//*****************************************************************************
//
// DC Cacheing -
//
// Support for misbehaved apps - which continue to use a DC that has been
// Released. Well the problem is WIN30 allows it, so we need to be
// compatible.
//
//
// 03-Feb-92 NanduriR Created.
//
//*****************************************************************************
#include "precomp.h"
#pragma hdrstop
MODNAME(wreldc.c);
BOOL GdiCleanCacheDC (HDC hdc16);
//*****************************************************************************
// count of currently cached DCs so that we can quickly check whether any
// ReleasedDCs are pending.
//
//*****************************************************************************
INT iReleasedDCs = 0;
//*****************************************************************************
// The head of the linked list of the DCs Info.
//
//*****************************************************************************
LPDCCACHE lpDCCache = NULL;
//*****************************************************************************
// ReleaseCachedDCs -
// ReleaseDC's a cached DC if it meets the 'search criterion'.
// The Search flag indicates which input arguments will be used.
// Unused arguments can be NULL or pure garbage.
//
// NOTE: this does not free the memory that has been allocated for
// the list.
//
// We reset the flag 'flState' and thus will be able to
// reuse the structure.
//
// Returns TRUE
//*****************************************************************************
BOOL ReleaseCachedDCs(HAND16 htask16, HAND16 hwnd16, HAND16 hdc16,
HWND hwnd32, UINT flSearch)
{
HAND16 hdcTemp;
LPDCCACHE lpT;
UNREFERENCED_PARAMETER(hdc16);
if (iReleasedDCs) {
for (lpT = lpDCCache; lpT != NULL; lpT = lpT->lpNext) {
if (!(lpT->flState & DCCACHE_STATE_RELPENDING))
continue;
hdcTemp = (HAND16)NULL;
if (flSearch & SRCHDC_TASK16_HWND16) {
if (lpT->htask16 == htask16 &&
lpT->hwnd16 == hwnd16)
hdcTemp = lpT->hdc16;
}
else if (flSearch & SRCHDC_TASK16) {
if (lpT->htask16 == htask16)
hdcTemp = lpT->hdc16;
}
else {
LOGDEBUG(0, ("ReleaseCachedDCs:Invalid Search Flag\n"));
}
if (hdcTemp) {
if (ReleaseDC(lpT->hwnd32, HDC32(hdcTemp))) {
LOGDEBUG(6,
("ReleaseCachedDCs: success hdc16 %04x - count %04x\n",
hdcTemp, (iReleasedDCs-1)));
}
else {
LOGDEBUG(7, ("ReleaseCachedDCs: FAILED hdc16 %04x\n",
hdcTemp));
}
// reset the state evenif ReleaseDC failed
lpT->flState = 0;
FREEHDC16(hdcTemp);
if (!(--iReleasedDCs))
break;
}
}
}
return TRUE;
}
//*****************************************************************************
// FreeCachedDCs -
// ReleaseDC's a cached DC - Normally called during taskexit.
//
// NOTE: this does not free the memory that has been allocated for
// the list.
//
// We reset the flag 'flState' and thus will be able to
// reuse the structure.
//
// Returns TRUE
//*****************************************************************************
BOOL FreeCachedDCs(HAND16 htask16)
{
HAND16 hdcTemp;
LPDCCACHE lpT;
for (lpT = lpDCCache; lpT != NULL; lpT = lpT->lpNext) {
if ((lpT->flState & DCCACHE_STATE_INUSE) &&
lpT->htask16 == htask16) {
hdcTemp = lpT->hdc16;
if (lpT->flState & DCCACHE_STATE_RELPENDING) {
if (ReleaseDC(lpT->hwnd32, HDC32(hdcTemp))) {
LOGDEBUG(6,
("FreeCachedDCs: success hdc16 %04x - task %04x\n",
hdcTemp, htask16));
}
else {
LOGDEBUG(7, ("FreeCachedDCs: FAILED hdc16 %04x - task %04x\n",
hdcTemp, htask16));
}
WOW32ASSERT(iReleasedDCs != 0);
--iReleasedDCs;
}
lpT->flState = 0;
FREEHDC16(hdcTemp);
}
}
return TRUE;
}
//*****************************************************************************
// StoredDC -
//
// Initializes a DCCACHE structure with appropriate values.
// Uses an empty slot in the linked list if available else
// allocates a new one and adds to the head of the list.
//
// Returns TRUE on success, FALSE on failure
//*****************************************************************************
BOOL StoreDC(HAND16 htask16, HAND16 hwnd16, HAND16 hdc16)
{
HAND16 hdcTemp = (HAND16)NULL;
LPDCCACHE lpT, lpNew;
// Check for an 'inuse' slot that will match the one that will be created
// or check for an empty slot.
//
// An existing 'inuse' slot may match the one that's being created if
// an app makes multiple calls to GetDC(hwnd) without an intervening
// ReleaseDC. eg. MathCad.
// - Nanduri
lpNew = (LPDCCACHE)NULL;
for (lpT = lpDCCache; lpT != NULL; lpT = lpT->lpNext) {
if (lpT->flState & DCCACHE_STATE_INUSE) {
if (lpT->hdc16 == hdc16) {
if (lpT->hwnd16 == hwnd16 &&
lpT->htask16 == htask16 ) {
LOGDEBUG(6, ("WOW:An identical second GetDC call without ReleaseDC\n"));
}
else {
LOGDEBUG(6, ("WOW:New DC 0x%04x exists - replacing old cache\n", hdc16));
}
if (lpT->flState & DCCACHE_STATE_RELPENDING) {
WOW32ASSERT(iReleasedDCs != 0);
--iReleasedDCs;
}
lpNew = lpT;
break;
}
}
else {
if (!lpNew)
lpNew = lpT;
}
}
lpT = lpNew;
if (lpT == NULL) {
lpT = (LPDCCACHE)malloc_w_small(sizeof(DCCACHE));
if (lpT) {
lpT->lpNext = lpDCCache;
lpDCCache = lpT;
}
else {
LOGDEBUG(0, ("StoreDC: malloc_w_small for cache failed\n"));
}
}
if (lpT != NULL) {
lpT->flState = DCCACHE_STATE_INUSE;
lpT->htask16 = htask16;
lpT->hwnd16 = hwnd16;
lpT->hdc16 = hdc16;
lpT->hwnd32 = HWND32(hwnd16);
LOGDEBUG(6, ("StoreDC: Added hdc %04x\n",hdc16));
return TRUE;
}
else
return FALSE;
}
//*****************************************************************************
// CacheReleasedDC -
//
// Increments iReleasedDCs to indicate that a ReleaseDC is pending.
//
// Increments the iReleasedDC only if there was a corresponding GetDC.
// i.e, only if the DC exists in the DCcache;
//
// This is to handle the scenrio below:
// hdc = BeginPaint(hwnd,..);
// ReleaseDC(hwnd, hdc);
// EndPaint(hwnd, ..);
//
//
// Returns TRUE on success, FALSE on failure
//*****************************************************************************
BOOL CacheReleasedDC(HAND16 htask16, HAND16 hwnd16, HAND16 hdc16)
{
HAND16 hdcTemp = (HAND16)NULL;
LPDCCACHE lpT;
for (lpT = lpDCCache; lpT != NULL; lpT = lpT->lpNext) {
if ((lpT->flState & DCCACHE_STATE_INUSE) &&
lpT->htask16 == htask16 &&
lpT->hwnd16 == hwnd16 &&
lpT->hdc16 == hdc16 ) {
// the app might do releasedc twice on the same dc by mistake
if (!(lpT->flState & DCCACHE_STATE_RELPENDING)) {
lpT->flState |= DCCACHE_STATE_RELPENDING;
iReleasedDCs++;
}
LOGDEBUG(6, ("CachedReleasedDC: Pending hdc %04x - count %04x\n",
hdc16, iReleasedDCs));
GdiCleanCacheDC (HDC32(hdc16));
// Fix apps that draw then do lots
// of disk activity, usually they do
// a releaseDC. This flush will syncronize
// the drawing with the beginning of the
// disk activity. Bug #9704 PackRats install program draws text too late
GdiFlush();
return TRUE;
}
}
return FALSE;
}
