7903019: jcstress: Very long exceptions break the VM data streams

Author: shipilev

jcstress-core/src/main/java/org/openjdk/jcstress/ForkedMain.java

@@ -80,10 +80,10 @@ public static void main(String[] args) throws Exception {
             forceExit = o.forceExit();
         } catch (ClassFormatError | NoClassDefFoundError | NoSuchMethodError | NoSuchFieldError e) {
             result = new TestResult(Status.API_MISMATCH);
-            result.addMessage(StringUtils.getStacktrace(e));
+            result.addMessages(e);
         } catch (Throwable ex) {
             result = new TestResult(Status.TEST_ERROR);
-            result.addMessage(StringUtils.getStacktrace(ex));
+            result.addMessages(ex);
         }
 
         if (forceExit) {

jcstress-core/src/main/java/org/openjdk/jcstress/TestExecutor.java

@@ -477,7 +477,7 @@ public synchronized void finish(TestResultCollector sink) {
             // There is a pending exception that terminated the target VM.
             if (pendingException != null) {
                 result = new TestResult(Status.VM_ERROR);
-                result.addMessage(pendingException.getMessage());
+                result.addMessages(pendingException);
                 result.setConfig(task);
                 sink.add(result);
                 return;
@@ -501,7 +501,7 @@ public synchronized void finish(TestResultCollector sink) {
                 sink.add(result);
             } catch (InterruptedException | ExecutionException ex) {
                 result = new TestResult(Status.VM_ERROR);
-                result.addMessage(ex.getMessage());
+                result.addMessages(ex);
                 result.setConfig(task);
                 sink.add(result);
             } finally {

jcstress-core/src/main/java/org/openjdk/jcstress/infra/collectors/TestResult.java

@@ -30,6 +30,7 @@
 import org.openjdk.jcstress.infra.runners.TestConfig;
 import org.openjdk.jcstress.util.Counter;
 import org.openjdk.jcstress.util.Environment;
+import org.openjdk.jcstress.util.StringUtils;
 
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
@@ -117,31 +118,27 @@ public void addMessage(String msg) {
         messages.add(msg);
     }
 
+    public void addMessages(Throwable throwable) {
+        addMessages(StringUtils.getStacktrace(throwable));
+    }
+
     public void addMessages(Collection<String> msgs) {
         for (String m : msgs) {
             addMessage(m);
         }
     }
 
-    public void addVMOut(String msg) {
-        if (ReportUtils.skipMessage(msg)) return;
-        vmOut.add(msg);
-    }
-
     public void addVMOuts(Collection<String> msgs) {
         for (String m : msgs) {
-            addVMOut(m);
+            if (ReportUtils.skipMessage(m)) continue;
+            vmOut.add(m);
         }
     }
 
-    public void addVMErr(String msg) {
-        if (ReportUtils.skipMessage(msg)) return;
-        vmErr.add(msg);
-    }
-
     public void addVMErrs(Collection<String> msgs) {
         for (String m : msgs) {
-            addVMErr(m);
+            if (ReportUtils.skipMessage(m)) continue;
+            vmErr.add(m);
         }
     }
 

jcstress-core/src/main/java/org/openjdk/jcstress/infra/runners/Runner.java

@@ -114,7 +114,7 @@ protected TestResult dumpFailure(Status status, String message) {
     protected TestResult dumpFailure(Status status, String message, Throwable aux) {
         TestResult r = new TestResult(status);
         r.addMessage(message);
-        r.addMessage(StringUtils.getStacktrace(aux));
+        r.addMessages(aux);
         return r;
     }
 

jcstress-core/src/main/java/org/openjdk/jcstress/util/StringUtils.java

@@ -27,6 +27,7 @@
 import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 
@@ -117,20 +118,12 @@ public static String join(int[] list, String delim) {
         return sb.toString();
     }
 
-    public static String getStacktrace(Throwable throwable) {
+    public static List<String> getStacktrace(Throwable throwable) {
         StringWriter sw = new StringWriter();
         PrintWriter pw = new PrintWriter(sw);
         throwable.printStackTrace(pw);
         pw.close();
-        return sw.toString();
-    }
-
-    public static String getFirstLine(String src) {
-        int endLine = src.indexOf("\n");
-        if (endLine > 0) {
-            return src.substring(0, endLine).trim();
-        }
-        return src;
+        return Arrays.asList(sw.toString().split(System.lineSeparator()));
     }
 
     static final String[] PADS;

jcstress-core/src/test/java/org/openjdk/jcstress/util/StringUtilsTest.java

@@ -28,6 +28,7 @@
 import org.junit.Test;
 
 import java.util.Arrays;
+import java.util.List;
 
 public class StringUtilsTest {
 
@@ -43,16 +44,10 @@ public void test() {
 
     @Test
     public void testGetStacktrace() {
-        String actual = StringUtils.getStacktrace(new NullPointerException("my message"));
-        String firstLine = StringUtils.getFirstLine(actual);
+        List<String> actual = StringUtils.getStacktrace(new NullPointerException("my message"));
+        String firstLine = actual.get(0);
 
-        Assert.assertEquals("java.lang.NullPointerException: my message", firstLine);
-    }
-
-    @Test
-    public void testGetFirstLine() {
-        Assert.assertEquals("First line", StringUtils.getFirstLine("First line"));
-        Assert.assertEquals("First line", StringUtils.getFirstLine("First line\nsecond line"));
+        Assert.assertTrue(firstLine, firstLine.startsWith("java.lang.NullPointerException: my message"));
     }
 
     @Test