feature: Add OffloadAllHandlers to config

If this flag is set to true, all event handlers will be fired and
forgotten. Allows owners of large bots to offload all events without
needing to shove them in a Task.Run.

feature request per @aStonedPenguin

src/Discord.Net.WebSocket/DiscordSocketClient.cs

@@ -58,6 +58,7 @@ namespace Discord.WebSocket
         internal WebSocketProvider WebSocketProvider { get; private set; }
         internal bool AlwaysDownloadUsers { get; private set; }
         internal int? HandlerTimeout { get; private set; }
+        internal bool OffloadAllHandlers { get; private set; }
 
         internal new DiscordSocketApiClient ApiClient => base.ApiClient as DiscordSocketApiClient;
         public override IReadOnlyCollection<SocketGuild> Guilds => State.Guilds;
@@ -84,9 +85,13 @@ namespace Discord.WebSocket
             WebSocketProvider = config.WebSocketProvider;
             AlwaysDownloadUsers = config.AlwaysDownloadUsers;
             HandlerTimeout = config.HandlerTimeout;
+            OffloadAllHandlers = config.OffloadAllHandlers;
             State = new ClientState(0, 0);
             _heartbeatTimes = new ConcurrentQueue<long>();
 
+            if (OffloadAllHandlers && !HandlerTimeout.HasValue)
+                throw new InvalidOperationException("If OffloadAllHandlers is set, the HandlerTimeout must also be set. To suppress this message, unset OffloadAllHandlers");
+
             _stateLock = new SemaphoreSlim(1, 1);
             _gatewayLogger = LogManager.CreateLogger(ShardId == 0 && TotalShards == 1 ? "Gateway" : $"Shard #{ShardId}");
             _connection = new ConnectionManager(_stateLock, _gatewayLogger, config.ConnectionTimeout,
@@ -1733,8 +1738,10 @@ namespace Discord.WebSocket
         {
             try
             {
-                var timeoutTask = Task.Delay(HandlerTimeout.Value);
                 var handlersTask = action();
+                if (OffloadAllHandlers)
+                    return;
+                var timeoutTask = Task.Delay(HandlerTimeout.Value);
                 if (await Task.WhenAny(timeoutTask, handlersTask).ConfigureAwait(false) == timeoutTask)
                 {
                     await _gatewayLogger.WarningAsync($"A {name} handler is blocking the gateway task.").ConfigureAwait(false);

src/Discord.Net.WebSocket/DiscordSocketConfig.cs

@@ -1,4 +1,4 @@
-using Discord.Net.Udp;
+using Discord.Net.Udp;
 using Discord.Net.WebSockets;
 using Discord.Rest;
 
@@ -35,6 +35,8 @@ namespace Discord.WebSocket
         public bool AlwaysDownloadUsers { get; set; } = false;
         /// <summary> Gets or sets the timeout for event handlers, in milliseconds, after which a warning will be logged. Null disables this check. </summary>
         public int? HandlerTimeout { get; set; } = 3000;
+        /// <summary> Gets or sets whether or not offload all event handlers from the gateway task. This can have dangerous consequences. </summary>
+        public bool OffloadAllHandlers { get; set; } = false;
 
         public DiscordSocketConfig()
         {