From de59aa099d9bee8350c74d8264fb610afa4b238b Mon Sep 17 00:00:00 2001
From: Chris Eager <chris@signal.org>
Date: Wed, 11 Aug 2021 18:04:24 -0500
Subject: [PATCH] Add uncaught exception handler

---
 .../textsecuregcm/WhisperServerService.java   |  5 +++-
 .../logging/UncaughtExceptionHandler.java     | 27 +++++++++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100644 service/src/main/java/org/whispersystems/textsecuregcm/util/logging/UncaughtExceptionHandler.java

diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java b/service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java
index d2a5be3f5..b47e2d5ca 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java
@@ -66,8 +66,8 @@ import org.whispersystems.dispatch.DispatchManager;
 import org.whispersystems.textsecuregcm.auth.AccountAuthenticator;
 import org.whispersystems.textsecuregcm.auth.AuthenticatedAccount;
 import org.whispersystems.textsecuregcm.auth.CertificateGenerator;
-import org.whispersystems.textsecuregcm.auth.DisabledPermittedAuthenticatedAccount;
 import org.whispersystems.textsecuregcm.auth.DisabledPermittedAccountAuthenticator;
+import org.whispersystems.textsecuregcm.auth.DisabledPermittedAuthenticatedAccount;
 import org.whispersystems.textsecuregcm.auth.ExternalServiceCredentialGenerator;
 import org.whispersystems.textsecuregcm.auth.TurnTokenGenerator;
 import org.whispersystems.textsecuregcm.configuration.DirectoryServerConfiguration;
@@ -194,6 +194,7 @@ import org.whispersystems.textsecuregcm.util.DynamoDbFromConfig;
 import org.whispersystems.textsecuregcm.util.HostnameUtil;
 import org.whispersystems.textsecuregcm.util.TorExitNodeManager;
 import org.whispersystems.textsecuregcm.util.logging.LoggingUnhandledExceptionMapper;
+import org.whispersystems.textsecuregcm.util.logging.UncaughtExceptionHandler;
 import org.whispersystems.textsecuregcm.websocket.AuthenticatedConnectListener;
 import org.whispersystems.textsecuregcm.websocket.DeadLetterHandler;
 import org.whispersystems.textsecuregcm.websocket.ProvisioningConnectListener;
@@ -253,6 +254,8 @@ public class WhisperServerService extends Application<WhisperServerConfiguration
   public void run(WhisperServerConfiguration config, Environment environment)
       throws Exception {
 
+    UncaughtExceptionHandler.register();
+
     SharedMetricRegistries.add(Constants.METRICS_NAME, environment.metrics());
 
     final DistributionStatisticConfig defaultDistributionStatisticConfig = DistributionStatisticConfig.builder()
diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/util/logging/UncaughtExceptionHandler.java b/service/src/main/java/org/whispersystems/textsecuregcm/util/logging/UncaughtExceptionHandler.java
new file mode 100644
index 000000000..35409fb05
--- /dev/null
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/util/logging/UncaughtExceptionHandler.java
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2021 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.whispersystems.textsecuregcm.util.logging;
+
+import javax.annotation.Nullable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class UncaughtExceptionHandler {
+
+  private static final Logger logger = LoggerFactory.getLogger(UncaughtExceptionHandler.class);
+
+  public static void register() {
+    @Nullable final Thread.UncaughtExceptionHandler current = Thread.getDefaultUncaughtExceptionHandler();
+
+    if (current != null) {
+      logger.warn("Uncaught exception handler already exists: {}", current);
+      return;
+    }
+
+    Thread.setDefaultUncaughtExceptionHandler((t, e) -> logger.error("Uncaught exception on thread {}", t, e));
+  }
+
+}