From 85d104269f8df2cb44707b21ab69aecd5e5c5f86 Mon Sep 17 00:00:00 2001
From: Sven <skbotnl@disroot.org>
Date: Thu, 17 Sep 2026 23:25:12 +0200
Subject: [PATCH] Prevent deadlock in internalAddToPlayerShards by introducing
 internalGetShardTypeShards

---
 .../diamondbankog/api/DiamondBankAPIKotlin.kt     | 15 ++++++++++-----
 .../diamondbankog/persistence/PostgreSQL.kt       | 15 ++++++++++++---
 2 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/src/main/kotlin/net/trueog/diamondbankog/api/DiamondBankAPIKotlin.kt b/src/main/kotlin/net/trueog/diamondbankog/api/DiamondBankAPIKotlin.kt
index 0734508..3d77675 100644
--- a/src/main/kotlin/net/trueog/diamondbankog/api/DiamondBankAPIKotlin.kt
+++ b/src/main/kotlin/net/trueog/diamondbankog/api/DiamondBankAPIKotlin.kt
@@ -35,7 +35,8 @@ class DiamondBankAPIKotlin {
 
         return transactionLock.withLockSuspend(uuid) {
             val player = Bukkit.getPlayer(uuid) ?: Bukkit.getOfflinePlayer(uuid)
-            if (player !is Player && !player.hasPlayedBefore()) return@withLockSuspend Result.failure(InvalidPlayerException())
+            if (player !is Player && !player.hasPlayedBefore())
+                return@withLockSuspend Result.failure(InvalidPlayerException())
 
             balanceManager.addToBankShards(uuid, shards.toLong()).getOrElse {
                 handleError(it)
@@ -68,7 +69,8 @@ class DiamondBankAPIKotlin {
 
         return transactionLock.withLockSuspend(uuid) {
             val player = Bukkit.getPlayer(uuid) ?: Bukkit.getOfflinePlayer(uuid)
-            if (player !is Player && !player.hasPlayedBefore()) return@withLockSuspend Result.failure(InvalidPlayerException())
+            if (player !is Player && !player.hasPlayedBefore())
+                return@withLockSuspend Result.failure(InvalidPlayerException())
 
             balanceManager.subtractFromBankShards(uuid, shards.toLong()).getOrElse {
                 if (it is InsufficientBalanceException) return@withLockSuspend Result.failure(it)
@@ -161,7 +163,8 @@ class DiamondBankAPIKotlin {
 
         return transactionLock.withLockSuspend(uuid) {
             val player = Bukkit.getOfflinePlayer(uuid)
-            if (player !is Player && !player.hasPlayedBefore()) return@withLockSuspend Result.failure(InvalidPlayerException())
+            if (player !is Player && !player.hasPlayedBefore())
+                return@withLockSuspend Result.failure(InvalidPlayerException())
 
             player.uniqueId
                 .withInventoryLockSuspend {
@@ -220,10 +223,12 @@ class DiamondBankAPIKotlin {
 
         return transactionLock.withLockSuspend(senderUuid) {
             val sender = Bukkit.getPlayer(senderUuid) ?: Bukkit.getOfflinePlayer(senderUuid)
-            if (sender !is Player && !sender.hasPlayedBefore()) return@withLockSuspend Result.failure(InvalidPlayerException())
+            if (sender !is Player && !sender.hasPlayedBefore())
+                return@withLockSuspend Result.failure(InvalidPlayerException())
 
             val receiver = Bukkit.getPlayer(receiverUuid) ?: Bukkit.getOfflinePlayer(receiverUuid)
-            if (receiver !is Player && !receiver.hasPlayedBefore()) return@withLockSuspend Result.failure(InvalidPlayerException())
+            if (receiver !is Player && !receiver.hasPlayedBefore())
+                return@withLockSuspend Result.failure(InvalidPlayerException())
 
             sender.uniqueId
                 .withInventoryLockSuspend {
diff --git a/src/main/kotlin/net/trueog/diamondbankog/persistence/PostgreSQL.kt b/src/main/kotlin/net/trueog/diamondbankog/persistence/PostgreSQL.kt
index 13aa1d4..9c7c654 100644
--- a/src/main/kotlin/net/trueog/diamondbankog/persistence/PostgreSQL.kt
+++ b/src/main/kotlin/net/trueog/diamondbankog/persistence/PostgreSQL.kt
@@ -139,7 +139,7 @@ internal class PostgreSQL private constructor() {
                 .await()
 
         if (result.rows.isEmpty()) {
-            val shards = getShardTypeShards(uuid, type).getOrElse { throw it }
+            val shards = internalGetShardTypeShards(uuid, type, conn).getOrElse { throw it }
             throw InsufficientBalanceException(shards)
         }
         val row = result.rows[0]
@@ -271,12 +271,21 @@ internal class PostgreSQL private constructor() {
     }
 
     suspend fun getShardTypeShards(uuid: UUID, type: ShardType): Result<Long> {
-        var shards: Long?
         try {
             val connection = pool.asSuspending.connect()
 
+            return internalGetShardTypeShards(uuid, type, connection)
+        } catch (e: Exception) {
+            plugin.logger.severe(e.toString())
+            return Result.failure(DatabaseException(e.message ?: "Database exception"))
+        }
+    }
+
+    private suspend fun internalGetShardTypeShards(uuid: UUID, type: ShardType, conn: Connection): Result<Long> {
+        var shards: Long?
+        try {
             val result =
-                connection
+                conn
                     .inTransaction { conn ->
                         conn.sendPreparedStatement(
                             "SELECT ${type.string} FROM diamond WHERE uuid = ? LIMIT 1",