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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#include "Hal.h"
#include "HalTypes.h"
#include <sys/types.h>
#include <sys/sysctl.h>
#include "mozilla/BitSet.h"
namespace mozilla::hal_impl {
mozilla::Maybe<hal::HeterogeneousCpuInfo> CreateHeterogeneousCpuInfo() {
#ifdef __aarch64__
// As of now on Apple Silicon the number of *.logicalcpu_max is the same as
// *.physicalcpu_max.
size_t len = sizeof(uint32_t);
uint32_t pCores = 0;
if (sysctlbyname("hw.perflevel0.logicalcpu_max", &pCores, &len, nullptr, 0)) {
return Nothing();
}
len = sizeof(uint32_t);
uint32_t eCores = 0;
if (sysctlbyname("hw.perflevel1.logicalcpu_max", &eCores, &len, nullptr, 0)) {
return Nothing();
}
hal::HeterogeneousCpuInfo info;
info.mTotalNumCpus = pCores + eCores;
// The API has currently a limit how many cpu cores it can tell about.
for (uint32_t i = 0; i < hal::HeterogeneousCpuInfo::MAX_CPUS; ++i) {
if (pCores) {
--pCores;
info.mBigCpus[i] = true;
} else if (eCores) {
--eCores;
info.mLittleCpus[i] = true;
} else {
break;
}
}
return Some(info);
#else
return Nothing();
#endif
}
const Maybe<hal::HeterogeneousCpuInfo>& GetHeterogeneousCpuInfo() {
static const Maybe<hal::HeterogeneousCpuInfo> cpuInfo =
CreateHeterogeneousCpuInfo();
return cpuInfo;
}
} // namespace mozilla::hal_impl