From aee939a887974495b3fc841d9a1fb81f9ed38435 Mon Sep 17 00:00:00 2001
From: ghubstan <36207203+ghubstan@users.noreply.github.com>
Date: Sat, 25 Jun 2022 14:11:06 -0300
Subject: [PATCH] Make GrpcStubs channel closeable by calling bot

Each bot has its own gRPC channel and set of service stubs,
and a single bot's channel & stubs last the bot's lifetime.
However, RegtestTradePaymentSimulator instance is a bot too, with it's
own channel & stubs, which should be closed at the end of each run().
---
 .../src/main/java/bisq/bots/GrpcStubs.java    | 27 ++++++++++++-------
 .../bots/RegtestTradePaymentSimulator.java    |  2 ++
 2 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/java-examples/src/main/java/bisq/bots/GrpcStubs.java b/java-examples/src/main/java/bisq/bots/GrpcStubs.java
index c6ed9fb..2f6d101 100644
--- a/java-examples/src/main/java/bisq/bots/GrpcStubs.java
+++ b/java-examples/src/main/java/bisq/bots/GrpcStubs.java
@@ -19,6 +19,7 @@ package bisq.bots;
 
 import bisq.proto.grpc.*;
 import io.grpc.CallCredentials;
+import io.grpc.ManagedChannel;
 import io.grpc.ManagedChannelBuilder;
 import lombok.extern.slf4j.Slf4j;
 
@@ -40,19 +41,13 @@ final class GrpcStubs {
     public final TradesGrpc.TradesBlockingStub tradesService;
     public final WalletsGrpc.WalletsBlockingStub walletsService;
 
+    private final ManagedChannel channel;
+
     public GrpcStubs(String apiHost, int apiPort, String apiPassword) {
         CallCredentials credentials = new PasswordCallCredentials(apiPassword);
 
-        var channel = ManagedChannelBuilder.forAddress(apiHost, apiPort).usePlaintext().build();
-        Runtime.getRuntime().addShutdownHook(new Thread(() -> {
-            try {
-                log.info("Shutting down bot's grpc channel.");
-                channel.shutdown().awaitTermination(1, SECONDS);
-                log.info("Bot channel shutdown complete.");
-            } catch (InterruptedException ex) {
-                throw new IllegalStateException(ex);
-            }
-        }));
+        this.channel = ManagedChannelBuilder.forAddress(apiHost, apiPort).usePlaintext().build();
+        Runtime.getRuntime().addShutdownHook(new Thread(this::close));
 
         this.disputeAgentsService = DisputeAgentsGrpc.newBlockingStub(channel).withCallCredentials(credentials);
         this.helpService = HelpGrpc.newBlockingStub(channel).withCallCredentials(credentials);
@@ -64,4 +59,16 @@ final class GrpcStubs {
         this.tradesService = TradesGrpc.newBlockingStub(channel).withCallCredentials(credentials);
         this.walletsService = WalletsGrpc.newBlockingStub(channel).withCallCredentials(credentials);
     }
+
+    public void close() {
+        try {
+            if (!channel.isShutdown()) {
+                log.info("Shutting down bot's grpc channel.");
+                channel.shutdown().awaitTermination(1, SECONDS);
+                log.info("Bot channel shutdown complete.");
+            }
+        } catch (InterruptedException ex) {
+            throw new IllegalStateException(ex);
+        }
+    }
 }
diff --git a/java-examples/src/main/java/bisq/bots/RegtestTradePaymentSimulator.java b/java-examples/src/main/java/bisq/bots/RegtestTradePaymentSimulator.java
index 3bac466..7d2d8c8 100644
--- a/java-examples/src/main/java/bisq/bots/RegtestTradePaymentSimulator.java
+++ b/java-examples/src/main/java/bisq/bots/RegtestTradePaymentSimulator.java
@@ -116,6 +116,8 @@ public class RegtestTradePaymentSimulator extends AbstractBot {
         sleep(pollingInterval);
         log.info("Trade is completed, printing all closed trades and exiting {}.", this.getClass().getSimpleName());
         printTradesSummary(CLOSED);
+        log.info("Closing {}'s gRPC channel.", this.getClass().getSimpleName());
+        super.grpcStubs.close();
     }
 
     private void waitForTakerDepositTxConfirmation() {