/*
 * Global heap functions
 *
 * Copyright 1995 Alexandre Julliard
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
/* 0xffff sometimes seems to mean: CURRENT_DS */

#include "config.h"
#include "wine/port.h"

#include <sys/types.h>
#include <stdlib.h>
#include <time.h>
#include <stdio.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#include <string.h>
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#ifdef HAVE_SYS_SYSCTL_H
#include <sys/sysctl.h>
#endif

#include "wine/winbase16.h"
#include "ntstatus.h"
#include "global.h"
#include "toolhelp.h"
#include "selectors.h"
#include "miscemu.h"
#include "stackframe.h"
#include "wine/debug.h"
#include "winerror.h"

WINE_DEFAULT_DEBUG_CHANNEL(global);

  /* Global arena block */
typedef struct
{
    DWORD     base;          /* Base address (0 if discarded) */
    DWORD     size;          /* Size in bytes (0 indicates a free block) */
    HGLOBAL16 handle;        /* Handle for this block */
    HGLOBAL16 hOwner;        /* Owner of this block */
    BYTE      lockCount;     /* Count of GlobalFix() calls */
    BYTE      pageLockCount; /* Count of GlobalPageLock() calls */
    BYTE      flags;         /* Allocation flags */
    BYTE      selCount;      /* Number of selectors allocated for this block */
} GLOBALARENA;

  /* Arena array */
/*static*/ GLOBALARENA *pGlobalArena = NULL;
/*static*/ int globalArenaSize = 0;

#define VALID_HANDLE(handle) (((handle)>>__AHSHIFT)<globalArenaSize)
#define GET_ARENA_PTR(handle)  (pGlobalArena + ((handle) >> __AHSHIFT))


/***********************************************************************
 *           GlobalLock16   (KERNEL32.25)
 *
 * This is the GlobalLock16() function used by 32-bit code.
 *
 * RETURNS
 *	Pointer to first byte of memory block
 *	NULL: Failure
 */
LPVOID WINAPI GlobalLock16(
              HGLOBAL16 handle /* [in] Handle of global memory object */
) {
    if (!handle) return 0;
    if (!VALID_HANDLE(handle))
	return 0;
    GET_ARENA_PTR(handle)->lockCount++;
    return (LPVOID)GET_ARENA_PTR(handle)->base;
}


/***********************************************************************
 *           FarGetOwner   (KERNEL.404)
 */
HANDLE16 WINAPI FarGetOwner16( HGLOBAL16 handle )
{
    if (!VALID_HANDLE(handle)) {
	WARN("Invalid handle 0x%04x passed to FarGetOwner!\n",handle);
	return 0;
    }
    return GET_ARENA_PTR(handle)->hOwner;
}