From a45d1e0d079665088afe89a5b9c1d54a6a8203a1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Hohwiller?= <hohwille@users.noreply.github.com>
Date: Tue, 10 Mar 2020 09:28:02 +0100
Subject: [PATCH] Support for Thread.UncaughtExceptionHandler (#483)

---
 .../TDefaultUncaughtExceptionHandler.java     | 29 +++++++++++++++++++
 .../org/teavm/classlib/java/lang/TThread.java | 27 +++++++++++++++++
 2 files changed, 56 insertions(+)
 create mode 100644 classlib/src/main/java/org/teavm/classlib/java/lang/TDefaultUncaughtExceptionHandler.java

diff --git a/classlib/src/main/java/org/teavm/classlib/java/lang/TDefaultUncaughtExceptionHandler.java b/classlib/src/main/java/org/teavm/classlib/java/lang/TDefaultUncaughtExceptionHandler.java
new file mode 100644
index 000000000..e0e2d7c7f
--- /dev/null
+++ b/classlib/src/main/java/org/teavm/classlib/java/lang/TDefaultUncaughtExceptionHandler.java
@@ -0,0 +1,29 @@
+/*
+ *  Copyright 2020 by Joerg Hohwiller
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.classlib.java.lang;
+
+import org.teavm.classlib.java.lang.TThread.UncaughtExceptionHandler;
+
+public class TDefaultUncaughtExceptionHandler implements UncaughtExceptionHandler {
+
+    @Override
+    public void uncaughtException(TThread t, Throwable e) {
+
+        // print to browser console by default
+        e.printStackTrace();
+    }
+
+}
diff --git a/classlib/src/main/java/org/teavm/classlib/java/lang/TThread.java b/classlib/src/main/java/org/teavm/classlib/java/lang/TThread.java
index 25a9f6222..3a9545f56 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/lang/TThread.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/lang/TThread.java
@@ -28,6 +28,8 @@ public class TThread extends TObject implements TRunnable {
     private static TThread currentThread = mainThread;
     private static int nextId = 1;
     private static int activeCount = 1;
+    private static UncaughtExceptionHandler defaultUncaughtExceptionHandler = new TDefaultUncaughtExceptionHandler();
+    private UncaughtExceptionHandler uncaughtExceptionHandler;
     private long id;
     private int priority;
     private boolean daemon;
@@ -76,6 +78,8 @@ public class TThread extends TObject implements TRunnable {
             activeCount++;
             setCurrentThread(TThread.this);
             TThread.this.run();
+        } catch (Throwable t) {
+            getUncaughtExceptionHandler().uncaughtException(this, t);
         } finally {
             synchronized (finishedLock) {
                 finishedLock.notifyAll();
@@ -269,4 +273,27 @@ public class TThread extends TObject implements TRunnable {
     public TClassLoader getContextClassLoader() {
         return TClassLoader.getSystemClassLoader();
     }
+    
+    public UncaughtExceptionHandler getUncaughtExceptionHandler() {
+        if (this.uncaughtExceptionHandler != null) {
+            return this.uncaughtExceptionHandler;
+        }
+        return defaultUncaughtExceptionHandler;
+    }
+    
+    public void setUncaughtExceptionHandler(UncaughtExceptionHandler uncaughtExceptionHandler) {
+        this.uncaughtExceptionHandler = uncaughtExceptionHandler;
+    }
+    
+    public static UncaughtExceptionHandler getDefaultUncaughtExceptionHandler() {
+        return defaultUncaughtExceptionHandler;
+    }
+    
+    public static void setDefaultUncaughtExceptionHandler(UncaughtExceptionHandler handler) {
+        defaultUncaughtExceptionHandler = handler;
+    }
+    
+    public interface UncaughtExceptionHandler {
+        void uncaughtException(TThread t, Throwable e);
+    }
 }