tvl-depot/absl/container/internal/counting_allocator.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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2.5 KiB
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// Copyright 2018 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_CONTAINER_INTERNAL_COUNTING_ALLOCATOR_H_
#define ABSL_CONTAINER_INTERNAL_COUNTING_ALLOCATOR_H_
#include <cassert>
#include <cstdint>
#include <memory>
#include "absl/base/config.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
// This is a stateful allocator, but the state lives outside of the
// allocator (in whatever test is using the allocator). This is odd
// but helps in tests where the allocator is propagated into nested
// containers - that chain of allocators uses the same state and is
// thus easier to query for aggregate allocation information.
template <typename T>
class CountingAllocator : public std::allocator<T> {
public:
using Alloc = std::allocator<T>;
using pointer = typename Alloc::pointer;
using size_type = typename Alloc::size_type;
CountingAllocator() : bytes_used_(nullptr) {}
explicit CountingAllocator(int64_t* b) : bytes_used_(b) {}
template <typename U>
CountingAllocator(const CountingAllocator<U>& x)
: Alloc(x), bytes_used_(x.bytes_used_) {}
pointer allocate(size_type n,
std::allocator<void>::const_pointer hint = nullptr) {
assert(bytes_used_ != nullptr);
*bytes_used_ += n * sizeof(T);
return Alloc::allocate(n, hint);
}
void deallocate(pointer p, size_type n) {
Alloc::deallocate(p, n);
assert(bytes_used_ != nullptr);
*bytes_used_ -= n * sizeof(T);
}
template<typename U>
class rebind {
public:
using other = CountingAllocator<U>;
};
friend bool operator==(const CountingAllocator& a,
const CountingAllocator& b) {
return a.bytes_used_ == b.bytes_used_;
}
friend bool operator!=(const CountingAllocator& a,
const CountingAllocator& b) {
return !(a == b);
}
int64_t* bytes_used_;
};
} // namespace container_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_CONTAINER_INTERNAL_COUNTING_ALLOCATOR_H_