Open-source the JUnit test runner.

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MOS_MIGRATED_REVID=112027454

1 files changed, 81 insertions, 0 deletions

diff --git a/src/java_tools/junitrunner/java/com/google/testing/junit/runner/internal/SignalHandlers.java b/src/java_tools/junitrunner/java/com/google/testing/junit/runner/internal/SignalHandlers.java
new file mode 100644
index 0000000000..c1573d5a78
--- /dev/null
+++ b/src/java_tools/junitrunner/java/com/google/testing/junit/runner/internal/SignalHandlers.java
@@ -0,0 +1,81 @@
+// Copyright 2010 The Bazel Authors. All Rights Reserved.
+//
+// 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 com.google.testing.junit.runner.internal;
+
+import com.google.inject.Inject;
+
+import sun.misc.Signal;
+import sun.misc.SignalHandler;
+
+import java.util.concurrent.atomic.AtomicReference;
+
+/**
+ * Helper class to install signal handlers.
+ */
+public class SignalHandlers {
+  private final HandlerInstaller handlerInstaller;
+
+  /**
+   * Creates a handler installer that installs signal handlers.
+   */
+  public static HandlerInstaller createRealHandlerInstaller() {
+    return new HandlerInstaller() {
+      @Override
+      public SignalHandler install(Signal signal, SignalHandler handler) {
+        return Signal.handle(signal, handler);
+      }
+    };
+  }
+
+  @Inject
+  public SignalHandlers(HandlerInstaller installer) {
+    this.handlerInstaller = installer;
+  }
+
+  /**
+   * Adds the given signal handler to the existing ones.
+   *
+   * <p>Signal handlers are responsible to catch any exception if the following
+   * handlers need to be executed when a handler throws an exception.
+   *
+   * @param signal The signal to handle.
+   * @param signalHandler The handler to install.
+   */
+  public void installHandler(Signal signal, final SignalHandler signalHandler) {
+    final AtomicReference<SignalHandler> previousHandlerReference =
+        new AtomicReference<>();
+    previousHandlerReference.set(handlerInstaller.install(signal, new SignalHandler() {
+      @Override
+      public void handle(Signal signal) {
+        signalHandler.handle(signal);
+        SignalHandler previousHandler = previousHandlerReference.get();
+        if (previousHandler != null) {
+          previousHandler.handle(signal);
+        }
+      }
+    }));
+  }
+
+  /**
+   * Wraps sun.misc.Signal#handle(sun.misc.Signal, sun.misc.SignalHandler)
+   * to help with testing.
+   */
+  public interface HandlerInstaller {
+    /**
+     * @see sun.misc.Signal#handle(sun.misc.Signal, sun.misc.SignalHandler)     
+     */
+    SignalHandler install(Signal signal, SignalHandler handler);
+  }
+}