wallets: Fix bitcoind deadlock

We parse stdout and wait for the "init message: Done loading" line to
detect when bitcoind is ready. After seeing this line, we stop reading
stdout causing the stdout buffer to fill up. When the stdout buffer
fills up, bitcoind waits until its parent process reads from it but this
unfortunately never happens leading to a deadlock.

wallets/process/src/main/java/bisq/wallets/process/DaemonProcess.java

@@ -25,6 +25,7 @@
 
 import java.io.IOException;
 import java.nio.file.Path;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -60,7 +61,7 @@ public void shutdown() {
         invokeStopRpcCall();
     }
 
-    private void waitUntilReady() {
+    protected void waitUntilReady() {
         FutureTask<Boolean> waitingFuture = new FutureTask<>(this::waitUntilLogContainsLines);
         Thread waitingThread = new Thread(waitingFuture);
         waitingThread.start();
@@ -79,7 +80,9 @@ private void waitUntilReady() {
         }
     }
 
-    protected abstract Set<String> getIsSuccessfulStartUpLogLines();
+    protected Set<String> getIsSuccessfulStartUpLogLines() {
+        return Collections.emptySet();
+    }
 
     public abstract void invokeStopRpcCall();
 
@@ -89,6 +92,7 @@ private Process createAndStartProcess() throws IOException {
 
         var processBuilder = new ProcessBuilder(args);
         processBuilder.redirectErrorStream(true);
+        processBuilder.redirectOutput(ProcessBuilder.Redirect.DISCARD);
 
         Map<String, String> environment = processBuilder.environment();
         environment.putAll(processConfig.getEnvironmentVars());
@@ -99,7 +103,9 @@ private Process createAndStartProcess() throws IOException {
 
     public abstract ProcessConfig createProcessConfig();
 
-    protected abstract LogScanner getLogScanner();
+    protected LogScanner getLogScanner() {
+        return null;
+    }
 
     protected boolean waitUntilLogContainsLines() {
         try {

wallets/regtest/src/main/java/bisq/wallets/regtest/bitcoind/BitcoindRegtestProcess.java

@@ -17,8 +17,6 @@
 
 package bisq.wallets.regtest.bitcoind;
 
-import bisq.common.file.InputStreamScanner;
-import bisq.common.file.LogScanner;
 import bisq.common.util.NetworkUtils;
 import bisq.wallets.bitcoind.rpc.BitcoindDaemon;
 import bisq.wallets.json_rpc.JsonRpcClient;
@@ -30,20 +28,25 @@
 import lombok.Getter;
 import lombok.extern.slf4j.Slf4j;
 
+import java.net.ConnectException;
 import java.nio.file.Path;
+import java.time.Instant;
+import java.time.temporal.ChronoUnit;
 import java.util.Collections;
 import java.util.List;
-import java.util.Set;
 
 @Slf4j
 public class BitcoindRegtestProcess extends DaemonProcess {
 
     @Getter
     protected final RpcConfig rpcConfig;
+    private final BitcoindDaemon bitcoindDaemon;
 
     public BitcoindRegtestProcess(RpcConfig rpcConfig, Path dataDir) {
         super(dataDir);
         this.rpcConfig = rpcConfig;
+        JsonRpcClient rpcClient = RpcClientFactory.createDaemonRpcClient(rpcConfig);
+        bitcoindDaemon = new BitcoindDaemon(rpcClient);
     }
 
     @Override
@@ -74,16 +77,39 @@ public ProcessConfig createProcessConfig() {
     }
 
     @Override
-    protected LogScanner getLogScanner() {
-        return new InputStreamScanner(
-                getIsSuccessfulStartUpLogLines(),
-                process.getInputStream()
-        );
+    protected void waitUntilReady() {
+        Instant timeoutInstant = Instant.now().plus(2, ChronoUnit.MINUTES);
+        int failedAttempts = 0;
+        while (true) {
+            try {
+                bitcoindDaemon.listWallets();
+                log.info("Connected to Bitcoin Core.");
+                break;
+            } catch (RpcCallFailureException e) {
+                if (e.getCause() instanceof ConnectException) {
+                    if (isAfterTimeout(timeoutInstant)) {
+                        throw new IllegalStateException("Bitcoin Core isn't ready after 2 minutes. Giving up.");
+                    }
+
+                    failedAttempts++;
+                    double msToWait = Math.min(300 * failedAttempts, 10_000);
+                    log.info("Bitcoind RPC isn't ready yet. Trying again in {}ms.", msToWait);
+                    sleepForMs(msToWait);
+                }
+            }
+        }
     }
 
-    @Override
-    protected Set<String> getIsSuccessfulStartUpLogLines() {
-        return Set.of("init message: Done loading");
+    private boolean isAfterTimeout(Instant timeoutInstant) {
+        return Instant.now().isAfter(timeoutInstant);
+    }
+
+    private void sleepForMs(double ms) {
+        try {
+            Thread.sleep((long) ms);
+        } catch (InterruptedException ex) {
+            throw new RuntimeException(ex);
+        }
     }
 
     @Override