Merge

hotspot/make/excludeSrc.make

@@ -77,30 +77,40 @@ ifeq ($(INCLUDE_ALL_GCS), false)
       CXXFLAGS += -DINCLUDE_ALL_GCS=0
       CFLAGS += -DINCLUDE_ALL_GCS=0
 
-      Src_Files_EXCLUDE += \
-	cmsAdaptiveSizePolicy.cpp cmsCollectorPolicy.cpp \
-	cmsGCAdaptivePolicyCounters.cpp cmsLockVerifier.cpp compactibleFreeListSpace.cpp \
-	concurrentMarkSweepGeneration.cpp concurrentMarkSweepThread.cpp \
-	freeChunk.cpp adaptiveFreeList.cpp promotionInfo.cpp vmCMSOperations.cpp \
-	collectionSetChooser.cpp concurrentG1Refine.cpp concurrentG1RefineThread.cpp \
-	concurrentMark.cpp concurrentMarkThread.cpp dirtyCardQueue.cpp g1AllocRegion.cpp \
-	g1BlockOffsetTable.cpp g1CardCounts.cpp g1CollectedHeap.cpp g1CollectorPolicy.cpp \
-	g1ErgoVerbose.cpp g1GCPhaseTimes.cpp g1HRPrinter.cpp g1HotCardCache.cpp g1Log.cpp \
-	g1MMUTracker.cpp g1MarkSweep.cpp g1MemoryPool.cpp g1MonitoringSupport.cpp g1OopClosures.cpp \
-	g1RemSet.cpp g1RemSetSummary.cpp g1SATBCardTableModRefBS.cpp g1StringDedup.cpp g1StringDedupStat.cpp \
-	g1StringDedupTable.cpp g1StringDedupThread.cpp g1StringDedupQueue.cpp g1_globals.cpp heapRegion.cpp \
-	g1BiasedArray.cpp heapRegionRemSet.cpp heapRegionSeq.cpp heapRegionSet.cpp heapRegionSets.cpp \
-	ptrQueue.cpp satbQueue.cpp sparsePRT.cpp survRateGroup.cpp vm_operations_g1.cpp g1CodeCacheRemSet.cpp \
-	adjoiningGenerations.cpp adjoiningVirtualSpaces.cpp asPSOldGen.cpp asPSYoungGen.cpp \
-	cardTableExtension.cpp gcTaskManager.cpp gcTaskThread.cpp objectStartArray.cpp \
-	parallelScavengeHeap.cpp parMarkBitMap.cpp pcTasks.cpp psAdaptiveSizePolicy.cpp \
-	psCompactionManager.cpp psGCAdaptivePolicyCounters.cpp psGenerationCounters.cpp \
-	psMarkSweep.cpp psMarkSweepDecorator.cpp psMemoryPool.cpp psOldGen.cpp \
-	psParallelCompact.cpp psPromotionLAB.cpp psPromotionManager.cpp psScavenge.cpp \
-	psTasks.cpp psVirtualspace.cpp psYoungGen.cpp vmPSOperations.cpp asParNewGeneration.cpp \
-	parCardTableModRefBS.cpp parGCAllocBuffer.cpp parNewGeneration.cpp mutableSpace.cpp \
-	gSpaceCounters.cpp allocationStats.cpp spaceCounters.cpp gcAdaptivePolicyCounters.cpp \
-	mutableNUMASpace.cpp immutableSpace.cpp yieldingWorkGroup.cpp hSpaceCounters.cpp
+      gc_impl := $(GAMMADIR)/src/share/vm/gc_implementation
+      gc_exclude :=							\
+	$(notdir $(wildcard $(gc_impl)/concurrentMarkSweep/*.cpp))	\
+	$(notdir $(wildcard $(gc_impl)/g1/*.cpp))			\
+	$(notdir $(wildcard $(gc_impl)/parallelScavenge/*.cpp))		\
+	$(notdir $(wildcard $(gc_impl)/parNew/*.cpp))
+      Src_Files_EXCLUDE += $(gc_exclude)
+
+      # Exclude everything in $(gc_impl)/shared except the files listed
+      # in $(gc_shared_keep).
+      gc_shared_all := $(notdir $(wildcard $(gc_impl)/shared/*.cpp))
+      gc_shared_keep :=							\
+	adaptiveSizePolicy.cpp						\
+	ageTable.cpp							\
+	collectorCounters.cpp						\
+	cSpaceCounters.cpp						\
+	gcPolicyCounters.cpp						\
+	gcStats.cpp							\
+	gcTimer.cpp							\
+	gcTrace.cpp							\
+	gcTraceSend.cpp							\
+	gcTraceTime.cpp							\
+	gcUtil.cpp							\
+	generationCounters.cpp						\
+	markSweep.cpp							\
+	objectCountEventSender.cpp					\
+	spaceDecorator.cpp						\
+	vmGCOperations.cpp
+      Src_Files_EXCLUDE += $(filter-out $(gc_shared_keep),$(gc_shared_all))
+
+      # src/share/vm/services
+      Src_Files_EXCLUDE +=						\
+	g1MemoryPool.cpp						\
+	psMemoryPool.cpp
 endif
 
 ifeq ($(INCLUDE_NMT), false)

hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp

@@ -819,7 +819,7 @@ void ConcurrentMark::set_concurrency_and_phase(uint active_tasks, bool concurren
     // false before we start remark. At this point we should also be
     // in a STW phase.
     assert(!concurrent_marking_in_progress(), "invariant");
-    assert(_finger == _heap_end,
+    assert(out_of_regions(),
            err_msg("only way to get here: _finger: "PTR_FORMAT", _heap_end: "PTR_FORMAT,
                    p2i(_finger), p2i(_heap_end)));
     update_g1_committed(true);
@@ -978,7 +978,9 @@ void ConcurrentMark::enter_first_sync_barrier(uint worker_id) {
   if (concurrent()) {
     SuspendibleThreadSet::leave();
   }
-  _first_overflow_barrier_sync.enter();
+
+  bool barrier_aborted = !_first_overflow_barrier_sync.enter();
+
   if (concurrent()) {
     SuspendibleThreadSet::join();
   }
@@ -986,7 +988,17 @@ void ConcurrentMark::enter_first_sync_barrier(uint worker_id) {
   // more work
 
   if (verbose_low()) {
-    gclog_or_tty->print_cr("[%u] leaving first barrier", worker_id);
+    if (barrier_aborted) {
+      gclog_or_tty->print_cr("[%u] aborted first barrier", worker_id);
+    } else {
+      gclog_or_tty->print_cr("[%u] leaving first barrier", worker_id);
+    }
+  }
+
+  if (barrier_aborted) {
+    // If the barrier aborted we ignore the overflow condition and
+    // just abort the whole marking phase as quickly as possible.
+    return;
   }
 
   // If we're executing the concurrent phase of marking, reset the marking
@@ -1026,14 +1038,20 @@ void ConcurrentMark::enter_second_sync_barrier(uint worker_id) {
   if (concurrent()) {
     SuspendibleThreadSet::leave();
   }
-  _second_overflow_barrier_sync.enter();
+
+  bool barrier_aborted = !_second_overflow_barrier_sync.enter();
+
   if (concurrent()) {
     SuspendibleThreadSet::join();
   }
   // at this point everything should be re-initialized and ready to go
 
   if (verbose_low()) {
-    gclog_or_tty->print_cr("[%u] leaving second barrier", worker_id);
+    if (barrier_aborted) {
+      gclog_or_tty->print_cr("[%u] aborted second barrier", worker_id);
+    } else {
+      gclog_or_tty->print_cr("[%u] leaving second barrier", worker_id);
+    }
   }
 }
 
@@ -3240,6 +3258,8 @@ void ConcurrentMark::abort() {
   for (uint i = 0; i < _max_worker_id; ++i) {
     _tasks[i]->clear_region_fields();
   }
+  _first_overflow_barrier_sync.abort();
+  _second_overflow_barrier_sync.abort();
   _has_aborted = true;
 
   SATBMarkQueueSet& satb_mq_set = JavaThread::satb_mark_queue_set();

hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp

@@ -542,8 +542,12 @@ protected:
   // frequently.
   HeapRegion* claim_region(uint worker_id);
 
-  // It determines whether we've run out of regions to scan
-  bool        out_of_regions() { return _finger == _heap_end; }
+  // It determines whether we've run out of regions to scan. Note that
+  // the finger can point past the heap end in case the heap was expanded
+  // to satisfy an allocation without doing a GC. This is fine, because all
+  // objects in those regions will be considered live anyway because of
+  // SATB guarantees (i.e. their TAMS will be equal to bottom).
+  bool        out_of_regions() { return _finger >= _heap_end; }
 
   // Returns the task with the given id
   CMTask* task(int id) {

hotspot/src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.cpp

@@ -96,7 +96,15 @@ void G1SATBCardTableModRefBS::g1_mark_as_young(const MemRegion& mr) {
   jbyte *const first = byte_for(mr.start());
   jbyte *const last = byte_after(mr.last());
 
-  memset(first, g1_young_gen, last - first);
+  // Below we may use an explicit loop instead of memset() because on
+  // certain platforms memset() can give concurrent readers phantom zeros.
+  if (UseMemSetInBOT) {
+    memset(first, g1_young_gen, last - first);
+  } else {
+    for (jbyte* i = first; i < last; i++) {
+      *i = g1_young_gen;
+    }
+  }
 }
 
 #ifndef PRODUCT

hotspot/src/share/vm/gc_implementation/g1/sparsePRT.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2014, 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
@@ -194,23 +194,16 @@ bool RSHashTable::add_card(RegionIdx_t region_ind, CardIdx_t card_index) {
 }
 
 bool RSHashTable::get_cards(RegionIdx_t region_ind, CardIdx_t* cards) {
-  int ind = (int) (region_ind & capacity_mask());
-  int cur_ind = _buckets[ind];
-  SparsePRTEntry* cur;
-  while (cur_ind != NullEntry &&
-         (cur = entry(cur_ind))->r_ind() != region_ind) {
-    cur_ind = cur->next_index();
+  SparsePRTEntry* entry = get_entry(region_ind);
+  if (entry == NULL) {
+    return false;
   }
-
-  if (cur_ind == NullEntry) return false;
   // Otherwise...
-  assert(cur->r_ind() == region_ind, "Postcondition of loop + test above.");
-  assert(cur->num_valid_cards() > 0, "Inv");
-  cur->copy_cards(cards);
+  entry->copy_cards(cards);
   return true;
 }
 
-SparsePRTEntry* RSHashTable::get_entry(RegionIdx_t region_ind) {
+SparsePRTEntry* RSHashTable::get_entry(RegionIdx_t region_ind) const {
   int ind = (int) (region_ind & capacity_mask());
   int cur_ind = _buckets[ind];
   SparsePRTEntry* cur;
@@ -246,28 +239,9 @@ bool RSHashTable::delete_entry(RegionIdx_t region_ind) {
   return true;
 }
 
-SparsePRTEntry*
-RSHashTable::entry_for_region_ind(RegionIdx_t region_ind) const {
-  assert(occupied_entries() < capacity(), "Precondition");
-  int ind = (int) (region_ind & capacity_mask());
-  int cur_ind = _buckets[ind];
-  SparsePRTEntry* cur;
-  while (cur_ind != NullEntry &&
-         (cur = entry(cur_ind))->r_ind() != region_ind) {
-    cur_ind = cur->next_index();
-  }
-
-  if (cur_ind != NullEntry) {
-    assert(cur->r_ind() == region_ind, "Loop postcondition + test");
-    return cur;
-  } else {
-    return NULL;
-  }
-}
-
 SparsePRTEntry*
 RSHashTable::entry_for_region_ind_create(RegionIdx_t region_ind) {
-  SparsePRTEntry* res = entry_for_region_ind(region_ind);
+  SparsePRTEntry* res = get_entry(region_ind);
   if (res == NULL) {
     int new_ind = alloc_entry();
     assert(0 <= new_ind && (size_t)new_ind < capacity(), "There should be room.");
@@ -365,7 +339,7 @@ bool RSHashTableIter::has_next(size_t& card_index) {
 }
 
 bool RSHashTable::contains_card(RegionIdx_t region_index, CardIdx_t card_index) const {
-  SparsePRTEntry* e = entry_for_region_ind(region_index);
+  SparsePRTEntry* e = get_entry(region_index);
   return (e != NULL && e->contains_card(card_index));
 }
 

hotspot/src/share/vm/gc_implementation/g1/sparsePRT.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2014, 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
@@ -119,12 +119,6 @@ class RSHashTable : public CHeapObj<mtGC> {
   int  _free_region;
   int  _free_list;
 
-  // Requires that the caller hold a lock preventing parallel modifying
-  // operations, and that the the table be less than completely full.  If
-  // an entry for "region_ind" is already in the table, finds it and
-  // returns its address; otherwise returns "NULL."
-  SparsePRTEntry* entry_for_region_ind(RegionIdx_t region_ind) const;
-
   // Requires that the caller hold a lock preventing parallel modifying
   // operations, and that the the table be less than completely full.  If
   // an entry for "region_ind" is already in the table, finds it and
@@ -158,7 +152,7 @@ public:
 
   void add_entry(SparsePRTEntry* e);
 
-  SparsePRTEntry* get_entry(RegionIdx_t region_id);
+  SparsePRTEntry* get_entry(RegionIdx_t region_id) const;
 
   void clear();
 

hotspot/src/share/vm/utilities/workgroup.cpp

@@ -378,21 +378,22 @@ const char* AbstractGangTask::name() const {
 
 WorkGangBarrierSync::WorkGangBarrierSync()
   : _monitor(Mutex::safepoint, "work gang barrier sync", true),
-    _n_workers(0), _n_completed(0), _should_reset(false) {
+    _n_workers(0), _n_completed(0), _should_reset(false), _aborted(false) {
 }
 
 WorkGangBarrierSync::WorkGangBarrierSync(uint n_workers, const char* name)
   : _monitor(Mutex::safepoint, name, true),
-    _n_workers(n_workers), _n_completed(0), _should_reset(false) {
+    _n_workers(n_workers), _n_completed(0), _should_reset(false), _aborted(false) {
 }
 
 void WorkGangBarrierSync::set_n_workers(uint n_workers) {
-  _n_workers   = n_workers;
-  _n_completed = 0;
+  _n_workers    = n_workers;
+  _n_completed  = 0;
   _should_reset = false;
+  _aborted      = false;
 }
 
-void WorkGangBarrierSync::enter() {
+bool WorkGangBarrierSync::enter() {
   MutexLockerEx x(monitor(), Mutex::_no_safepoint_check_flag);
   if (should_reset()) {
     // The should_reset() was set and we are the first worker to enter
@@ -415,10 +416,17 @@ void WorkGangBarrierSync::enter() {
     set_should_reset(true);
     monitor()->notify_all();
   } else {
-    while (n_completed() != n_workers()) {
+    while (n_completed() != n_workers() && !aborted()) {
       monitor()->wait(/* no_safepoint_check */ true);
     }
   }
+  return !aborted();
+}
+
+void WorkGangBarrierSync::abort() {
+  MutexLockerEx x(monitor(), Mutex::_no_safepoint_check_flag);
+  set_aborted();
+  monitor()->notify_all();
 }
 
 // SubTasksDone functions.

hotspot/src/share/vm/utilities/workgroup.hpp

@@ -359,18 +359,20 @@ class FlexibleWorkGang: public WorkGang {
 class WorkGangBarrierSync : public StackObj {
 protected:
   Monitor _monitor;
-  uint     _n_workers;
-  uint     _n_completed;
+  uint    _n_workers;
+  uint    _n_completed;
   bool    _should_reset;
+  bool    _aborted;
 
   Monitor* monitor()        { return &_monitor; }
   uint     n_workers()      { return _n_workers; }
   uint     n_completed()    { return _n_completed; }
   bool     should_reset()   { return _should_reset; }
+  bool     aborted()        { return _aborted; }
 
   void     zero_completed() { _n_completed = 0; }
   void     inc_completed()  { _n_completed++; }
-
+  void     set_aborted()    { _aborted = true; }
   void     set_should_reset(bool v) { _should_reset = v; }
 
 public:
@@ -383,8 +385,14 @@ public:
 
   // Enter the barrier. A worker that enters the barrier will
   // not be allowed to leave until all other threads have
-  // also entered the barrier.
-  void enter();
+  // also entered the barrier or the barrier is aborted.
+  // Returns false if the barrier was aborted.
+  bool enter();
+
+  // Aborts the barrier and wakes up any threads waiting for
+  // the barrier to complete. The barrier will remain in the
+  // aborted state until the next call to set_n_workers().
+  void abort();
 };
 
 // A class to manage claiming of subtasks within a group of tasks.  The

hotspot/test/gc/arguments/TestDynMaxHeapFreeRatio.java

@@ -21,6 +21,11 @@
  * questions.
  */
 
+import static com.oracle.java.testlibrary.Asserts.assertEQ;
+import static com.oracle.java.testlibrary.Asserts.assertFalse;
+import static com.oracle.java.testlibrary.Asserts.assertTrue;
+import com.oracle.java.testlibrary.DynamicVMOption;
+
 /**
  * @test TestDynMaxHeapFreeRatio
  * @bug 8028391
@@ -33,32 +38,45 @@
  * @run main/othervm -XX:MinHeapFreeRatio=51 -XX:MaxHeapFreeRatio=52 TestDynMaxHeapFreeRatio
  * @run main/othervm -XX:MinHeapFreeRatio=75 -XX:MaxHeapFreeRatio=100 TestDynMaxHeapFreeRatio
  */
-import com.oracle.java.testlibrary.TestDynamicVMOption;
-import com.oracle.java.testlibrary.DynamicVMOptionChecker;
-
-public class TestDynMaxHeapFreeRatio extends TestDynamicVMOption {
-
-    public static final String MinFreeRatioFlagName = "MinHeapFreeRatio";
-    public static final String MaxFreeRatioFlagName = "MaxHeapFreeRatio";
-
-    public TestDynMaxHeapFreeRatio() {
-        super(MaxFreeRatioFlagName);
-    }
-
-    public void test() {
-
-        int minHeapFreeValue = DynamicVMOptionChecker.getIntValue(MinFreeRatioFlagName);
-        System.out.println(MinFreeRatioFlagName + " = " + minHeapFreeValue);
-
-        testPercentageValues();
-
-        checkInvalidValue(Integer.toString(minHeapFreeValue - 1));
-        checkValidValue(Integer.toString(minHeapFreeValue));
-        checkValidValue("100");
-    }
+public class TestDynMaxHeapFreeRatio {
 
     public static void main(String args[]) throws Exception {
-        new TestDynMaxHeapFreeRatio().test();
-    }
 
+        // low boundary value
+        int minValue = DynamicVMOption.getInt("MinHeapFreeRatio");
+        System.out.println("MinHeapFreeRatio= " + minValue);
+
+        String badValues[] = {
+            null,
+            "",
+            "not a number",
+            "8.5", "-0.01",
+            Integer.toString(Integer.MIN_VALUE),
+            Integer.toString(Integer.MAX_VALUE),
+            Integer.toString(minValue - 1),
+            "-1024", "-1", "101", "1997"
+        };
+
+        String goodValues[] = {
+            Integer.toString(minValue),
+            Integer.toString(minValue + 1),
+            Integer.toString((minValue + 100) / 2),
+            "99", "100"
+        };
+
+        DynamicVMOption option = new DynamicVMOption("MaxHeapFreeRatio");
+
+        assertTrue(option.isWriteable(), "Option " + option.name
+                + " is expected to be writable");
+
+        for (String v : badValues) {
+            assertFalse(option.isValidValue(v),
+                    "'" + v + "' is expected to be illegal for flag " + option.name);
+        }
+        for (String v : goodValues) {
+            option.setValue(v);
+            String newValue = option.getValue();
+            assertEQ(v, newValue);
+        }
+    }
 }

hotspot/test/gc/arguments/TestDynMinHeapFreeRatio.java

@@ -33,30 +33,52 @@
  * @run main/othervm -XX:MinHeapFreeRatio=51 -XX:MaxHeapFreeRatio=52 TestDynMinHeapFreeRatio
  * @run main/othervm -XX:MinHeapFreeRatio=75 -XX:MaxHeapFreeRatio=100 TestDynMinHeapFreeRatio
  */
-import com.oracle.java.testlibrary.TestDynamicVMOption;
-import com.oracle.java.testlibrary.DynamicVMOptionChecker;
+import static com.oracle.java.testlibrary.Asserts.assertEQ;
+import static com.oracle.java.testlibrary.Asserts.assertFalse;
+import static com.oracle.java.testlibrary.Asserts.assertTrue;
+import com.oracle.java.testlibrary.DynamicVMOption;
 
-public class TestDynMinHeapFreeRatio extends TestDynamicVMOption {
-
-    public static final String MinFreeRatioFlagName = "MinHeapFreeRatio";
-    public static final String MaxFreeRatioFlagName = "MaxHeapFreeRatio";
-
-    public TestDynMinHeapFreeRatio() {
-        super(MinFreeRatioFlagName);
-    }
-
-    public void test() {
-        int maxHeapFreeValue = DynamicVMOptionChecker.getIntValue(MaxFreeRatioFlagName);
-        System.out.println(MaxFreeRatioFlagName + " = " + maxHeapFreeValue);
-
-        testPercentageValues();
-
-        checkInvalidValue(Integer.toString(maxHeapFreeValue + 1));
-        checkValidValue(Integer.toString(maxHeapFreeValue));
-        checkValidValue("0");
-    }
+public class TestDynMinHeapFreeRatio {
 
     public static void main(String args[]) throws Exception {
-        new TestDynMinHeapFreeRatio().test();
+
+        // high boundary value
+        int maxValue = DynamicVMOption.getInt("MaxHeapFreeRatio");
+        System.out.println("MaxHeapFreeRatio= " + maxValue);
+
+        String badValues[] = {
+            null,
+            "",
+            "not a number",
+            "8.5", "-0.01",
+            Integer.toString(Integer.MIN_VALUE),
+            Integer.toString(Integer.MAX_VALUE),
+            Integer.toString(maxValue + 1),
+            "-1024", "-1", "101", "1997"
+        };
+
+        String goodValues[] = {
+            Integer.toString(maxValue),
+            Integer.toString(maxValue - 1),
+            Integer.toString(maxValue / 2),
+            "0", "1"
+        };
+
+        // option under test
+        DynamicVMOption option = new DynamicVMOption("MinHeapFreeRatio");
+
+        assertTrue(option.isWriteable(), "Option " + option.name
+                + " is expected to be writable");
+
+        for (String v : badValues) {
+            assertFalse(option.isValidValue(v),
+                    "'" + v + "' is expected to be illegal for flag " + option.name);
+        }
+
+        for (String v : goodValues) {
+            option.setValue(v);
+            String newValue = option.getValue();
+            assertEQ(v, newValue);
+        }
     }
 }

hotspot/test/gc/g1/TestGCLogMessages.java

@@ -22,7 +22,7 @@
  */
 
 /*
- * @test TestPrintGCDetails
+ * @test TestGCLogMessages
  * @bug 8035406 8027295 8035398 8019342
  * @summary Ensure that the PrintGCDetails output for a minor GC with G1
  * includes the expected necessary messages.
@@ -90,12 +90,6 @@ public class TestGCLogMessages {
     output.shouldContain("[String Dedup Fixup");
     output.shouldContain("[Young Free CSet");
     output.shouldContain("[Non-Young Free CSet");
-
-    // also check evacuation failure messages once
-    output.shouldNotContain("[Evacuation Failure");
-    output.shouldNotContain("[Recalculate Used");
-    output.shouldNotContain("[Remove Self Forwards");
-    output.shouldNotContain("[Restore RemSet");
     output.shouldHaveExitValue(0);
   }
 

hotspot/test/gc/parallelScavenge/TestDynShrinkHeap.java

@@ -28,8 +28,7 @@
  * @library /testlibrary
  * @run main/othervm -XX:+UseAdaptiveSizePolicyWithSystemGC -XX:+UseParallelGC -XX:MinHeapFreeRatio=0 -XX:MaxHeapFreeRatio=100 -verbose:gc TestDynShrinkHeap
  */
-
-import com.oracle.java.testlibrary.TestDynamicVMOption;
+import com.oracle.java.testlibrary.DynamicVMOption;
 import java.lang.management.ManagementFactory;
 import java.lang.management.MemoryUsage;
 import java.util.ArrayList;
@@ -44,12 +43,7 @@ public class TestDynShrinkHeap {
     private static ArrayList<byte[]> list = new ArrayList<>(0);
     private static final int M = 1024 * 1024; // to make heap more manageable by test code
 
-    private final TestDynamicVMOption maxRatioOption;
-    private final TestDynamicVMOption minRatioOption;
-
     public TestDynShrinkHeap() {
-        minRatioOption = new TestDynamicVMOption(MIN_FREE_RATIO_FLAG_NAME);
-        maxRatioOption = new TestDynamicVMOption(MAX_FREE_RATIO_FLAG_NAME);
     }
 
     private final void test() {
@@ -86,7 +80,8 @@ public class TestDynShrinkHeap {
     }
 
     private void free() {
-        maxRatioOption.setIntValue(minRatioOption.getIntValue() + 1);
+        int min = DynamicVMOption.getInt(MIN_FREE_RATIO_FLAG_NAME);
+        DynamicVMOption.setInt(MAX_FREE_RATIO_FLAG_NAME, min);
         System.gc();
         MemoryUsagePrinter.printMemoryUsage("under pressure");
     }

hotspot/test/testlibrary/com/oracle/java/testlibrary/DynamicVMOption.java

@@ -0,0 +1,165 @@
+/*
+ * Copyright (c) 2014, 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.
+ */
+package com.oracle.java.testlibrary;
+
+import com.sun.management.HotSpotDiagnosticMXBean;
+import java.lang.management.ManagementFactory;
+
+/**
+ * A utility class to work with VM options which could be altered during
+ * execution.
+ *
+ * This class is a wrapper around {@code com.sun.management.VMOption}.
+ * It provides more convenient interface to read/write the values.
+ *
+ */
+public class DynamicVMOption {
+
+    private final HotSpotDiagnosticMXBean mxBean;
+
+    /**
+     * VM option name, like "MinHeapFreeRatio".
+     */
+    public final String name;
+
+    /**
+     * Creates an instance of DynamicVMOption.
+     *
+     * @param name the VM option name
+     */
+    public DynamicVMOption(String name) {
+        this.name = name;
+        mxBean = ManagementFactory.getPlatformMXBean(HotSpotDiagnosticMXBean.class);
+    }
+
+    /**
+     * Sets a new value for the option.
+     * Trying to set not applicable value will cause IllegalArgumentException.
+     * Behavior with null is undefined, most likely NPE will be thrown.
+     *
+     * @param newValue the value to be set
+     * @see #getValue()
+     * @throws IllegalArgumentException if newValue is not applicable to the option
+     */
+    public final void setValue(String newValue) {
+        mxBean.setVMOption(name, newValue);
+    }
+
+    /**
+     * Returns the value of option.
+     *
+     * @return the current option value
+     * @see #setValue(java.lang.String)
+     */
+    public final String getValue() {
+        return mxBean.getVMOption(name).getValue();
+    }
+
+    /**
+     * Returns true, if option is writable, false otherwise.
+     *
+     * @return true, if option is writable, false otherwise
+     */
+    public final boolean isWriteable() {
+        return mxBean.getVMOption(name).isWriteable();
+    }
+
+    /**
+     * Checks if the given value is applicable for the option.
+     *
+     * This method tries to set the option to the new value. If no exception
+     * has been thrown the value is treated as valid.
+     *
+     * Calling this method will not change the option value. After an attempt
+     * to set a new value, the option will be restored to its previous value.
+     *
+     * @param value the value to verify
+     * @return true if option could be set to the given value
+     */
+    public boolean isValidValue(String value) {
+        boolean isValid = true;
+        String oldValue = getValue();
+        try {
+            setValue(value);
+        } catch (NullPointerException e) {
+            if (value == null) {
+                isValid = false;
+            }
+        } catch (IllegalArgumentException e) {
+            isValid = false;
+        } finally {
+            setValue(oldValue);
+        }
+        return isValid;
+    }
+
+    /**
+     * Returns the value of the given VM option as String.
+     *
+     * This is a simple shortcut for {@code new DynamicVMOption(name).getValue()}
+     *
+     * @param name the name of VM option
+     * @return value as a string
+     * @see #getValue()
+     */
+    public static String getString(String name) {
+        return new DynamicVMOption(name).getValue();
+    }
+
+    /**
+     * Returns the value of the given option as int.
+     *
+     * @param name the name of VM option
+     * @return value parsed as integer
+     * @see #getString(java.lang.String)
+     *
+     */
+    public static int getInt(String name) {
+        return Integer.parseInt(getString(name));
+    }
+
+    /**
+     * Sets the VM option to a new value.
+     *
+     * This is a simple shortcut for {@code new DynamicVMOption(name).setValue(value)}
+     *
+     * @param name the name of VM option
+     * @param value the value to be set
+     * @see #setValue(java.lang.String)
+     */
+    public static void setString(String name, String value) {
+        new DynamicVMOption(name).setValue(value);
+    }
+
+    /**
+     * Sets the VM option value to a new integer value.
+     *
+     * @param name the name of VM option
+     * @param value the integer value to be set
+     * @see #setString(java.lang.String, java.lang.String)
+     */
+    public static void setInt(String name, int value) {
+        new DynamicVMOption(name).setValue(Integer.toString(value));
+    }
+
+}

hotspot/test/testlibrary/com/oracle/java/testlibrary/DynamicVMOptionChecker.java

@@ -1,121 +0,0 @@
-/*
- * Copyright (c) 2014, 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.
- */
-package com.oracle.java.testlibrary;
-
-import com.sun.management.HotSpotDiagnosticMXBean;
-import com.sun.management.VMOption;
-import java.lang.management.ManagementFactory;
-
-/**
- * Simple class to check writeability, invalid and valid values for VMOption
- */
-public class DynamicVMOptionChecker {
-
-    /**
-     * Reads VM option from PlatformMXBean and parse it to integer value
-     *
-     * @param name of option
-     * @return parsed value
-     */
-    public static int getIntValue(String name) {
-
-        VMOption option = ManagementFactory.
-                getPlatformMXBean(HotSpotDiagnosticMXBean.class).
-                getVMOption(name);
-
-        return Integer.parseInt(option.getValue());
-    }
-
-    /**
-     * Sets VM option value
-     *
-     * @param name of option
-     * @param value to set
-     */
-    public static void setIntValue(String name, int value) {
-        ManagementFactory.getPlatformMXBean(HotSpotDiagnosticMXBean.class).setVMOption(name, Integer.toString(value));
-    }
-
-    /**
-     * Checks that VM option is dynamically writable
-     *
-     * @param name
-     * @throws RuntimeException if option if not writable
-     * @return always true
-     */
-    public static boolean checkIsWritable(String name) {
-        VMOption option = ManagementFactory.
-                getPlatformMXBean(HotSpotDiagnosticMXBean.class).
-                getVMOption(name);
-
-        if (!option.isWriteable()) {
-            throw new RuntimeException(name + " is not writable");
-        }
-
-        return true;
-    }
-
-    /**
-     * Checks that value cannot be set
-     *
-     * @param name of flag
-     * @param value string representation of value to set
-     * @throws RuntimeException on error - when expected exception hasn't been thrown
-     */
-    public static void checkInvalidValue(String name, String value) {
-        // should throw
-        try {
-            ManagementFactory.
-                    getPlatformMXBean(HotSpotDiagnosticMXBean.class).
-                    setVMOption(name, value);
-
-        } catch (IllegalArgumentException e) {
-            return;
-        }
-
-        throw new RuntimeException("Expected IllegalArgumentException was not thrown, " + name + "= " + value);
-    }
-
-    /**
-     * Checks that value can be set
-     *
-     * @param name of flag to set
-     * @param value string representation of value to set
-     * @throws RuntimeException on error - when value in VM is not equal to origin
-     */
-    public static void checkValidValue(String name, String value) {
-        ManagementFactory.
-                getPlatformMXBean(HotSpotDiagnosticMXBean.class).
-                setVMOption(name, value);
-
-        VMOption option = ManagementFactory.
-                getPlatformMXBean(HotSpotDiagnosticMXBean.class).
-                getVMOption(name);
-
-        if (!option.getValue().equals(value)) {
-            throw new RuntimeException("Actual value of " + name + " \"" + option.getValue()
-                    + "\" not equal origin \"" + value + "\"");
-        }
-    }
-
-}

hotspot/test/testlibrary/com/oracle/java/testlibrary/TestDynamicVMOption.java

@@ -1,104 +0,0 @@
-/*
- * Copyright (c) 2014, 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.
- */
-package com.oracle.java.testlibrary;
-
-/**
- * Simple class to check writeability, invalid and valid values for concrete VMOption
- */
-public class TestDynamicVMOption {
-
-    private final String name;
-    private final int value;
-
-    /**
-     * Constructor
-     *
-     * @param name of VM option to test
-     */
-    public TestDynamicVMOption(String name) {
-        this.name = name;
-        this.value = DynamicVMOptionChecker.getIntValue(name);
-        System.out.println(this.name + " = " + this.value);
-    }
-
-    /**
-     * Checks that this value can accept valid percentage values and cannot accept invalid percentage values
-     *
-     * @throws RuntimeException
-     */
-    public void testPercentageValues() {
-        checkInvalidValue(Integer.toString(Integer.MIN_VALUE));
-        checkInvalidValue(Integer.toString(Integer.MAX_VALUE));
-        checkInvalidValue("-10");
-        checkInvalidValue("190");
-    }
-
-    /**
-     * Reads VM option from PlatformMXBean and parse it to integer value
-     *
-     * @return value
-     */
-    public int getIntValue() {
-        return DynamicVMOptionChecker.getIntValue(this.name);
-    }
-
-    /**
-     * Sets VM option value
-     *
-     * @param value to set
-     */
-    public void setIntValue(int value) {
-        DynamicVMOptionChecker.setIntValue(this.name, value);
-    }
-
-    /**
-     * Checks that this VM option is dynamically writable
-     *
-     * @throws RuntimeException if option if not writable
-     * @return true
-     */
-    public boolean checkIsWritable() throws RuntimeException {
-        return DynamicVMOptionChecker.checkIsWritable(this.name);
-    }
-
-    /**
-     * Checks that value for this VM option cannot be set
-     *
-     * @param value to check
-     * @throws RuntimeException on error - when expected exception hasn't been thrown
-     */
-    public void checkInvalidValue(String value) {
-        DynamicVMOptionChecker.checkInvalidValue(this.name, value);
-    }
-
-    /**
-     * Checks that value for this VM option can be set
-     *
-     * @param value to check
-     * @throws RuntimeException on error - when value in VM is not equal to origin
-     */
-    public void checkValidValue(String value) {
-        DynamicVMOptionChecker.checkValidValue(this.name, value);
-    }
-
-}