source: trunk/src/kernel32/heapshared.cpp@ 8877

/* $Id: heapshared.cpp,v 1.9 2002-07-15 14:28:51 sandervl Exp $ */
/*
 * Shared heap functions for OS/2
 *
 * Initially commit 16 kb, add more when required
 *
 * NOTE: Hardcoded limit of 512 KB (increase when required)
 *
 * TODO: Not process/thread safe (initializing/destroying heap)
 * 
 * ASSUMPTION: Rtl library takes care of protection of heap increase/decrease
 *             (from multiple threads/processes)
 *
 * Copyright 1999 Sander van Leeuwen (sandervl@xs4all.nl)
 *
 */
#define INCL_BASE
#define INCL_DOSMEMMGR
#include <os2wrap.h>
#include <misc.h>
#include <heapshared.h>

#define DBG_LOCALLOG    DBG_heapshared
#include "dbglocal.h"

//Global DLL Data
#pragma data_seg(_GLOBALDATA)
       Heap_t  sharedHeap = 0;
static PVOID   pSharedMem = NULL;
static BYTE    pageBitmap[MAX_HEAPPAGES] = {0};
static ULONG   refCount = 0;
#pragma data_seg()

void * _LNK_CONV getmoreShared(Heap_t pHeap, size_t *size, int *clean);
void _LNK_CONV releaseShared(Heap_t pHeap, void *block, size_t size);

//******************************************************************************
//******************************************************************************
BOOL InitializeSharedHeap()
{
    APIRET rc;

    if(pSharedMem == NULL) {
            rc = DosAllocSharedMem(&pSharedMem, NULL, MAX_HEAPSIZE, PAG_READ|PAG_WRITE|OBJ_GETTABLE);
            if(rc != 0) {
                dprintf(("InitializeSharedHeap: DosAllocSharedMem failed with %d", rc));
                    return FALSE;
            }
            rc = DosSetMem(pSharedMem, INCR_HEAPSIZE, PAG_READ|PAG_WRITE|PAG_COMMIT);
            if(rc != 0) {
                DosFreeMem(pSharedMem);
                    dprintf(("InitializeSharedHeap: DosSetMem failed with %d", rc));
                    return FALSE;
            }
            sharedHeap = _ucreate(pSharedMem, INCR_HEAPSIZE, _BLOCK_CLEAN, _HEAP_REGULAR|_HEAP_SHARED,
                                  getmoreShared, releaseShared);

            if(sharedHeap == NULL) {
                DosFreeMem(pSharedMem);
                    dprintf(("InitializeSharedHeap: _ucreate failed!"));
                    return FALSE;
            }
            dprintf(("KERNEL32: First InitializeSharedHeap %x %x", pSharedMem, sharedHeap));
            for(int i=0;i<INCR_HEAPSIZE/PAGE_SIZE;i++) {
                pageBitmap[i] = 1; //mark as committed
        }
    }
    else {
        if(DosGetSharedMem(pSharedMem, PAG_READ|PAG_WRITE) != 0) {
                    dprintf(("InitializeSharedHeap: DosGetSharedMem failed!"));
                    return FALSE;
            }
            dprintf(("KERNEL32: InitializeSharedHeap %x %x refcount %d", pSharedMem, sharedHeap, refCount));
            if(_uopen(sharedHeap) != 0) {
                dprintf(("InitializeSharedHeap: unable to open shared heap!"));
                    return FALSE;
            }
    }
    refCount++;
    return TRUE;
}
//******************************************************************************
//******************************************************************************
void DestroySharedHeap()
{
    dprintf(("KERNEL32: DestroySharedHeap %d", refCount));
    if(--refCount == 0) {
            if(sharedHeap) {
                _uclose(sharedHeap);
                    _udestroy(sharedHeap, _FORCE);
                    sharedHeap = NULL;
            }
            if(pSharedMem) {
                DosFreeMem(pSharedMem);
                    pSharedMem = NULL;
            }
    }
    else {
        _uclose(sharedHeap);
    }
}
//******************************************************************************
//******************************************************************************
ULONG GetPageRangeFree(ULONG pageoffset)
{
    dprintf(("KERNEL32: GetPageRangeFree(%08xh)", pageoffset));

    for(int i=pageoffset;i<MAX_HEAPPAGES;i++) {
        if(pageBitmap[i] == 1) {
                    break;
            }
    }
    return i-pageoffset;
}
//******************************************************************************
//******************************************************************************
void * _LNK_CONV getmoreShared(Heap_t pHeap, size_t *size, int *clean)
{
    APIRET rc;
    ULONG newsize;
    PVOID newblock;

    dprintf(("KERNEL32: getmoreShared(%08xh, %08xh, %08xh)\n", pHeap, *size, *clean));

    /* round the size up to a multiple of 4K */
    // *size = (*size / 4096) * 4096 + 4096;
    // @@@PH speed improvement
    *size = (*size + 4096) & 0xFFFFF000;
    *size = max(*size, INCR_HEAPSIZE);

    for(int i=0;i<MAX_HEAPPAGES;i++)
    {
        int nrpagesfree = GetPageRangeFree(i);
        if(nrpagesfree >= *size/PAGE_SIZE) {
                    newblock = (PVOID)((ULONG)pSharedMem + i*PAGE_SIZE);
                    rc = DosSetMem(newblock, *size, PAG_READ|PAG_WRITE|PAG_COMMIT);
                    if(rc != 0) {
                        dprintf(("getmoreShared: DosSetMem failed with %d", rc));
                            return NULL;
                    }
                    for(int j=0;j < *size/PAGE_SIZE; j++)
            {
                            pageBitmap[i+j] = 1; //mark as committed
                    }

                    *clean = _BLOCK_CLEAN;
                    dprintf(("KERNEL32: getmoreShared %x %d", newblock, *size));
                    return newblock;
            }
            if(nrpagesfree)
                i += nrpagesfree-1;
    }
    dprintf(("KERNEL32: getmoreShared NOTHING LEFT (%d)", *size));
    return NULL;
}
//******************************************************************************
//******************************************************************************
void _LNK_CONV releaseShared(Heap_t pHeap, void *block, size_t size)
{
    ULONG pagenr;

    dprintf(("KERNEL32: releaseShared %x %d", block, size));
    DosSetMem(block, size, PAG_READ|PAG_WRITE|PAG_DECOMMIT);

    pagenr  = (ULONG)block - (ULONG)pSharedMem;
    pagenr /= PAGE_SIZE;
    for(int i=pagenr;i<pagenr+size/PAGE_SIZE;i++) {
            pageBitmap[i] = 0; //mark as decommitted
    }
}
//******************************************************************************
//******************************************************************************
DWORD  HeapGetSharedMemBase()
{
    dprintf(("KERNEL32: HeapGetSharedMemBase()\n"));
    return (DWORD) pSharedMem;
}
//******************************************************************************
//******************************************************************************