8010463: G1: Crashes with -UseTLAB and heap verification

Summary: Some parts of the G1 heap can only be walked during a safepoint. Skip verifying these parts of the heap when verifying during JVM startup.
Reviewed-by: brutisso, tschatzl

src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp

@@ -3288,12 +3288,12 @@ void G1CollectedHeap::verify(bool silent) {
 
 void G1CollectedHeap::verify(bool silent,
                              VerifyOption vo) {
-  if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) {
+  if (SafepointSynchronize::is_at_safepoint()) {
     if (!silent) { gclog_or_tty->print("Roots "); }
     VerifyRootsClosure rootsCl(vo);
 
     assert(Thread::current()->is_VM_thread(),
-      "Expected to be executed serially by the VM thread at this point");
+           "Expected to be executed serially by the VM thread at this point");
 
     CodeBlobToOopClosure blobsCl(&rootsCl, /*do_marking=*/ false);
     VerifyKlassClosure klassCl(this, &rootsCl);
@@ -3378,7 +3378,8 @@ void G1CollectedHeap::verify(bool silent,
     }
     guarantee(!failures, "there should not have been any failures");
   } else {
-    if (!silent) gclog_or_tty->print("(SKIPPING roots, heapRegions, remset) ");
+    if (!silent)
+      gclog_or_tty->print("(SKIPPING roots, heapRegionSets, heapRegions, remset) ");
   }
 }
 

src/share/vm/memory/universe.cpp

@@ -953,15 +953,6 @@ void Universe::update_heap_info_at_gc() {
 void universe2_init() {
   EXCEPTION_MARK;
   Universe::genesis(CATCH);
-  // Although we'd like to verify here that the state of the heap
-  // is good, we can't because the main thread has not yet added
-  // itself to the threads list (so, using current interfaces
-  // we can't "fill" its TLAB), unless TLABs are disabled.
-  if (VerifyBeforeGC && !UseTLAB &&
-      Universe::heap()->total_collections() >= VerifyGCStartAt) {
-     Universe::heap()->prepare_for_verify();
-     Universe::verify();   // make sure we're starting with a clean slate
-  }
 }
 
 

src/share/vm/runtime/init.cpp

@@ -132,15 +132,6 @@ jint init_globals() {
   javaClasses_init();   // must happen after vtable initialization
   stubRoutines_init2(); // note: StubRoutines need 2-phase init
 
-  // Although we'd like to, we can't easily do a heap verify
-  // here because the main thread isn't yet a JavaThread, so
-  // its TLAB may not be made parseable from the usual interfaces.
-  if (VerifyBeforeGC && !UseTLAB &&
-      Universe::heap()->total_collections() >= VerifyGCStartAt) {
-    Universe::heap()->prepare_for_verify();
-    Universe::verify();   // make sure we're starting with a clean slate
-  }
-
   // All the flags that get adjusted by VM_Version_init and os::init_2
   // have been set so dump the flags now.
   if (PrintFlagsFinal) {

src/share/vm/runtime/thread.cpp

@@ -3423,12 +3423,6 @@ jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
   // real raw monitor. VM is setup enough here for raw monitor enter.
   JvmtiExport::transition_pending_onload_raw_monitors();
 
-  if (VerifyBeforeGC &&
-      Universe::heap()->total_collections() >= VerifyGCStartAt) {
-    Universe::heap()->prepare_for_verify();
-    Universe::verify();   // make sure we're starting with a clean slate
-  }
-
   // Fully start NMT
   MemTracker::start();
 
@@ -3452,6 +3446,11 @@ jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
   }
 
   assert (Universe::is_fully_initialized(), "not initialized");
+  if (VerifyBeforeGC && VerifyGCStartAt == 0) {
+    Universe::heap()->prepare_for_verify();
+    Universe::verify();   // make sure we're starting with a clean slate
+  }
+
   EXCEPTION_MARK;
 
   // At this point, the Universe is initialized, but we have not executed

test/gc/TestVerifyBeforeGCDuringStartup.java

+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/* @test TestVerifyBeforeGCDuringStartup.java
+ * @key gc
+ * @bug 8010463
+ * @summary Simple test run with -XX:+VerifyBeforeGC -XX:-UseTLAB to verify 8010463
+ * @library /testlibrary
+ */
+
+import com.oracle.java.testlibrary.OutputAnalyzer;
+import com.oracle.java.testlibrary.ProcessTools;
+
+public class TestVerifyBeforeGCDuringStartup {
+  public static void main(String args[]) throws Exception {
+    ProcessBuilder pb =
+      ProcessTools.createJavaProcessBuilder(System.getProperty("test.vm.opts"),
+                                            "-XX:-UseTLAB",
+                                            "-XX:+UnlockDiagnosticVMOptions",
+                                            "-XX:+VerifyBeforeGC", "-version");
+    OutputAnalyzer output = new OutputAnalyzer(pb.start());
+    output.shouldContain("[Verifying");
+    output.shouldHaveExitValue(0);
+  }
+}