1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
|
// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BASE_SYSTEM_SYS_INFO_INTERNAL_H_
#define BASE_SYSTEM_SYS_INFO_INTERNAL_H_
#include "base/base_export.h"
#include "build/build_config.h"
#if BUILDFLAG(IS_APPLE)
#include <optional>
#endif
namespace base {
namespace internal {
template <typename T, T (*F)(void)>
class LazySysInfoValue {
public:
LazySysInfoValue() : value_(F()) {}
LazySysInfoValue(const LazySysInfoValue&) = delete;
LazySysInfoValue& operator=(const LazySysInfoValue&) = delete;
~LazySysInfoValue() = default;
T value() { return value_; }
private:
const T value_;
};
#if BUILDFLAG(IS_MAC)
// Exposed for testing.
BASE_EXPORT std::optional<int> NumberOfPhysicalProcessors();
// When CPU security mitigation is enabled, return number of "physical"
// cores and not the number of "logical" cores. CPU security mitigations
// disables hyper-threading for the current application, which effectively
// limits the number of concurrently executing threads to the number of
// physical cores.
std::optional<int> NumberOfProcessorsWhenCpuSecurityMitigationEnabled();
#endif
#if BUILDFLAG(IS_APPLE)
std::optional<int> GetSysctlIntValue(const char* key_name);
#endif
} // namespace internal
} // namespace base
#endif // BASE_SYSTEM_SYS_INFO_INTERNAL_H_
|
