Fixup bad threading (no, you cannot access rcheevo's _runtime in a separate thread! main thread use only!). Should fix up some random crashes

Slightly change up the request model, now InternalDoRequest does not block
Fixup logic of ToSoftcoreMode (and comments so it isn't screwed up again)

src/BizHawk.Client.EmuHawk/RetroAchievements/RCheevos.Achievements.cs

@@ -145,50 +145,62 @@ namespace BizHawk.Client.EmuHawk
 
 			_activeModeUnlocksRequest.Wait();
 
-			foreach (var cheevo in _gameData.CheevoEnumerable)
+			DeactivateCheevos(HardcoreMode);
-			{
-				if (cheevo.IsEnabled && !cheevo.IsUnlocked(HardcoreMode))
-				{
-					_lib.rc_runtime_deactivate_achievement(ref _runtime, cheevo.ID);
-				}
-			}
-
 			AllowUnofficialCheevos ^= true;
-
+			ActivateCheevos(HardcoreMode);
-			foreach (var cheevo in _gameData.CheevoEnumerable)
-			{
-				if (cheevo.IsEnabled && !cheevo.IsUnlocked(HardcoreMode))
-				{
-					_lib.rc_runtime_activate_achievement(ref _runtime, cheevo.ID, cheevo.Definition, IntPtr.Zero, 0);
-				}
-			}
 		}
 
 		private void ToSoftcoreMode()
 		{
 			if (_gameData == null || _gameData.GameID == 0) return;
+			
+			// don't worry if the meanings of _active and _inactive are wrong
+			// if they are, then they're both already finished
 
+			// first deactivate any hardcore cheevos
+			// if _activeModeUnlocksRequest is still active, it's hardcore mode
+			_activeModeUnlocksRequest.Wait();
+			DeactivateCheevos(true);
+
+			// now activate the softcore cheevos
+			// if _inactiveModeUnlocksRequest is still active, it's softcore mode
 			_inactiveModeUnlocksRequest.Wait();
+			ActivateCheevos(false);
 
+			Update();
+		}
+
+		private void DeactivateCheevos(bool hardcore)
+		{
 			foreach (var cheevo in _gameData.CheevoEnumerable)
 			{
-				if (cheevo.IsEnabled && !cheevo.IsUnlocked(false))
+				if (cheevo.IsEnabled && !cheevo.IsUnlocked(hardcore))
 				{
 					_lib.rc_runtime_deactivate_achievement(ref _runtime, cheevo.ID);
 				}
 			}
+		}
 
-			_activeModeUnlocksRequest.Wait();
+		private bool _activeModeCheevosOnceActivated;
 
+		private void ActivateCheevos(bool hardcore)
+		{
 			foreach (var cheevo in _gameData.CheevoEnumerable)
 			{
-				if (cheevo.IsEnabled && !cheevo.IsUnlocked(true))
+				if (cheevo.IsEnabled && !cheevo.IsUnlocked(hardcore))
 				{
 					_lib.rc_runtime_activate_achievement(ref _runtime, cheevo.ID, cheevo.Definition, IntPtr.Zero, 0);
 				}
 			}
 
-			Update();
+			_activeModeCheevosOnceActivated = true;
+		}
+
+		private void OneShotActivateActiveModeCheevos()
+		{
+			if (_activeModeCheevosOnceActivated) return;
+			_activeModeUnlocksRequest.Wait();
+			ActivateCheevos(HardcoreMode);
 		}
 	}
 }

src/BizHawk.Client.EmuHawk/RetroAchievements/RCheevos.GameInfo.cs

@@ -25,7 +25,6 @@ namespace BizHawk.Client.EmuHawk
 		{
 			private LibRCheevos.rc_api_fetch_user_unlocks_request_t _apiParams;
 			private readonly IReadOnlyDictionary<int, Cheevo> _cheevos;
-			private readonly Action _activeModeCallback;
 
 			protected override void ResponseCallback(byte[] serv_resp)
 			{
@@ -43,8 +42,6 @@ namespace BizHawk.Client.EmuHawk
 							}
 						}
 					}
-
-					_activeModeCallback?.Invoke();
 				}
 				else
 				{
@@ -60,12 +57,10 @@ namespace BizHawk.Client.EmuHawk
 				InternalDoRequest(apiParamsResult, ref api_req);
 			}
 
-			public UserUnlocksRequest(string username, string api_token, int game_id, bool hardcore,
+			public UserUnlocksRequest(string username, string api_token, int game_id, bool hardcore, IReadOnlyDictionary<int, Cheevo> cheevos)
-				IReadOnlyDictionary<int, Cheevo> cheevos, Action activeModeCallback = null)
 			{
 				_apiParams = new(username, api_token, game_id, hardcore);
 				_cheevos = cheevos;
-				_activeModeCallback = activeModeCallback;
 			}
 		}
 
@@ -167,9 +162,9 @@ namespace BizHawk.Client.EmuHawk
 			public Cheevo GetCheevoById(int i) => _cheevos[i];
 			public LBoard GetLboardById(int i) => _lboards[i];
 
-			public UserUnlocksRequest InitUnlocks(string username, string api_token, bool hardcore, Action callback = null)
+			public UserUnlocksRequest InitUnlocks(string username, string api_token, bool hardcore)
 			{
-				return new(username, api_token, GameID, hardcore, _cheevos, callback);
+				return new(username, api_token, GameID, hardcore, _cheevos);
 			}
 
 			public IEnumerable<RCheevoHttpRequest> LoadImages()
@@ -301,16 +296,7 @@ namespace BizHawk.Client.EmuHawk
 
 		private void InitGameData()
 		{
-			_activeModeUnlocksRequest = _gameData.InitUnlocks(Username, ApiToken, HardcoreMode, () =>
+			_activeModeUnlocksRequest = _gameData.InitUnlocks(Username, ApiToken, HardcoreMode);
-			{
-				foreach (var cheevo in _gameData.CheevoEnumerable)
-				{
-					if (cheevo.IsEnabled && !cheevo.IsUnlocked(HardcoreMode))
-					{
-						_lib.rc_runtime_activate_achievement(ref _runtime, cheevo.ID, cheevo.Definition, IntPtr.Zero, 0);
-					}
-				}
-			});
 			_inactiveHttpRequests.Push(_activeModeUnlocksRequest);
 
 			_inactiveModeUnlocksRequest = _gameData.InitUnlocks(Username, ApiToken, !HardcoreMode);

src/BizHawk.Client.EmuHawk/RetroAchievements/RCheevos.Http.cs

@@ -112,20 +112,23 @@ namespace BizHawk.Client.EmuHawk
 					: HttpGet(request.URL);
 				apiTask.ConfigureAwait(false);
 
-				_lib.rc_api_destroy_request(ref request);
+				apiTask.ContinueWith(async t =>
-				var result = apiTask.Result; // FIXME: THIS IS BAD (but kind of needed?)
-
-				if (result is null) // likely a timeout
 				{
-					ShouldRetry = true;
+					var result = await t;
-					_completionEvent.Set();
+					if (result is null) // likely a timeout
-					return;
+					{
-				}
+						ShouldRetry = true;
+						_completionEvent.Set();
+					}
+					else
+					{
+						ResponseCallback(result);
+						ShouldRetry = false; // this is a bit naive, but if the response callback "fails," retrying will just result in the same thing
+						_completionEvent.Set();
+					}
+				});
 
-				ResponseCallback(result);
+				_lib.rc_api_destroy_request(ref request);
-
-				ShouldRetry = false; // this is a bit naive, but if the response callback "fails," retrying will just result in the same thing
-				_completionEvent.Set();
 			}
 		}
 
@@ -158,14 +161,14 @@ namespace BizHawk.Client.EmuHawk
 			{
 				while (_inactiveHttpRequests.TryPop(out var request))
 				{
-					Task.Run(request.DoRequest);
+					request.DoRequest();
 					_activeHttpRequests.Add(request);
 				}
 
 				foreach (var activeRequest in _activeHttpRequests.Where(activeRequest => activeRequest.IsCompleted && activeRequest.ShouldRetry).ToArray())
 				{
 					activeRequest.Reset();
-					Task.Run(activeRequest.DoRequest);
+					activeRequest.DoRequest();
 				}
 
 				_activeHttpRequests.RemoveAll(activeRequest =>

src/BizHawk.Client.EmuHawk/RetroAchievements/RCheevos.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Threading;
 using System.Windows.Forms;
 
 using BizHawk.BizInvoke;
@@ -120,7 +121,6 @@ namespace BizHawk.Client.EmuHawk
 			enableHardcoreItem.CheckedChanged += (_, _) =>
 			{
 				_hardcoreMode ^= true;
-				enableLboardsItem.Enabled = HardcoreMode;
 
 				if (HardcoreMode)
 				{
@@ -130,6 +130,8 @@ namespace BizHawk.Client.EmuHawk
 				{
 					ToSoftcoreMode();
 				}
+
+				enableLboardsItem.Enabled = HardcoreMode;
 			};
 			raDropDownItems.Add(enableHardcoreItem);
 
@@ -195,7 +197,7 @@ namespace BizHawk.Client.EmuHawk
 			: base(mainForm, inputManager, tools, getConfig, raDropDownItems, shutdownRACallback)
 		{
 			_isActive = true;
-			_httpThread = new(HttpRequestThreadProc) { IsBackground = true };
+			_httpThread = new(HttpRequestThreadProc) { IsBackground = true, Priority = ThreadPriority.BelowNormal };
 			_httpThread.Start();
 
 			_runtime = default;
@@ -243,7 +245,8 @@ namespace BizHawk.Client.EmuHawk
 				return;
 			}
 
-			_activeModeUnlocksRequest.Wait();
+			OneShotActivateActiveModeCheevos();
+
 			var size = _lib.rc_runtime_progress_size(ref _runtime, IntPtr.Zero);
 			if (size > 0)
 			{
@@ -266,7 +269,8 @@ namespace BizHawk.Client.EmuHawk
 				HandleHardcoreModeDisable("Loading savestates is not allowed in hardcore mode.");
 			}
 
-			_activeModeUnlocksRequest.Wait();
+			OneShotActivateActiveModeCheevos();
+
 			_lib.rc_runtime_reset(ref _runtime);
 
 			if (!File.Exists(path + ".rap")) return;
@@ -314,6 +318,8 @@ namespace BizHawk.Client.EmuHawk
 				}
 			}
 
+			_activeModeCheevosOnceActivated = false;
+
 			if (!LoggedIn)
 			{
 				return;
@@ -599,6 +605,8 @@ namespace BizHawk.Client.EmuHawk
 				return;
 			}
 
+			OneShotActivateActiveModeCheevos();
+
 			var input = _inputManager.ControllerOutput;
 			if (input.Definition.BoolButtons.Any(b => (b.Contains("Power") || b.Contains("Reset")) && input.IsPressed(b)))
 			{