From b4a4a6b01fde193fde1be77bcec1712e82faf6a5 Mon Sep 17 00:00:00 2001 From: Derek Mauro Date: Wed, 9 Nov 2022 18:06:05 -0800 Subject: [PATCH] Replace std::atomic_flag with std::atomic to avoid the C++20 deprecation of ATOMIC_FLAG_INIT. Another option would have been to use macros to only initialize std::atomic_flag before C++20, but I decided to use one compilation path instead. The major difference between std::atomic_flag and std::atomic is that the former is guaranteed to be lock-free, but we already assume std::atomic is lock-free in many places. https://en.cppreference.com/w/cpp/atomic/atomic_flag PiperOrigin-RevId: 487397075 Change-Id: I3f1c539ec8b2ca58547282e69ed73e93243e8efe --- absl/debugging/internal/stacktrace_x86-inl.inc | 1 + absl/log/internal/log_message.cc | 8 ++++++-- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/absl/debugging/internal/stacktrace_x86-inl.inc b/absl/debugging/internal/stacktrace_x86-inl.inc index 9fbfcf76..2f8bf428 100644 --- a/absl/debugging/internal/stacktrace_x86-inl.inc +++ b/absl/debugging/internal/stacktrace_x86-inl.inc @@ -29,6 +29,7 @@ #include #include +#include "absl/base/attributes.h" #include "absl/base/macros.h" #include "absl/base/port.h" #include "absl/debugging/internal/address_is_readable.h" diff --git a/absl/log/internal/log_message.cc b/absl/log/internal/log_message.cc index a044a5a7..20050a04 100644 --- a/absl/log/internal/log_message.cc +++ b/absl/log/internal/log_message.cc @@ -372,12 +372,16 @@ void LogMessage::Flush() { } // Have we already seen a fatal message? - ABSL_CONST_INIT static std::atomic_flag seen_fatal = ATOMIC_FLAG_INIT; + ABSL_CONST_INIT static std::atomic seen_fatal(false); if (data_->entry.log_severity() == absl::LogSeverity::kFatal && absl::log_internal::ExitOnDFatal()) { // Exactly one LOG(FATAL) message is responsible for aborting the process, // even if multiple threads LOG(FATAL) concurrently. - data_->first_fatal = !seen_fatal.test_and_set(std::memory_order_relaxed); + bool expected_seen_fatal = false; + if (seen_fatal.compare_exchange_strong(expected_seen_fatal, true, + std::memory_order_relaxed)) { + data_->first_fatal = true; + } } data_->entry.text_message_with_prefix_and_newline_and_nul_ =