8289739: Add G1 specific GC breakpoints for testing

Reviewed-by: kbarrett, iwalulya

src/hotspot/share/gc/g1/g1ConcurrentMarkThread.cpp

@@ -234,6 +234,7 @@ bool G1ConcurrentMarkThread::subphase_remark() {
 }
 
 bool G1ConcurrentMarkThread::phase_rebuild_remembered_sets() {
+  ConcurrentGCBreakpoints::at("AFTER REBUILD STARTED");
   G1ConcPhaseTimer p(_cm, "Concurrent Rebuild Remembered Sets");
   _cm->rebuild_rem_set_concurrently();
   return _cm->has_aborted();
@@ -245,12 +246,14 @@ bool G1ConcurrentMarkThread::phase_delay_to_keep_mmu_before_cleanup() {
 }
 
 bool G1ConcurrentMarkThread::phase_cleanup() {
+  ConcurrentGCBreakpoints::at("BEFORE REBUILD COMPLETED");
   VM_G1PauseCleanup op;
   VMThread::execute(&op);
   return _cm->has_aborted();
 }
 
 bool G1ConcurrentMarkThread::phase_clear_bitmap_for_next_mark() {
+  ConcurrentGCBreakpoints::at("AFTER CLEANUP STARTED");
   G1ConcPhaseTimer p(_cm, "Concurrent Cleanup for Next Mark");
   _cm->cleanup_for_next_mark();
   return _cm->has_aborted();
@@ -318,6 +321,7 @@ void G1ConcurrentMarkThread::concurrent_undo_cycle_do() {
 }
 
 void G1ConcurrentMarkThread::concurrent_cycle_end(bool mark_cycle_completed) {
+  ConcurrentGCBreakpoints::at("BEFORE CLEANUP COMPLETED");
   // Update the number of full collections that have been
   // completed. This will also notify the G1OldGCCount_lock in case a
   // Java thread is waiting for a full GC to happen (e.g., it

test/hotspot/jtreg/gc/TestConcurrentGCBreakpoints.java

@@ -42,6 +42,13 @@ public class TestConcurrentGCBreakpoints {
 
     private static final WhiteBox WB = WhiteBox.getWhiteBox();
 
+    private static void testG1SpecificBreakpoints() {
+        WB.concurrentGCRunTo(WB.G1_AFTER_REBUILD_STARTED);
+        WB.concurrentGCRunTo(WB.G1_BEFORE_REBUILD_COMPLETED);
+        WB.concurrentGCRunTo(WB.G1_AFTER_CLEANUP_STARTED);
+        WB.concurrentGCRunTo(WB.G1_BEFORE_CLEANUP_COMPLETED);
+    }
+
     // All testN() assume initial state is idle, and restore that state.
 
     // Step through the common breakpoints.
@@ -51,10 +58,16 @@ private static void testSimpleCycle() throws Exception {
             // Run one cycle.
             WB.concurrentGCRunTo(WB.AFTER_MARKING_STARTED);
             WB.concurrentGCRunTo(WB.BEFORE_MARKING_COMPLETED);
+            if (GC.G1.isSelected()) {
+                testG1SpecificBreakpoints();
+            }
             WB.concurrentGCRunToIdle();
             // Run a second cycle.
             WB.concurrentGCRunTo(WB.AFTER_MARKING_STARTED);
             WB.concurrentGCRunTo(WB.BEFORE_MARKING_COMPLETED);
+            if (GC.G1.isSelected()) {
+                testG1SpecificBreakpoints();
+            }
             WB.concurrentGCRunToIdle();
         } finally {
             WB.concurrentGCRunToIdle();

test/lib/sun/hotspot/WhiteBox.java

@@ -488,6 +488,12 @@ private void checkConcurrentGCIsControlled() {
   public final String AFTER_CONCURRENT_REFERENCE_PROCESSING_STARTED =
     "AFTER CONCURRENT REFERENCE PROCESSING STARTED";
 
+  // G1 specific GC breakpoints.
+  public final String G1_AFTER_REBUILD_STARTED = "AFTER REBUILD STARTED";
+  public final String G1_BEFORE_REBUILD_COMPLETED = "BEFORE REBUILD COMPLETED";
+  public final String G1_AFTER_CLEANUP_STARTED = "AFTER CLEANUP STARTED";
+  public final String G1_BEFORE_CLEANUP_COMPLETED = "BEFORE CLEANUP COMPLETED";
+
   public void concurrentGCAcquireControl() {
     checkConcurrentGCBreakpointsSupported();
     if (concurrentGCIsControlled) {