1 files changed, 146 insertions, 0 deletions
diff --git a/src/common/tuklib_physmem.c b/src/common/tuklib_physmem.c
new file mode 100644
index 00000000..b2d21283
--- /dev/null
+++ b/src/common/tuklib_physmem.c
@@ -0,0 +1,146 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       tuklib_physmem.c
+/// \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.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "tuklib_physmem.h"
+
+// 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(__OS2__)
+#	define INCL_DOSMISC
+#	include <os2.h>
+
+#elif defined(__DJGPP__)
+#	include <dpmi.h>
+
+#elif defined(__VMS)
+#	include <lib$routines.h>
+#	include <syidef.h>
+#	include <ssdef.h>
+
+#elif defined(TUKLIB_PHYSMEM_SYSCONF)
+#	include <unistd.h>
+
+#elif defined(TUKLIB_PHYSMEM_SYSCTL)
+#	ifdef HAVE_SYS_PARAM_H
+#		include <sys/param.h>
+#	endif
+#	include <sys/sysctl.h>
+
+// This sysinfo() is Linux-specific.
+#elif defined(TUKLIB_PHYSMEM_SYSINFO)
+#	include <sys/sysinfo.h>
+#endif
+
+
+extern uint64_t
+tuklib_physmem(void)
+{
+	uint64_t ret = 0;
+
+#if defined(_WIN32) || defined(__CYGWIN__)
+	if ((GetVersion() & 0xFF) >= 5) {
+		// Windows 2000 and later have GlobalMemoryStatusEx() which
+		// supports reporting values greater than 4 GiB. To keep the
+		// code working also on older Windows versions, use
+		// GlobalMemoryStatusEx() conditionally.
+		HMODULE kernel32 = GetModuleHandle("kernel32.dll");
+		if (kernel32 != NULL) {
+			BOOL (WINAPI *gmse)(LPMEMORYSTATUSEX) = GetProcAddress(
+					kernel32, "GlobalMemoryStatusEx");
+			if (gmse != NULL) {
+				MEMORYSTATUSEX meminfo;
+				meminfo.dwLength = sizeof(meminfo);
+				if (gmse(&meminfo))
+					ret = meminfo.ullTotalPhys;
+			}
+		}
+	}
+
+	if (ret == 0) {
+		// GlobalMemoryStatus() is supported by Windows 95 and later,
+		// so it is fine to link against it unconditionally. Note that
+		// GlobalMemoryStatus() has no return value.
+		MEMORYSTATUS meminfo;
+		meminfo.dwLength = sizeof(meminfo);
+		GlobalMemoryStatus(&meminfo);
+		ret = meminfo.dwTotalPhys;
+	}
+
+#elif defined(__OS2__)
+	unsigned long mem;
+	if (DosQuerySysInfo(QSV_TOTPHYSMEM, QSV_TOTPHYSMEM,
+			&mem, sizeof(mem)) == 0)
+		ret = mem;
+
+#elif defined(__DJGPP__)
+	__dpmi_free_mem_info meminfo;
+	if (__dpmi_get_free_memory_information(&meminfo) == 0
+			&& meminfo.total_number_of_physical_pages
+				!= (unsigned long)-1)
+		ret = (uint64_t)meminfo.total_number_of_physical_pages * 4096;
+
+#elif defined(__VMS)
+	int vms_mem;
+	int val = SYI$_MEMSIZE;
+	if (LIB$GETSYI(&val, &vms_mem, 0, 0, 0, 0) == SS$_NORMAL)
+		ret = (uint64_t)vms_mem * 8192;
+
+#elif defined(TUKLIB_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(TUKLIB_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, 0) != -1) {
+		// 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(TUKLIB_PHYSMEM_SYSINFO)
+	struct sysinfo si;
+	if (sysinfo(&si) == 0)
+		ret = (uint64_t)si.totalram * si.mem_unit;
+#endif
+
+	return ret;
+}