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
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
|
///////////////////////////////////////////////////////////////////////////////
//
/// \file physmem.h
/// \brief Get the amount of physical memory
//
// Author: Lasse Collin
//
// This file has been put into the public domain.
// You can do whatever you want with this file.
//
///////////////////////////////////////////////////////////////////////////////
#ifndef PHYSMEM_H
#define PHYSMEM_H
#if defined(HAVE_PHYSMEM_SYSCONF)
# include <unistd.h>
#elif defined(HAVE_PHYSMEM_SYSCTL)
# ifdef HAVE_SYS_PARAM_H
# include <sys/param.h>
# endif
# ifdef HAVE_SYS_SYSCTL_H
# include <sys/sysctl.h>
# endif
#elif defined(HAVE_PHYSMEM_SYSINFO)
# include <sys/sysinfo.h>
#elif defined(_WIN32)
# ifndef _WIN32_WINNT
# define _WIN32_WINNT 0x0500
# endif
# include <windows.h>
#elif defined(__DJGPP__)
# include <dpmi.h>
#endif
/// \brief Get the amount of physical memory in bytes
///
/// \return Amount of physical memory in bytes. On error, zero is
/// returned.
static inline uint64_t
physmem(void)
{
uint64_t ret = 0;
#if defined(HAVE_PHYSMEM_SYSCONF)
const long pagesize = sysconf(_SC_PAGESIZE);
const long pages = sysconf(_SC_PHYS_PAGES);
if (pagesize != -1 || pages != -1)
// According to docs, pagesize * pages can overflow.
// Simple case is 32-bit box with 4 GiB or more RAM,
// which may report exactly 4 GiB of RAM, and "long"
// being 32-bit will overflow. Casting to uint64_t
// hopefully avoids overflows in the near future.
ret = (uint64_t)(pagesize) * (uint64_t)(pages);
#elif defined(HAVE_PHYSMEM_SYSCTL)
int name[2] = {
CTL_HW,
#ifdef HW_PHYSMEM64
HW_PHYSMEM64
#else
HW_PHYSMEM
#endif
};
union {
uint32_t u32;
uint64_t u64;
} mem;
size_t mem_ptr_size = sizeof(mem.u64);
if (!sysctl(name, 2, &mem.u64, &mem_ptr_size, NULL, NULL)) {
// IIRC, 64-bit "return value" is possible on some 64-bit
// BSD systems even with HW_PHYSMEM (instead of HW_PHYSMEM64),
// so support both.
if (mem_ptr_size == sizeof(mem.u64))
ret = mem.u64;
else if (mem_ptr_size == sizeof(mem.u32))
ret = mem.u32;
}
#elif defined(HAVE_PHYSMEM_SYSINFO)
struct sysinfo si;
if (sysinfo(&si) == 0)
ret = (uint64_t)(si.totalram) * si.mem_unit;
#elif defined(_WIN32)
if ((GetVersion() & 0xFF) >= 5) {
// Windows 2000 and later have GlobalMemoryStatusEx() which
// supports reporting values greater than 4 GiB. To keep the
// code working also on older Windows versions, use
// GlobalMemoryStatusEx() conditionally.
HMODULE kernel32 = GetModuleHandle("kernel32.dll");
if (kernel32 != NULL) {
BOOL (WINAPI *gmse)(LPMEMORYSTATUSEX) = GetProcAddress(
kernel32, "GlobalMemoryStatusEx");
if (gmse != NULL) {
MEMORYSTATUSEX meminfo;
meminfo.dwLength = sizeof(meminfo);
if (gmse(&meminfo))
ret = meminfo.ullTotalPhys;
}
}
}
if (ret == 0) {
// GlobalMemoryStatus() is supported by Windows 95 and later,
// so it is fine to link against it unconditionally. Note that
// GlobalMemoryStatus() has no return value.
MEMORYSTATUS meminfo;
meminfo.dwLength = sizeof(meminfo);
GlobalMemoryStatus(&meminfo);
ret = meminfo.dwTotalPhys;
}
#elif defined(__DJGPP__)
__dpmi_free_mem_info meminfo;
if (__dpmi_get_free_memory_information(&meminfo) == 0
&& meminfo.total_number_of_physical_pages
!= (unsigned long)(-1))
ret = (uint64_t)(meminfo.total_number_of_physical_pages)
* 4096;
#endif
return ret;
}
#endif
|
