//
// System.Threading.Timer.cs
//
// Authors:
// Dick Porter (dick@ximian.com)
// Gonzalo Paniagua Javier (gonzalo@ximian.com)
//
// (C) 2001, 2002 Ximian, Inc. http://www.ximian.com
// Copyright (C) 2004-2009 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System.Runtime.InteropServices;
using System.Collections;
namespace System.Threading{
[ComVisible (true)]
public sealed class Timer : MarshalByRefObject, IDisposable
{
static Scheduler scheduler = Scheduler.Instance;
#region Timer instance fields
TimerCallback callback;
object state;
long due_time_ms;
long period_ms;
long next_run; // in ticks. Only 'Scheduler' can change it except for new timers without due time.
bool disposed;
#endregion
public Timer (TimerCallback callback, object state, int dueTime, int period)
{
Init (callback, state, dueTime, period);
}
public Timer (TimerCallback callback, object state, long dueTime, long period)
{
Init (callback, state, dueTime, period);
}
public Timer (TimerCallback callback, object state, TimeSpan dueTime, TimeSpan period)
{
Init (callback, state, (long)dueTime.TotalMilliseconds, (long)period.TotalMilliseconds);
}
[CLSCompliant(false)]
public Timer (TimerCallback callback, object state, uint dueTime, uint period)
{
// convert all values to long - with a special case for -1 / 0xffffffff
long d = (dueTime == UInt32.MaxValue) ? Timeout.Infinite : (long) dueTime;
long p = (period == UInt32.MaxValue) ? Timeout.Infinite : (long) period;
Init (callback, state, d, p);
}
public Timer (TimerCallback callback)
{
Init (callback, this, Timeout.Infinite, Timeout.Infinite);
}
void Init (TimerCallback callback, object state, long dueTime, long period)
{
if (callback == null)
throw new ArgumentNullException ("callback");
this.callback = callback;
this.state = state;
Change (dueTime, period, true);
}
public bool Change (int dueTime, int period)
{
return Change (dueTime, period, false);
}
public bool Change (TimeSpan dueTime, TimeSpan period)
{
return Change ((long)dueTime.TotalMilliseconds, (long)period.TotalMilliseconds, false);
}
[CLSCompliant(false)]
public bool Change (uint dueTime, uint period)
{
// convert all values to long - with a special case for -1 / 0xffffffff
long d = (dueTime == UInt32.MaxValue) ? Timeout.Infinite : (long) dueTime;
long p = (period == UInt32.MaxValue) ? Timeout.Infinite : (long) period;
return Change (d, p, false);
}
public void Dispose ()
{
if (disposed)
return;
disposed = true;
scheduler.Remove (this);
}
public bool Change (long dueTime, long period)
{
return Change (dueTime, period, false);
}
const long MaxValue = UInt32.MaxValue - 1;
bool Change (long dueTime, long period, bool first)
{
if (dueTime > MaxValue)
throw new ArgumentOutOfRangeException ("Due time too large");
if (period > MaxValue)
throw new ArgumentOutOfRangeException ("Period too large");
// Timeout.Infinite == -1, so this accept everything greater than -1
if (dueTime < Timeout.Infinite)
throw new ArgumentOutOfRangeException ("dueTime");
if (period < Timeout.Infinite)
throw new ArgumentOutOfRangeException ("period");
if (disposed)
return false;
due_time_ms = dueTime;
period_ms = period;
long nr;
if (dueTime == 0) {
nr = 0; // Due now
} else if (dueTime < 0) { // Infinite == -1
nr = long.MaxValue;
/* No need to call Change () */
if (first) {
next_run = nr;
return true;
}
} else {
nr = dueTime * TimeSpan.TicksPerMillisecond + DateTime.GetTimeMonotonic ();
}
scheduler.Change (this, nr);
return true;
}
public bool Dispose (WaitHandle notifyObject)
{
if (notifyObject == null)
throw new ArgumentNullException ("notifyObject");
Dispose ();
NativeEventCalls.SetEvent_internal (notifyObject.Handle);
return true;
}
sealed class TimerComparer : IComparer {
public int Compare (object x, object y)
{
Timer tx = (x as Timer);
if (tx == null)
return -1;
Timer ty = (y as Timer);
if (ty == null)
return 1;
long result = tx.next_run - ty.next_run;
if (result == 0)
return x == y ? 0 : -1;
return result > 0 ? 1 : -1;
}
}
sealed class Scheduler {
static Scheduler instance;
SortedList list;
static Scheduler ()
{
instance = new Scheduler ();
}
public static Scheduler Instance {
get { return instance; }
}
private Scheduler ()
{
list = new SortedList (new TimerComparer (), 1024);
Thread thread = new Thread (SchedulerThread);
thread.IsBackground = true;
thread.Start ();
}
public void Remove (Timer timer)
{
// We do not keep brand new items or those with no due time.
if (timer.next_run == 0 || timer.next_run == Int64.MaxValue)
return;
lock (this) {
// If this is the next item due (index = 0), the scheduler will wake up and find nothing.
// No need to Pulse ()
InternalRemove (timer);
}
}
public void Change (Timer timer, long new_next_run)
{
lock (this) {
InternalRemove (timer);
if (new_next_run == Int64.MaxValue) {
timer.next_run = new_next_run;
return;
}
if (!timer.disposed) {
// We should only change next_run after removing and before adding
timer.next_run = new_next_run;
Add (timer);
// If this timer is next in line, wake up the scheduler
if (list.GetByIndex (0) == timer)
Monitor.Pulse (this);
}
}
}
// This should be the only caller to list.Add!
void Add (Timer timer)
{
// Make sure there are no collisions (10000 ticks == 1ms, so we should be safe here)
int idx = list.IndexOfKey (timer);
if (idx != -1) {
bool up = (Int64.MaxValue - timer.next_run) > 20000 ? true : false;
while (true) {
idx++;
if (up)
timer.next_run++;
else
timer.next_run--;
if (idx >= list.Count)
break;
Timer t2 = (Timer) list.GetByIndex (idx);
if (t2.next_run != timer.next_run)
break;
}
}
list.Add (timer, timer);
//PrintList ();
}
int InternalRemove (Timer timer)
{
int idx = list.IndexOfKey (timer);
if (idx >= 0)
list.RemoveAt (idx);
return idx;
}
void SchedulerThread ()
{
Thread.CurrentThread.Name = "Timer-Scheduler";
ArrayList new_time = new ArrayList (512);
while (true) {
long ticks = DateTime.GetTimeMonotonic ();
lock (this) {
//PrintList ();
int i;
int count = list.Count;
for (i = 0; i < count; i++) {
Timer timer = (Timer) list.GetByIndex (i);
if (timer.next_run > ticks)
break;
list.RemoveAt (i);
count--;
i--;
ThreadPool.QueueUserWorkItem (new WaitCallback (timer.callback), timer.state);
long period = timer.period_ms;
long due_time = timer.due_time_ms;
bool no_more = (period == -1 || ((period == 0 || period == Timeout.Infinite) && due_time != Timeout.Infinite));
if (no_more) {
timer.next_run = Int64.MaxValue;
} else {
timer.next_run = DateTime.GetTimeMonotonic () + TimeSpan.TicksPerMillisecond * timer.period_ms;
new_time.Add (timer);
}
}
// Reschedule timers with a new due time
count = new_time.Count;
for (i = 0; i < count; i++) {
Timer timer = (Timer) new_time [i];
Add (timer);
}
new_time.Clear ();
ShrinkIfNeeded (new_time, 512);
// Shrink the list
int capacity = list.Capacity;
count = list.Count;
if (capacity > 1024 && count > 0 && (capacity / count) > 3)
list.Capacity = count * 2;
long min_next_run = Int64.MaxValue;
if (list.Count > 0)
min_next_run = ((Timer) list.GetByIndex (0)).next_run;
//PrintList ();
int ms_wait = -1;
if (min_next_run != Int64.MaxValue) {
long diff = min_next_run - DateTime.GetTimeMonotonic ();
ms_wait = (int)(diff / TimeSpan.TicksPerMillisecond);
if (ms_wait < 0)
ms_wait = 0;
}
// Wait until due time or a timer is changed and moves from/to the first place in the list.
Monitor.Wait (this, ms_wait);
}
}
}
void ShrinkIfNeeded (ArrayList list, int initial)
{
int capacity = list.Capacity;
int count = list.Count;
if (capacity > initial && count > 0 && (capacity / count) > 3)
list.Capacity = count * 2;
}
/*
void PrintList ()
{
Console.WriteLine ("BEGIN--");
for (int i = 0; i < list.Count; i++) {
Timer timer = (Timer) list.GetByIndex (i);
Console.WriteLine ("{0}: {1}", i, timer.next_run);
}
Console.WriteLine ("END----");
}
*/
}
}
}
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