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5bf048b842
-- 730bb88bee556aa11fa19aa33e1434cb6fa78985 by Evan Brown <ezb@google.com>: Support missing allocator-related constructors in b-tree. See [reference](https://en.cppreference.com/w/cpp/container/set/set). Also use allocator_traits::select_on_container_copy_construction() to get allocator for copy construction. PiperOrigin-RevId: 339058322 -- b6cc121689ae3e452d1db2d66122cb198d25142b by Derek Mauro <dmauro@google.com>: Fix more sign-compare warnings PiperOrigin-RevId: 339057920 -- 0e2c62da1dcaf6529abab952bdcc96c6de2d9506 by Abseil Team <absl-team@google.com>: Add missing <limits> include PiperOrigin-RevId: 339054753 -- d5a9ec2d1e40fe6359e720942e4955009ee415ec by Derek Mauro <dmauro@google.com>: Stop disabling sign-compare warnings for non-test targets. Our users complain about these. This does not catch issues in header-only libraries (like btree.h) but we may work on those in the future PiperOrigin-RevId: 338967089 -- 0c062c542a4c61ea0f65d25811827c0858e3adde by Abseil Team <absl-team@google.com>: Improve cache-locality for ThreadIdentity and PerThreadSynch. This is a change based on an observation in RPC benchmarks that shows significant cycles being spent in waking up a thread, 99.8% of which was on cache misses. Investigating this a bit more, it turns out to be due to sharing the cache line with the waiter state. To fix this issue, the following changes are introduced: - Reorder fields in PerThreadSync so that it fits in a single cache line The size of this structure was 80 bytes before this change. Note: Manually inspected all booleans to make sure they are not modified by multiple threads concurrently. PiperOrigin-RevId: 338852058 -- a90d6f2b2346385017e32dd8ae1b5ca691a5863f by Derek Mauro <dmauro@google.com>: Delete GCC 4.9 test script. It is no longer supported PiperOrigin-RevId: 338779452 -- 7274008d4757e88869110be9db39d03d911ae2b5 by Abseil Team <absl-team@google.com>: Fix the usage example in which SetFlag should take a pointer. PiperOrigin-RevId: 338744529 GitOrigin-RevId: 730bb88bee556aa11fa19aa33e1434cb6fa78985 Change-Id: Iff99594c4022e60e482a392d334b376c7ae8883e
91 lines
2.8 KiB
C++
91 lines
2.8 KiB
C++
//
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// Copyright 2020 The Abseil Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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// -----------------------------------------------------------------------------
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// File: reflection.h
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// -----------------------------------------------------------------------------
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//
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// This file defines the routines to access and operate on an Abseil Flag's
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// reflection handle.
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#ifndef ABSL_FLAGS_REFLECTION_H_
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#define ABSL_FLAGS_REFLECTION_H_
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#include <string>
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#include "absl/base/config.h"
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#include "absl/container/flat_hash_map.h"
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#include "absl/flags/commandlineflag.h"
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#include "absl/flags/internal/commandlineflag.h"
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namespace absl {
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ABSL_NAMESPACE_BEGIN
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namespace flags_internal {
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class FlagSaverImpl;
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} // namespace flags_internal
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// FindCommandLineFlag()
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//
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// Returns the reflection handle of an Abseil flag of the specified name, or
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// `nullptr` if not found. This function will emit a warning if the name of a
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// 'retired' flag is specified.
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absl::CommandLineFlag* FindCommandLineFlag(absl::string_view name);
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// Returns current state of the Flags registry in a form of mapping from flag
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// name to a flag reflection handle.
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absl::flat_hash_map<absl::string_view, absl::CommandLineFlag*> GetAllFlags();
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//------------------------------------------------------------------------------
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// FlagSaver
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//------------------------------------------------------------------------------
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//
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// A FlagSaver object stores the state of flags in the scope where the FlagSaver
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// is defined, allowing modification of those flags within that scope and
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// automatic restoration of the flags to their previous state upon leaving the
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// scope.
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//
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// A FlagSaver can be used within tests to temporarily change the test
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// environment and restore the test case to its previous state.
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//
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// Example:
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//
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// void MyFunc() {
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// absl::FlagSaver fs;
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// ...
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// absl::SetFlag(&FLAGS_myFlag, otherValue);
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// ...
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// } // scope of FlagSaver left, flags return to previous state
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//
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// This class is thread-safe.
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class FlagSaver {
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public:
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FlagSaver();
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~FlagSaver();
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FlagSaver(const FlagSaver&) = delete;
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void operator=(const FlagSaver&) = delete;
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private:
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flags_internal::FlagSaverImpl* impl_;
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};
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//-----------------------------------------------------------------------------
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ABSL_NAMESPACE_END
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} // namespace absl
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#endif // ABSL_FLAGS_REFLECTION_H_
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