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pigweed / third_party / github / abseil / abseil-cpp / 1cf6469b372a0ab2787ad95f1ebb611c81b968b3
commit1cf6469b372a0ab2787ad95f1ebb611c81b968b3[log] [tgz]
authorAbseil Team <absl-team@google.com>Fri Sep 08 05:55:49 2023 -0700
committerCopybara-Service <copybara-worker@google.com>Fri Sep 08 05:56:44 2023 -0700
tree532947bb3c26e99758d91bad9e3e2787fb749f6a
parentb9980dd454cf1849721d81b201173f9ced53f6bc [diff]
absl: inline and de-dup Mutex::Await/LockWhen/CondVar::Wait

Mutex::Await/LockWhen/CondVar::Wait duplicate code, and cause additional
calls at runtime and code bloat.
Inline thin wrappers that just convert argument types and
add a single de-duped implementation for these methods.

This reduces code size, shaves off 55K from the mutex_test in release build,
and should make things marginally faster.

$ nm -nS mutex_test | egrep "(_ZN4absl5Mutex.*(Await|LockWhen))|(_ZN4absl7CondVar.*Wait)"

before:
00000000000912c0 00000000000001a8 T _ZN4absl7CondVar4WaitEPNS_5MutexE
00000000000988c0 0000000000000c36 T _ZN4absl7CondVar16WaitWithDeadlineEPNS_5MutexENS_4TimeE
000000000009a6e0 0000000000000041 T _ZN4absl5Mutex19LockWhenWithTimeoutERKNS_9ConditionENS_8DurationE
00000000000a28c0 0000000000000779 T _ZN4absl5Mutex17AwaitWithDeadlineERKNS_9ConditionENS_4TimeE
00000000000cf4e0 0000000000000011 T _ZN4absl5Mutex8LockWhenERKNS_9ConditionE
00000000000cf500 0000000000000041 T _ZN4absl5Mutex20LockWhenWithDeadlineERKNS_9ConditionENS_4TimeE
00000000000cf560 0000000000000011 T _ZN4absl5Mutex14ReaderLockWhenERKNS_9ConditionE
00000000000cf580 0000000000000041 T _ZN4absl5Mutex26ReaderLockWhenWithDeadlineERKNS_9ConditionENS_4TimeE
00000000000cf5e0 0000000000000766 T _ZN4absl5Mutex5AwaitERKNS_9ConditionE
00000000000cfd60 00000000000007b5 T _ZN4absl5Mutex16AwaitWithTimeoutERKNS_9ConditionENS_8DurationE
00000000000d0700 00000000000003cf T _ZN4absl7CondVar15WaitWithTimeoutEPNS_5MutexENS_8DurationE
000000000011c280 0000000000000041 T _ZN4absl5Mutex25ReaderLockWhenWithTimeoutERKNS_9ConditionENS_8DurationE

after:
000000000009c300 00000000000007ed T _ZN4absl7CondVar10WaitCommonEPNS_5MutexENS_24synchronization_internal13KernelTimeoutE
00000000000a03c0 00000000000006fe T _ZN4absl5Mutex11AwaitCommonERKNS_9ConditionENS_24synchronization_internal13KernelTimeoutE
000000000011ae00 0000000000000025 T _ZN4absl5Mutex14LockWhenCommonERKNS_9ConditionENS_24synchronization_internal13KernelTimeoutEb
PiperOrigin-RevId: 563729364
Change-Id: Ic6b43761f76719c01e03d43cc0e0c419e41a85c1
2 files changed
tree: 532947bb3c26e99758d91bad9e3e2787fb749f6a
  1. .github/
  2. absl/
  3. ci/
  4. CMake/
  5. .clang-format
  6. .gitignore
  7. ABSEIL_ISSUE_TEMPLATE.md
  8. AUTHORS
  9. BUILD.bazel
  10. CMakeLists.txt
  11. conanfile.py
  12. CONTRIBUTING.md
  13. create_lts.py
  14. FAQ.md
  15. LICENSE
  16. README.md
  17. UPGRADES.md
  18. WORKSPACE
README.md

Abseil - C++ Common Libraries

The repository contains the Abseil C++ library code. Abseil is an open-source collection of C++ code (compliant to C++14) designed to augment the C++ standard library.

Table of Contents

About Abseil

Abseil is an open-source collection of C++ library code designed to augment the C++ standard library. The Abseil library code is collected from Google's own C++ code base, has been extensively tested and used in production, and is the same code we depend on in our daily coding lives.

In some cases, Abseil provides pieces missing from the C++ standard; in others, Abseil provides alternatives to the standard for special needs we've found through usage in the Google code base. We denote those cases clearly within the library code we provide you.

Abseil is not meant to be a competitor to the standard library; we've just found that many of these utilities serve a purpose within our code base, and we now want to provide those resources to the C++ community as a whole.

Quickstart

If you want to just get started, make sure you at least run through the Abseil Quickstart. The Quickstart contains information about setting up your development environment, downloading the Abseil code, running tests, and getting a simple binary working.

Building Abseil

Bazel and CMake are the official build systems for Abseil. See the quickstart for more information on building Abseil using the Bazel build system. If you require CMake support, please check the CMake build instructions and CMake Quickstart.

Support

Abseil follows Google's Foundational C++ Support Policy. See this table for a list of currently supported versions compilers, platforms, and build tools.

Codemap

Abseil contains the following C++ library components:

  • base
    The base library contains initialization code and other code which all other Abseil code depends on. Code within base may not depend on any other code (other than the C++ standard library).
  • algorithm
    The algorithm library contains additions to the C++ <algorithm> library and container-based versions of such algorithms.
  • cleanup
    The cleanup library contains the control-flow-construct-like type absl::Cleanup which is used for executing a callback on scope exit.
  • container
    The container library contains additional STL-style containers, including Abseil's unordered “Swiss table” containers.
  • crc The crc library contains code for computing error-detecting cyclic redundancy checks on data.
  • debugging
    The debugging library contains code useful for enabling leak checks, and stacktrace and symbolization utilities.
  • flags
    The flags library contains code for handling command line flags for libraries and binaries built with Abseil.
  • hash
    The hash library contains the hashing framework and default hash functor implementations for hashable types in Abseil.
  • log
    The log library contains LOG and CHECK macros and facilities for writing logged messages out to disk, stderr, or user-extensible destinations.
  • memory
    The memory library contains memory management facilities that augment C++'s <memory> library.
  • meta
    The meta library contains compatible versions of type checks available within C++14 and C++17 versions of the C++ <type_traits> library.
  • numeric
    The numeric library contains 128-bit integer types as well as implementations of C++20's bitwise math functions.
  • profiling
    The profiling library contains utility code for profiling C++ entities. It is currently a private dependency of other Abseil libraries.
  • random
    The random library contains functions for generating psuedorandom values.
  • status
    The status library contains abstractions for error handling, specifically absl::Status and absl::StatusOr<T>.
  • strings
    The strings library contains a variety of strings routines and utilities, including a C++14-compatible version of the C++17 std::string_view type.
  • synchronization
    The synchronization library contains concurrency primitives (Abseil's absl::Mutex class, an alternative to std::mutex) and a variety of synchronization abstractions.
  • time
    The time library contains abstractions for computing with absolute points in time, durations of time, and formatting and parsing time within time zones.
  • types
    The types library contains non-container utility types, like a C++14-compatible version of the C++17 std::optional type.
  • utility
    The utility library contains utility and helper code.

Releases

Abseil recommends users “live-at-head” (update to the latest commit from the master branch as often as possible). However, we realize this philosophy doesn't work for every project, so we also provide Long Term Support Releases to which we backport fixes for severe bugs. See our release management document for more details.

License

The Abseil C++ library is licensed under the terms of the Apache license. See LICENSE for more information.

Links

For more information about Abseil: