Fix tor access (#1591)

* Support closure on TorClientHolder + Add TorClient accessMutex * Reset after dispose * Check nativeHandle * Changelog update
Electric-Coin-Company · Sep 16, 2024 · e63df56 · e63df56
1 parent 7398cbc
commit e63df56
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Showing 3 changed files with 22 additions and 10 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -6,7 +6,7 @@ and this library adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-## [2.2.4] - 2024-09-12
+## [2.2.4] - 2024-09-16
 
 ### Added
 - `TransactionOverview.isShielding` has been added to indicate the shielding transaction type
@@ -18,6 +18,7 @@ and this library adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 - Android 15 (SDK level 35) support added for 16 KB memory page size
+- The disposing logic of `TorClient` (the USD/ZEC rate fetching component) has been improved
 
 ## [2.2.3] - 2024-09-09
 

diff --git a/backend-lib/src/main/java/cash/z/ecc/android/sdk/internal/model/TorClient.kt b/backend-lib/src/main/java/cash/z/ecc/android/sdk/internal/model/TorClient.kt
@@ -5,21 +5,31 @@ import cash.z.ecc.android.sdk.internal.ext.mkdirsSuspend
 import cash.z.ecc.android.sdk.internal.jni.RustBackend
 import dalvik.annotation.optimization.CriticalNative
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
 import kotlinx.coroutines.withContext
 import java.io.File
 import java.math.BigDecimal
 
 class TorClient private constructor(
-    private val nativeHandle: Long?,
+    private var nativeHandle: Long?,
 ) {
+    private val accessMutex = Mutex()
+
     suspend fun dispose() =
-        withContext(Dispatchers.IO) {
-            nativeHandle?.let { freeTorRuntime(it) }
+        accessMutex.withLock {
+            withContext(Dispatchers.IO) {
+                nativeHandle?.let { freeTorRuntime(it) }
+                nativeHandle = null
+            }
         }
 
     suspend fun getExchangeRateUsd(): BigDecimal =
-        withContext(Dispatchers.IO) {
-            getExchangeRateUsd(nativeHandle!!)
+        accessMutex.withLock {
+            withContext(Dispatchers.IO) {
+                checkNotNull(nativeHandle) { "TorClient is disposed" }
+                getExchangeRateUsd(nativeHandle!!)
+            }
         }
 
     companion object {
@@ -33,7 +43,7 @@ class TorClient private constructor(
                     error("${torDir.path} directory does not exist and could not be created.")
                 }
 
-                TorClient(createTorRuntime(torDir.path))
+                TorClient(nativeHandle = createTorRuntime(torDir.path))
             }
 
         //

diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/exchange/UsdExchangeRateFetcher.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/exchange/UsdExchangeRateFetcher.kt
@@ -19,7 +19,7 @@ internal class UsdExchangeRateFetcher(torDir: File) {
             val rate =
                 try {
                     Twig.info { "[USD] Fetch start" }
-                    torHolder().getExchangeRateUsd()
+                    torHolder { it.getExchangeRateUsd() }
                 } catch (e: Exception) {
                     Twig.error(e) { "[USD] Fetch failed" }
                     return FetchFiatCurrencyResult.Error(e)
@@ -69,16 +69,17 @@ private class TorClientHolder(private val torDir: File) {
     private val mutex = Mutex()
     private var torClient: TorClient? = null
 
-    suspend operator fun invoke(): TorClient =
+    suspend operator fun <T> invoke(block: suspend (TorClient) -> T): T =
         mutex.withLock {
             if (torClient == null) {
                 torClient = TorClient.new(torDir)
             }
-            return torClient!!
+            return block(torClient!!)
         }
 
     suspend fun dispose() =
         mutex.withLock {
             torClient?.dispose()
+            torClient = null
         }
 }