1、各平台调用接口

2、接口实现#if defined(_WIN32)

#include

#elif defined(__unix__) || defined(__unix) || defined(unix) || (defined(__APPLE__) && defined(__MACH__))

#include

#include

#include

#if defined(BSD)

#include

#endif

#else

#error "Unable to define getMemorySize( ) for an unknown OS."

#endif

size_t getMemorySize( )

{

#if defined(_WIN32) && (defined(__CYGWIN__) || defined(__CYGWIN32__))

/* Cygwin under Windows. ------------------------------------ */

/* New 64-bit MEMORYSTATUSEX isn't available. Use old 32.bit */

MEMORYSTATUS status;

status.dwLength = sizeof(status);

GlobalMemoryStatus( &status );

return (size_t)status.dwTotalPhys;

#elif defined(_WIN32)

/* Windows. ------------------------------------------------- */

/* Use new 64-bit MEMORYSTATUSEX, not old 32-bit MEMORYSTATUS */

MEMORYSTATUSEX status;

status.dwLength = sizeof(status);

GlobalMemoryStatusEx( &status );

return (size_t)status.ullTotalPhys;

#elif defined(__unix__) || defined(__unix) || defined(unix) || (defined(__APPLE__) && defined(__MACH__))

/* UNIX variants. ------------------------------------------- */

/* Prefer sysctl() over sysconf() except sysctl() HW_REALMEM and HW_PHYSMEM */

#if defined(CTL_HW) && (defined(HW_MEMSIZE) || defined(HW_PHYSMEM64))

int mib[2];

mib[0] = CTL_HW;

#if defined(HW_MEMSIZE)

mib[1] = HW_MEMSIZE; /* OSX. --------------------- */

#elif defined(HW_PHYSMEM64)

mib[1] = HW_PHYSMEM64; /* NetBSD, OpenBSD. --------- */

#endif

int64_t size = 0; /* 64-bit */

size_t len = sizeof( size );

if ( sysctl( mib, 2, &size, &len, NULL, 0 ) == 0 )

return (size_t)size;

return 0L; /* Failed? */

#elif defined(_SC_AIX_REALMEM)

/* AIX. ----------------------------------------------------- */

return (size_t)sysconf( _SC_AIX_REALMEM ) * (size_t)1024L;

#elif defined(_SC_PHYS_PAGES) && defined(_SC_PAGESIZE)

/* FreeBSD, Linux, OpenBSD, and Solaris. -------------------- */

return (size_t)sysconf( _SC_PHYS_PAGES ) *

(size_t)sysconf( _SC_PAGESIZE );

#elif defined(_SC_PHYS_PAGES) && defined(_SC_PAGE_SIZE)

/* Legacy. -------------------------------------------------- */

return (size_t)sysconf( _SC_PHYS_PAGES ) *

(size_t)sysconf( _SC_PAGE_SIZE );

#elif defined(CTL_HW) && (defined(HW_PHYSMEM) || defined(HW_REALMEM))

/* DragonFly BSD, FreeBSD, NetBSD, OpenBSD, and OSX. -------- */

int mib[2];

mib[0] = CTL_HW;

#if defined(HW_REALMEM)

mib[1] = HW_REALMEM; /* FreeBSD. ----------------- */

#elif defined(HW_PYSMEM)

mib[1] = HW_PHYSMEM; /* Others. ------------------ */

#endif

unsigned int size = 0; /* 32-bit */

size_t len = sizeof( size );

if ( sysctl( mib, 2, &size, &len, NULL, 0 ) == 0 )

return (size_t)size;

return 0L; /* Failed? */

#endif /* sysctl and sysconf variants */

#else

return 0L; /* Unknown OS. */

#endif

}

使用

size_t memorySize = getMemorySize( );