public void Stop()
{
// try to aquire lock, if fail then kill process anyways.
var lockAquried = Monitor.TryEnter(_lockObject, 500);
if (IsRunning)
{
CloseGameProcess();
if (Memory != null)
{
Memory.Dispose();
Memory = null;
}
IsRunning = false;
StartupSequenceIsComplete = false;
if (LockToken != null)
{
LockToken.Dispose();
LockToken = null;
}
}
if (lockAquried)
{
Monitor.Exit(_lockObject);
}
Profile.Status = "Stopped";
}
/// <summary>
/// This writes a message to the output stream
/// </summary>
/// <param name="physical">The phsyical connection to write to.</param>
/// <param name="message">The message to be written.</param>
internal ValueTask <WriteResult> WriteMessageTakingWriteLockAsync(PhysicalConnection physical, Message message)
{
Trace("Writing: " + message);
message.SetEnqueued(physical); // this also records the read/write stats at this point
bool releaseLock = false;
LockToken token = default;
try
{
// try to acquire it synchronously
// note: timeout is specified in mutex-constructor
var pending = _singleWriterMutex.TryWaitAsync(options: MutexSlim.WaitOptions.DisableAsyncContext);
if (!pending.IsCompletedSuccessfully)
{
return(WriteMessageTakingDelayedWriteLockAsync(pending, physical, message));
}
releaseLock = true;
token = pending.Result; // we can't use "using" for this, because we might not want to kill it yet
if (!token.Success) // (in particular, me might hand the lifetime to CompleteWriteAndReleaseLockAsync)
{
message.Cancel();
Multiplexer?.OnMessageFaulted(message, null);
this.CompleteSyncOrAsync(message);
return(new ValueTask <WriteResult>(WriteResult.TimeoutBeforeWrite));
}
var result = WriteMessageInsideLock(physical, message);
if (result == WriteResult.Success)
{
var flush = physical.FlushAsync(false);
if (!flush.IsCompletedSuccessfully)
{
releaseLock = false; // so we don't release prematurely
return(CompleteWriteAndReleaseLockAsync(token, flush, message));
}
result = flush.Result; // we know it was completed, this is fine
}
UnmarkActiveMessage(message);
physical.SetIdle();
return(new ValueTask <WriteResult>(result));
}
catch (Exception ex) { return(new ValueTask <WriteResult>(HandleWriteException(message, ex))); }
finally
{
if (releaseLock)
{
token.Dispose();
}
}
}
internal WriteResult WriteMessageTakingWriteLockSync(PhysicalConnection physical, Message message)
{
Trace("Writing: " + message);
message.SetEnqueued(physical); // this also records the read/write stats at this point
LockToken token = default;
try
{
token = _singleWriterMutex.TryWait(WaitOptions.NoDelay);
if (!token.Success)
{
// we can't get it *instantaneously*; is there
// perhaps a backlog and active backlog processor?
bool haveBacklog;
lock (_backlog)
{
haveBacklog = _backlog.Count != 0;
}
if (haveBacklog)
{
PushToBacklog(message);
return(WriteResult.Success); // queued counts as success
}
// no backlog... try to wait with the timeout;
// if we *still* can't get it: that counts as
// an actual timeout
token = _singleWriterMutex.TryWait();
if (!token.Success)
{
message.Cancel();
Multiplexer?.OnMessageFaulted(message, null);
message.Complete();
return(WriteResult.TimeoutBeforeWrite);
}
}
var result = WriteMessageInsideLock(physical, message);
if (result == WriteResult.Success)
{
#pragma warning disable CS0618
result = physical.FlushSync(false, TimeoutMilliseconds);
#pragma warning restore CS0618
}
UnmarkActiveMessage(message);
physical.SetIdle();
return(result);
}
catch (Exception ex) { return(HandleWriteException(message, ex)); }
finally { token.Dispose(); }
}
/// <summary>
/// This writes a message to the output stream
/// </summary>
/// <param name="physical">The phsyical connection to write to.</param>
/// <param name="message">The message to be written.</param>
internal ValueTask <WriteResult> WriteMessageTakingWriteLockAsync(PhysicalConnection physical, Message message)
{
Trace("Writing: " + message);
message.SetEnqueued(physical); // this also records the read/write stats at this point
bool releaseLock = true;
LockToken token = default;
try
{
// try to acquire it synchronously
// note: timeout is specified in mutex-constructor
token = _singleWriterMutex.TryWait(options: WaitOptions.NoDelay);
if (!token.Success) // (in particular, me might hand the lifetime to CompleteWriteAndReleaseLockAsync)
{
PushToBacklog(message);
return(new ValueTask <WriteResult>(WriteResult.Success)); // queued counts as success
}
var result = WriteMessageInsideLock(physical, message);
if (result == WriteResult.Success)
{
var flush = physical.FlushAsync(false);
if (!flush.IsCompletedSuccessfully)
{
releaseLock = false; // so we don't release prematurely
return(CompleteWriteAndReleaseLockAsync(token, flush, message));
}
result = flush.Result; // we know it was completed, this is fine
}
UnmarkActiveMessage(message);
physical.SetIdle();
return(new ValueTask <WriteResult>(result));
}
catch (Exception ex) { return(new ValueTask <WriteResult>(HandleWriteException(message, ex))); }
finally
{
if (releaseLock)
{
token.Dispose();
}
}
}
private void ProcessBacklog()
{
LockToken token = default;
try
{
while (true)
{
// try and get the lock; if unsuccessful, check for termination
token = _singleWriterMutex.TryWait();
if (token)
{
break; // got the lock
}
lock (_backlog) { if (_backlog.Count == 0)
{
return;
}
}
}
// so now we are the writer; write some things!
Message message;
var timeout = TimeoutMilliseconds;
while (true)
{
lock (_backlog)
{
if (_backlog.Count == 0)
{
break; // all done
}
message = _backlog.Dequeue();
}
try
{
if (message.HasAsyncTimedOut(Environment.TickCount, timeout, out var elapsed))
{
var ex = Multiplexer.GetException(WriteResult.TimeoutBeforeWrite, message, ServerEndPoint);
message.SetExceptionAndComplete(ex, this);
}
else
{
var result = WriteMessageInsideLock(physical, message);
if (result == WriteResult.Success)
{
#pragma warning disable CS0618
result = physical.FlushSync(false, timeout);
#pragma warning restore CS0618
}
UnmarkActiveMessage(message);
if (result != WriteResult.Success)
{
var ex = Multiplexer.GetException(result, message, ServerEndPoint);
HandleWriteException(message, ex);
}
}
}
catch (Exception ex)
{
HandleWriteException(message, ex);
}
}
physical.SetIdle();
}
finally
{
token.Dispose();
}
}
/// <summary>
/// This writes a message to the output stream
/// </summary>
/// <param name="physical">The phsyical connection to write to.</param>
/// <param name="message">The message to be written.</param>
internal ValueTask <WriteResult> WriteMessageTakingWriteLockAsync(PhysicalConnection physical, Message message)
{
/* design decision/choice; the code works fine either way, but if this is
* set to *true*, then when we can't take the writer-lock *right away*,
* we push the message to the backlog (starting a worker if needed)
*
* otherwise, we go for a TryWaitAsync and rely on the await machinery
*
* "true" seems to give faster times *when under heavy contention*, based on profiling
* but it involves the backlog concept; "false" works well under low contention, and
* makes more use of async
*/
const bool ALWAYS_USE_BACKLOG_IF_CANNOT_GET_SYNC_LOCK = true;
Trace("Writing: " + message);
message.SetEnqueued(physical); // this also records the read/write stats at this point
bool releaseLock = true; // fine to default to true, as it doesn't matter until token is a "success"
LockToken token = default;
try
{
// try to acquire it synchronously
// note: timeout is specified in mutex-constructor
token = _singleWriterMutex.TryWait(options: WaitOptions.NoDelay);
if (!token.Success)
{
// we can't get it *instantaneously*; is there
// perhaps a backlog and active backlog processor?
if (PushToBacklog(message, onlyIfExists: !ALWAYS_USE_BACKLOG_IF_CANNOT_GET_SYNC_LOCK))
{
return(new ValueTask <WriteResult>(WriteResult.Success)); // queued counts as success
}
// no backlog... try to wait with the timeout;
// if we *still* can't get it: that counts as
// an actual timeout
var pending = _singleWriterMutex.TryWaitAsync(options: WaitOptions.DisableAsyncContext);
if (!pending.IsCompletedSuccessfully)
{
return(WriteMessageTakingWriteLockAsync_Awaited(pending, physical, message));
}
token = pending.Result; // fine since we know we got a result
if (!token.Success)
{
return(new ValueTask <WriteResult>(TimedOutBeforeWrite(message)));
}
}
var result = WriteMessageInsideLock(physical, message);
if (result == WriteResult.Success)
{
var flush = physical.FlushAsync(false);
if (!flush.IsCompletedSuccessfully)
{
releaseLock = false; // so we don't release prematurely
return(CompleteWriteAndReleaseLockAsync(token, flush, message));
}
result = flush.Result; // we know it was completed, this is fine
}
UnmarkActiveMessage(message);
physical.SetIdle();
return(new ValueTask <WriteResult>(result));
}
catch (Exception ex) { return(new ValueTask <WriteResult>(HandleWriteException(message, ex))); }
finally
{
if (releaseLock)
{
token.Dispose();
}
}
}