tvl-depot/absl/synchronization/internal/create_thread_identity.h
Abseil Team 12bc53e031 Export of internal Abseil changes
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c99f979ad34f155fbeeea69b88bdc7458d89a21c by Derek Mauro <dmauro@google.com>:

Remove a floating point division by zero test.

This isn't testing behavior related to the library, and MSVC warns
about it in opt mode.

PiperOrigin-RevId: 285220804

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68b015491f0dbf1ab547994673281abd1f34cd4b by Gennadiy Rozental <rogeeff@google.com>:

This CL introduces following changes to the class FlagImpl:
* We eliminate the CommandLineFlagLocks struct. Instead callback guard and callback function are combined into a single CallbackData struct, while primary data lock is stored separately.
* CallbackData member of class FlagImpl is initially set to be nullptr and is only allocated and initialized when a flag's callback is being set. For most flags we do not pay for the extra space and extra absl::Mutex now.
* Primary data guard is stored in data_guard_ data member. This is a properly aligned character buffer of necessary size. During initialization of the flag we construct absl::Mutex in this space using placement new call.
* We now avoid extra value copy after successful attempt to parse value out of string. Instead we swap flag's current value with tentative value we just produced.

PiperOrigin-RevId: 285132636

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ed45d118fb818969eb13094cf7827c885dfc562c by Tom Manshreck <shreck@google.com>:

Change null-term* (and nul-term*) to NUL-term* in comments

PiperOrigin-RevId: 285036610

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729619017944db895ce8d6d29c1995aa2e5628a5 by Derek Mauro <dmauro@google.com>:

Use the Posix implementation of thread identity on MinGW.
Some versions of MinGW suffer from thread_local bugs.

PiperOrigin-RevId: 285022920

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39a25493503c76885bc3254c28f66a251c5b5bb0 by Greg Falcon <gfalcon@google.com>:

Implementation detail change.

Add further ABSL_NAMESPACE_BEGIN and _END annotation macros to files in Abseil.

PiperOrigin-RevId: 285012012
GitOrigin-RevId: c99f979ad34f155fbeeea69b88bdc7458d89a21c
Change-Id: I4c85d3704e45d11a9ac50d562f39640a6adbedc1
2019-12-12 15:37:13 -05:00

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/*
* Copyright 2017 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.
*/
// Interface for getting the current ThreadIdentity, creating one if necessary.
// See thread_identity.h.
//
// This file is separate from thread_identity.h because creating a new
// ThreadIdentity requires slightly higher level libraries (per_thread_sem
// and low_level_alloc) than accessing an existing one. This separation allows
// us to have a smaller //absl/base:base.
#ifndef ABSL_SYNCHRONIZATION_INTERNAL_CREATE_THREAD_IDENTITY_H_
#define ABSL_SYNCHRONIZATION_INTERNAL_CREATE_THREAD_IDENTITY_H_
#include "absl/base/internal/thread_identity.h"
#include "absl/base/port.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace synchronization_internal {
// Allocates and attaches a ThreadIdentity object for the calling thread.
// For private use only.
base_internal::ThreadIdentity* CreateThreadIdentity();
// A per-thread destructor for reclaiming associated ThreadIdentity objects.
// For private use only.
void ReclaimThreadIdentity(void* v);
// Returns the ThreadIdentity object representing the calling thread; guaranteed
// to be unique for its lifetime. The returned object will remain valid for the
// program's lifetime; although it may be re-assigned to a subsequent thread.
// If one does not exist for the calling thread, allocate it now.
inline base_internal::ThreadIdentity* GetOrCreateCurrentThreadIdentity() {
base_internal::ThreadIdentity* identity =
base_internal::CurrentThreadIdentityIfPresent();
if (ABSL_PREDICT_FALSE(identity == nullptr)) {
return CreateThreadIdentity();
}
return identity;
}
} // namespace synchronization_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_SYNCHRONIZATION_INTERNAL_CREATE_THREAD_IDENTITY_H_