Export of internal Abseil changes
--
5ff0c4b38386ae80b25e9f8d0e1bac07fd7ce92c by Martijn Vels <mvels@google.com>:
Add CordzUpdateTracker class
PiperOrigin-RevId: 368469046
--
4de916b1ba4b5480b4dbe93d28c5eaa110449c66 by Derek Mauro <dmauro@google.com>:
Adds `ABSL_ATTRIBUTE_LIFETIME_BOUND` to `absl::Span`s initializer_list
constructor.
Compilers that support this attribute will emit a warning
if the parameter does not have sufficient lifetime.
For more information, see
https://github.com/abseil/abseil-cpp/blob/b97a1ecda869ca8754d467a56c50275cebfeb328/absl/types/span.h#L209-L248
PiperOrigin-RevId: 368429085
--
bb6669016412bf5afffc02d0818a66dfe1c524cf by Martijn Vels <mvels@google.com>:
Reorganize internal cord code in CMakeLists.txt into cord_internal library
PiperOrigin-RevId: 368423765
--
d1d7fce066172d5fcfa0310c4e27631d895d7e50 by Derek Mauro <dmauro@google.com>:
Internal change
PiperOrigin-RevId: 368346725
GitOrigin-RevId: 5ff0c4b38386ae80b25e9f8d0e1bac07fd7ce92c
Change-Id: Ic4627eab4f0274e400a6d12cde3341fb538de075
diff --git a/CMake/AbseilDll.cmake b/CMake/AbseilDll.cmake
index 253c73f..4527ca1 100644
--- a/CMake/AbseilDll.cmake
+++ b/CMake/AbseilDll.cmake
@@ -203,6 +203,7 @@
"strings/internal/cord_rep_ring.cc"
"strings/internal/cord_rep_ring.h"
"strings/internal/cord_rep_ring_reader.h"
+ "strings/internal/cordz_update_tracker.h"
"strings/internal/charconv_bigint.cc"
"strings/internal/charconv_bigint.h"
"strings/internal/charconv_parse.cc"
diff --git a/absl/strings/BUILD.bazel b/absl/strings/BUILD.bazel
index 123b5ef..1138516 100644
--- a/absl/strings/BUILD.bazel
+++ b/absl/strings/BUILD.bazel
@@ -297,6 +297,26 @@
)
cc_library(
+ name = "cordz_update_tracker",
+ hdrs = ["internal/cordz_update_tracker.h"],
+ copts = ABSL_DEFAULT_COPTS,
+ visibility = ["//visibility:private"],
+ deps = ["//absl/base:config"],
+)
+
+cc_test(
+ name = "cordz_update_tracker_test",
+ srcs = ["internal/cordz_update_tracker_test.cc"],
+ deps = [
+ ":cordz_update_tracker",
+ "//absl/base:config",
+ "//absl/base:core_headers",
+ "//absl/synchronization",
+ "@com_google_googletest//:gtest_main",
+ ],
+)
+
+cc_library(
name = "cord",
srcs = [
"cord.cc",
@@ -307,6 +327,7 @@
copts = ABSL_DEFAULT_COPTS,
deps = [
":cord_internal",
+ ":cordz_update_tracker",
":internal",
":str_format",
":strings",
diff --git a/absl/strings/CMakeLists.txt b/absl/strings/CMakeLists.txt
index 3b7ae63..0d93d5f 100644
--- a/absl/strings/CMakeLists.txt
+++ b/absl/strings/CMakeLists.txt
@@ -552,24 +552,71 @@
absl_cc_library(
NAME
+ cord_internal
+ HDRS
+ "internal/cord_internal.h"
+ "internal/cord_rep_flat.h"
+ "internal/cord_rep_ring.h"
+ "internal/cord_rep_ring_reader.h"
+ SRCS
+ "internal/cord_internal.cc"
+ "internal/cord_rep_ring.cc"
+ COPTS
+ ${ABSL_TEST_COPTS}
+ DEPS
+ absl::base_internal
+ absl::compressed_tuple
+ absl::config
+ absl::core_headers
+ absl::endian
+ absl::inlined_vector
+ absl::layout
+ absl::raw_logging_internal
+ absl::strings
+ absl::throw_delegate
+ absl::type_traits
+)
+
+absl_cc_library(
+ NAME
+ cordz_update_tracker
+ HDRS
+ "internal/cordz_update_tracker.h"
+ COPTS
+ ${ABSL_TEST_COPTS}
+ DEPS
+ absl::config
+)
+
+absl_cc_test(
+ NAME
+ cordz_update_tracker_test
+ SRCS
+ "internal/cordz_update_tracker_test.cc"
+ COPTS
+ ${ABSL_TEST_COPTS}
+ DEPS
+ absl::config
+ absl::cordz_update_tracker
+ absl::core_headers
+ absl::synchronization
+ gmock_main
+)
+
+absl_cc_library(
+ NAME
cord
HDRS
"cord.h"
SRCS
"cord.cc"
- "internal/cord_internal.cc"
- "internal/cord_internal.h"
- "internal/cord_rep_ring.h"
- "internal/cord_rep_ring.cc"
- "internal/cord_rep_ring_reader.h"
- "internal/cord_rep_flat.h"
COPTS
${ABSL_DEFAULT_COPTS}
DEPS
absl::base
- absl::base_internal
- absl::compressed_tuple
absl::config
+ absl::cord_internal
+ absl::cordz_update_tracker
absl::core_headers
absl::endian
absl::fixed_array
@@ -578,8 +625,6 @@
absl::optional
absl::raw_logging_internal
absl::strings
- absl::strings_internal
- absl::throw_delegate
absl::type_traits
PUBLIC
)
@@ -624,12 +669,12 @@
COPTS
${ABSL_TEST_COPTS}
DEPS
- absl::config
- absl::cord
- absl::strings
absl::base
+ absl::config
+ absl::cord_internal
absl::core_headers
absl::raw_logging_internal
+ absl::strings
gmock_main
)
@@ -641,9 +686,9 @@
COPTS
${ABSL_TEST_COPTS}
DEPS
- absl::cord
- absl::strings
absl::base
+ absl::cord_internal
absl::core_headers
+ absl::strings
gmock_main
)
diff --git a/absl/strings/internal/cordz_update_tracker.h b/absl/strings/internal/cordz_update_tracker.h
new file mode 100644
index 0000000..3c617e9
--- /dev/null
+++ b/absl/strings/internal/cordz_update_tracker.h
@@ -0,0 +1,96 @@
+// Copyright 2021 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.
+
+#ifndef ABSL_STRINGS_INTERNAL_CORDZ_UPDATE_TRACKER_H_
+#define ABSL_STRINGS_INTERNAL_CORDZ_UPDATE_TRACKER_H_
+
+#include <atomic>
+#include <cstdint>
+
+#include "absl/base/config.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace cord_internal {
+
+// CordzUpdateTracker tracks counters for Cord update methods.
+//
+// The purpose of CordzUpdateTracker is to track the number of calls to methods
+// updating Cord data for sampled cords. The class internally uses 'lossy'
+// atomic operations: Cord is thread-compatible, so there is no need to
+// synchronize updates. However, Cordz collection threads may call 'Value()' at
+// any point, so the class needs to provide thread safe access.
+//
+// This class is thread-safe. But as per above comments, all non-const methods
+// should be used single-threaded only: updates are thread-safe but lossy.
+class CordzUpdateTracker {
+ public:
+ // Tracked update methods.
+ enum MethodIdentifier {
+ kAssignString,
+ kAssignCord,
+ kMoveAssignCord,
+ kAppendString,
+ kAppendCord,
+ kMoveAppendCord,
+ kPrependString,
+ kPrependCord,
+ kMovePrependCord,
+ kAppendExternalMemory,
+ kFlatten,
+ kGetAppendRegion,
+ kRemovePrefix,
+ kRemoveSuffic,
+ kSubCord,
+
+ // kNumMethods defines the number of entries: must be the last entry.
+ kNumMethods,
+ };
+
+ // Constructs a new instance. All counters are zero-initialized.
+ constexpr CordzUpdateTracker() noexcept : values_{} {}
+
+ // Copy constructs a new instance.
+ CordzUpdateTracker(const CordzUpdateTracker& rhs) noexcept { *this = rhs; }
+
+ // Assigns the provided value to this instance.
+ CordzUpdateTracker& operator=(const CordzUpdateTracker& rhs) noexcept {
+ for (int i = 0; i < kNumMethods; ++i) {
+ values_[i].store(rhs.values_[i].load(std::memory_order_relaxed),
+ std::memory_order_relaxed);
+ }
+ return *this;
+ }
+
+ // Returns the value for the specified method.
+ int64_t Value(MethodIdentifier method) const {
+ return values_[method].load(std::memory_order_relaxed);
+ }
+
+ // Increases the value for the specified method by `n`
+ void LossyAdd(MethodIdentifier method, int64_t n = 1) {
+ auto& value = values_[method];
+ value.store(value.load(std::memory_order_relaxed) + n,
+ std::memory_order_relaxed);
+ }
+
+ private:
+ std::atomic<int64_t> values_[kNumMethods];
+};
+
+} // namespace cord_internal
+ABSL_NAMESPACE_END
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_CORDZ_UPDATE_TRACKER_H_
diff --git a/absl/strings/internal/cordz_update_tracker_test.cc b/absl/strings/internal/cordz_update_tracker_test.cc
new file mode 100644
index 0000000..4578204
--- /dev/null
+++ b/absl/strings/internal/cordz_update_tracker_test.cc
@@ -0,0 +1,130 @@
+// Copyright 2021 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 "absl/strings/internal/cordz_update_tracker.h"
+
+#include <array>
+#include <thread> // NOLINT
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "absl/base/attributes.h"
+#include "absl/base/config.h"
+#include "absl/synchronization/notification.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace cord_internal {
+namespace {
+
+using ::testing::AnyOf;
+using ::testing::Eq;
+
+using Method = CordzUpdateTracker::MethodIdentifier;
+using Methods = std::array<Method, Method::kNumMethods>;
+
+// Returns an array of all methods defined in `MethodIdentifier`
+Methods AllMethods() {
+ return Methods{Method::kAssignString, Method::kAssignCord,
+ Method::kMoveAssignCord, Method::kAppendString,
+ Method::kAppendCord, Method::kMoveAppendCord,
+ Method::kPrependString, Method::kPrependCord,
+ Method::kMovePrependCord, Method::kAppendExternalMemory,
+ Method::kFlatten, Method::kGetAppendRegion,
+ Method::kRemovePrefix, Method::kRemoveSuffic,
+ Method::kSubCord};
+}
+
+TEST(CordzUpdateTracker, IsConstExprAndInitializesToZero) {
+ constexpr CordzUpdateTracker tracker;
+ for (Method method : AllMethods()) {
+ ASSERT_THAT(tracker.Value(method), Eq(0));
+ }
+}
+
+TEST(CordzUpdateTracker, LossyAdd) {
+ int64_t n = 1;
+ CordzUpdateTracker tracker;
+ for (Method method : AllMethods()) {
+ tracker.LossyAdd(method, n);
+ EXPECT_THAT(tracker.Value(method), Eq(n));
+ n += 2;
+ }
+}
+
+TEST(CordzUpdateTracker, CopyConstructor) {
+ int64_t n = 1;
+ CordzUpdateTracker src;
+ for (Method method : AllMethods()) {
+ src.LossyAdd(method, n);
+ n += 2;
+ }
+
+ n = 1;
+ CordzUpdateTracker tracker(src);
+ for (Method method : AllMethods()) {
+ EXPECT_THAT(tracker.Value(method), Eq(n));
+ n += 2;
+ }
+}
+
+TEST(CordzUpdateTracker, OperatorAssign) {
+ int64_t n = 1;
+ CordzUpdateTracker src;
+ CordzUpdateTracker tracker;
+ for (Method method : AllMethods()) {
+ src.LossyAdd(method, n);
+ n += 2;
+ }
+
+ n = 1;
+ tracker = src;
+ for (Method method : AllMethods()) {
+ EXPECT_THAT(tracker.Value(method), Eq(n));
+ n += 2;
+ }
+}
+
+TEST(CordzUpdateTracker, ThreadSanitizedValueCheck) {
+ absl::Notification done;
+ CordzUpdateTracker tracker;
+
+ std::thread reader([&done, &tracker] {
+ while (!done.HasBeenNotified()) {
+ int n = 1;
+ for (Method method : AllMethods()) {
+ EXPECT_THAT(tracker.Value(method), AnyOf(Eq(n), Eq(0)));
+ n += 2;
+ }
+ }
+ int n = 1;
+ for (Method method : AllMethods()) {
+ EXPECT_THAT(tracker.Value(method), Eq(n));
+ n += 2;
+ }
+ });
+
+ int64_t n = 1;
+ for (Method method : AllMethods()) {
+ tracker.LossyAdd(method, n);
+ n += 2;
+ }
+ done.Notify();
+ reader.join();
+}
+
+} // namespace
+} // namespace cord_internal
+ABSL_NAMESPACE_END
+} // namespace absl
diff --git a/absl/types/span.h b/absl/types/span.h
index 95fe792..41db342 100644
--- a/absl/types/span.h
+++ b/absl/types/span.h
@@ -243,8 +243,8 @@
//
template <typename LazyT = T,
typename = EnableIfConstView<LazyT>>
- Span(
- std::initializer_list<value_type> v) noexcept // NOLINT(runtime/explicit)
+ Span(std::initializer_list<value_type> v
+ ABSL_ATTRIBUTE_LIFETIME_BOUND) noexcept // NOLINT(runtime/explicit)
: Span(v.begin(), v.size()) {}
// Accessors
