runtime/gc/heap_test.cc - LeafOS-Project/android_art - Gitiles

 /*
  * Copyright (C) 2011 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 <algorithm>

 #include "base/metrics/metrics.h"
 #include "class_linker-inl.h"
 #include "common_runtime_test.h"
 #include "gc/accounting/card_table-inl.h"
 #include "gc/accounting/space_bitmap-inl.h"
 #include "handle_scope-inl.h"
 #include "mirror/class-inl.h"
 #include "mirror/object-inl.h"
 #include "mirror/object_array-alloc-inl.h"
 #include "mirror/object_array-inl.h"
 #include "scoped_thread_state_change-inl.h"

 namespace art HIDDEN {
 namespace gc {

 class HeapTest : public CommonRuntimeTest {
  public:
   HeapTest() {
     use_boot_image_ = true;  // Make the Runtime creation cheaper.
   }

   void SetUp() override {
     MemMap::Init();
     std::string error_msg;
     // Reserve the preferred address to force the heap to use another one for testing.
     reserved_ = MemMap::MapAnonymous("ReserveMap",
                                      gc::Heap::kPreferredAllocSpaceBegin,
                                      16 * KB,
                                      PROT_READ,
                                      /*low_4gb=*/ true,
                                      /*reuse=*/ false,
                                      /*reservation=*/ nullptr,
                                      &error_msg);
     // There is no guarantee that reserved_ will be valid (due to ASLR). See b/175018342.
     CommonRuntimeTest::SetUp();
   }

  private:
   MemMap reserved_;
 };

 TEST_F(HeapTest, ClearGrowthLimit) {
   Heap* heap = Runtime::Current()->GetHeap();
   int64_t max_memory_before = heap->GetMaxMemory();
   int64_t total_memory_before = heap->GetTotalMemory();
   heap->ClearGrowthLimit();
   int64_t max_memory_after = heap->GetMaxMemory();
   int64_t total_memory_after = heap->GetTotalMemory();
   EXPECT_GE(max_memory_after, max_memory_before);
   EXPECT_GE(total_memory_after, total_memory_before);
 }

 TEST_F(HeapTest, GarbageCollectClassLinkerInit) {
   {
     ScopedObjectAccess soa(Thread::Current());
     // garbage is created during ClassLinker::Init

     StackHandleScope<1> hs(soa.Self());
     Handle<mirror::Class> c(
         hs.NewHandle(class_linker_->FindSystemClass(soa.Self(), "[Ljava/lang/Object;")));
     for (size_t i = 0; i < 1024; ++i) {
       StackHandleScope<1> hs2(soa.Self());
       Handle<mirror::ObjectArray<mirror::Object>> array(hs2.NewHandle(
           mirror::ObjectArray<mirror::Object>::Alloc(soa.Self(), c.Get(), 2048)));
       for (size_t j = 0; j < 2048; ++j) {
         ObjPtr<mirror::String> string =
             mirror::String::AllocFromModifiedUtf8(soa.Self(), "hello, world!");
         // handle scope operator -> deferences the handle scope before running the method.
         array->Set<false>(j, string);
       }
     }
   }
   Runtime::Current()->GetHeap()->CollectGarbage(/* clear_soft_references= */ false);
 }

 TEST_F(HeapTest, HeapBitmapCapacityTest) {
   uint8_t* heap_begin = reinterpret_cast<uint8_t*>(0x1000);
   const size_t heap_capacity = kObjectAlignment * (sizeof(intptr_t) * 8 + 1);
   accounting::ContinuousSpaceBitmap bitmap(
       accounting::ContinuousSpaceBitmap::Create("test bitmap", heap_begin, heap_capacity));
   mirror::Object* fake_end_of_heap_object =
       reinterpret_cast<mirror::Object*>(&heap_begin[heap_capacity - kObjectAlignment]);
   bitmap.Set(fake_end_of_heap_object);
 }

 TEST_F(HeapTest, DumpGCPerformanceOnShutdown) {
   Runtime::Current()->GetHeap()->CollectGarbage(/* clear_soft_references= */ false);
   Runtime::Current()->SetDumpGCPerformanceOnShutdown(true);
 }

 bool AnyIsFalse(bool x, bool y) { return !x || !y; }

 TEST_F(HeapTest, GCMetrics) {
   // Allocate a few string objects (to be collected), then trigger garbage
   // collection, and check that GC metrics are updated (where applicable).
   Heap* heap = Runtime::Current()->GetHeap();
   {
     constexpr const size_t kNumObj = 128;
     ScopedObjectAccess soa(Thread::Current());
     StackHandleScope<kNumObj> hs(soa.Self());
     for (size_t i = 0u; i < kNumObj; ++i) {
       Handle<mirror::String> string [[maybe_unused]] (
           hs.NewHandle(mirror::String::AllocFromModifiedUtf8(soa.Self(), "test")));
     }
     // Do one GC while the temporary objects are reachable, forcing the GC to scan something.
     // The subsequent GC at line 127 may not scan anything but will certainly free some bytes.
     // Together the two GCs ensure success of the test.
     heap->CollectGarbage(/* clear_soft_references= */ false);
   }
   heap->CollectGarbage(/* clear_soft_references= */ false);

   // ART Metrics.
   metrics::ArtMetrics* metrics = Runtime::Current()->GetMetrics();
   // ART full-heap GC metrics.
   metrics::MetricsBase<int64_t>* full_gc_collection_time = metrics->FullGcCollectionTime();
   metrics::MetricsBase<uint64_t>* full_gc_count = metrics->FullGcCount();
   metrics::MetricsBase<uint64_t>* full_gc_count_delta = metrics->FullGcCountDelta();
   metrics::MetricsBase<int64_t>* full_gc_throughput = metrics->FullGcThroughput();
   metrics::MetricsBase<int64_t>* full_gc_tracing_throughput = metrics->FullGcTracingThroughput();
   metrics::MetricsBase<uint64_t>* full_gc_throughput_avg = metrics->FullGcThroughputAvg();
   metrics::MetricsBase<uint64_t>* full_gc_tracing_throughput_avg =
       metrics->FullGcTracingThroughputAvg();
   metrics::MetricsBase<uint64_t>* full_gc_scanned_bytes = metrics->FullGcScannedBytes();
   metrics::MetricsBase<uint64_t>* full_gc_scanned_bytes_delta = metrics->FullGcScannedBytesDelta();
   metrics::MetricsBase<uint64_t>* full_gc_freed_bytes = metrics->FullGcFreedBytes();
   metrics::MetricsBase<uint64_t>* full_gc_freed_bytes_delta = metrics->FullGcFreedBytesDelta();
   metrics::MetricsBase<uint64_t>* full_gc_duration = metrics->FullGcDuration();
   metrics::MetricsBase<uint64_t>* full_gc_duration_delta = metrics->FullGcDurationDelta();
   // ART young-generation GC metrics.
   metrics::MetricsBase<int64_t>* young_gc_collection_time = metrics->YoungGcCollectionTime();
   metrics::MetricsBase<uint64_t>* young_gc_count = metrics->YoungGcCount();
   metrics::MetricsBase<uint64_t>* young_gc_count_delta = metrics->YoungGcCountDelta();
   metrics::MetricsBase<int64_t>* young_gc_throughput = metrics->YoungGcThroughput();
   metrics::MetricsBase<int64_t>* young_gc_tracing_throughput = metrics->YoungGcTracingThroughput();
   metrics::MetricsBase<uint64_t>* young_gc_throughput_avg = metrics->YoungGcThroughputAvg();
   metrics::MetricsBase<uint64_t>* young_gc_tracing_throughput_avg =
       metrics->YoungGcTracingThroughputAvg();
   metrics::MetricsBase<uint64_t>* young_gc_scanned_bytes = metrics->YoungGcScannedBytes();
   metrics::MetricsBase<uint64_t>* young_gc_scanned_bytes_delta =
       metrics->YoungGcScannedBytesDelta();
   metrics::MetricsBase<uint64_t>* young_gc_freed_bytes = metrics->YoungGcFreedBytes();
   metrics::MetricsBase<uint64_t>* young_gc_freed_bytes_delta = metrics->YoungGcFreedBytesDelta();
   metrics::MetricsBase<uint64_t>* young_gc_duration = metrics->YoungGcDuration();
   metrics::MetricsBase<uint64_t>* young_gc_duration_delta = metrics->YoungGcDurationDelta();

   CollectorType fg_collector_type = heap->GetForegroundCollectorType();
   if (fg_collector_type == kCollectorTypeCC || fg_collector_type == kCollectorTypeCMC) {
     // Only the Concurrent Copying and Concurrent Mark-Compact collectors enable
     // GC metrics at the moment.
     if (heap->GetUseGenerationalCC()) {
       // Check that full-heap and/or young-generation GC metrics are non-null
       // after trigerring the collection.
       EXPECT_PRED2(
           AnyIsFalse, full_gc_collection_time->IsNull(), young_gc_collection_time->IsNull());
       EXPECT_PRED2(AnyIsFalse, full_gc_count->IsNull(), young_gc_count->IsNull());
       EXPECT_PRED2(AnyIsFalse, full_gc_count_delta->IsNull(), young_gc_count_delta->IsNull());
       EXPECT_PRED2(AnyIsFalse, full_gc_throughput->IsNull(), young_gc_throughput->IsNull());
       EXPECT_PRED2(
           AnyIsFalse, full_gc_tracing_throughput->IsNull(), young_gc_tracing_throughput->IsNull());
       EXPECT_PRED2(AnyIsFalse, full_gc_throughput_avg->IsNull(), young_gc_throughput_avg->IsNull());
       EXPECT_PRED2(AnyIsFalse,
                    full_gc_tracing_throughput_avg->IsNull(),
                    young_gc_tracing_throughput_avg->IsNull());
       EXPECT_PRED2(AnyIsFalse, full_gc_scanned_bytes->IsNull(), young_gc_scanned_bytes->IsNull());
       EXPECT_PRED2(AnyIsFalse,
                    full_gc_scanned_bytes_delta->IsNull(),
                    young_gc_scanned_bytes_delta->IsNull());
       EXPECT_PRED2(AnyIsFalse, full_gc_freed_bytes->IsNull(), young_gc_freed_bytes->IsNull());
       EXPECT_PRED2(
           AnyIsFalse, full_gc_freed_bytes_delta->IsNull(), young_gc_freed_bytes_delta->IsNull());
       // We have observed that sometimes the GC duration (both for full-heap and
       // young-generation collections) is null (b/271112044). Temporarily
       // suspend the following checks while we investigate.
       //
       // TODO(b/271112044): Investigate and adjust these expectations and/or the
       // corresponding metric logic.
 #if 0
       EXPECT_PRED2(AnyIsFalse, full_gc_duration->IsNull(), young_gc_duration->IsNull());
       EXPECT_PRED2(AnyIsFalse, full_gc_duration_delta->IsNull(), young_gc_duration_delta->IsNull());
 #endif
     } else {
       // Check that only full-heap GC metrics are non-null after trigerring the collection.
       EXPECT_FALSE(full_gc_collection_time->IsNull());
       EXPECT_FALSE(full_gc_count->IsNull());
       EXPECT_FALSE(full_gc_count_delta->IsNull());
       EXPECT_FALSE(full_gc_throughput->IsNull());
       EXPECT_FALSE(full_gc_tracing_throughput->IsNull());
       EXPECT_FALSE(full_gc_throughput_avg->IsNull());
       EXPECT_FALSE(full_gc_tracing_throughput_avg->IsNull());
       EXPECT_FALSE(full_gc_scanned_bytes->IsNull());
       EXPECT_FALSE(full_gc_scanned_bytes_delta->IsNull());
       EXPECT_FALSE(full_gc_freed_bytes->IsNull());
       EXPECT_FALSE(full_gc_freed_bytes_delta->IsNull());
       EXPECT_FALSE(full_gc_duration->IsNull());
       EXPECT_FALSE(full_gc_duration_delta->IsNull());

       EXPECT_TRUE(young_gc_collection_time->IsNull());
       EXPECT_TRUE(young_gc_count->IsNull());
       EXPECT_TRUE(young_gc_count_delta->IsNull());
       EXPECT_TRUE(young_gc_throughput->IsNull());
       EXPECT_TRUE(young_gc_tracing_throughput->IsNull());
       EXPECT_TRUE(young_gc_throughput_avg->IsNull());
       EXPECT_TRUE(young_gc_tracing_throughput_avg->IsNull());
       EXPECT_TRUE(young_gc_scanned_bytes->IsNull());
       EXPECT_TRUE(young_gc_scanned_bytes_delta->IsNull());
       EXPECT_TRUE(young_gc_freed_bytes->IsNull());
       EXPECT_TRUE(young_gc_freed_bytes_delta->IsNull());
       EXPECT_TRUE(young_gc_duration->IsNull());
       EXPECT_TRUE(young_gc_duration_delta->IsNull());
     }
   } else {
     // Check that all metrics are null after trigerring the collection.
     EXPECT_TRUE(full_gc_collection_time->IsNull());
     EXPECT_TRUE(full_gc_count->IsNull());
     EXPECT_TRUE(full_gc_count_delta->IsNull());
     EXPECT_TRUE(full_gc_throughput->IsNull());
     EXPECT_TRUE(full_gc_tracing_throughput->IsNull());
     EXPECT_TRUE(full_gc_throughput_avg->IsNull());
     EXPECT_TRUE(full_gc_tracing_throughput_avg->IsNull());
     EXPECT_TRUE(full_gc_scanned_bytes->IsNull());
     EXPECT_TRUE(full_gc_scanned_bytes_delta->IsNull());
     EXPECT_TRUE(full_gc_freed_bytes->IsNull());
     EXPECT_TRUE(full_gc_freed_bytes_delta->IsNull());
     EXPECT_TRUE(full_gc_duration->IsNull());
     EXPECT_TRUE(full_gc_duration_delta->IsNull());

     EXPECT_TRUE(young_gc_collection_time->IsNull());
     EXPECT_TRUE(young_gc_count->IsNull());
     EXPECT_TRUE(young_gc_count_delta->IsNull());
     EXPECT_TRUE(young_gc_throughput->IsNull());
     EXPECT_TRUE(young_gc_tracing_throughput->IsNull());
     EXPECT_TRUE(young_gc_throughput_avg->IsNull());
     EXPECT_TRUE(young_gc_tracing_throughput_avg->IsNull());
     EXPECT_TRUE(young_gc_scanned_bytes->IsNull());
     EXPECT_TRUE(young_gc_scanned_bytes_delta->IsNull());
     EXPECT_TRUE(young_gc_freed_bytes->IsNull());
     EXPECT_TRUE(young_gc_freed_bytes_delta->IsNull());
     EXPECT_TRUE(young_gc_duration->IsNull());
     EXPECT_TRUE(young_gc_duration_delta->IsNull());
   }
 }

 class ZygoteHeapTest : public CommonRuntimeTest {
  public:
   ZygoteHeapTest() {
     use_boot_image_ = true;  // Make the Runtime creation cheaper.
   }

   void SetUpRuntimeOptions(RuntimeOptions* options) override {
     CommonRuntimeTest::SetUpRuntimeOptions(options);
     options->push_back(std::make_pair("-Xzygote", nullptr));
   }
 };

 TEST_F(ZygoteHeapTest, PreZygoteFork) {
   // Exercise Heap::PreZygoteFork() to check it does not crash.
   Runtime::Current()->GetHeap()->PreZygoteFork();
 }

 }  // namespace gc
 }  // namespace art
	/*
	* Copyright (C) 2011 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 <algorithm>

	#include "base/metrics/metrics.h"
	#include "class_linker-inl.h"
	#include "common_runtime_test.h"
	#include "gc/accounting/card_table-inl.h"
	#include "gc/accounting/space_bitmap-inl.h"
	#include "handle_scope-inl.h"
	#include "mirror/class-inl.h"
	#include "mirror/object-inl.h"
	#include "mirror/object_array-alloc-inl.h"
	#include "mirror/object_array-inl.h"
	#include "scoped_thread_state_change-inl.h"

	namespace art HIDDEN {
	namespace gc {

	class HeapTest : public CommonRuntimeTest {
	public:
	HeapTest() {
	use_boot_image_ = true; // Make the Runtime creation cheaper.
	}

	void SetUp() override {
	MemMap::Init();
	std::string error_msg;
	// Reserve the preferred address to force the heap to use another one for testing.
	reserved_ = MemMap::MapAnonymous("ReserveMap",
	gc::Heap::kPreferredAllocSpaceBegin,
	16 * KB,
	PROT_READ,
	/low_4gb=/ true,
	/reuse=/ false,
	/reservation=/ nullptr,
	&error_msg);
	// There is no guarantee that reserved_ will be valid (due to ASLR). See b/175018342.
	CommonRuntimeTest::SetUp();
	}

	private:
	MemMap reserved_;
	};

	TEST_F(HeapTest, ClearGrowthLimit) {
	Heap* heap = Runtime::Current()->GetHeap();
	int64_t max_memory_before = heap->GetMaxMemory();
	int64_t total_memory_before = heap->GetTotalMemory();
	heap->ClearGrowthLimit();
	int64_t max_memory_after = heap->GetMaxMemory();
	int64_t total_memory_after = heap->GetTotalMemory();
	EXPECT_GE(max_memory_after, max_memory_before);
	EXPECT_GE(total_memory_after, total_memory_before);
	}

	TEST_F(HeapTest, GarbageCollectClassLinkerInit) {
	{
	ScopedObjectAccess soa(Thread::Current());
	// garbage is created during ClassLinker::Init

	StackHandleScope<1> hs(soa.Self());
	Handle<mirror::Class> c(
	hs.NewHandle(class_linker_->FindSystemClass(soa.Self(), "[Ljava/lang/Object;")));
	for (size_t i = 0; i < 1024; ++i) {
	StackHandleScope<1> hs2(soa.Self());
	Handle<mirror::ObjectArray<mirror::Object>> array(hs2.NewHandle(
	mirror::ObjectArray<mirror::Object>::Alloc(soa.Self(), c.Get(), 2048)));
	for (size_t j = 0; j < 2048; ++j) {
	ObjPtr<mirror::String> string =
	mirror::String::AllocFromModifiedUtf8(soa.Self(), "hello, world!");
	// handle scope operator -> deferences the handle scope before running the method.
	array->Set<false>(j, string);
	}
	}
	}
	Runtime::Current()->GetHeap()->CollectGarbage(/* clear_soft_references= */ false);
	}

	TEST_F(HeapTest, HeapBitmapCapacityTest) {
	uint8_t* heap_begin = reinterpret_cast<uint8_t*>(0x1000);
	const size_t heap_capacity = kObjectAlignment * (sizeof(intptr_t) * 8 + 1);
	accounting::ContinuousSpaceBitmap bitmap(
	accounting::ContinuousSpaceBitmap::Create("test bitmap", heap_begin, heap_capacity));
	mirror::Object* fake_end_of_heap_object =
	reinterpret_cast<mirror::Object*>(&heap_begin[heap_capacity - kObjectAlignment]);
	bitmap.Set(fake_end_of_heap_object);
	}

	TEST_F(HeapTest, DumpGCPerformanceOnShutdown) {
	Runtime::Current()->GetHeap()->CollectGarbage(/* clear_soft_references= */ false);
	Runtime::Current()->SetDumpGCPerformanceOnShutdown(true);
	}

	bool AnyIsFalse(bool x, bool y) { return !x \|\| !y; }

	TEST_F(HeapTest, GCMetrics) {
	// Allocate a few string objects (to be collected), then trigger garbage
	// collection, and check that GC metrics are updated (where applicable).
	Heap* heap = Runtime::Current()->GetHeap();
	{
	constexpr const size_t kNumObj = 128;
	ScopedObjectAccess soa(Thread::Current());
	StackHandleScope<kNumObj> hs(soa.Self());
	for (size_t i = 0u; i < kNumObj; ++i) {
	Handle<mirror::String> string [[maybe_unused]] (
	hs.NewHandle(mirror::String::AllocFromModifiedUtf8(soa.Self(), "test")));
	}
	// Do one GC while the temporary objects are reachable, forcing the GC to scan something.
	// The subsequent GC at line 127 may not scan anything but will certainly free some bytes.
	// Together the two GCs ensure success of the test.
	heap->CollectGarbage(/* clear_soft_references= */ false);
	}
	heap->CollectGarbage(/* clear_soft_references= */ false);

	// ART Metrics.
	metrics::ArtMetrics* metrics = Runtime::Current()->GetMetrics();
	// ART full-heap GC metrics.
	metrics::MetricsBase<int64_t>* full_gc_collection_time = metrics->FullGcCollectionTime();
	metrics::MetricsBase<uint64_t>* full_gc_count = metrics->FullGcCount();
	metrics::MetricsBase<uint64_t>* full_gc_count_delta = metrics->FullGcCountDelta();
	metrics::MetricsBase<int64_t>* full_gc_throughput = metrics->FullGcThroughput();
	metrics::MetricsBase<int64_t>* full_gc_tracing_throughput = metrics->FullGcTracingThroughput();
	metrics::MetricsBase<uint64_t>* full_gc_throughput_avg = metrics->FullGcThroughputAvg();
	metrics::MetricsBase<uint64_t>* full_gc_tracing_throughput_avg =
	metrics->FullGcTracingThroughputAvg();
	metrics::MetricsBase<uint64_t>* full_gc_scanned_bytes = metrics->FullGcScannedBytes();
	metrics::MetricsBase<uint64_t>* full_gc_scanned_bytes_delta = metrics->FullGcScannedBytesDelta();
	metrics::MetricsBase<uint64_t>* full_gc_freed_bytes = metrics->FullGcFreedBytes();
	metrics::MetricsBase<uint64_t>* full_gc_freed_bytes_delta = metrics->FullGcFreedBytesDelta();
	metrics::MetricsBase<uint64_t>* full_gc_duration = metrics->FullGcDuration();
	metrics::MetricsBase<uint64_t>* full_gc_duration_delta = metrics->FullGcDurationDelta();
	// ART young-generation GC metrics.
	metrics::MetricsBase<int64_t>* young_gc_collection_time = metrics->YoungGcCollectionTime();
	metrics::MetricsBase<uint64_t>* young_gc_count = metrics->YoungGcCount();
	metrics::MetricsBase<uint64_t>* young_gc_count_delta = metrics->YoungGcCountDelta();
	metrics::MetricsBase<int64_t>* young_gc_throughput = metrics->YoungGcThroughput();
	metrics::MetricsBase<int64_t>* young_gc_tracing_throughput = metrics->YoungGcTracingThroughput();
	metrics::MetricsBase<uint64_t>* young_gc_throughput_avg = metrics->YoungGcThroughputAvg();
	metrics::MetricsBase<uint64_t>* young_gc_tracing_throughput_avg =
	metrics->YoungGcTracingThroughputAvg();
	metrics::MetricsBase<uint64_t>* young_gc_scanned_bytes = metrics->YoungGcScannedBytes();
	metrics::MetricsBase<uint64_t>* young_gc_scanned_bytes_delta =
	metrics->YoungGcScannedBytesDelta();
	metrics::MetricsBase<uint64_t>* young_gc_freed_bytes = metrics->YoungGcFreedBytes();
	metrics::MetricsBase<uint64_t>* young_gc_freed_bytes_delta = metrics->YoungGcFreedBytesDelta();
	metrics::MetricsBase<uint64_t>* young_gc_duration = metrics->YoungGcDuration();
	metrics::MetricsBase<uint64_t>* young_gc_duration_delta = metrics->YoungGcDurationDelta();

	CollectorType fg_collector_type = heap->GetForegroundCollectorType();
	if (fg_collector_type == kCollectorTypeCC \|\| fg_collector_type == kCollectorTypeCMC) {
	// Only the Concurrent Copying and Concurrent Mark-Compact collectors enable
	// GC metrics at the moment.
	if (heap->GetUseGenerationalCC()) {
	// Check that full-heap and/or young-generation GC metrics are non-null
	// after trigerring the collection.
	EXPECT_PRED2(
	AnyIsFalse, full_gc_collection_time->IsNull(), young_gc_collection_time->IsNull());
	EXPECT_PRED2(AnyIsFalse, full_gc_count->IsNull(), young_gc_count->IsNull());
	EXPECT_PRED2(AnyIsFalse, full_gc_count_delta->IsNull(), young_gc_count_delta->IsNull());
	EXPECT_PRED2(AnyIsFalse, full_gc_throughput->IsNull(), young_gc_throughput->IsNull());
	EXPECT_PRED2(
	AnyIsFalse, full_gc_tracing_throughput->IsNull(), young_gc_tracing_throughput->IsNull());
	EXPECT_PRED2(AnyIsFalse, full_gc_throughput_avg->IsNull(), young_gc_throughput_avg->IsNull());
	EXPECT_PRED2(AnyIsFalse,
	full_gc_tracing_throughput_avg->IsNull(),
	young_gc_tracing_throughput_avg->IsNull());
	EXPECT_PRED2(AnyIsFalse, full_gc_scanned_bytes->IsNull(), young_gc_scanned_bytes->IsNull());
	EXPECT_PRED2(AnyIsFalse,
	full_gc_scanned_bytes_delta->IsNull(),
	young_gc_scanned_bytes_delta->IsNull());
	EXPECT_PRED2(AnyIsFalse, full_gc_freed_bytes->IsNull(), young_gc_freed_bytes->IsNull());
	EXPECT_PRED2(
	AnyIsFalse, full_gc_freed_bytes_delta->IsNull(), young_gc_freed_bytes_delta->IsNull());
	// We have observed that sometimes the GC duration (both for full-heap and
	// young-generation collections) is null (b/271112044). Temporarily
	// suspend the following checks while we investigate.
	//
	// TODO(b/271112044): Investigate and adjust these expectations and/or the
	// corresponding metric logic.
	#if 0
	EXPECT_PRED2(AnyIsFalse, full_gc_duration->IsNull(), young_gc_duration->IsNull());
	EXPECT_PRED2(AnyIsFalse, full_gc_duration_delta->IsNull(), young_gc_duration_delta->IsNull());
	#endif
	} else {
	// Check that only full-heap GC metrics are non-null after trigerring the collection.
	EXPECT_FALSE(full_gc_collection_time->IsNull());
	EXPECT_FALSE(full_gc_count->IsNull());
	EXPECT_FALSE(full_gc_count_delta->IsNull());
	EXPECT_FALSE(full_gc_throughput->IsNull());
	EXPECT_FALSE(full_gc_tracing_throughput->IsNull());
	EXPECT_FALSE(full_gc_throughput_avg->IsNull());
	EXPECT_FALSE(full_gc_tracing_throughput_avg->IsNull());
	EXPECT_FALSE(full_gc_scanned_bytes->IsNull());
	EXPECT_FALSE(full_gc_scanned_bytes_delta->IsNull());
	EXPECT_FALSE(full_gc_freed_bytes->IsNull());
	EXPECT_FALSE(full_gc_freed_bytes_delta->IsNull());
	EXPECT_FALSE(full_gc_duration->IsNull());
	EXPECT_FALSE(full_gc_duration_delta->IsNull());

	EXPECT_TRUE(young_gc_collection_time->IsNull());
	EXPECT_TRUE(young_gc_count->IsNull());
	EXPECT_TRUE(young_gc_count_delta->IsNull());
	EXPECT_TRUE(young_gc_throughput->IsNull());
	EXPECT_TRUE(young_gc_tracing_throughput->IsNull());
	EXPECT_TRUE(young_gc_throughput_avg->IsNull());
	EXPECT_TRUE(young_gc_tracing_throughput_avg->IsNull());
	EXPECT_TRUE(young_gc_scanned_bytes->IsNull());
	EXPECT_TRUE(young_gc_scanned_bytes_delta->IsNull());
	EXPECT_TRUE(young_gc_freed_bytes->IsNull());
	EXPECT_TRUE(young_gc_freed_bytes_delta->IsNull());
	EXPECT_TRUE(young_gc_duration->IsNull());
	EXPECT_TRUE(young_gc_duration_delta->IsNull());
	}
	} else {
	// Check that all metrics are null after trigerring the collection.
	EXPECT_TRUE(full_gc_collection_time->IsNull());
	EXPECT_TRUE(full_gc_count->IsNull());
	EXPECT_TRUE(full_gc_count_delta->IsNull());
	EXPECT_TRUE(full_gc_throughput->IsNull());
	EXPECT_TRUE(full_gc_tracing_throughput->IsNull());
	EXPECT_TRUE(full_gc_throughput_avg->IsNull());
	EXPECT_TRUE(full_gc_tracing_throughput_avg->IsNull());
	EXPECT_TRUE(full_gc_scanned_bytes->IsNull());
	EXPECT_TRUE(full_gc_scanned_bytes_delta->IsNull());
	EXPECT_TRUE(full_gc_freed_bytes->IsNull());
	EXPECT_TRUE(full_gc_freed_bytes_delta->IsNull());
	EXPECT_TRUE(full_gc_duration->IsNull());
	EXPECT_TRUE(full_gc_duration_delta->IsNull());

	EXPECT_TRUE(young_gc_collection_time->IsNull());
	EXPECT_TRUE(young_gc_count->IsNull());
	EXPECT_TRUE(young_gc_count_delta->IsNull());
	EXPECT_TRUE(young_gc_throughput->IsNull());
	EXPECT_TRUE(young_gc_tracing_throughput->IsNull());
	EXPECT_TRUE(young_gc_throughput_avg->IsNull());
	EXPECT_TRUE(young_gc_tracing_throughput_avg->IsNull());
	EXPECT_TRUE(young_gc_scanned_bytes->IsNull());
	EXPECT_TRUE(young_gc_scanned_bytes_delta->IsNull());
	EXPECT_TRUE(young_gc_freed_bytes->IsNull());
	EXPECT_TRUE(young_gc_freed_bytes_delta->IsNull());
	EXPECT_TRUE(young_gc_duration->IsNull());
	EXPECT_TRUE(young_gc_duration_delta->IsNull());
	}
	}

	class ZygoteHeapTest : public CommonRuntimeTest {
	public:
	ZygoteHeapTest() {
	use_boot_image_ = true; // Make the Runtime creation cheaper.
	}

	void SetUpRuntimeOptions(RuntimeOptions* options) override {
	CommonRuntimeTest::SetUpRuntimeOptions(options);
	options->push_back(std::make_pair("-Xzygote", nullptr));
	}
	};

	TEST_F(ZygoteHeapTest, PreZygoteFork) {
	// Exercise Heap::PreZygoteFork() to check it does not crash.
	Runtime::Current()->GetHeap()->PreZygoteFork();
	}

	} // namespace gc
	} // namespace art