Moved creation of RubyString inside generateString, this avoid to keep alive a reference to a 2GB Java String

andsel · andsel · commit b60ca787b0c7 · 2025-03-20T11:06:42.000+01:00
diff --git a/logstash-core/build.gradle b/logstash-core/build.gradle
@@ -124,7 +124,8 @@ tasks.register("javaTests", Test) {
     exclude '/org/logstash/plugins/factory/PluginFactoryExtTest.class'
     exclude '/org/logstash/execution/ObservedExecutionTest.class'
 
-    maxHeapSize = "12g"
+    maxHeapSize = "10g"
+    jvmArgs '-XX:+HeapDumpOnOutOfMemoryError'
 
     jacoco {
         enabled = true
diff --git a/logstash-core/src/test/java/org/logstash/common/BufferedTokenizerExtWithSizeLimitTest.java b/logstash-core/src/test/java/org/logstash/common/BufferedTokenizerExtWithSizeLimitTest.java
@@ -117,25 +117,25 @@ public void giveMultipleSegmentsThatGeneratesMultipleBufferFullErrorsThenIsAbleT
     @Test
     public void givenMaliciousInputExtractDoesntOverflow() {
         assertEquals("Xmx must equals to what's defined in the Gradle's javaTests task",
-                12L * GB, Runtime.getRuntime().maxMemory());
+                10L * GB, Runtime.getRuntime().maxMemory());
 
         // re-init the tokenizer with big sizeLimit
         initSUTWithSizeLimit((int) (2L * GB) - 3);
         // Integer.MAX_VALUE is 2 * GB
-        String bigFirstPiece = generateString("a", Integer.MAX_VALUE - 1024);
-        sut.extract(context, RubyUtil.RUBY.newString(bigFirstPiece));
+        RubyString bigFirstPiece = generateString("a", Integer.MAX_VALUE - 1024);
+        sut.extract(context, bigFirstPiece);
 
         // add another small fragment to trigger int overflow
         // sizeLimit is (2^32-1)-3 first segment length is (2^32-1) - 1024 second is 1024 +2
-        // so the combined length of first and second is > sizeLimit and should throw an expection
+        // so the combined length of first and second is > sizeLimit and should throw an exception
         // but because of overflow it's negative and happens to be < sizeLimit
         Exception thrownException = assertThrows(IllegalStateException.class, () -> {
-            sut.extract(context, RubyUtil.RUBY.newString(generateString("a", 1024 + 2)));
+            sut.extract(context, generateString("a", 1024 + 2));
         });
         assertThat(thrownException.getMessage(), containsString("input buffer full"));
     }
 
-    private String generateString(String fill, int size) {
-        return fill.repeat(size);
+    private RubyString generateString(String fill, int size) {
+        return RubyUtil.RUBY.newString(fill.repeat(size));
     }
 }
