Leaked source code of windows server 2003
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/******************************Module*Header*******************************\
* Module Name: heap.c
*
* This module contains the routines for a 2-d heap. It is used primarily
* for allocating space for device-format-bitmaps in off-screen memory.
*
* Off-screen bitmaps are a big deal on NT because:
*
* 1) It reduces the working set. Any bitmap stored in off-screen
* memory is a bitmap that isn't taking up space in main memory.
*
* 2) There is a speed win by using the accelerator hardware for
* drawing, in place of NT's GDI code. NT's GDI is written entirely
* in 'C++' and perhaps isn't as fast as it could be.
*
* 3) It leads naturally to nifty tricks that can take advantage of
* the hardware, such as MaskBlt support and cheap double buffering
* for OpenGL.
*
* The heap algorithm employed herein attempts to solve an unsolvable
* problem: the problem of keeping arbitrary sized bitmaps as packed as
* possible in a 2-d space, when the bitmaps can come and go at random.
*
* This problem is due entirely to the nature of the hardware for which this
* driver is written: the hardware treats everything as 2-d quantities. If
* the hardware bitmap pitch could be changed so that the bitmaps could be
* packed linearly in memory, the problem would be infinitely easier (it is
* much easier to track the memory, and the accelerator can be used to re-pack
* the heap to avoid segmentation).
*
* If your hardware can treat bitmaps as one dimensional quantities (as can
* the XGA and ATI), by all means please implement a new off-screen heap.
*
* When the heap gets full, old allocations will automatically be punted
* from off-screen and copied to DIBs, which we'll let GDI draw on.
*
* Note that this heap manages reverse-L shape off-screen memory
* configurations (where the scan pitch is longer than the visible screen,
* such as happens at 800x600 when the scan length must be a multiple of
* 1024).
*
* NOTE: All heap operations must be done under some sort of synchronization,
* whether it's controlled by GDI or explicitly by the driver. All
* the routines in this module assume that they have exclusive access
* to the heap data structures; multiple threads partying in here at
* the same time would be a Bad Thing. (By default, GDI does NOT
* synchronize drawing on device-created bitmaps.)
*
* Copyright (c) 1993-1994 Microsoft Corporation
\**************************************************************************/
#include "precomp.h"
#define OH_ALLOC_SIZE 4000 // Do all memory allocations in 4k chunks
#define OH_QUANTUM 8 // The minimum dimension of an allocation
#define CXCY_SENTINEL 0x7fffffff // The sentinel at the end of the available
// list has this very large 'cxcy' value
// This macro results in the available list being maintained with a
// cx-major, cy-minor sort:
#define CXCY(cx, cy) (((cx) << 16) | (cy))
/******************************Public*Routine******************************\
* OH* pohNewNode
*
* Allocates a basic memory unit in which we'll pack our data structures.
*
* Since we'll have a lot of OH nodes, most of which we will be
* occasionally traversing, we do our own memory allocation scheme to
* keep them densely packed in memory.
*
* It would be the worst possible thing for the working set to simply
* call EngAllocMem(sizeof(OH)) every time we needed a new node. There
* would be no locality; OH nodes would get scattered throughout memory,
* and as we traversed the available list for one of our allocations,
* it would be far more likely that we would hit a hard page fault.
\**************************************************************************/
OH* pohNewNode(
PDEV* ppdev)
{
LONG i;
LONG cOhs;
OHALLOC* poha;
OH* poh;
if (ppdev->heap.pohFreeList == NULL)
{
// We zero-init to initialize all the OH flags, and to help in
// debugging (we can afford to do this since we'll be doing this
// very infrequently):
poha = EngAllocMem(FL_ZERO_MEMORY, OH_ALLOC_SIZE, ALLOC_TAG);
if (poha == NULL)
return(NULL);
// Insert this OHALLOC at the begining of the OHALLOC chain:
poha->pohaNext = ppdev->heap.pohaChain;
ppdev->heap.pohaChain = poha;
// This has a '+ 1' because OHALLOC includes an extra OH in its
// structure declaration:
cOhs = (OH_ALLOC_SIZE - sizeof(OHALLOC)) / sizeof(OH) + 1;
// The big OHALLOC allocation is simply a container for a bunch of
// OH data structures in an array. The new OH data structures are
// linked together and added to the OH free list:
poh = &poha->aoh[0];
for (i = cOhs - 1; i != 0; i--)
{
poh->pohNext = poh + 1;
poh = poh + 1;
}
poh->pohNext = NULL;
ppdev->heap.pohFreeList = &poha->aoh[0];
}
poh = ppdev->heap.pohFreeList;
ppdev->heap.pohFreeList = poh->pohNext;
return(poh);
}
/******************************Public*Routine******************************\
* VOID vOhFreeNode
*
* Frees our basic data structure allocation unit by adding it to a free
* list.
*
\**************************************************************************/
VOID vOhFreeNode(
PDEV* ppdev,
OH* poh)
{
if (poh == NULL)
return;
poh->pohNext = ppdev->heap.pohFreeList;
ppdev->heap.pohFreeList = poh;
poh->ofl = 0;
}
/******************************Public*Routine******************************\
* OH* pohFree
*
* Frees an off-screen heap allocation. The free space will be combined
* with any adjacent free spaces to avoid segmentation of the 2-d heap.
*
* Note: A key idea here is that the data structure for the upper-left-
* most node must be kept at the same physical CPU memory so that
* adjacency links are kept correctly (when two free spaces are
* merged, the lower or right node can be freed).
*
\**************************************************************************/
OH* pohFree(
PDEV* ppdev,
OH* poh)
{
ULONG cxcy;
OH* pohBeside;
OH* pohNext;
OH* pohPrev;
if (poh == NULL)
return(NULL);
DISPDBG((1, "Freeing %li x %li at (%li, %li)",
poh->cx, poh->cy, poh->x, poh->y));
#if DEBUG_HEAP
{
RECTL rclBitmap;
RBRUSH_COLOR rbc;
LONG xOffset;
LONG yOffset;
rclBitmap.left = poh->x;
rclBitmap.top = poh->y;
rclBitmap.right = poh->x + poh->cx;
rclBitmap.bottom = poh->y + poh->cy;
xOffset = ppdev->xOffset;
yOffset = ppdev->yOffset;
ppdev->xOffset = 0;
ppdev->yOffset = 0;
ppdev->pfnFillSolid(ppdev, 1, &rclBitmap, LOGICAL_0, LOGICAL_0, rbc,
NULL);
ppdev->xOffset = xOffset;
ppdev->yOffset = yOffset;
}
#endif
// Update the uniqueness to show that space has been freed, so that
// we may decide to see if some DIBs can be moved back into off-screen
// memory:
ppdev->iHeapUniq++;
MergeLoop:
ASSERTDD(!(poh->ofl & OFL_PERMANENT), "Can't free permanents for now");
// Try merging with the right sibling:
pohBeside = poh->pohRight;
if ((pohBeside->ofl & OFL_AVAILABLE) &&
(pohBeside->cy == poh->cy) &&
(pohBeside->pohUp == poh->pohUp) &&
(pohBeside->pohDown == poh->pohDown) &&
(pohBeside->pohRight->pohLeft != pohBeside))
{
// Add the right rectangle to ours:
poh->cx += pohBeside->cx;
poh->pohRight = pohBeside->pohRight;
// Remove 'pohBeside' from the ??? list and free it:
pohBeside->pohNext->pohPrev = pohBeside->pohPrev;
pohBeside->pohPrev->pohNext = pohBeside->pohNext;
vOhFreeNode(ppdev, pohBeside);
goto MergeLoop;
}
// Try merging with the lower sibling:
pohBeside = poh->pohDown;
if ((pohBeside->ofl & OFL_AVAILABLE) &&
(pohBeside->cx == poh->cx) &&
(pohBeside->pohLeft == poh->pohLeft) &&
(pohBeside->pohRight == poh->pohRight) &&
(pohBeside->pohDown->pohUp != pohBeside))
{
poh->cy += pohBeside->cy;
poh->pohDown = pohBeside->pohDown;
pohBeside->pohNext->pohPrev = pohBeside->pohPrev;
pohBeside->pohPrev->pohNext = pohBeside->pohNext;
vOhFreeNode(ppdev, pohBeside);
goto MergeLoop;
}
// Try merging with the left sibling:
pohBeside = poh->pohLeft;
if ((pohBeside->ofl & OFL_AVAILABLE) &&
(pohBeside->cy == poh->cy) &&
(pohBeside->pohUp == poh->pohUp) &&
(pohBeside->pohDown == poh->pohDown) &&
(pohBeside->pohRight == poh) &&
(poh->pohRight->pohLeft != poh))
{
// We add our rectangle to the one to the left:
pohBeside->cx += poh->cx;
pohBeside->pohRight = poh->pohRight;
// Remove 'poh' from the ??? list and free it:
poh->pohNext->pohPrev = poh->pohPrev;
poh->pohPrev->pohNext = poh->pohNext;
vOhFreeNode(ppdev, poh);
poh = pohBeside;
goto MergeLoop;
}
// Try merging with the upper sibling:
pohBeside = poh->pohUp;
if ((pohBeside->ofl & OFL_AVAILABLE) &&
(pohBeside->cx == poh->cx) &&
(pohBeside->pohLeft == poh->pohLeft) &&
(pohBeside->pohRight == poh->pohRight) &&
(pohBeside->pohDown == poh) &&
(poh->pohDown->pohUp != poh))
{
pohBeside->cy += poh->cy;
pohBeside->pohDown = poh->pohDown;
poh->pohNext->pohPrev = poh->pohPrev;
poh->pohPrev->pohNext = poh->pohNext;
vOhFreeNode(ppdev, poh);
poh = pohBeside;
goto MergeLoop;
}
// Remove the node from the ???list if it was in use (we wouldn't
// want to do this for a OFL_PERMANENT node that had been freed):
poh->pohNext->pohPrev = poh->pohPrev;
poh->pohPrev->pohNext = poh->pohNext;
cxcy = CXCY(poh->cx, poh->cy);
// Insert the node into the available list:
pohNext = ppdev->heap.ohAvailable.pohNext;
while (pohNext->cxcy < cxcy)
{
pohNext = pohNext->pohNext;
}
pohPrev = pohNext->pohPrev;
pohPrev->pohNext = poh;
pohNext->pohPrev = poh;
poh->pohPrev = pohPrev;
poh->pohNext = pohNext;
poh->ofl = OFL_AVAILABLE;
poh->cxcy = cxcy;
// Return the node pointer for the new and improved available rectangle:
return(poh);
}
/******************************Public*Routine******************************\
* OH* pohAllocate
*
* Allocates space for an off-screen rectangle. It will attempt to find
* the smallest available free rectangle, and will allocate the block out
* of its upper-left corner. The remaining two rectangles will be placed
* on the available free space list.
*
* If the rectangle would have been large enough to fit into off-screen
* memory, but there is not enough available free space, we will boot
* bitmaps out of off-screen and into DIBs until there is enough room.
*
\**************************************************************************/
OH* pohAllocate(
PDEV* ppdev,
LONG cxThis, // Width of rectangle to be allocated
LONG cyThis, // Height of rectangle to be allocated
FLOH floh) // Allocation flags
{
ULONG cxcyThis; // Width and height search key
OH* pohThis; // Points to found available rectangle we'll use
ULONG cxcy; // Temporary versions
OH* pohNext;
OH* pohPrev;
LONG cxRem;
LONG cyRem;
OH* pohBelow;
LONG cxBelow;
LONG cyBelow;
OH* pohBeside;
LONG cxBeside;
LONG cyBeside;
DISPDBG((1, "Allocating %li x %li...", cxThis, cyThis));
ASSERTDD((cxThis > 0) && (cyThis > 0), "Illegal allocation size");
// Increase the width to get the proper alignment (thus ensuring that all
// allocations will be properly aligned):
cxThis = (cxThis + (HEAP_X_ALIGNMENT - 1)) & ~(HEAP_X_ALIGNMENT - 1);
// We can't succeed if the requested rectangle is larger than the
// largest possible available rectangle:
if ((cxThis > ppdev->heap.cxMax) || (cyThis > ppdev->heap.cyMax))
return(NULL);
// Find the first available rectangle the same size or larger than
// the requested one:
cxcyThis = CXCY(cxThis, cyThis);
pohThis = ppdev->heap.ohAvailable.pohNext;
while (pohThis->cxcy < cxcyThis)
{
pohThis = pohThis->pohNext;
}
while (pohThis->cy < cyThis)
{
pohThis = pohThis->pohNext;
}
if (pohThis->cxcy == CXCY_SENTINEL)
{
// There was no space large enough...
if (floh & FLOH_ONLY_IF_ROOM)
return(NULL);
// We couldn't find an available rectangle that was big enough
// to fit our request. So throw things out of the heap until we
// have room:
do {
pohThis = ppdev->heap.ohDfb.pohPrev; // Least-recently blitted
ASSERTDD(pohThis != &ppdev->heap.ohDfb, "Ran out of in-use entries");
// We can safely exit here if we have to:
pohThis = pohMoveOffscreenDfbToDib(ppdev, pohThis);
if (pohThis == NULL)
return(NULL);
} while ((pohThis->cx < cxThis) || (pohThis->cy < cyThis));
}
// We've now found an available rectangle that is the same size or
// bigger than our requested rectangle. We're going to use the
// upper-left corner of our found rectangle, and divide the unused
// remainder into two rectangles which will go on the available
// list.
// Compute the width of the unused rectangle to the right, and the
// height of the unused rectangle below:
cyRem = pohThis->cy - cyThis;
cxRem = pohThis->cx - cxThis;
// Given finite area, we wish to find the two rectangles that are
// most square -- i.e., the arrangement that gives two rectangles
// with the least perimiter:
cyBelow = cyRem;
cxBeside = cxRem;
if (cxRem <= cyRem)
{
cxBelow = cxThis + cxRem;
cyBeside = cyThis;
}
else
{
cxBelow = cxThis;
cyBeside = cyThis + cyRem;
}
// We only make new available rectangles of the unused right and bottom
// portions if they're greater in dimension than OH_QUANTUM (it hardly
// makes sense to do the book-work to keep around a 2-pixel wide
// available space, for example):
pohBeside = NULL;
if (cxBeside >= OH_QUANTUM)
{
pohBeside = pohNewNode(ppdev);
if (pohBeside == NULL)
return(NULL);
}
pohBelow = NULL;
if (cyBelow >= OH_QUANTUM)
{
pohBelow = pohNewNode(ppdev);
if (pohBelow == NULL)
{
vOhFreeNode(ppdev, pohBeside);
return(NULL);
}
// Insert this rectangle into the available list (which is
// sorted on ascending cxcy):
cxcy = CXCY(cxBelow, cyBelow);
pohNext = ppdev->heap.ohAvailable.pohNext;
while (pohNext->cxcy < cxcy)
{
pohNext = pohNext->pohNext;
}
pohPrev = pohNext->pohPrev;
pohPrev->pohNext = pohBelow;
pohNext->pohPrev = pohBelow;
pohBelow->pohPrev = pohPrev;
pohBelow->pohNext = pohNext;
// Now update the adjacency information:
pohBelow->pohLeft = pohThis->pohLeft;
pohBelow->pohUp = pohThis;
pohBelow->pohRight = pohThis->pohRight;
pohBelow->pohDown = pohThis->pohDown;
// Update the rest of the new node information:
pohBelow->cxcy = cxcy;
pohBelow->ofl = OFL_AVAILABLE;
pohBelow->x = pohThis->x;
pohBelow->y = pohThis->y + cyThis;
pohBelow->cx = cxBelow;
pohBelow->cy = cyBelow;
// Modify the current node to reflect the changes we've made:
pohThis->cy = cyThis;
}
if (cxBeside >= OH_QUANTUM)
{
// Insert this rectangle into the available list (which is
// sorted on ascending cxcy):
cxcy = CXCY(cxBeside, cyBeside);
pohNext = ppdev->heap.ohAvailable.pohNext;
while (pohNext->cxcy < cxcy)
{
pohNext = pohNext->pohNext;
}
pohPrev = pohNext->pohPrev;
pohPrev->pohNext = pohBeside;
pohNext->pohPrev = pohBeside;
pohBeside->pohPrev = pohPrev;
pohBeside->pohNext = pohNext;
// Now update the adjacency information:
pohBeside->pohUp = pohThis->pohUp;
pohBeside->pohLeft = pohThis;
pohBeside->pohDown = pohThis->pohDown;
pohBeside->pohRight = pohThis->pohRight;
// Update the rest of the new node information:
pohBeside->cxcy = cxcy;
pohBeside->ofl = OFL_AVAILABLE;
pohBeside->x = pohThis->x + cxThis;
pohBeside->y = pohThis->y;
pohBeside->cx = cxBeside;
pohBeside->cy = cyBeside;
// Modify the current node to reflect the changes we've made:
pohThis->cx = cxThis;
}
if (pohBelow != NULL)
{
pohThis->pohDown = pohBelow;
if ((pohBeside != NULL) && (cyBeside == pohThis->cy))
pohBeside->pohDown = pohBelow;
}
if (pohBeside != NULL)
{
pohThis->pohRight = pohBeside;
if ((pohBelow != NULL) && (cxBelow == pohThis->cx))
pohBelow->pohRight = pohBeside;
}
pohThis->ofl = OFL_INUSE;
pohThis->cxcy = CXCY(pohThis->cx, pohThis->cy);
pohThis->pdsurf = NULL; // Caller is responsible for
// setting this field
// Remove this from the available list:
pohThis->pohPrev->pohNext = pohThis->pohNext;
pohThis->pohNext->pohPrev = pohThis->pohPrev;
// Now insert this at the head of the DFB list:
pohThis->pohNext = ppdev->heap.ohDfb.pohNext;
pohThis->pohPrev = &ppdev->heap.ohDfb;
ppdev->heap.ohDfb.pohNext->pohPrev = pohThis;
ppdev->heap.ohDfb.pohNext = pohThis;
DISPDBG((1, " Allocated at (%li, %li)", pohThis->x, pohThis->y));
return(pohThis);
}
/******************************Public*Routine******************************\
* VOID vCalculateMaxmimum
*
* Traverses the list of in-use and available rectangles to find the one
* with the maximal area.
*
\**************************************************************************/
VOID vCalculateMaximum(
PDEV* ppdev)
{
OH* poh;
OH* pohSentinel;
LONG lArea;
LONG lMaxArea;
LONG cxMax;
LONG cyMax;
LONG i;
lMaxArea = 0;
cxMax = 0;
cyMax = 0;
// First time through, loop through the list of available rectangles:
pohSentinel = &ppdev->heap.ohAvailable;
for (i = 2; i != 0; i--)
{
for (poh = pohSentinel->pohNext; poh != pohSentinel; poh = poh->pohNext)
{
ASSERTDD(!(poh->ofl & OFL_PERMANENT),
"Permanent in available/DFB chain?");
// We don't have worry about this multiply overflowing
// because we are dealing in physical screen coordinates,
// which will probably never be more than 15 bits:
lArea = poh->cx * poh->cy;
if (lArea > lMaxArea)
{
cxMax = poh->cx;
cyMax = poh->cy;
lMaxArea = lArea;
}
}
// Second time through, loop through the list of in-use rectangles:
pohSentinel = &ppdev->heap.ohDfb;
}
// All that we are interested in is the dimensions of the rectangle
// that has the largest possible available area (and remember that
// there might not be any possible available area):
ppdev->heap.cxMax = cxMax;
ppdev->heap.cyMax = cyMax;
}
/******************************Public*Routine******************************\
* OH* pohAllocatePermanent
*
* Allocates an off-screen rectangle that can never be booted of the heap.
* It's the caller's responsibility to manage the rectangle, which includes
* what to do with the memory in DrvAssertMode when the display is changed
* to full-screen mode.
*
\**************************************************************************/
OH* pohAllocatePermanent(
PDEV* ppdev,
LONG cx,
LONG cy)
{
OH* poh;
poh = pohAllocate(ppdev, cx, cy, 0);
if (poh != NULL)
{
// Mark the rectangle as permanent:
poh->ofl = OFL_PERMANENT;
// Remove the node from the most-recently blitted list:
poh->pohPrev->pohNext = poh->pohNext;
poh->pohNext->pohPrev = poh->pohPrev;
poh->pohPrev = NULL;
poh->pohNext = NULL;
// Now calculate the new maximum size rectangle available in the
// heap:
vCalculateMaximum(ppdev);
}
return(poh);
}
/******************************Public*Routine******************************\
* BOOL bMoveDibToOffscreenDfbIfRoom
*
* Converts the DIB DFB to an off-screen DFB, if there's room for it in
* off-screen memory.
*
* Returns: FALSE if there wasn't room, TRUE if successfully moved.
*
\**************************************************************************/
BOOL bMoveDibToOffscreenDfbIfRoom(
PDEV* ppdev,
DSURF* pdsurf)
{
OH* poh;
SURFOBJ* pso;
RECTL rclDst;
POINTL ptlSrc;
HSURF hsurf;
ASSERTDD(pdsurf->dt == DT_DIB,
"Can't move a bitmap off-screen when it's already off-screen");
// If we're in full-screen mode, we can't move anything to off-screen
// memory:
if (!ppdev->bEnabled)
return(FALSE);
poh = pohAllocate(ppdev, pdsurf->sizl.cx, pdsurf->sizl.cy,
FLOH_ONLY_IF_ROOM);
if (poh == NULL)
{
// There wasn't any free room.
return(FALSE);
}
// 'pdsurf->sizl' is the actual bitmap dimension, not 'poh->cx' or
// 'poh->cy'.
rclDst.left = poh->x;
rclDst.top = poh->y;
rclDst.right = rclDst.left + pdsurf->sizl.cx;
rclDst.bottom = rclDst.top + pdsurf->sizl.cy;
ptlSrc.x = 0;
ptlSrc.y = 0;
vPutBits(ppdev, pdsurf->pso, &rclDst, &ptlSrc);
// Update the data structures to reflect the new off-screen node:
pso = pdsurf->pso;
pdsurf->dt = DT_SCREEN;
pdsurf->poh = poh;
poh->pdsurf = pdsurf;
// Now free the DIB. Get the hsurf from the SURFOBJ before we unlock
// it (it's not legal to dereference psoDib when it's unlocked):
hsurf = pso->hsurf;
EngUnlockSurface(pso);
EngDeleteSurface(hsurf);
return(TRUE);
}
/******************************Public*Routine******************************\
* OH* pohMoveOffscreenDfbToDib
*
* Converts the DFB from being off-screen to being a DIB.
*
* Note: The caller does NOT have to call 'pohFree' on 'poh' after making
* this call.
*
* Returns: NULL if the function failed (due to a memory allocation).
* Otherwise, it returns a pointer to the coalesced off-screen heap
* node that has been made available for subsequent allocations
* (useful when trying to free enough memory to make a new
* allocation).
\**************************************************************************/
OH* pohMoveOffscreenDfbToDib(
PDEV* ppdev,
OH* poh)
{
DSURF* pdsurf;
HBITMAP hbmDib;
SURFOBJ* pso;
RECTL rclDst;
POINTL ptlSrc;
DISPDBG((1, "Throwing out %li x %li at (%li, %li)!",
poh->cx, poh->cy, poh->x, poh->y));
pdsurf = poh->pdsurf;
ASSERTDD((poh->x != 0) || (poh->y != 0),
"Can't make the visible screen into a DIB");
ASSERTDD(pdsurf->dt != DT_DIB,
"Can't make a DIB into even more of a DIB");
hbmDib = EngCreateBitmap(pdsurf->sizl, 0, ppdev->iBitmapFormat,
BMF_TOPDOWN, NULL);
if (hbmDib)
{
if (EngAssociateSurface((HSURF) hbmDib, ppdev->hdevEng, 0))
{
pso = EngLockSurface((HSURF) hbmDib);
if (pso != NULL)
{
rclDst.left = 0;
rclDst.top = 0;
rclDst.right = pdsurf->sizl.cx;
rclDst.bottom = pdsurf->sizl.cy;
ptlSrc.x = poh->x;
ptlSrc.y = poh->y;
vGetBits(ppdev, pso, &rclDst, &ptlSrc);
pdsurf->dt = DT_DIB;
pdsurf->pso = pso;
// Don't even bother checking to see if this DIB should
// be put back into off-screen memory until the next
// heap 'free' occurs:
pdsurf->iUniq = ppdev->iHeapUniq;
pdsurf->cBlt = 0;
// Remove this node from the off-screen DFB list, and free
// it. 'pohFree' will never return NULL:
return(pohFree(ppdev, poh));
}
}
// Fail case:
EngDeleteSurface((HSURF) hbmDib);
}
return(NULL);
}
/******************************Public*Routine******************************\
* BOOL bMoveEverythingFromOffscreenToDibs
*
* This function is used when we're about to enter full-screen mode, which
* would wipe all our off-screen bitmaps. GDI can ask us to draw on
* device bitmaps even when we're in full-screen mode, and we do NOT have
* the option of stalling the call until we switch out of full-screen.
* We have no choice but to move all the off-screen DFBs to DIBs.
*
* Returns TRUE if all DSURFs have been successfully moved.
*
\**************************************************************************/
BOOL bMoveAllDfbsFromOffscreenToDibs(
PDEV* ppdev)
{
OH* poh;
OH* pohNext;
BOOL bRet;
bRet = TRUE;
poh = ppdev->heap.ohDfb.pohNext;
while (poh != &ppdev->heap.ohDfb)
{
pohNext = poh->pohNext;
// If something's already a DIB, we shouldn't try to make it even
// more of a DIB:
if (poh->pdsurf->dt == DT_SCREEN)
{
if (!pohMoveOffscreenDfbToDib(ppdev, poh))
bRet = FALSE;
}
poh = pohNext;
}
return(bRet);
}
/******************************Public*Routine******************************\
* HBITMAP DrvCreateDeviceBitmap
*
* Function called by GDI to create a device-format-bitmap (DFB). We will
* always try to allocate the bitmap in off-screen; if we can't, we simply
* fail the call and GDI will create and manage the bitmap itself.
*
* Note: We do not have to zero the bitmap bits. GDI will automatically
* call us via DrvBitBlt to zero the bits (which is a security
* consideration).
*
\**************************************************************************/
HBITMAP DrvCreateDeviceBitmap(
DHPDEV dhpdev,
SIZEL sizl,
ULONG iFormat)
{
PDEV* ppdev;
OH* poh;
DSURF* pdsurf;
HBITMAP hbmDevice;
FLONG flHooks;
ppdev = (PDEV*) dhpdev;
// If we're in full-screen mode, we hardly have any off-screen memory
// in which to allocate a DFB. LATER: We could still allocate an
// OH node and put the bitmap on the DIB DFB list for later promotion.
if (!ppdev->bEnabled)
return(0);
// We only support device bitmaps that are the same colour depth
// as our display.
//
// Actually, those are the only kind GDI will ever call us with,
// but we may as well check. Note that this implies you'll never
// get a crack at 1bpp bitmaps.
if (iFormat != ppdev->iBitmapFormat)
return(0);
poh = pohAllocate(ppdev, sizl.cx, sizl.cy, 0);
if (poh != NULL)
{
pdsurf = EngAllocMem(0, sizeof(DSURF), ALLOC_TAG);
if (pdsurf != NULL)
{
hbmDevice = EngCreateDeviceBitmap((DHSURF) pdsurf, sizl, iFormat);
if (hbmDevice != NULL)
{
flHooks = ppdev->flHooks;
#if SYNCHRONIZEACCESS_WORKS
{
// Setting the SYNCHRONIZEACCESS flag tells GDI that we
// want all drawing to the bitmaps to be synchronized (GDI
// is multi-threaded and by default does not synchronize
// device bitmap drawing -- it would be a Bad Thing for us
// to have multiple threads using the accelerator at the
// same time):
flHooks |= HOOK_SYNCHRONIZEACCESS;
}
#endif // SYNCHRONIZEACCESS_WORKS
if (EngAssociateSurface((HSURF) hbmDevice, ppdev->hdevEng,
flHooks))
{
pdsurf->dt = DT_SCREEN;
pdsurf->poh = poh;
pdsurf->sizl = sizl;
pdsurf->ppdev = ppdev;
poh->pdsurf = pdsurf;
return(hbmDevice);
}
EngDeleteSurface((HSURF) hbmDevice);
}
EngFreeMem(pdsurf);
}
pohFree(ppdev, poh);
}
return(0);
}
/******************************Public*Routine******************************\
* VOID DrvDeleteDeviceBitmap
*
* Deletes a DFB.
*
\**************************************************************************/
VOID DrvDeleteDeviceBitmap(
DHSURF dhsurf)
{
DSURF* pdsurf;
PDEV* ppdev;
SURFOBJ* psoDib;
HSURF hsurfDib;
pdsurf = (DSURF*) dhsurf;
ppdev = pdsurf->ppdev;
if (pdsurf->dt == DT_SCREEN)
{
pohFree(ppdev, pdsurf->poh);
}
else
{
ASSERTDD(pdsurf->dt == DT_DIB, "Expected DIB type");
psoDib = pdsurf->pso;
// Get the hsurf from the SURFOBJ before we unlock it (it's not
// legal to dereference psoDib when it's unlocked):
hsurfDib = psoDib->hsurf;
EngUnlockSurface(psoDib);
EngDeleteSurface(hsurfDib);
}
EngFreeMem(pdsurf);
}
/******************************Public*Routine******************************\
* BOOL bAssertModeOffscreenHeap
*
* This function is called whenever we switch in or out of full-screen
* mode. We have to convert all the off-screen bitmaps to DIBs when
* we switch to full-screen (because we may be asked to draw on them even
* when in full-screen, and the mode switch would probably nuke the video
* memory contents anyway).
*
\**************************************************************************/
BOOL bAssertModeOffscreenHeap(
PDEV* ppdev,
BOOL bEnable)
{
BOOL b;
b = TRUE;
if (!bEnable)
{
b = bMoveAllDfbsFromOffscreenToDibs(ppdev);
}
return(b);
}
/******************************Public*Routine******************************\
* VOID vDisableOffscreenHeap
*
* Frees any resources allocated by the off-screen heap.
*
\**************************************************************************/
VOID vDisableOffscreenHeap(
PDEV* ppdev)
{
OHALLOC* poha;
OHALLOC* pohaNext;
poha = ppdev->heap.pohaChain;
while (poha != NULL)
{
pohaNext = poha->pohaNext; // Grab the next pointer before it's freed
EngFreeMem(poha);
poha = pohaNext;
}
}
/******************************Public*Routine******************************\
* BOOL bEnableOffscreenHeap
*
* Initializes the off-screen heap using all available video memory,
* accounting for the portion taken by the visible screen.
*
* Input: ppdev->cxScreen
* ppdev->cyScreen
* ppdev->cxMemory
* ppdev->cyMemory
*
\**************************************************************************/
BOOL bEnableOffscreenHeap(
PDEV* ppdev)
{
OH* poh;
DISPDBG((5, "Screen: %li x %li Memory: %li x %li",
ppdev->cxScreen, ppdev->cyScreen, ppdev->cxMemory, ppdev->cyMemory));
ppdev->heap.pohaChain = NULL;
ppdev->heap.pohFreeList = NULL;
// Initialize the available list, which will be a circular
// doubly-linked list kept in ascending 'cxcy' order, with a
// 'sentinel' at the end of the list:
poh = pohNewNode(ppdev);
if (poh == NULL)
goto ReturnFalse;
// The first node describes the entire video memory size:
poh->pohNext = &ppdev->heap.ohAvailable;
poh->pohPrev = &ppdev->heap.ohAvailable;
poh->ofl = OFL_AVAILABLE;
poh->x = 0;
poh->y = 0;
poh->cx = ppdev->cxMemory;
poh->cy = ppdev->cyMemory;
poh->cxcy = CXCY(ppdev->cxMemory, ppdev->cyMemory);
poh->pohLeft = &ppdev->heap.ohAvailable;
poh->pohUp = &ppdev->heap.ohAvailable;
poh->pohRight = &ppdev->heap.ohAvailable;
poh->pohDown = &ppdev->heap.ohAvailable;
// The second node is our available list sentinel:
ppdev->heap.ohAvailable.pohNext = poh;
ppdev->heap.ohAvailable.pohPrev = poh;
ppdev->heap.ohAvailable.cxcy = CXCY_SENTINEL;
ppdev->heap.ohAvailable.cx = 0x7fffffff;
ppdev->heap.ohAvailable.cy = 0x7fffffff;
ppdev->heap.ohAvailable.ofl = OFL_PERMANENT;
ppdev->heap.ohDfb.pohLeft = NULL;
ppdev->heap.ohDfb.pohUp = NULL;
ppdev->heap.ohDfb.pohRight = NULL;
ppdev->heap.ohDfb.pohDown = NULL;
// Initialize the most-recently-blitted DFB list, which will be
// a circular doubly-linked list kept in order, with a sentinel at
// the end. This node is also used for the screen-surface, for its
// offset:
ppdev->heap.ohDfb.pohNext = &ppdev->heap.ohDfb;
ppdev->heap.ohDfb.pohPrev = &ppdev->heap.ohDfb;
ppdev->heap.ohDfb.ofl = OFL_PERMANENT;
// For the moment, make the max really big so that the first
// allocation we're about to do will succeed:
ppdev->heap.cxMax = 0x7fffffff;
ppdev->heap.cyMax = 0x7fffffff;
// Finally, reserve the upper-left corner for the screen. We can
// actually throw away 'poh' because we'll never need it again
// (not even for disabling the off-screen heap since everything is
// freed using OHALLOCs):
poh = pohAllocatePermanent(ppdev, ppdev->cxScreen, ppdev->cyScreen);
ASSERTDD((poh != NULL) && (poh->x == 0) && (poh->y == 0),
"We assumed allocator would use the upper-left corner");
DISPDBG((5, "Passed bEnableOffscreenHeap"));
if (poh != NULL)
return(TRUE);
vDisableOffscreenHeap(ppdev);
ReturnFalse:
DISPDBG((0, "Failed bEnableOffscreenHeap"));
return(FALSE);
}