fix: eliminate race condition when updating BlockchainState that resu…

…lts in "Syncing..." for a long time
dashpay · Dec 16, 2023 · ec08533 · ec08533
1 parent 3b0d1ea
commit ec08533
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Showing 2 changed files with 12 additions and 20 deletions.
diff --git a/wallet/src/de/schildbach/wallet/service/BlockchainServiceImpl.java b/wallet/src/de/schildbach/wallet/service/BlockchainServiceImpl.java
@@ -501,6 +501,7 @@ public void run() {
         protected void progress(double pct, int blocksLeft, Date date) {
             super.progress(pct, blocksLeft, date);
             syncPercentage = pct > 0.0 ? (int)pct : 0;
+            log.info("progress {}", syncPercentage);
             if (syncPercentage > 100) {
                 syncPercentage = 100;
             }
@@ -513,9 +514,11 @@ protected void progress(double pct, int blocksLeft, Date date) {
         @Override
         protected void doneDownload() {
             super.doneDownload();
-            updateBlockchainState();
+            log.info("DoneDownload {}", syncPercentage);
+            // if the chain is already synced from a previous session, then syncPercentage = 0
+            // set to 100% so that observers will see that sync is completed
             syncPercentage = 100;
-            setBlockchainDownloaded();
+            updateBlockchainState();
         }
 
         @Override
@@ -1169,10 +1172,6 @@ private void updateBlockchainState() {
         blockchainStateDataProvider.updateBlockchainState(blockChain, impediments, percentageSync());
     }
 
-    public void setBlockchainDownloaded() {
-        blockchainStateDataProvider.setBlockchainDownloaded();
-    }
-
     @Override
     public List<Peer> getConnectedPeers() {
         if (peerGroup != null)

diff --git a/wallet/src/de/schildbach/wallet/service/BlockchainStateDataProvider.kt b/wallet/src/de/schildbach/wallet/service/BlockchainStateDataProvider.kt
@@ -23,7 +23,7 @@ import dagger.hilt.android.qualifiers.ApplicationContext
 import de.schildbach.wallet.Constants
 import de.schildbach.wallet.database.dao.BlockchainStateDao
 import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.asCoroutineDispatcher
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.launch
@@ -39,10 +39,12 @@ import org.dash.wallet.common.WalletDataProvider
 import org.dash.wallet.common.data.entity.BlockchainState
 import org.dash.wallet.common.data.entity.BlockchainState.Impediment
 import org.dash.wallet.common.services.BlockchainStateProvider
+import org.slf4j.LoggerFactory
 import java.io.IOException
 import java.io.InputStream
 import java.math.BigInteger
 import java.util.EnumSet
+import java.util.concurrent.Executors
 import javax.inject.Inject
 import kotlin.math.min
 
@@ -74,7 +76,8 @@ class BlockchainStateDataProvider @Inject constructor(
         const val MASTERNODE_COUNT = 3800
     }
 
-    private val coroutineScope = CoroutineScope(Dispatchers.IO)
+    // this coroutineScope should execute all jobs sequentially
+    private val coroutineScope = CoroutineScope(Executors.newSingleThreadExecutor().asCoroutineDispatcher())
 
     override suspend fun getState(): BlockchainState? {
         return blockchainStateDao.getState()
@@ -95,8 +98,8 @@ class BlockchainStateDataProvider @Inject constructor(
         }
     }
 
-     fun updateBlockchainState(blockChain: BlockChain, impediments: Set<Impediment>, percentageSync: Int) {
-         coroutineScope.launch {
+    fun updateBlockchainState(blockChain: BlockChain, impediments: Set<Impediment>, percentageSync: Int) {
+        coroutineScope.launch {
             var blockchainState = blockchainStateDao.getState()
             if (blockchainState == null) {
                 blockchainState = BlockchainState()
@@ -115,16 +118,6 @@ class BlockchainStateDataProvider @Inject constructor(
         }
     }
 
-    fun setBlockchainDownloaded() {
-        coroutineScope.launch {
-            val blockchainState = blockchainStateDao.getState()
-            if (blockchainState != null && blockchainState.percentageSync != 100) {
-                blockchainState.percentageSync = 100
-                blockchainStateDao.saveState(blockchainState)
-            }
-        }
-    }
-
     fun resetBlockchainState() {
         coroutineScope.launch {
             blockchainStateDao.saveState(