[Java] Restore the original behavior around the signal handling by no…

…t delegating to the previously registered handler. This effectively reverts the pull request that was raised to address the #270, because the approach in that PR broke the existing code that was using the `ShutdownSignalBarrier`.
real-logic · Jul 11, 2023 · e439036 · e439036
1 parent 068298b
commit e439036
Show file tree

Hide file tree

Showing 2 changed files with 6 additions and 33 deletions.
diff --git a/agrona/src/main/java/org/agrona/concurrent/SigInt.java b/agrona/src/main/java/org/agrona/concurrent/SigInt.java
@@ -17,7 +17,6 @@
 
 import org.agrona.LangUtil;
 import sun.misc.Signal;
-import sun.misc.SignalHandler;
 
 import java.util.Objects;
 
@@ -40,11 +39,8 @@ static void register(final String signalName, final Runnable task)
     {
         Objects.requireNonNull(task);
 
-        final Signal namedSignal = new Signal(signalName);
-        final SignalHandler previousHandler = Signal.handle(namedSignal, (signal) -> {});
-
         Signal.handle(
-            namedSignal,
+            new Signal(signalName),
             (signal) ->
             {
                 Throwable error = null;
@@ -57,25 +53,6 @@ static void register(final String signalName, final Runnable task)
                     error = t;
                 }
 
-                if (null != previousHandler)
-                {
-                    try
-                    {
-                        previousHandler.handle(signal);
-                    }
-                    catch (final Throwable t)
-                    {
-                        if (null != error)
-                        {
-                            error.addSuppressed(t);
-                        }
-                        else
-                        {
-                            error = t;
-                        }
-                    }
-                }
-
                 LangUtil.rethrowUnchecked(error);
             });
     }

diff --git a/agrona/src/test/java/org/agrona/concurrent/SigIntTest.java b/agrona/src/test/java/org/agrona/concurrent/SigIntTest.java
@@ -25,7 +25,7 @@
 
 import java.util.concurrent.CountDownLatch;
 
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertThrowsExactly;
 import static org.mockito.Mockito.*;
 
 class SigIntTest
@@ -38,7 +38,7 @@ void throwsNullPointerExceptionIfRunnableIsNull()
 
     @ParameterizedTest
     @ValueSource(strings = { "INT", "TERM" })
-    void shouldInstallHandlerThatWillDelegateToTheExistingHandler(final String name) throws InterruptedException
+    void shouldReplaceExistingSignalHandler(final String name) throws InterruptedException
     {
         final Thread.UncaughtExceptionHandler defaultUncaughtExceptionHandler =
             Thread.getDefaultUncaughtExceptionHandler();
@@ -55,9 +55,8 @@ void shouldInstallHandlerThatWillDelegateToTheExistingHandler(final String name)
                 return null;
             }).when(exceptionHandler).uncaughtException(any(), any());
             Thread.setDefaultUncaughtExceptionHandler(exceptionHandler);
+
             final SignalHandler oldHandler = mock(SignalHandler.class);
-            final NumberFormatException secondException = new NumberFormatException("NaN");
-            doThrow(secondException).when(oldHandler).handle(signal);
             Signal.handle(signal, oldHandler);
 
             final Runnable newHandler = mock(Runnable.class);
@@ -70,15 +69,12 @@ void shouldInstallHandlerThatWillDelegateToTheExistingHandler(final String name)
 
             executed.await();
 
-            final InOrder inOrder = inOrder(newHandler, oldHandler, exceptionHandler);
+            final InOrder inOrder = inOrder(newHandler, exceptionHandler);
             inOrder.verify(newHandler).run();
-            inOrder.verify(oldHandler).handle(signal);
             inOrder.verify(exceptionHandler).uncaughtException(any(), eq(firstException));
             inOrder.verifyNoMoreInteractions();
 
-            final Throwable[] suppressed = firstException.getSuppressed();
-            assertEquals(1, suppressed.length);
-            assertSame(secondException, suppressed[0]);
+            verifyNoInteractions(oldHandler);
         }
         finally
         {