
duration_of_previous_task = (end_time_of_previous_task - start_time).TotalSeconds;
}
// Execute all shutdown tasks
foreach (Task task in shutdown_task_queue)
if (! task.Cancelled && ! task.Blocked)
task.DoTask ();
// Call Cleanup on all of our unexecuted tasks
foreach (Task task in tasks_by_tag.Values)
task.Cleanup ();
if (Debug)
Logger.Log.Debug ("Scheduler.Worker finished");
}
public TaskGroupPrivate (string name,
Hook pre_hook,
Hook post_hook)
{
this.name = name;
this.pre_hook = pre_hook;
this.post_hook = post_hook;
}
//////////////////////////////////////////////////////////////////////////////
//
// Task Groups
//
public static TaskGroup NewTaskGroup (string name, Hook pre_hook, Hook post_hook)
{
return new TaskGroupPrivate (name, pre_hook, post_hook);
}
