vn-verdnaturachat/ios/Pods/Folly/folly/memory/MallctlHelper.h

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/*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* 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
*
* http://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.
*/
// Some helper functions for mallctl.
#pragma once
#include <folly/Likely.h>
#include <folly/memory/Malloc.h>
#include <stdexcept>
namespace folly {
namespace detail {
[[noreturn]] void handleMallctlError(const char* cmd, int err);
template <typename T>
void mallctlHelper(const char* cmd, T* out, T* in) {
if (UNLIKELY(!usingJEMalloc())) {
throw std::logic_error("Calling mallctl when not using jemalloc.");
}
size_t outLen = sizeof(T);
int err = mallctl(cmd, out, out ? &outLen : nullptr, in, in ? sizeof(T) : 0);
if (UNLIKELY(err != 0)) {
handleMallctlError(cmd, err);
}
}
} // namespace detail
template <typename T>
void mallctlRead(const char* cmd, T* out) {
detail::mallctlHelper(cmd, out, static_cast<T*>(nullptr));
}
template <typename T>
void mallctlWrite(const char* cmd, T in) {
detail::mallctlHelper(cmd, static_cast<T*>(nullptr), &in);
}
template <typename T>
void mallctlReadWrite(const char* cmd, T* out, T in) {
detail::mallctlHelper(cmd, out, &in);
}
inline void mallctlCall(const char* cmd) {
// Use <unsigned> rather than <void> to avoid sizeof(void).
mallctlRead<unsigned>(cmd, nullptr);
}
} // namespace folly