#include <windows.h>
#include <stdio.h>
#include <stdlib.h>

static void EnableLockPagesPrivilege(void);

void main(int argc, char *argv[])
{
	SIZE_T		largePageSize = 0;
	HANDLE hmap;
	int pages = 1;

	largePageSize = GetLargePageMinimum();
	printf("large page size = %u\n", largePageSize);

	EnableLockPagesPrivilege();

	if (argc > 1)
		pages = atoi(argv[1]);
	printf("allocating %d large pages...\n", pages);

	hmap = CreateFileMapping(INVALID_HANDLE_VALUE, NULL,
		PAGE_READWRITE | SEC_COMMIT | SEC_LARGE_PAGES,
		0, largePageSize * pages,
		"myshmem");
	if (hmap)
		printf("allocated large pages successfully\n");
	else
		printf("CreateFileMapping failed: error code = %u", GetLastError());
}

static void
EnableLockPagesPrivilege(void)
{
	HANDLE hToken;
	TOKEN_PRIVILEGES tp;
	LUID luid;

	if (!OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, &hToken))
	{
		printf("OpenProcessToken failed: error code = %u", GetLastError());
		exit(1);
	}

	if (!LookupPrivilegeValue(NULL, SE_LOCK_MEMORY_NAME, &luid))
	{
		printf("LookupPrivilegeValue failed: error code = %u", GetLastError());
		exit(1);
	}
	tp.PrivilegeCount = 1;
	tp.Privileges[0].Luid = luid;
	tp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;

	if (!AdjustTokenPrivileges(hToken, FALSE, &tp, 0, NULL, NULL))
	{
		printf("AdjustTokenPrivileges failed: error code = %u", GetLastError());
		exit(1);
	}

	if (GetLastError() != ERROR_SUCCESS)
	{
		if (GetLastError() == ERROR_NOT_ALL_ASSIGNED)
			printf("could not enable Lock Pages in Memory user right");
		else
			printf("AdjustTokenPrivileges failed: error code = %u", GetLastError());
		exit(1);
	}

	CloseHandle(hToken);
}