Add support for persistent sparse histograms.

base/metrics/sparse_histogram_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/metrics/sparse_histogram.h"
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram_base.h"
 #include "base/metrics/histogram_samples.h"
+#include "base/metrics/persistent_histogram_allocator.h"
+#include "base/metrics/persistent_memory_allocator.h"
 #include "base/metrics/sample_map.h"
 #include "base/metrics/statistics_recorder.h"
 #include "base/pickle.h"
 #include "base/strings/stringprintf.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 
-class SparseHistogramTest : public testing::Test {
+// Test parameter indicates if a persistent memory allocator should be used
+// for histogram allocation. False will allocate histograms from the process
+// heap.
+class SparseHistogramTest : public testing::TestWithParam<bool> {
  protected:
+  const int32_t kAllocatorMemorySize = 8 << 20;  // 8 MiB
+
+  SparseHistogramTest() : use_persistent_histogram_allocator_(GetParam()) {}
+
   void SetUp() override {
+    if (use_persistent_histogram_allocator_)
+      CreatePersistentMemoryAllocator();
+
     // Each test will have a clean state (no Histogram / BucketRanges
     // registered).
     InitializeStatisticsRecorder();
   }
 
-  void TearDown() override { UninitializeStatisticsRecorder(); }
+  void TearDown() override {
+    if (allocator_) {
+      ASSERT_FALSE(allocator_->IsFull());
+      ASSERT_FALSE(allocator_->IsCorrupt());
+    }
+    UninitializeStatisticsRecorder();
+    DestroyPersistentMemoryAllocator();
+  }
 
   void InitializeStatisticsRecorder() {
+    StatisticsRecorder::ResetForTesting();
     statistics_recorder_ = new StatisticsRecorder();
   }
 
   void UninitializeStatisticsRecorder() {
     delete statistics_recorder_;
     statistics_recorder_ = NULL;
   }
 
+  void CreatePersistentMemoryAllocator() {
+    // By getting the results-histogram before any persistent allocator
+    // is attached, that histogram is guaranteed not to be stored in
+    // any persistent memory segment (which simplifies some tests).
+    PersistentHistogramAllocator::GetCreateHistogramResultHistogram();
+
+    PersistentHistogramAllocator::CreateGlobalAllocatorOnLocalMemory(
+        kAllocatorMemorySize, 0, "SparseHistogramAllocatorTest");
+    allocator_ =
+        PersistentHistogramAllocator::GetGlobalAllocator()->memory_allocator();
+  }
+
+  void DestroyPersistentMemoryAllocator() {
+    allocator_ = nullptr;
+    PersistentHistogramAllocator::ReleaseGlobalAllocatorForTesting();
+  }
+
   scoped_ptr<SparseHistogram> NewSparseHistogram(const std::string& name) {
     return scoped_ptr<SparseHistogram>(new SparseHistogram(name));
   }
 
+  const bool use_persistent_histogram_allocator_;
+
   StatisticsRecorder* statistics_recorder_;
+  scoped_ptr<char[]> allocator_memory_;
+  PersistentMemoryAllocator* allocator_ = nullptr;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(SparseHistogramTest);
 };
 
-TEST_F(SparseHistogramTest, BasicTest) {
+// Run all HistogramTest cases with both heap and persistent memory.
+INSTANTIATE_TEST_CASE_P(HeapAndPersistent,
+                        SparseHistogramTest,
+                        testing::Bool());
+
+
+TEST_P(SparseHistogramTest, BasicTest) {
   scoped_ptr<SparseHistogram> histogram(NewSparseHistogram("Sparse"));
   scoped_ptr<HistogramSamples> snapshot(histogram->SnapshotSamples());
   EXPECT_EQ(0, snapshot->TotalCount());
   EXPECT_EQ(0, snapshot->sum());
 
   histogram->Add(100);
   scoped_ptr<HistogramSamples> snapshot1(histogram->SnapshotSamples());
   EXPECT_EQ(1, snapshot1->TotalCount());
   EXPECT_EQ(1, snapshot1->GetCount(100));
 
   histogram->Add(100);
   histogram->Add(101);
   scoped_ptr<HistogramSamples> snapshot2(histogram->SnapshotSamples());
   EXPECT_EQ(3, snapshot2->TotalCount());
   EXPECT_EQ(2, snapshot2->GetCount(100));
   EXPECT_EQ(1, snapshot2->GetCount(101));
 }
 
-TEST_F(SparseHistogramTest, BasicTestAddCount) {
+TEST_P(SparseHistogramTest, BasicTestAddCount) {
   scoped_ptr<SparseHistogram> histogram(NewSparseHistogram("Sparse"));
   scoped_ptr<HistogramSamples> snapshot(histogram->SnapshotSamples());
   EXPECT_EQ(0, snapshot->TotalCount());
   EXPECT_EQ(0, snapshot->sum());
 
   histogram->AddCount(100, 15);
   scoped_ptr<HistogramSamples> snapshot1(histogram->SnapshotSamples());
   EXPECT_EQ(15, snapshot1->TotalCount());
   EXPECT_EQ(15, snapshot1->GetCount(100));
 
   histogram->AddCount(100, 15);
   histogram->AddCount(101, 25);
   scoped_ptr<HistogramSamples> snapshot2(histogram->SnapshotSamples());
   EXPECT_EQ(55, snapshot2->TotalCount());
   EXPECT_EQ(30, snapshot2->GetCount(100));
   EXPECT_EQ(25, snapshot2->GetCount(101));
 }
 
-TEST_F(SparseHistogramTest, AddCount_LargeValuesDontOverflow) {
+TEST_P(SparseHistogramTest, AddCount_LargeValuesDontOverflow) {
   scoped_ptr<SparseHistogram> histogram(NewSparseHistogram("Sparse"));
   scoped_ptr<HistogramSamples> snapshot(histogram->SnapshotSamples());
   EXPECT_EQ(0, snapshot->TotalCount());
   EXPECT_EQ(0, snapshot->sum());
 
   histogram->AddCount(1000000000, 15);
   scoped_ptr<HistogramSamples> snapshot1(histogram->SnapshotSamples());
   EXPECT_EQ(15, snapshot1->TotalCount());
   EXPECT_EQ(15, snapshot1->GetCount(1000000000));
 
   histogram->AddCount(1000000000, 15);
   histogram->AddCount(1010000000, 25);
   scoped_ptr<HistogramSamples> snapshot2(histogram->SnapshotSamples());
   EXPECT_EQ(55, snapshot2->TotalCount());
   EXPECT_EQ(30, snapshot2->GetCount(1000000000));
   EXPECT_EQ(25, snapshot2->GetCount(1010000000));
   EXPECT_EQ(55250000000LL, snapshot2->sum());
 }
 
-TEST_F(SparseHistogramTest, MacroBasicTest) {
+TEST_P(SparseHistogramTest, MacroBasicTest) {
   UMA_HISTOGRAM_SPARSE_SLOWLY("Sparse", 100);
   UMA_HISTOGRAM_SPARSE_SLOWLY("Sparse", 200);
   UMA_HISTOGRAM_SPARSE_SLOWLY("Sparse", 100);
 
   StatisticsRecorder::Histograms histograms;
   StatisticsRecorder::GetHistograms(&histograms);
 
   ASSERT_EQ(1U, histograms.size());
   HistogramBase* sparse_histogram = histograms[0];
 
   EXPECT_EQ(SPARSE_HISTOGRAM, sparse_histogram->GetHistogramType());
   EXPECT_EQ("Sparse", sparse_histogram->histogram_name());
-  EXPECT_EQ(HistogramBase::kUmaTargetedHistogramFlag,
-            sparse_histogram->flags());
+  EXPECT_EQ(
+      HistogramBase::kUmaTargetedHistogramFlag |
+          (use_persistent_histogram_allocator_ ? HistogramBase::kIsPersistent
+                                               : 0),
+      sparse_histogram->flags());
 
   scoped_ptr<HistogramSamples> samples = sparse_histogram->SnapshotSamples();
   EXPECT_EQ(3, samples->TotalCount());
   EXPECT_EQ(2, samples->GetCount(100));
   EXPECT_EQ(1, samples->GetCount(200));
 }
 
-TEST_F(SparseHistogramTest, MacroInLoopTest) {
+TEST_P(SparseHistogramTest, MacroInLoopTest) {
   // Unlike the macros in histogram.h, SparseHistogram macros can have a
   // variable as histogram name.
   for (int i = 0; i < 2; i++) {
     std::string name = StringPrintf("Sparse%d", i + 1);
     UMA_HISTOGRAM_SPARSE_SLOWLY(name, 100);
   }
 
   StatisticsRecorder::Histograms histograms;
   StatisticsRecorder::GetHistograms(&histograms);
   ASSERT_EQ(2U, histograms.size());
 
   std::string name1 = histograms[0]->histogram_name();
   std::string name2 = histograms[1]->histogram_name();
   EXPECT_TRUE(("Sparse1" == name1 && "Sparse2" == name2) ||
               ("Sparse2" == name1 && "Sparse1" == name2));
 }
 
-TEST_F(SparseHistogramTest, Serialize) {
+TEST_P(SparseHistogramTest, Serialize) {
   scoped_ptr<SparseHistogram> histogram(NewSparseHistogram("Sparse"));
   histogram->SetFlags(HistogramBase::kIPCSerializationSourceFlag);
 
   Pickle pickle;
   histogram->SerializeInfo(&pickle);
 
   PickleIterator iter(pickle);
 
   int type;
   EXPECT_TRUE(iter.ReadInt(&type));
   EXPECT_EQ(SPARSE_HISTOGRAM, type);
 
   std::string name;
   EXPECT_TRUE(iter.ReadString(&name));
   EXPECT_EQ("Sparse", name);
 
   int flag;
   EXPECT_TRUE(iter.ReadInt(&flag));
   EXPECT_EQ(HistogramBase::kIPCSerializationSourceFlag, flag);
 
   // No more data in the pickle.
   EXPECT_FALSE(iter.SkipBytes(1));
 }
 
+TEST_P(SparseHistogramTest, FactoryTime) {
+  const int kTestCreateCount = 1 << 10;  // Must be power-of-2.
+  const int kTestLookupCount = 100000;
+  const int kTestAddCount = 100000;
+
+  // Create all histogram names in advance for accurate timing below.
+  std::vector<std::string> histogram_names;
+  for (int i = 0; i < kTestCreateCount; ++i) {
+    histogram_names.push_back(
+        StringPrintf("TestHistogram.%d", i % kTestCreateCount));
+  }
+
+  // Calculate cost of creating histograms.
+  TimeTicks create_start = TimeTicks::Now();
+  for (int i = 0; i < kTestCreateCount; ++i)
+    SparseHistogram::FactoryGet(histogram_names[i], HistogramBase::kNoFlags);
+  TimeDelta create_ticks = TimeTicks::Now() - create_start;
+  int64_t create_ms = create_ticks.InMilliseconds();
+
+  VLOG(1) << kTestCreateCount << " histogram creations took " << create_ms
+          << "ms or about "
+          << (create_ms * 1000000) / kTestCreateCount
+          << "ns each.";
+
+  // Calculate cost of looking up existing histograms.
+  TimeTicks lookup_start = TimeTicks::Now();
+  for (int i = 0; i < kTestLookupCount; ++i) {
+    // 6007 is co-prime with kTestCreateCount and so will do lookups in an
+    // order less likely to be cacheable (but still hit them all) should the
+    // underlying storage use the exact histogram name as the key.
+    const int i_mult = 6007;
+    static_assert(i_mult < INT_MAX / kTestCreateCount, "Multiplier too big");
+    int index = (i * i_mult) & (kTestCreateCount - 1);
+    SparseHistogram::FactoryGet(histogram_names[index],
+                                HistogramBase::kNoFlags);
+  }
+  TimeDelta lookup_ticks = TimeTicks::Now() - lookup_start;
+  int64_t lookup_ms = lookup_ticks.InMilliseconds();
+
+  VLOG(1) << kTestLookupCount << " histogram lookups took " << lookup_ms
+          << "ms or about "
+          << (lookup_ms * 1000000) / kTestLookupCount
+          << "ns each.";
+
+  // Calculate cost of accessing histograms.
+  HistogramBase* histogram =
+      SparseHistogram::FactoryGet(histogram_names[0], HistogramBase::kNoFlags);
+  ASSERT_TRUE(histogram);
+  TimeTicks add_start = TimeTicks::Now();
+  for (int i = 0; i < kTestAddCount; ++i)
+    histogram->Add(i & 127);
+  TimeDelta add_ticks = TimeTicks::Now() - add_start;
+  int64_t add_ms = add_ticks.InMilliseconds();
+
+  VLOG(1) << kTestAddCount << " histogram adds took " << add_ms
+          << "ms or about "
+          << (add_ms * 1000000) / kTestAddCount
+          << "ns each.";
+}
+
 }  // namespace base