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Diffstat (limited to 'Build/source/extra/xz-4.999.9beta/src/common/physmem.h')
-rw-r--r-- | Build/source/extra/xz-4.999.9beta/src/common/physmem.h | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/Build/source/extra/xz-4.999.9beta/src/common/physmem.h b/Build/source/extra/xz-4.999.9beta/src/common/physmem.h new file mode 100644 index 00000000000..63482c6c868 --- /dev/null +++ b/Build/source/extra/xz-4.999.9beta/src/common/physmem.h @@ -0,0 +1,134 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \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 + +// Test for Windows first, because we want to use Windows-specific code +// on Cygwin, which also has memory information available via sysconf(), but +// on Cygwin 1.5 and older it gives wrong results (from our point of view). +#if defined(_WIN32) || defined(__CYGWIN__) +# ifndef _WIN32_WINNT +# define _WIN32_WINNT 0x0500 +# endif +# include <windows.h> + +#elif 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(__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(_WIN32) || defined(__CYGWIN__) + 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(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(__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 |