runtime/indirect_reference_table_test.cc - platform/art - Gitiles

 /*
  * Copyright (C) 2009 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include "indirect_reference_table-inl.h"

 #include "android-base/stringprintf.h"

 #include "class_linker-inl.h"
 #include "common_runtime_test.h"
 #include "mirror/object-inl.h"
 #include "scoped_thread_state_change-inl.h"

 namespace art {

 using android::base::StringPrintf;

 class IndirectReferenceTableTest : public CommonRuntimeTest {};

 static void CheckDump(IndirectReferenceTable* irt, size_t num_objects, size_t num_unique)
     REQUIRES_SHARED(Locks::mutator_lock_) {
   std::ostringstream oss;
   irt->Dump(oss);
   if (num_objects == 0) {
     EXPECT_EQ(oss.str().find("java.lang.Object"), std::string::npos) << oss.str();
   } else if (num_objects == 1) {
     EXPECT_NE(oss.str().find("1 of java.lang.Object"), std::string::npos) << oss.str();
   } else {
     EXPECT_NE(oss.str().find(StringPrintf("%zd of java.lang.Object (%zd unique instances)",
                                           num_objects, num_unique)),
               std::string::npos)
                   << "\n Expected number of objects: " << num_objects
                   << "\n Expected unique objects: " << num_unique << "\n"
                   << oss.str();
   }
 }

 TEST_F(IndirectReferenceTableTest, BasicTest) {
   // This will lead to error messages in the log.
   ScopedLogSeverity sls(LogSeverity::FATAL);

   ScopedObjectAccess soa(Thread::Current());
   static const size_t kTableMax = 20;
   std::string error_msg;
   IndirectReferenceTable irt(kTableMax,
                              kGlobal,
                              IndirectReferenceTable::ResizableCapacity::kNo,
                              &error_msg);
   ASSERT_TRUE(irt.IsValid()) << error_msg;

   StackHandleScope<5> hs(soa.Self());
   Handle<mirror::Class> c =
       hs.NewHandle(class_linker_->FindSystemClass(soa.Self(), "Ljava/lang/Object;"));
   ASSERT_TRUE(c != nullptr);
   Handle<mirror::Object> obj0 = hs.NewHandle(c->AllocObject(soa.Self()));
   ASSERT_TRUE(obj0 != nullptr);
   Handle<mirror::Object> obj1 = hs.NewHandle(c->AllocObject(soa.Self()));
   ASSERT_TRUE(obj1 != nullptr);
   Handle<mirror::Object> obj2 = hs.NewHandle(c->AllocObject(soa.Self()));
   ASSERT_TRUE(obj2 != nullptr);
   Handle<mirror::Object> obj3 = hs.NewHandle(c->AllocObject(soa.Self()));
   ASSERT_TRUE(obj3 != nullptr);

   const IRTSegmentState cookie = kIRTFirstSegment;

   CheckDump(&irt, 0, 0);

   IndirectRef iref0 = (IndirectRef) 0x11110;
   EXPECT_FALSE(irt.Remove(cookie, iref0)) << "unexpectedly successful removal";

   // Add three, check, remove in the order in which they were added.
   iref0 = irt.Add(cookie, obj0.Get(), &error_msg);
   EXPECT_TRUE(iref0 != nullptr);
   CheckDump(&irt, 1, 1);
   IndirectRef iref1 = irt.Add(cookie, obj1.Get(), &error_msg);
   EXPECT_TRUE(iref1 != nullptr);
   CheckDump(&irt, 2, 2);
   IndirectRef iref2 = irt.Add(cookie, obj2.Get(), &error_msg);
   EXPECT_TRUE(iref2 != nullptr);
   CheckDump(&irt, 3, 3);

   EXPECT_OBJ_PTR_EQ(obj0.Get(), irt.Get(iref0));
   EXPECT_OBJ_PTR_EQ(obj1.Get(), irt.Get(iref1));
   EXPECT_OBJ_PTR_EQ(obj2.Get(), irt.Get(iref2));

   EXPECT_TRUE(irt.Remove(cookie, iref0));
   CheckDump(&irt, 2, 2);
   EXPECT_TRUE(irt.Remove(cookie, iref1));
   CheckDump(&irt, 1, 1);
   EXPECT_TRUE(irt.Remove(cookie, iref2));
   CheckDump(&irt, 0, 0);

   // Table should be empty now.
   EXPECT_EQ(0U, irt.Capacity());

   // Get invalid entry (off the end of the list).
   EXPECT_TRUE(irt.Get(iref0) == nullptr);

   // Add three, remove in the opposite order.
   iref0 = irt.Add(cookie, obj0.Get(), &error_msg);
   EXPECT_TRUE(iref0 != nullptr);
   iref1 = irt.Add(cookie, obj1.Get(), &error_msg);
   EXPECT_TRUE(iref1 != nullptr);
   iref2 = irt.Add(cookie, obj2.Get(), &error_msg);
   EXPECT_TRUE(iref2 != nullptr);
   CheckDump(&irt, 3, 3);

   ASSERT_TRUE(irt.Remove(cookie, iref2));
   CheckDump(&irt, 2, 2);
   ASSERT_TRUE(irt.Remove(cookie, iref1));
   CheckDump(&irt, 1, 1);
   ASSERT_TRUE(irt.Remove(cookie, iref0));
   CheckDump(&irt, 0, 0);

   // Table should be empty now.
   ASSERT_EQ(0U, irt.Capacity());

   // Add three, remove middle / middle / bottom / top.  (Second attempt
   // to remove middle should fail.)
   iref0 = irt.Add(cookie, obj0.Get(), &error_msg);
   EXPECT_TRUE(iref0 != nullptr);
   iref1 = irt.Add(cookie, obj1.Get(), &error_msg);
   EXPECT_TRUE(iref1 != nullptr);
   iref2 = irt.Add(cookie, obj2.Get(), &error_msg);
   EXPECT_TRUE(iref2 != nullptr);
   CheckDump(&irt, 3, 3);

   ASSERT_EQ(3U, irt.Capacity());

   ASSERT_TRUE(irt.Remove(cookie, iref1));
   CheckDump(&irt, 2, 2);
   ASSERT_FALSE(irt.Remove(cookie, iref1));
   CheckDump(&irt, 2, 2);

   // Get invalid entry (from hole).
   EXPECT_TRUE(irt.Get(iref1) == nullptr);

   ASSERT_TRUE(irt.Remove(cookie, iref2));
   CheckDump(&irt, 1, 1);
   ASSERT_TRUE(irt.Remove(cookie, iref0));
   CheckDump(&irt, 0, 0);

   // Table should be empty now.
   ASSERT_EQ(0U, irt.Capacity());

   // Add four entries.  Remove #1, add new entry, verify that table size
   // is still 4 (i.e. holes are getting filled).  Remove #1 and #3, verify
   // that we delete one and don't hole-compact the other.
   iref0 = irt.Add(cookie, obj0.Get(), &error_msg);
   EXPECT_TRUE(iref0 != nullptr);
   iref1 = irt.Add(cookie, obj1.Get(), &error_msg);
   EXPECT_TRUE(iref1 != nullptr);
   iref2 = irt.Add(cookie, obj2.Get(), &error_msg);
   EXPECT_TRUE(iref2 != nullptr);
   IndirectRef iref3 = irt.Add(cookie, obj3.Get(), &error_msg);
   EXPECT_TRUE(iref3 != nullptr);
   CheckDump(&irt, 4, 4);

   ASSERT_TRUE(irt.Remove(cookie, iref1));
   CheckDump(&irt, 3, 3);

   iref1 = irt.Add(cookie, obj1.Get(), &error_msg);
   EXPECT_TRUE(iref1 != nullptr);

   ASSERT_EQ(4U, irt.Capacity()) << "hole not filled";
   CheckDump(&irt, 4, 4);

   ASSERT_TRUE(irt.Remove(cookie, iref1));
   CheckDump(&irt, 3, 3);
   ASSERT_TRUE(irt.Remove(cookie, iref3));
   CheckDump(&irt, 2, 2);

   ASSERT_EQ(3U, irt.Capacity()) << "should be 3 after two deletions";

   ASSERT_TRUE(irt.Remove(cookie, iref2));
   CheckDump(&irt, 1, 1);
   ASSERT_TRUE(irt.Remove(cookie, iref0));
   CheckDump(&irt, 0, 0);

   ASSERT_EQ(0U, irt.Capacity()) << "not empty after split remove";

   // Add an entry, remove it, add a new entry, and try to use the original
   // iref.  They have the same slot number but are for different objects.
   // With the extended checks in place, this should fail.
   iref0 = irt.Add(cookie, obj0.Get(), &error_msg);
   EXPECT_TRUE(iref0 != nullptr);
   CheckDump(&irt, 1, 1);
   ASSERT_TRUE(irt.Remove(cookie, iref0));
   CheckDump(&irt, 0, 0);
   iref1 = irt.Add(cookie, obj1.Get(), &error_msg);
   EXPECT_TRUE(iref1 != nullptr);
   CheckDump(&irt, 1, 1);
   ASSERT_FALSE(irt.Remove(cookie, iref0)) << "mismatched del succeeded";
   CheckDump(&irt, 1, 1);
   ASSERT_TRUE(irt.Remove(cookie, iref1)) << "switched del failed";
   ASSERT_EQ(0U, irt.Capacity()) << "switching del not empty";
   CheckDump(&irt, 0, 0);

   // Same as above, but with the same object.  A more rigorous checker
   // (e.g. with slot serialization) will catch this.
   iref0 = irt.Add(cookie, obj0.Get(), &error_msg);
   EXPECT_TRUE(iref0 != nullptr);
   CheckDump(&irt, 1, 1);
   ASSERT_TRUE(irt.Remove(cookie, iref0));
   CheckDump(&irt, 0, 0);
   iref1 = irt.Add(cookie, obj0.Get(), &error_msg);
   EXPECT_TRUE(iref1 != nullptr);
   CheckDump(&irt, 1, 1);
   if (iref0 != iref1) {
     // Try 0, should not work.
     ASSERT_FALSE(irt.Remove(cookie, iref0)) << "temporal del succeeded";
   }
   ASSERT_TRUE(irt.Remove(cookie, iref1)) << "temporal cleanup failed";
   ASSERT_EQ(0U, irt.Capacity()) << "temporal del not empty";
   CheckDump(&irt, 0, 0);

   // null isn't a valid iref.
   ASSERT_TRUE(irt.Get(nullptr) == nullptr);

   // Stale lookup.
   iref0 = irt.Add(cookie, obj0.Get(), &error_msg);
   EXPECT_TRUE(iref0 != nullptr);
   CheckDump(&irt, 1, 1);
   ASSERT_TRUE(irt.Remove(cookie, iref0));
   EXPECT_TRUE(irt.Get(iref0) == nullptr) << "stale lookup succeeded";
   CheckDump(&irt, 0, 0);

   // Test table resizing.
   // These ones fit...
   static const size_t kTableInitial = kTableMax / 2;
   IndirectRef manyRefs[kTableInitial];
   for (size_t i = 0; i < kTableInitial; i++) {
     manyRefs[i] = irt.Add(cookie, obj0.Get(), &error_msg);
     ASSERT_TRUE(manyRefs[i] != nullptr) << "Failed adding " << i;
     CheckDump(&irt, i + 1, 1);
   }
   // ...this one causes overflow.
   iref0 = irt.Add(cookie, obj0.Get(), &error_msg);
   ASSERT_TRUE(iref0 != nullptr);
   ASSERT_EQ(kTableInitial + 1, irt.Capacity());
   CheckDump(&irt, kTableInitial + 1, 1);

   for (size_t i = 0; i < kTableInitial; i++) {
     ASSERT_TRUE(irt.Remove(cookie, manyRefs[i])) << "failed removing " << i;
     CheckDump(&irt, kTableInitial - i, 1);
   }
   // Because of removal order, should have 11 entries, 10 of them holes.
   ASSERT_EQ(kTableInitial + 1, irt.Capacity());

   ASSERT_TRUE(irt.Remove(cookie, iref0)) << "multi-remove final failed";

   ASSERT_EQ(0U, irt.Capacity()) << "multi-del not empty";
   CheckDump(&irt, 0, 0);
 }

 TEST_F(IndirectReferenceTableTest, Holes) {
   // Test the explicitly named cases from the IRT implementation:
   //
   // 1) Segment with holes (current_num_holes_ > 0), push new segment, add/remove reference
   // 2) Segment with holes (current_num_holes_ > 0), pop segment, add/remove reference
   // 3) Segment with holes (current_num_holes_ > 0), push new segment, pop segment, add/remove
   //    reference
   // 4) Empty segment, push new segment, create a hole, pop a segment, add/remove a reference
   // 5) Base segment, push new segment, create a hole, pop a segment, push new segment, add/remove
   //    reference

   ScopedObjectAccess soa(Thread::Current());
   static const size_t kTableMax = 10;

   StackHandleScope<6> hs(soa.Self());
   Handle<mirror::Class> c = hs.NewHandle(
       class_linker_->FindSystemClass(soa.Self(), "Ljava/lang/Object;"));
   ASSERT_TRUE(c != nullptr);
   Handle<mirror::Object> obj0 = hs.NewHandle(c->AllocObject(soa.Self()));
   ASSERT_TRUE(obj0 != nullptr);
   Handle<mirror::Object> obj1 = hs.NewHandle(c->AllocObject(soa.Self()));
   ASSERT_TRUE(obj1 != nullptr);
   Handle<mirror::Object> obj2 = hs.NewHandle(c->AllocObject(soa.Self()));
   ASSERT_TRUE(obj2 != nullptr);
   Handle<mirror::Object> obj3 = hs.NewHandle(c->AllocObject(soa.Self()));
   ASSERT_TRUE(obj3 != nullptr);
   Handle<mirror::Object> obj4 = hs.NewHandle(c->AllocObject(soa.Self()));
   ASSERT_TRUE(obj4 != nullptr);

   std::string error_msg;

   // 1) Segment with holes (current_num_holes_ > 0), push new segment, add/remove reference.
   {
     IndirectReferenceTable irt(kTableMax,
                                kGlobal,
                                IndirectReferenceTable::ResizableCapacity::kNo,
                                &error_msg);
     ASSERT_TRUE(irt.IsValid()) << error_msg;

     const IRTSegmentState cookie0 = kIRTFirstSegment;

     CheckDump(&irt, 0, 0);

     IndirectRef iref0 = irt.Add(cookie0, obj0.Get(), &error_msg);
     IndirectRef iref1 = irt.Add(cookie0, obj1.Get(), &error_msg);
     IndirectRef iref2 = irt.Add(cookie0, obj2.Get(), &error_msg);

     EXPECT_TRUE(irt.Remove(cookie0, iref1));

     // New segment.
     const IRTSegmentState cookie1 = irt.GetSegmentState();

     IndirectRef iref3 = irt.Add(cookie1, obj3.Get(), &error_msg);

     // Must not have filled the previous hole.
     EXPECT_EQ(irt.Capacity(), 4u);
     EXPECT_TRUE(irt.Get(iref1) == nullptr);
     CheckDump(&irt, 3, 3);

     UNUSED(iref0, iref1, iref2, iref3);
   }

   // 2) Segment with holes (current_num_holes_ > 0), pop segment, add/remove reference
   {
     IndirectReferenceTable irt(kTableMax,
                                kGlobal,
                                IndirectReferenceTable::ResizableCapacity::kNo,
                                &error_msg);
     ASSERT_TRUE(irt.IsValid()) << error_msg;

     const IRTSegmentState cookie0 = kIRTFirstSegment;

     CheckDump(&irt, 0, 0);

     IndirectRef iref0 = irt.Add(cookie0, obj0.Get(), &error_msg);

     // New segment.
     const IRTSegmentState cookie1 = irt.GetSegmentState();

     IndirectRef iref1 = irt.Add(cookie1, obj1.Get(), &error_msg);
     IndirectRef iref2 = irt.Add(cookie1, obj2.Get(), &error_msg);
     IndirectRef iref3 = irt.Add(cookie1, obj3.Get(), &error_msg);

     EXPECT_TRUE(irt.Remove(cookie1, iref2));

     // Pop segment.
     irt.SetSegmentState(cookie1);

     IndirectRef iref4 = irt.Add(cookie1, obj4.Get(), &error_msg);

     EXPECT_EQ(irt.Capacity(), 2u);
     EXPECT_TRUE(irt.Get(iref2) == nullptr);
     CheckDump(&irt, 2, 2);

     UNUSED(iref0, iref1, iref2, iref3, iref4);
   }

   // 3) Segment with holes (current_num_holes_ > 0), push new segment, pop segment, add/remove
   //    reference.
   {
     IndirectReferenceTable irt(kTableMax,
                                kGlobal,
                                IndirectReferenceTable::ResizableCapacity::kNo,
                                &error_msg);
     ASSERT_TRUE(irt.IsValid()) << error_msg;

     const IRTSegmentState cookie0 = kIRTFirstSegment;

     CheckDump(&irt, 0, 0);

     IndirectRef iref0 = irt.Add(cookie0, obj0.Get(), &error_msg);

     // New segment.
     const IRTSegmentState cookie1 = irt.GetSegmentState();

     IndirectRef iref1 = irt.Add(cookie1, obj1.Get(), &error_msg);
     IndirectRef iref2 = irt.Add(cookie1, obj2.Get(), &error_msg);

     EXPECT_TRUE(irt.Remove(cookie1, iref1));

     // New segment.
     const IRTSegmentState cookie2 = irt.GetSegmentState();

     IndirectRef iref3 = irt.Add(cookie2, obj3.Get(), &error_msg);

     // Pop segment.
     irt.SetSegmentState(cookie2);

     IndirectRef iref4 = irt.Add(cookie1, obj4.Get(), &error_msg);

     EXPECT_EQ(irt.Capacity(), 3u);
     EXPECT_TRUE(irt.Get(iref1) == nullptr);
     CheckDump(&irt, 3, 3);

     UNUSED(iref0, iref1, iref2, iref3, iref4);
   }

   // 4) Empty segment, push new segment, create a hole, pop a segment, add/remove a reference.
   {
     IndirectReferenceTable irt(kTableMax,
                                kGlobal,
                                IndirectReferenceTable::ResizableCapacity::kNo,
                                &error_msg);
     ASSERT_TRUE(irt.IsValid()) << error_msg;

     const IRTSegmentState cookie0 = kIRTFirstSegment;

     CheckDump(&irt, 0, 0);

     IndirectRef iref0 = irt.Add(cookie0, obj0.Get(), &error_msg);

     // New segment.
     const IRTSegmentState cookie1 = irt.GetSegmentState();

     IndirectRef iref1 = irt.Add(cookie1, obj1.Get(), &error_msg);
     EXPECT_TRUE(irt.Remove(cookie1, iref1));

     // Emptied segment, push new one.
     const IRTSegmentState cookie2 = irt.GetSegmentState();

     IndirectRef iref2 = irt.Add(cookie1, obj1.Get(), &error_msg);
     IndirectRef iref3 = irt.Add(cookie1, obj2.Get(), &error_msg);
     IndirectRef iref4 = irt.Add(cookie1, obj3.Get(), &error_msg);

     EXPECT_TRUE(irt.Remove(cookie1, iref3));

     // Pop segment.
     UNUSED(cookie2);
     irt.SetSegmentState(cookie1);

     IndirectRef iref5 = irt.Add(cookie1, obj4.Get(), &error_msg);

     EXPECT_EQ(irt.Capacity(), 2u);
     EXPECT_TRUE(irt.Get(iref3) == nullptr);
     CheckDump(&irt, 2, 2);

     UNUSED(iref0, iref1, iref2, iref3, iref4, iref5);
   }

   // 5) Base segment, push new segment, create a hole, pop a segment, push new segment, add/remove
   //    reference
   {
     IndirectReferenceTable irt(kTableMax,
                                kGlobal,
                                IndirectReferenceTable::ResizableCapacity::kNo,
                                &error_msg);
     ASSERT_TRUE(irt.IsValid()) << error_msg;

     const IRTSegmentState cookie0 = kIRTFirstSegment;

     CheckDump(&irt, 0, 0);

     IndirectRef iref0 = irt.Add(cookie0, obj0.Get(), &error_msg);

     // New segment.
     const IRTSegmentState cookie1 = irt.GetSegmentState();

     IndirectRef iref1 = irt.Add(cookie1, obj1.Get(), &error_msg);
     IndirectRef iref2 = irt.Add(cookie1, obj1.Get(), &error_msg);
     IndirectRef iref3 = irt.Add(cookie1, obj2.Get(), &error_msg);

     EXPECT_TRUE(irt.Remove(cookie1, iref2));

     // Pop segment.
     irt.SetSegmentState(cookie1);

     // Push segment.
     const IRTSegmentState cookie1_second = irt.GetSegmentState();
     UNUSED(cookie1_second);

     IndirectRef iref4 = irt.Add(cookie1, obj3.Get(), &error_msg);

     EXPECT_EQ(irt.Capacity(), 2u);
     EXPECT_TRUE(irt.Get(iref3) == nullptr);
     CheckDump(&irt, 2, 2);

     UNUSED(iref0, iref1, iref2, iref3, iref4);
   }
 }

 TEST_F(IndirectReferenceTableTest, Resize) {
   ScopedObjectAccess soa(Thread::Current());
   static const size_t kTableMax = 512;

   StackHandleScope<2> hs(soa.Self());
   Handle<mirror::Class> c = hs.NewHandle(
       class_linker_->FindSystemClass(soa.Self(), "Ljava/lang/Object;"));
   ASSERT_TRUE(c != nullptr);
   Handle<mirror::Object> obj0 = hs.NewHandle(c->AllocObject(soa.Self()));
   ASSERT_TRUE(obj0 != nullptr);

   std::string error_msg;
   IndirectReferenceTable irt(kTableMax,
                              kLocal,
                              IndirectReferenceTable::ResizableCapacity::kYes,
                              &error_msg);
   ASSERT_TRUE(irt.IsValid()) << error_msg;

   CheckDump(&irt, 0, 0);
   const IRTSegmentState cookie = kIRTFirstSegment;

   for (size_t i = 0; i != kTableMax + 1; ++i) {
     irt.Add(cookie, obj0.Get(), &error_msg);
   }

   EXPECT_EQ(irt.Capacity(), kTableMax + 1);
 }

 }  // namespace art
	/*
	* Copyright (C) 2009 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include "indirect_reference_table-inl.h"

	#include "android-base/stringprintf.h"

	#include "class_linker-inl.h"
	#include "common_runtime_test.h"
	#include "mirror/object-inl.h"
	#include "scoped_thread_state_change-inl.h"

	namespace art {

	using android::base::StringPrintf;

	class IndirectReferenceTableTest : public CommonRuntimeTest {};

	static void CheckDump(IndirectReferenceTable* irt, size_t num_objects, size_t num_unique)
	REQUIRES_SHARED(Locks::mutator_lock_) {
	std::ostringstream oss;
	irt->Dump(oss);
	if (num_objects == 0) {
	EXPECT_EQ(oss.str().find("java.lang.Object"), std::string::npos) << oss.str();
	} else if (num_objects == 1) {
	EXPECT_NE(oss.str().find("1 of java.lang.Object"), std::string::npos) << oss.str();
	} else {
	EXPECT_NE(oss.str().find(StringPrintf("%zd of java.lang.Object (%zd unique instances)",
	num_objects, num_unique)),
	std::string::npos)
	<< "\n Expected number of objects: " << num_objects
	<< "\n Expected unique objects: " << num_unique << "\n"
	<< oss.str();
	}
	}

	TEST_F(IndirectReferenceTableTest, BasicTest) {
	// This will lead to error messages in the log.
	ScopedLogSeverity sls(LogSeverity::FATAL);

	ScopedObjectAccess soa(Thread::Current());
	static const size_t kTableMax = 20;
	std::string error_msg;
	IndirectReferenceTable irt(kTableMax,
	kGlobal,
	IndirectReferenceTable::ResizableCapacity::kNo,
	&error_msg);
	ASSERT_TRUE(irt.IsValid()) << error_msg;

	StackHandleScope<5> hs(soa.Self());
	Handle<mirror::Class> c =
	hs.NewHandle(class_linker_->FindSystemClass(soa.Self(), "Ljava/lang/Object;"));
	ASSERT_TRUE(c != nullptr);
	Handle<mirror::Object> obj0 = hs.NewHandle(c->AllocObject(soa.Self()));
	ASSERT_TRUE(obj0 != nullptr);
	Handle<mirror::Object> obj1 = hs.NewHandle(c->AllocObject(soa.Self()));
	ASSERT_TRUE(obj1 != nullptr);
	Handle<mirror::Object> obj2 = hs.NewHandle(c->AllocObject(soa.Self()));
	ASSERT_TRUE(obj2 != nullptr);
	Handle<mirror::Object> obj3 = hs.NewHandle(c->AllocObject(soa.Self()));
	ASSERT_TRUE(obj3 != nullptr);

	const IRTSegmentState cookie = kIRTFirstSegment;

	CheckDump(&irt, 0, 0);

	IndirectRef iref0 = (IndirectRef) 0x11110;
	EXPECT_FALSE(irt.Remove(cookie, iref0)) << "unexpectedly successful removal";

	// Add three, check, remove in the order in which they were added.
	iref0 = irt.Add(cookie, obj0.Get(), &error_msg);
	EXPECT_TRUE(iref0 != nullptr);
	CheckDump(&irt, 1, 1);
	IndirectRef iref1 = irt.Add(cookie, obj1.Get(), &error_msg);
	EXPECT_TRUE(iref1 != nullptr);
	CheckDump(&irt, 2, 2);
	IndirectRef iref2 = irt.Add(cookie, obj2.Get(), &error_msg);
	EXPECT_TRUE(iref2 != nullptr);
	CheckDump(&irt, 3, 3);

	EXPECT_OBJ_PTR_EQ(obj0.Get(), irt.Get(iref0));
	EXPECT_OBJ_PTR_EQ(obj1.Get(), irt.Get(iref1));
	EXPECT_OBJ_PTR_EQ(obj2.Get(), irt.Get(iref2));

	EXPECT_TRUE(irt.Remove(cookie, iref0));
	CheckDump(&irt, 2, 2);
	EXPECT_TRUE(irt.Remove(cookie, iref1));
	CheckDump(&irt, 1, 1);
	EXPECT_TRUE(irt.Remove(cookie, iref2));
	CheckDump(&irt, 0, 0);

	// Table should be empty now.
	EXPECT_EQ(0U, irt.Capacity());

	// Get invalid entry (off the end of the list).
	EXPECT_TRUE(irt.Get(iref0) == nullptr);

	// Add three, remove in the opposite order.
	iref0 = irt.Add(cookie, obj0.Get(), &error_msg);
	EXPECT_TRUE(iref0 != nullptr);
	iref1 = irt.Add(cookie, obj1.Get(), &error_msg);
	EXPECT_TRUE(iref1 != nullptr);
	iref2 = irt.Add(cookie, obj2.Get(), &error_msg);
	EXPECT_TRUE(iref2 != nullptr);
	CheckDump(&irt, 3, 3);

	ASSERT_TRUE(irt.Remove(cookie, iref2));
	CheckDump(&irt, 2, 2);
	ASSERT_TRUE(irt.Remove(cookie, iref1));
	CheckDump(&irt, 1, 1);
	ASSERT_TRUE(irt.Remove(cookie, iref0));
	CheckDump(&irt, 0, 0);

	// Table should be empty now.
	ASSERT_EQ(0U, irt.Capacity());

	// Add three, remove middle / middle / bottom / top. (Second attempt
	// to remove middle should fail.)
	iref0 = irt.Add(cookie, obj0.Get(), &error_msg);
	EXPECT_TRUE(iref0 != nullptr);
	iref1 = irt.Add(cookie, obj1.Get(), &error_msg);
	EXPECT_TRUE(iref1 != nullptr);
	iref2 = irt.Add(cookie, obj2.Get(), &error_msg);
	EXPECT_TRUE(iref2 != nullptr);
	CheckDump(&irt, 3, 3);

	ASSERT_EQ(3U, irt.Capacity());

	ASSERT_TRUE(irt.Remove(cookie, iref1));
	CheckDump(&irt, 2, 2);
	ASSERT_FALSE(irt.Remove(cookie, iref1));
	CheckDump(&irt, 2, 2);

	// Get invalid entry (from hole).
	EXPECT_TRUE(irt.Get(iref1) == nullptr);

	ASSERT_TRUE(irt.Remove(cookie, iref2));
	CheckDump(&irt, 1, 1);
	ASSERT_TRUE(irt.Remove(cookie, iref0));
	CheckDump(&irt, 0, 0);

	// Table should be empty now.
	ASSERT_EQ(0U, irt.Capacity());

	// Add four entries. Remove #1, add new entry, verify that table size
	// is still 4 (i.e. holes are getting filled). Remove #1 and #3, verify
	// that we delete one and don't hole-compact the other.
	iref0 = irt.Add(cookie, obj0.Get(), &error_msg);
	EXPECT_TRUE(iref0 != nullptr);
	iref1 = irt.Add(cookie, obj1.Get(), &error_msg);
	EXPECT_TRUE(iref1 != nullptr);
	iref2 = irt.Add(cookie, obj2.Get(), &error_msg);
	EXPECT_TRUE(iref2 != nullptr);
	IndirectRef iref3 = irt.Add(cookie, obj3.Get(), &error_msg);
	EXPECT_TRUE(iref3 != nullptr);
	CheckDump(&irt, 4, 4);

	ASSERT_TRUE(irt.Remove(cookie, iref1));
	CheckDump(&irt, 3, 3);

	iref1 = irt.Add(cookie, obj1.Get(), &error_msg);
	EXPECT_TRUE(iref1 != nullptr);

	ASSERT_EQ(4U, irt.Capacity()) << "hole not filled";
	CheckDump(&irt, 4, 4);

	ASSERT_TRUE(irt.Remove(cookie, iref1));
	CheckDump(&irt, 3, 3);
	ASSERT_TRUE(irt.Remove(cookie, iref3));
	CheckDump(&irt, 2, 2);

	ASSERT_EQ(3U, irt.Capacity()) << "should be 3 after two deletions";

	ASSERT_TRUE(irt.Remove(cookie, iref2));
	CheckDump(&irt, 1, 1);
	ASSERT_TRUE(irt.Remove(cookie, iref0));
	CheckDump(&irt, 0, 0);

	ASSERT_EQ(0U, irt.Capacity()) << "not empty after split remove";

	// Add an entry, remove it, add a new entry, and try to use the original
	// iref. They have the same slot number but are for different objects.
	// With the extended checks in place, this should fail.
	iref0 = irt.Add(cookie, obj0.Get(), &error_msg);
	EXPECT_TRUE(iref0 != nullptr);
	CheckDump(&irt, 1, 1);
	ASSERT_TRUE(irt.Remove(cookie, iref0));
	CheckDump(&irt, 0, 0);
	iref1 = irt.Add(cookie, obj1.Get(), &error_msg);
	EXPECT_TRUE(iref1 != nullptr);
	CheckDump(&irt, 1, 1);
	ASSERT_FALSE(irt.Remove(cookie, iref0)) << "mismatched del succeeded";
	CheckDump(&irt, 1, 1);
	ASSERT_TRUE(irt.Remove(cookie, iref1)) << "switched del failed";
	ASSERT_EQ(0U, irt.Capacity()) << "switching del not empty";
	CheckDump(&irt, 0, 0);

	// Same as above, but with the same object. A more rigorous checker
	// (e.g. with slot serialization) will catch this.
	iref0 = irt.Add(cookie, obj0.Get(), &error_msg);
	EXPECT_TRUE(iref0 != nullptr);
	CheckDump(&irt, 1, 1);
	ASSERT_TRUE(irt.Remove(cookie, iref0));
	CheckDump(&irt, 0, 0);
	iref1 = irt.Add(cookie, obj0.Get(), &error_msg);
	EXPECT_TRUE(iref1 != nullptr);
	CheckDump(&irt, 1, 1);
	if (iref0 != iref1) {
	// Try 0, should not work.
	ASSERT_FALSE(irt.Remove(cookie, iref0)) << "temporal del succeeded";
	}
	ASSERT_TRUE(irt.Remove(cookie, iref1)) << "temporal cleanup failed";
	ASSERT_EQ(0U, irt.Capacity()) << "temporal del not empty";
	CheckDump(&irt, 0, 0);

	// null isn't a valid iref.
	ASSERT_TRUE(irt.Get(nullptr) == nullptr);

	// Stale lookup.
	iref0 = irt.Add(cookie, obj0.Get(), &error_msg);
	EXPECT_TRUE(iref0 != nullptr);
	CheckDump(&irt, 1, 1);
	ASSERT_TRUE(irt.Remove(cookie, iref0));
	EXPECT_TRUE(irt.Get(iref0) == nullptr) << "stale lookup succeeded";
	CheckDump(&irt, 0, 0);

	// Test table resizing.
	// These ones fit...
	static const size_t kTableInitial = kTableMax / 2;
	IndirectRef manyRefs[kTableInitial];
	for (size_t i = 0; i < kTableInitial; i++) {
	manyRefs[i] = irt.Add(cookie, obj0.Get(), &error_msg);
	ASSERT_TRUE(manyRefs[i] != nullptr) << "Failed adding " << i;
	CheckDump(&irt, i + 1, 1);
	}
	// ...this one causes overflow.
	iref0 = irt.Add(cookie, obj0.Get(), &error_msg);
	ASSERT_TRUE(iref0 != nullptr);
	ASSERT_EQ(kTableInitial + 1, irt.Capacity());
	CheckDump(&irt, kTableInitial + 1, 1);

	for (size_t i = 0; i < kTableInitial; i++) {
	ASSERT_TRUE(irt.Remove(cookie, manyRefs[i])) << "failed removing " << i;
	CheckDump(&irt, kTableInitial - i, 1);
	}
	// Because of removal order, should have 11 entries, 10 of them holes.
	ASSERT_EQ(kTableInitial + 1, irt.Capacity());

	ASSERT_TRUE(irt.Remove(cookie, iref0)) << "multi-remove final failed";

	ASSERT_EQ(0U, irt.Capacity()) << "multi-del not empty";
	CheckDump(&irt, 0, 0);
	}

	TEST_F(IndirectReferenceTableTest, Holes) {
	// Test the explicitly named cases from the IRT implementation:
	//
	// 1) Segment with holes (current_num_holes_ > 0), push new segment, add/remove reference
	// 2) Segment with holes (current_num_holes_ > 0), pop segment, add/remove reference
	// 3) Segment with holes (current_num_holes_ > 0), push new segment, pop segment, add/remove
	// reference
	// 4) Empty segment, push new segment, create a hole, pop a segment, add/remove a reference
	// 5) Base segment, push new segment, create a hole, pop a segment, push new segment, add/remove
	// reference

	ScopedObjectAccess soa(Thread::Current());
	static const size_t kTableMax = 10;

	StackHandleScope<6> hs(soa.Self());
	Handle<mirror::Class> c = hs.NewHandle(
	class_linker_->FindSystemClass(soa.Self(), "Ljava/lang/Object;"));
	ASSERT_TRUE(c != nullptr);
	Handle<mirror::Object> obj0 = hs.NewHandle(c->AllocObject(soa.Self()));
	ASSERT_TRUE(obj0 != nullptr);
	Handle<mirror::Object> obj1 = hs.NewHandle(c->AllocObject(soa.Self()));
	ASSERT_TRUE(obj1 != nullptr);
	Handle<mirror::Object> obj2 = hs.NewHandle(c->AllocObject(soa.Self()));
	ASSERT_TRUE(obj2 != nullptr);
	Handle<mirror::Object> obj3 = hs.NewHandle(c->AllocObject(soa.Self()));
	ASSERT_TRUE(obj3 != nullptr);
	Handle<mirror::Object> obj4 = hs.NewHandle(c->AllocObject(soa.Self()));
	ASSERT_TRUE(obj4 != nullptr);

	std::string error_msg;

	// 1) Segment with holes (current_num_holes_ > 0), push new segment, add/remove reference.
	{
	IndirectReferenceTable irt(kTableMax,
	kGlobal,
	IndirectReferenceTable::ResizableCapacity::kNo,
	&error_msg);
	ASSERT_TRUE(irt.IsValid()) << error_msg;

	const IRTSegmentState cookie0 = kIRTFirstSegment;

	CheckDump(&irt, 0, 0);

	IndirectRef iref0 = irt.Add(cookie0, obj0.Get(), &error_msg);
	IndirectRef iref1 = irt.Add(cookie0, obj1.Get(), &error_msg);
	IndirectRef iref2 = irt.Add(cookie0, obj2.Get(), &error_msg);

	EXPECT_TRUE(irt.Remove(cookie0, iref1));

	// New segment.
	const IRTSegmentState cookie1 = irt.GetSegmentState();

	IndirectRef iref3 = irt.Add(cookie1, obj3.Get(), &error_msg);

	// Must not have filled the previous hole.
	EXPECT_EQ(irt.Capacity(), 4u);
	EXPECT_TRUE(irt.Get(iref1) == nullptr);
	CheckDump(&irt, 3, 3);

	UNUSED(iref0, iref1, iref2, iref3);
	}

	// 2) Segment with holes (current_num_holes_ > 0), pop segment, add/remove reference
	{
	IndirectReferenceTable irt(kTableMax,
	kGlobal,
	IndirectReferenceTable::ResizableCapacity::kNo,
	&error_msg);
	ASSERT_TRUE(irt.IsValid()) << error_msg;

	const IRTSegmentState cookie0 = kIRTFirstSegment;

	CheckDump(&irt, 0, 0);

	IndirectRef iref0 = irt.Add(cookie0, obj0.Get(), &error_msg);

	// New segment.
	const IRTSegmentState cookie1 = irt.GetSegmentState();

	IndirectRef iref1 = irt.Add(cookie1, obj1.Get(), &error_msg);
	IndirectRef iref2 = irt.Add(cookie1, obj2.Get(), &error_msg);
	IndirectRef iref3 = irt.Add(cookie1, obj3.Get(), &error_msg);

	EXPECT_TRUE(irt.Remove(cookie1, iref2));

	// Pop segment.
	irt.SetSegmentState(cookie1);

	IndirectRef iref4 = irt.Add(cookie1, obj4.Get(), &error_msg);

	EXPECT_EQ(irt.Capacity(), 2u);
	EXPECT_TRUE(irt.Get(iref2) == nullptr);
	CheckDump(&irt, 2, 2);

	UNUSED(iref0, iref1, iref2, iref3, iref4);
	}

	// 3) Segment with holes (current_num_holes_ > 0), push new segment, pop segment, add/remove
	// reference.
	{
	IndirectReferenceTable irt(kTableMax,
	kGlobal,
	IndirectReferenceTable::ResizableCapacity::kNo,
	&error_msg);
	ASSERT_TRUE(irt.IsValid()) << error_msg;

	const IRTSegmentState cookie0 = kIRTFirstSegment;

	CheckDump(&irt, 0, 0);

	IndirectRef iref0 = irt.Add(cookie0, obj0.Get(), &error_msg);

	// New segment.
	const IRTSegmentState cookie1 = irt.GetSegmentState();

	IndirectRef iref1 = irt.Add(cookie1, obj1.Get(), &error_msg);
	IndirectRef iref2 = irt.Add(cookie1, obj2.Get(), &error_msg);

	EXPECT_TRUE(irt.Remove(cookie1, iref1));

	// New segment.
	const IRTSegmentState cookie2 = irt.GetSegmentState();

	IndirectRef iref3 = irt.Add(cookie2, obj3.Get(), &error_msg);

	// Pop segment.
	irt.SetSegmentState(cookie2);

	IndirectRef iref4 = irt.Add(cookie1, obj4.Get(), &error_msg);

	EXPECT_EQ(irt.Capacity(), 3u);
	EXPECT_TRUE(irt.Get(iref1) == nullptr);
	CheckDump(&irt, 3, 3);

	UNUSED(iref0, iref1, iref2, iref3, iref4);
	}

	// 4) Empty segment, push new segment, create a hole, pop a segment, add/remove a reference.
	{
	IndirectReferenceTable irt(kTableMax,
	kGlobal,
	IndirectReferenceTable::ResizableCapacity::kNo,
	&error_msg);
	ASSERT_TRUE(irt.IsValid()) << error_msg;

	const IRTSegmentState cookie0 = kIRTFirstSegment;

	CheckDump(&irt, 0, 0);

	IndirectRef iref0 = irt.Add(cookie0, obj0.Get(), &error_msg);

	// New segment.
	const IRTSegmentState cookie1 = irt.GetSegmentState();

	IndirectRef iref1 = irt.Add(cookie1, obj1.Get(), &error_msg);
	EXPECT_TRUE(irt.Remove(cookie1, iref1));

	// Emptied segment, push new one.
	const IRTSegmentState cookie2 = irt.GetSegmentState();

	IndirectRef iref2 = irt.Add(cookie1, obj1.Get(), &error_msg);
	IndirectRef iref3 = irt.Add(cookie1, obj2.Get(), &error_msg);
	IndirectRef iref4 = irt.Add(cookie1, obj3.Get(), &error_msg);

	EXPECT_TRUE(irt.Remove(cookie1, iref3));

	// Pop segment.
	UNUSED(cookie2);
	irt.SetSegmentState(cookie1);

	IndirectRef iref5 = irt.Add(cookie1, obj4.Get(), &error_msg);

	EXPECT_EQ(irt.Capacity(), 2u);
	EXPECT_TRUE(irt.Get(iref3) == nullptr);
	CheckDump(&irt, 2, 2);

	UNUSED(iref0, iref1, iref2, iref3, iref4, iref5);
	}

	// 5) Base segment, push new segment, create a hole, pop a segment, push new segment, add/remove
	// reference
	{
	IndirectReferenceTable irt(kTableMax,
	kGlobal,
	IndirectReferenceTable::ResizableCapacity::kNo,
	&error_msg);
	ASSERT_TRUE(irt.IsValid()) << error_msg;

	const IRTSegmentState cookie0 = kIRTFirstSegment;

	CheckDump(&irt, 0, 0);

	IndirectRef iref0 = irt.Add(cookie0, obj0.Get(), &error_msg);

	// New segment.
	const IRTSegmentState cookie1 = irt.GetSegmentState();

	IndirectRef iref1 = irt.Add(cookie1, obj1.Get(), &error_msg);
	IndirectRef iref2 = irt.Add(cookie1, obj1.Get(), &error_msg);
	IndirectRef iref3 = irt.Add(cookie1, obj2.Get(), &error_msg);

	EXPECT_TRUE(irt.Remove(cookie1, iref2));

	// Pop segment.
	irt.SetSegmentState(cookie1);

	// Push segment.
	const IRTSegmentState cookie1_second = irt.GetSegmentState();
	UNUSED(cookie1_second);

	IndirectRef iref4 = irt.Add(cookie1, obj3.Get(), &error_msg);

	EXPECT_EQ(irt.Capacity(), 2u);
	EXPECT_TRUE(irt.Get(iref3) == nullptr);
	CheckDump(&irt, 2, 2);

	UNUSED(iref0, iref1, iref2, iref3, iref4);
	}
	}

	TEST_F(IndirectReferenceTableTest, Resize) {
	ScopedObjectAccess soa(Thread::Current());
	static const size_t kTableMax = 512;

	StackHandleScope<2> hs(soa.Self());
	Handle<mirror::Class> c = hs.NewHandle(
	class_linker_->FindSystemClass(soa.Self(), "Ljava/lang/Object;"));
	ASSERT_TRUE(c != nullptr);
	Handle<mirror::Object> obj0 = hs.NewHandle(c->AllocObject(soa.Self()));
	ASSERT_TRUE(obj0 != nullptr);

	std::string error_msg;
	IndirectReferenceTable irt(kTableMax,
	kLocal,
	IndirectReferenceTable::ResizableCapacity::kYes,
	&error_msg);
	ASSERT_TRUE(irt.IsValid()) << error_msg;

	CheckDump(&irt, 0, 0);
	const IRTSegmentState cookie = kIRTFirstSegment;

	for (size_t i = 0; i != kTableMax + 1; ++i) {
	irt.Add(cookie, obj0.Get(), &error_msg);
	}

	EXPECT_EQ(irt.Capacity(), kTableMax + 1);
	}

	} // namespace art