### Changes/Fixes:
* Adds timer pooling.
* Allows pool to be configurable in ModernUO.json
* Pool replenishes itself asynchronously if depleted.
* Fixes an issue with barkeeps and town criers
* Fixes an issue with incognito buff icons not being removed
* Fixes an issue with polymorph name mod not being removed
* Fixes several places where timers go on forever even after an object is deleted, keeping a reference (memory leak)
* Eliminates the timer for MiningCart altogether.
* Deletes `AcidSlime` since it is a duplicate of `PoolOfAcid`
* Fixes HonorableExecution and standardizes the code for other Bushido moves.
## Changes to the Timer API:
```cs
public class Timer
{
// Creates a timer that will be returned to the pool once execution stops.
public static void StartTimer(Action callback);
public static void StartTimer(TimeSpan delay, Action callback);
public static void StartTimer(TimeSpan delay, TimeSpan interval, Action callback);
public static void StartTimer(TimeSpan interval, int count, Action callback);
public static void StartTimer(TimeSpan delay, TimeSpan interval, int count, Action callback);
// Creates a timer and returns a token for more control. Requires manual cancellation in order for the timer to be returned to the pool.
// If the token is dereferenced, the timer will be dereferenced too. While not returning a timer to the pool is not considered hazardous, it does defeat the purpose of pooled timers.
public static void StartTimer(Action callback, out TimerExecutionToken token);
public static void StartTimer(TimeSpan delay, Action callback, out TimerExecutionToken token);
public static void StartTimer(TimeSpan delay, TimeSpan interval, Action callback, out TimerExecutionToken token);
public static void StartTimer(TimeSpan interval, int count, Action callback, out TimerExecutionToken token);
public static void StartTimer(TimeSpan delay, TimeSpan interval, int count, Action callback, out TimerExecutionToken token);
// If you aren't sure how to use the API above, or you don't care about performance, then you can use the old RunUO Timer.DelayCall
public static DelayCallTimer DelayCall(Action callback);
public static DelayCallTimer DelayCall(TimeSpan delay, Action callback);
public static DelayCallTimer DelayCall(TimeSpan delay, TimeSpan interval, Action callback);
public static DelayCallTimer DelayCall(TimeSpan interval, int count, Action callback);
public static DelayCallTimer DelayCall(TimeSpan delay, TimeSpan interval, int count, Action callback);
}
public struct TimerExecutionToken
{
public bool Running { get; }
public int Index { get; }
public int RemainingCount { get; }
public DateTime Next { get; }
}
```
## When to use `TimerExecutionToken`?
Use tokens when you want to gain the performance benefit of using a pooled timer, but you need one of the following:
* Access to the next time the timer will tick:`token.Next`
* Access to which interval, how many intervals there are, or how many are remaining: `token.Index`, `token.Count`, and `token.RemainingCount`
* Stop a timer manually.
* Determine if the timer is running: `timer.Running`
* See notes below about requirements for using tokens!
## Notes about using the TimerExecutionToken:
When you opt-in to receive a token, you must call `Cancel()` to return the timer. This can be done inside of the callback, or outside of the callback at any time.
If this is not called and your timer is an infinite interval, then you will create a potential memory leak, or null pointer exception in your callback.
If the timer ends and is stopped, but cancel is not called, then the timer will never return to the pool and stay referenced until the token is deleted or cancel is called. (Memory leak)
## Is this thread safe?
No. The ModernUO timer system is not thread safe at all. If you require a thread safe timer system, contact me and I'll help adapt this system. Keep in mind that there is a massive performance hit to make this thread safe when there are literally no use cases for it.
If you need to synchronize execution, meaning you want to execute code from another thread on the core thread. Let's say you have a discord bot that is pushing commands to the game server. Then use `EventLoopContext.Post(SendOrPostCallback callback, object state);`.
- [X] Caches DateTime.NowUtc on the game loop (not other threads)
- [X] Replaces all locations where it makes sense
- [X] Adds Min/Max for `IComparable` (TimeSpan, DateTimes, etc)
Closes#261
SpanWriter now has an argument that allows it to be resizable.
```cs
public SpanWriter(Span<byte> initialBuffer, bool resize = false)
public SpanWriter(int initialCapacity, bool resize = false)
```
If a SpanWriter is set to be resizable, or given an initial capacity instead of a buffer, it must be disposed:
```cs
public static void SomeMethod()
{
using var writer = new SpanWriter(stackalloc byte[512], true);
// stuff
// Automatic Dispose of writer
}
```
This is because the SpanWriter uses `ArrayPool<byte>.Shared` _rented buffers_ to resize. If the writer is not disposed, those buffers will never be reused resulting in a _memory leak_.
It is possible that the SpanWriter will outright ditch the initial buffer if resize is set to true and growing is needed. To check/account for that we can do the following:
```cs
public static void SomeMethod()
{
Span<byte> span = stackalloc byte[512];
using var writer = new SpanWriter(span, true);
// write some stuff that causes the span to grow
span = writer.RawBuffer;
// Do stuff with the span
}
```
Make sure you don't accidentally `Dispose()` the writer or use the `RawBuffer` outside of the `using` block. If you do, bad things will happen! (NullPointerException, or a fresh SpanWriter with no buffer, depending on the situation).
SpanWriter can also now be used with a fixed statement since it has a `PinnableReference()` function.
- [X] Fixes an edge case where the cycle index goes negative and crashes
- [X] Fixes average CPS calculation
- [X] Fixes issue with logout delay
- [X] Bumps release version
- [X] Updates Movement packets
- [X] Adds OSI fastwalk packets. These aren't used on OSi anymore.
- [X] Adds new movement handling, but looks like the client doesn't use it. (Also leaving the 0x4000 Character List Flag off)
- [X] Adds time sync request handler, but also looks like the client doesn't use it.
- [X] Adds time sync response for time sync, just in case, but it isn't used, so not sure about the arguments.
- [X] Reimplements RunUO's fastwalk to use a circular array on the netstate instead of every mobile
- [X] Removes ClearFastwalkStack from RunUO implementation. This shouldn't be needed anymore
Changed fastwalk settings:
```cs
public static int WalkFootDelay { get; set; } = 440;
public static int RunFootDelay { get; set; } = 220;
public static int WalkMountDelay { get; set; } = 220;
public static int RunMountDelay { get; set; } = 110;
public static bool EnableFastwalkPrevention { get; set; } = true;
public static AccessLevel FastwalkExemptionLevel { get; set; } = AccessLevel.Counselor;
// If this is changed during runtime, then the steps array needs resizing.
public static int MaxSteps { get; private set; } = 4;
```
modernuo.json
```json
{
"settings": {
"movement.delay.runFoot": "220",
"movement.delay.runMount": "110",
"movement.delay.walkFoot": "440",
"movement.delay.walkMount": "220",
"movement.enableFastWalkPrevention": "True",
"movement.fastwalkExemptionLevel": "Counselor",
"movement.maxSteps": "4"
}
}
```
Notes about OSI fastwalk:
While it does work, I can't find a benefit in using it because of the variable speeds. If players moved at a single speed then we could refill the stack every X milliseconds with 6 keys and use a naive token bucket implementation.
Unfortunately variable speeds mount/run/walk/etc means we would have to use a leaky bucket algorithm.
If we are using a leaky bucket algorithm with a variable leak, then we don't need to send tokens because we are already tracking it on the server side.
ModernUO vs OSI Fastwalk:
When the fastwalk was implemented on OSI, it used up to 6 tokens. These tokens were probably distributed every 600-750 milliseconds. To get the same effect, the new fastwalk settings might need to be adjusted. I would tweak them and feel free to let me know what worked for you!
Bumps release version
- [X] Fixes several bugs
- [X] Updates more ordinal issues
- [X] Cleans up the code a bit
- [X] Turns classes static that should have been
- [X] Changes TcpServer.Instances to a HashSet
Bumps release version
