feat: Mutex redesign - isolate event processing for better ordering and throughput (#2137)

* fix: improve message resend logic by adding checks for message IDs

* Revert "fix: improve message resend logic by adding checks for message IDs"

This reverts commit c03f9d8e6fc6cbfbb9d1f8f67c169700e704213d.

* fix: introduce separate mutexes for message, receipt, app state patch, and notification processing

* fix: remove unused processing mutex for notifications

src/Socket/chats.ts

@@ -72,8 +72,18 @@ export const makeChatsSocket = (config: SocketConfig) => {
 	let privacySettings: { [_: string]: string } | undefined
 
 	let syncState: SyncState = SyncState.Connecting
-	/** this mutex ensures that the notifications (receipts, messages etc.) are processed in order */
-	const processingMutex = makeMutex()
+
+	/** this mutex ensures that messages are processed in order */
+	const messageMutex = makeMutex()
+
+	/** this mutex ensures that receipts are processed in order */
+	const receiptMutex = makeMutex()
+
+	/** this mutex ensures that app state patches are processed in order */
+	const appStatePatchMutex = makeMutex()
+
+	/** this mutex ensures that notifications are processed in order */
+	const notificationMutex = makeMutex()
 
 	// Timeout for AwaitingInitialSync state
 	let awaitingSyncTimeout: NodeJS.Timeout | undefined
@@ -748,7 +758,7 @@ export const makeChatsSocket = (config: SocketConfig) => {
 		let initial: LTHashState
 		let encodeResult: { patch: proto.ISyncdPatch; state: LTHashState }
 
-		await processingMutex.mutex(async () => {
+		await appStatePatchMutex.mutex(async () => {
 			await authState.keys.transaction(async () => {
 				logger.debug({ patch: patchCreate }, 'applying app patch')
 
@@ -1180,7 +1190,10 @@ export const makeChatsSocket = (config: SocketConfig) => {
 		...sock,
 		createCallLink,
 		getBotListV2,
-		processingMutex,
+		messageMutex,
+		receiptMutex,
+		appStatePatchMutex,
+		notificationMutex,
 		fetchPrivacySettings,
 		upsertMessage,
 		appPatch,