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-rw-r--r--absl/container/BUILD.bazel16
-rw-r--r--absl/container/CMakeLists.txt15
-rw-r--r--absl/container/internal/hashtablez_sampler.cc15
-rw-r--r--absl/container/internal/hashtablez_sampler.h9
-rw-r--r--absl/container/internal/hashtablez_sampler_test.cc19
-rw-r--r--absl/container/internal/raw_hash_set.h2
-rw-r--r--absl/container/internal/raw_hash_set_test.cc1
-rw-r--r--absl/container/sample_element_size_test.cc114
8 files changed, 180 insertions, 11 deletions
diff --git a/absl/container/BUILD.bazel b/absl/container/BUILD.bazel
index d1df524a..ffaee19c 100644
--- a/absl/container/BUILD.bazel
+++ b/absl/container/BUILD.bazel
@@ -876,6 +876,22 @@ cc_test(
],
)
+cc_test(
+ name = "sample_element_size_test",
+ srcs = ["sample_element_size_test.cc"],
+ copts = ABSL_TEST_COPTS,
+ linkopts = ABSL_DEFAULT_LINKOPTS,
+ tags = NOTEST_TAGS_NONMOBILE,
+ visibility = ["//visibility:private"],
+ deps = [
+ ":flat_hash_map",
+ ":flat_hash_set",
+ ":node_hash_map",
+ ":node_hash_set",
+ "@com_google_googletest//:gtest_main",
+ ],
+)
+
cc_library(
name = "btree",
srcs = [
diff --git a/absl/container/CMakeLists.txt b/absl/container/CMakeLists.txt
index 9b8a7509..78584d2c 100644
--- a/absl/container/CMakeLists.txt
+++ b/absl/container/CMakeLists.txt
@@ -894,3 +894,18 @@ absl_cc_test(
absl::unordered_map_modifiers_test
GTest::gmock_main
)
+
+absl_cc_test(
+ NAME
+ sample_element_size_test
+ SRCS
+ "sample_element_size_test.cc"
+ COPTS
+ ${ABSL_TEST_COPTS}
+ DEPS
+ absl::flat_hash_map
+ absl::flat_hash_set
+ absl::node_hash_map
+ absl::node_hash_set
+ GTest::gmock_main
+)
diff --git a/absl/container/internal/hashtablez_sampler.cc b/absl/container/internal/hashtablez_sampler.cc
index 7070912e..40cce047 100644
--- a/absl/container/internal/hashtablez_sampler.cc
+++ b/absl/container/internal/hashtablez_sampler.cc
@@ -55,6 +55,9 @@ HashtablezSampler& GlobalHashtablezSampler() {
return *sampler;
}
+// TODO(bradleybear): The comments at this constructors declaration say that the
+// fields are not initialized, but this definition does initialize the fields.
+// Something needs to be cleaned up.
HashtablezInfo::HashtablezInfo() { PrepareForSampling(); }
HashtablezInfo::~HashtablezInfo() = default;
@@ -98,10 +101,12 @@ static bool ShouldForceSampling() {
return state == kForce;
}
-HashtablezInfo* SampleSlow(int64_t* next_sample) {
+HashtablezInfo* SampleSlow(int64_t* next_sample, size_t inline_element_size) {
if (ABSL_PREDICT_FALSE(ShouldForceSampling())) {
*next_sample = 1;
- return GlobalHashtablezSampler().Register();
+ HashtablezInfo* result = GlobalHashtablezSampler().Register();
+ result->inline_element_size = inline_element_size;
+ return result;
}
#if !defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
@@ -123,10 +128,12 @@ HashtablezInfo* SampleSlow(int64_t* next_sample) {
// that case.
if (first) {
if (ABSL_PREDICT_TRUE(--*next_sample > 0)) return nullptr;
- return SampleSlow(next_sample);
+ return SampleSlow(next_sample, inline_element_size);
}
- return GlobalHashtablezSampler().Register();
+ HashtablezInfo* result = GlobalHashtablezSampler().Register();
+ result->inline_element_size = inline_element_size;
+ return result;
#endif
}
diff --git a/absl/container/internal/hashtablez_sampler.h b/absl/container/internal/hashtablez_sampler.h
index 812118e3..91fcdb34 100644
--- a/absl/container/internal/hashtablez_sampler.h
+++ b/absl/container/internal/hashtablez_sampler.h
@@ -91,6 +91,7 @@ struct HashtablezInfo : public profiling_internal::Sample<HashtablezInfo> {
absl::Time create_time;
int32_t depth;
void* stack[kMaxStackDepth];
+ size_t inline_element_size;
};
inline void RecordRehashSlow(HashtablezInfo* info, size_t total_probe_length) {
@@ -143,7 +144,7 @@ inline void RecordEraseSlow(HashtablezInfo* info) {
std::memory_order_relaxed);
}
-HashtablezInfo* SampleSlow(int64_t* next_sample);
+HashtablezInfo* SampleSlow(int64_t* next_sample, size_t inline_element_size);
void UnsampleSlow(HashtablezInfo* info);
#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
@@ -238,12 +239,14 @@ extern ABSL_PER_THREAD_TLS_KEYWORD int64_t global_next_sample;
// Returns an RAII sampling handle that manages registration and unregistation
// with the global sampler.
-inline HashtablezInfoHandle Sample() {
+inline HashtablezInfoHandle Sample(
+ size_t inline_element_size ABSL_ATTRIBUTE_UNUSED) {
#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
if (ABSL_PREDICT_TRUE(--global_next_sample > 0)) {
return HashtablezInfoHandle(nullptr);
}
- return HashtablezInfoHandle(SampleSlow(&global_next_sample));
+ return HashtablezInfoHandle(
+ SampleSlow(&global_next_sample, inline_element_size));
#else
return HashtablezInfoHandle(nullptr);
#endif // !ABSL_PER_THREAD_TLS
diff --git a/absl/container/internal/hashtablez_sampler_test.cc b/absl/container/internal/hashtablez_sampler_test.cc
index f053c19b..449619a3 100644
--- a/absl/container/internal/hashtablez_sampler_test.cc
+++ b/absl/container/internal/hashtablez_sampler_test.cc
@@ -78,10 +78,12 @@ HashtablezInfo* Register(HashtablezSampler* s, size_t size) {
TEST(HashtablezInfoTest, PrepareForSampling) {
absl::Time test_start = absl::Now();
+ const size_t test_element_size = 17;
HashtablezInfo info;
absl::MutexLock l(&info.init_mu);
info.PrepareForSampling();
+ info.inline_element_size = test_element_size;
EXPECT_EQ(info.capacity.load(), 0);
EXPECT_EQ(info.size.load(), 0);
EXPECT_EQ(info.num_erases.load(), 0);
@@ -93,6 +95,7 @@ TEST(HashtablezInfoTest, PrepareForSampling) {
EXPECT_EQ(info.hashes_bitwise_xor.load(), 0);
EXPECT_EQ(info.max_reserve.load(), 0);
EXPECT_GE(info.create_time, test_start);
+ EXPECT_EQ(info.inline_element_size, test_element_size);
info.capacity.store(1, std::memory_order_relaxed);
info.size.store(1, std::memory_order_relaxed);
@@ -116,6 +119,7 @@ TEST(HashtablezInfoTest, PrepareForSampling) {
EXPECT_EQ(info.hashes_bitwise_and.load(), ~size_t{});
EXPECT_EQ(info.hashes_bitwise_xor.load(), 0);
EXPECT_EQ(info.max_reserve.load(), 0);
+ EXPECT_EQ(info.inline_element_size, test_element_size);
EXPECT_GE(info.create_time, test_start);
}
@@ -154,9 +158,11 @@ TEST(HashtablezInfoTest, RecordInsert) {
}
TEST(HashtablezInfoTest, RecordErase) {
+ const size_t test_element_size = 29;
HashtablezInfo info;
absl::MutexLock l(&info.init_mu);
info.PrepareForSampling();
+ info.inline_element_size = test_element_size;
EXPECT_EQ(info.num_erases.load(), 0);
EXPECT_EQ(info.size.load(), 0);
RecordInsertSlow(&info, 0x0000FF00, 6 * kProbeLength);
@@ -164,12 +170,15 @@ TEST(HashtablezInfoTest, RecordErase) {
RecordEraseSlow(&info);
EXPECT_EQ(info.size.load(), 0);
EXPECT_EQ(info.num_erases.load(), 1);
+ EXPECT_EQ(info.inline_element_size, test_element_size);
}
TEST(HashtablezInfoTest, RecordRehash) {
+ const size_t test_element_size = 31;
HashtablezInfo info;
absl::MutexLock l(&info.init_mu);
info.PrepareForSampling();
+ info.inline_element_size = test_element_size;
RecordInsertSlow(&info, 0x1, 0);
RecordInsertSlow(&info, 0x2, kProbeLength);
RecordInsertSlow(&info, 0x4, kProbeLength);
@@ -188,6 +197,7 @@ TEST(HashtablezInfoTest, RecordRehash) {
EXPECT_EQ(info.total_probe_length.load(), 3);
EXPECT_EQ(info.num_erases.load(), 0);
EXPECT_EQ(info.num_rehashes.load(), 1);
+ EXPECT_EQ(info.inline_element_size, test_element_size);
}
TEST(HashtablezInfoTest, RecordReservation) {
@@ -208,12 +218,13 @@ TEST(HashtablezInfoTest, RecordReservation) {
#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
TEST(HashtablezSamplerTest, SmallSampleParameter) {
+ const size_t test_element_size = 31;
SetHashtablezEnabled(true);
SetHashtablezSampleParameter(100);
for (int i = 0; i < 1000; ++i) {
int64_t next_sample = 0;
- HashtablezInfo* sample = SampleSlow(&next_sample);
+ HashtablezInfo* sample = SampleSlow(&next_sample, test_element_size);
EXPECT_GT(next_sample, 0);
EXPECT_NE(sample, nullptr);
UnsampleSlow(sample);
@@ -221,12 +232,13 @@ TEST(HashtablezSamplerTest, SmallSampleParameter) {
}
TEST(HashtablezSamplerTest, LargeSampleParameter) {
+ const size_t test_element_size = 31;
SetHashtablezEnabled(true);
SetHashtablezSampleParameter(std::numeric_limits<int32_t>::max());
for (int i = 0; i < 1000; ++i) {
int64_t next_sample = 0;
- HashtablezInfo* sample = SampleSlow(&next_sample);
+ HashtablezInfo* sample = SampleSlow(&next_sample, test_element_size);
EXPECT_GT(next_sample, 0);
EXPECT_NE(sample, nullptr);
UnsampleSlow(sample);
@@ -234,13 +246,14 @@ TEST(HashtablezSamplerTest, LargeSampleParameter) {
}
TEST(HashtablezSamplerTest, Sample) {
+ const size_t test_element_size = 31;
SetHashtablezEnabled(true);
SetHashtablezSampleParameter(100);
int64_t num_sampled = 0;
int64_t total = 0;
double sample_rate = 0.0;
for (int i = 0; i < 1000000; ++i) {
- HashtablezInfoHandle h = Sample();
+ HashtablezInfoHandle h = Sample(test_element_size);
++total;
if (HashtablezInfoHandlePeer::IsSampled(h)) {
++num_sampled;
diff --git a/absl/container/internal/raw_hash_set.h b/absl/container/internal/raw_hash_set.h
index 47e5a228..12682b35 100644
--- a/absl/container/internal/raw_hash_set.h
+++ b/absl/container/internal/raw_hash_set.h
@@ -1643,7 +1643,7 @@ class raw_hash_set {
// bound more carefully.
if (std::is_same<SlotAlloc, std::allocator<slot_type>>::value &&
slots_ == nullptr) {
- infoz() = Sample();
+ infoz() = Sample(sizeof(slot_type));
}
char* mem = static_cast<char*>(Allocate<alignof(slot_type)>(
diff --git a/absl/container/internal/raw_hash_set_test.cc b/absl/container/internal/raw_hash_set_test.cc
index b46c4920..362b3cae 100644
--- a/absl/container/internal/raw_hash_set_test.cc
+++ b/absl/container/internal/raw_hash_set_test.cc
@@ -2075,6 +2075,7 @@ TEST(RawHashSamplerTest, Sample) {
std::memory_order_relaxed)]++;
reservations[info.max_reserve.load(std::memory_order_relaxed)]++;
}
+ EXPECT_EQ(info.inline_element_size, sizeof(int64_t));
++end_size;
});
diff --git a/absl/container/sample_element_size_test.cc b/absl/container/sample_element_size_test.cc
new file mode 100644
index 00000000..b23626b4
--- /dev/null
+++ b/absl/container/sample_element_size_test.cc
@@ -0,0 +1,114 @@
+// Copyright 2018 The Abseil Authors.
+//
+// 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
+//
+// https://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 "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "absl/container/flat_hash_map.h"
+#include "absl/container/flat_hash_set.h"
+#include "absl/container/node_hash_map.h"
+#include "absl/container/node_hash_set.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace container_internal {
+namespace {
+
+#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
+// Create some tables of type `Table`, then look at all the new
+// `HashtablezInfo`s to make sure that the `inline_element_size ==
+// expected_element_size`. The `inline_element_size` is the amount of memory
+// allocated for each slot of a hash table, that is `sizeof(slot_type)`. Add
+// the new `HashtablezInfo`s to `preexisting_info`. Store all the new tables
+// into `tables`.
+template <class Table>
+void TestInlineElementSize(
+ HashtablezSampler& sampler,
+ // clang-tidy gives a false positive on this declaration. This unordered
+ // set cannot be flat_hash_set, however, since that would introduce a mutex
+ // deadlock.
+ std::unordered_set<const HashtablezInfo*>& preexisting_info, // NOLINT
+ std::vector<Table>& tables, const typename Table::value_type& elt,
+ size_t expected_element_size) {
+ for (int i = 0; i < 10; ++i) {
+ // We create a new table and must store it somewhere so that when we store
+ // a pointer to the resulting `HashtablezInfo` into `preexisting_info`
+ // that we aren't storing a dangling pointer.
+ tables.emplace_back();
+ // We must insert an element to get a hashtablez to instantiate.
+ tables.back().insert(elt);
+ }
+ size_t new_count = 0;
+ sampler.Iterate([&](const HashtablezInfo& info) {
+ if (preexisting_info.insert(&info).second) {
+ EXPECT_EQ(info.inline_element_size, expected_element_size);
+ ++new_count;
+ }
+ });
+ // Make sure we actually did get a new hashtablez.
+ EXPECT_GT(new_count, 0);
+}
+
+struct bigstruct {
+ char a[1000];
+ friend bool operator==(const bigstruct& x, const bigstruct& y) {
+ return memcmp(x.a, y.a, sizeof(x.a)) == 0;
+ }
+ template <typename H>
+ friend H AbslHashValue(H h, const bigstruct& c) {
+ return H::combine_contiguous(std::move(h), c.a, sizeof(c.a));
+ }
+};
+#endif
+
+TEST(FlatHashMap, SampleElementSize) {
+#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
+ // Enable sampling even if the prod default is off.
+ SetHashtablezEnabled(true);
+ SetHashtablezSampleParameter(1);
+
+ auto& sampler = GlobalHashtablezSampler();
+ std::vector<flat_hash_map<int, bigstruct>> flat_map_tables;
+ std::vector<flat_hash_set<bigstruct>> flat_set_tables;
+ std::vector<node_hash_map<int, bigstruct>> node_map_tables;
+ std::vector<node_hash_set<bigstruct>> node_set_tables;
+
+ // It takes thousands of new tables after changing the sampling parameters
+ // before you actually get some instrumentation. And if you must actually
+ // put something into those tables.
+ for (int i = 0; i < 10000; ++i) {
+ flat_map_tables.emplace_back();
+ flat_map_tables.back()[i] = bigstruct{};
+ }
+
+ // clang-tidy gives a false positive on this declaration. This unordered set
+ // cannot be a flat_hash_set, however, since that would introduce a mutex
+ // deadlock.
+ std::unordered_set<const HashtablezInfo*> preexisting_info; // NOLINT
+ sampler.Iterate(
+ [&](const HashtablezInfo& info) { preexisting_info.insert(&info); });
+ TestInlineElementSize(sampler, preexisting_info, flat_map_tables,
+ {0, bigstruct{}}, sizeof(int) + sizeof(bigstruct));
+ TestInlineElementSize(sampler, preexisting_info, node_map_tables,
+ {0, bigstruct{}}, sizeof(void*));
+ TestInlineElementSize(sampler, preexisting_info, flat_set_tables, //
+ bigstruct{}, sizeof(bigstruct));
+ TestInlineElementSize(sampler, preexisting_info, node_set_tables, //
+ bigstruct{}, sizeof(void*));
+#endif
+}
+
+} // namespace
+} // namespace container_internal
+ABSL_NAMESPACE_END
+} // namespace absl
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-29 04:18:54 +0000