WXUTIL.CPP
//==========================================================================;
//
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
// KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR
// PURPOSE.
//
// Copyright (c) 1992 - 1997 Microsoft Corporation. All Rights Reserved.
//
//--------------------------------------------------------------------------;
//
// helper classes for building multimedia filters
//
#include <streams.h>
//
// Declare function from largeint.h we need so that PPC can build
//
//
// Enlarged integer divide - 64-bits / 32-bits > 32-bits
//
#ifndef _X86_
#define LLtoU64(x) (*(unsigned __int64*)(void*)(&(x)))
__inline
ULONG
WINAPI
EnlargedUnsignedDivide (
IN ULARGE_INTEGER Dividend,
IN ULONG Divisor,
IN PULONG Remainder
)
{
// return remainder if necessary
if (Remainder != NULL)
*Remainder = (ULONG)(LLtoU64(Dividend) % Divisor);
return (ULONG)(LLtoU64(Dividend) / Divisor);
}
#else
__inline
ULONG
WINAPI
EnlargedUnsignedDivide (
IN ULARGE_INTEGER Dividend,
IN ULONG Divisor,
IN PULONG Remainder
)
{
ULONG ulResult;
_asm {
mov eax,Dividend.LowPart
mov edx,Dividend.HighPart
mov ecx,Remainder
div Divisor
or ecx,ecx
jz short label
mov [ecx],edx
label:
mov ulResult,eax
}
return ulResult;
}
#endif
// --- CAMEvent -----------------------
CAMEvent::CAMEvent(BOOL fManualReset)
{
m_hEvent = CreateEvent(NULL, fManualReset, FALSE, NULL);
ASSERT(m_hEvent);
}
CAMEvent::~CAMEvent()
{
if (m_hEvent) {
EXECUTE_ASSERT(CloseHandle(m_hEvent));
}
}
// --- CAMMsgEvent -----------------------
// One routine. The rest is handled in CAMEvent
BOOL CAMMsgEvent::WaitMsg(DWORD dwTimeout)
{
// wait for the event to be signalled, or for the
// timeout (in MS) to expire. allow SENT messages
// to be processed while we wait
DWORD dwWait;
DWORD dwStartTime;
// set the waiting period.
DWORD dwWaitTime = dwTimeout;
// the timeout will eventually run down as we iterate
// processing messages. grab the start time so that
// we can calculate elapsed times.
if (dwWaitTime != INFINITE) {
dwStartTime = timeGetTime();
}
do {
dwWait = MsgWaitForMultipleObjects(1,&m_hEvent,FALSE, dwWaitTime, QS_SENDMESSAGE);
if (dwWait == WAIT_OBJECT_0 + 1) {
MSG Message;
PeekMessage(&Message,NULL,0,0,PM_NOREMOVE);
// If we have an explicit length of time to wait calculate
// the next wake up point - which might be now.
// If dwTimeout is INFINITE, it stays INFINITE
if (dwWaitTime != INFINITE) {
DWORD dwElapsed = timeGetTime()-dwStartTime;
dwWaitTime =
(dwElapsed >= dwTimeout)
? 0 // wake up with WAIT_TIMEOUT
: dwTimeout-dwElapsed;
}
}
} while (dwWait == WAIT_OBJECT_0 + 1);
// return TRUE if we woke on the event handle,
// FALSE if we timed out.
return (dwWait == WAIT_OBJECT_0);
}
// --- CAMThread ----------------------
CAMThread::CAMThread()
: m_EventSend(TRUE) // must be manual-reset for CheckRequest()
{
m_hThread = NULL;
}
CAMThread::~CAMThread() {
Close();
}
// when the thread starts, it calls this function. We unwrap the 'this'
//pointer and call ThreadProc.
DWORD WINAPI
CAMThread::InitialThreadProc(LPVOID pv)
{
CAMThread * pThread = (CAMThread *) pv;
return pThread->ThreadProc();
}
BOOL
CAMThread::Create()
{
DWORD threadid;
CAutoLock lock(&m_AccessLock);
if (ThreadExists()) {
return FALSE;
}
m_hThread = CreateThread(
NULL,
0,
CAMThread::InitialThreadProc,
this,
0,
&threadid);
if (!m_hThread) {
return FALSE;
}
return TRUE;
}
DWORD
CAMThread::CallWorker(DWORD dwParam)
{
// lock access to the worker thread for scope of this object
CAutoLock lock(&m_AccessLock);
if (!ThreadExists()) {
return (DWORD) E_FAIL;
}
// set the parameter
m_dwParam = dwParam;
// signal the worker thread
m_EventSend.Set();
// wait for the completion to be signalled
m_EventComplete.Wait();
// done - this is the thread's return value
return m_dwReturnVal;
}
// Wait for a request from the client
DWORD
CAMThread::GetRequest()
{
m_EventSend.Wait();
return m_dwParam;
}
// is there a request?
BOOL
CAMThread::CheckRequest(DWORD * pParam)
{
if (!m_EventSend.Check()) {
return FALSE;
} else {
if (pParam) {
*pParam = m_dwParam;
}
return TRUE;
}
}
// reply to the request
void
CAMThread::Reply(DWORD dw)
{
m_dwReturnVal = dw;
// The request is now complete so CheckRequest should fail from
// now on
//
// This event should be reset BEFORE we signal the client or
// the client may Set it before we reset it and we'll then
// reset it (!)
m_EventSend.Reset();
// Tell the client we're finished
m_EventComplete.Set();
}
// destructor for CMsgThread - cleans up any messages left in the
// queue when the thread exited
CMsgThread::~CMsgThread()
{
if (m_hThread != NULL) {
WaitForSingleObject(m_hThread, INFINITE);
EXECUTE_ASSERT(CloseHandle(m_hThread));
}
POSITION pos = m_ThreadQueue.GetHeadPosition();
while (pos) {
CMsg * pMsg = m_ThreadQueue.GetNext(pos);
delete pMsg;
}
m_ThreadQueue.RemoveAll();
if (m_hSem != NULL) {
EXECUTE_ASSERT(CloseHandle(m_hSem));
}
}
BOOL
CMsgThread::CreateThread(
)
{
m_hSem = CreateSemaphore(NULL, 0, 0x7FFFFFFF, NULL);
if (m_hSem == NULL) {
return FALSE;
}
m_hThread = ::CreateThread(NULL, 0, DefaultThreadProc,
(LPVOID)this, 0, &m_ThreadId);
return m_hThread != NULL;
}
// This is the threads message pump. Here we get and dispatch messages to
// clients thread proc until the client refuses to process a message.
// The client returns a non-zero value to stop the message pump, this
// value becomes the threads exit code.
DWORD WINAPI
CMsgThread::DefaultThreadProc(
LPVOID lpParam
)
{
CMsgThread *lpThis = (CMsgThread *)lpParam;
CMsg msg;
LRESULT lResult;
// !!!
CoInitialize(NULL);
// allow a derived class to handle thread startup
lpThis->OnThreadInit();
do {
lpThis->GetThreadMsg(&msg);
lResult = lpThis->ThreadMessageProc(msg.uMsg,msg.dwFlags,
msg.lpParam, msg.pEvent);
} while (lResult == 0L);
// !!!
CoUninitialize();
return (DWORD)lResult;
}
// Block until the next message is placed on the list m_ThreadQueue.
// copies the message to the message pointed to by *pmsg
void
CMsgThread::GetThreadMsg(CMsg *msg)
{
CMsg * pmsg = NULL;
// keep trying until a message appears
while (TRUE) {
{
CAutoLock lck(&m_Lock);
pmsg = m_ThreadQueue.RemoveHead();
if (pmsg == NULL) {
m_lWaiting++;
} else {
break;
}
}
// the semaphore will be signalled when it is non-empty
WaitForSingleObject(m_hSem, INFINITE);
}
// copy fields to caller's CMsg
*msg = *pmsg;
// this CMsg was allocated by the 'new' in PutThreadMsg
delete pmsg;
}
#ifndef UNICODE
// NOTE: as we need to use the same binaries on Win95 as on NT this code should
// be compiled WITHOUT unicode being defined. Otherwise we will not pick up
// these internal routines and the binary will not run on Win95.
// Windows 95 doesn't implement this, so we provide an implementation.
LPWSTR
WINAPI
lstrcpyWInternal(
LPWSTR lpString1,
LPCWSTR lpString2
)
{
LPWSTR lpReturn = lpString1;
while (*lpString1++ = *lpString2++);
return lpReturn;
}
// Windows 95 doesn't implement this, so we provide an implementation.
LPWSTR
WINAPI
lstrcpynWInternal(
LPWSTR lpString1,
LPCWSTR lpString2,
int iMaxLength
)
{
ASSERT(iMaxLength);
LPWSTR lpReturn = lpString1;
if (iMaxLength) {
while (--iMaxLength && (*lpString1++ = *lpString2++));
// If we ran out of room (which will be the case if
// iMaxLength is now 0) we still need to terminate the
// string.
if (!iMaxLength) *lpString1 = L'\0';
}
return lpReturn;
}
int
WINAPI
lstrcmpWInternal(
LPCWSTR lpString1,
LPCWSTR lpString2
)
{
do {
WCHAR c1 = *lpString1;
WCHAR c2 = *lpString2;
if (c1 != c2)
return (int) c1 - (int) c2;
} while (*lpString1++ && *lpString2++);
return 0;
}
int
WINAPI
lstrcmpiWInternal(
LPCWSTR lpString1,
LPCWSTR lpString2
)
{
do {
WCHAR c1 = *lpString1;
WCHAR c2 = *lpString2;
if (c1 >= L'A' && c1 <= L'Z')
c1 -= (WCHAR) (L'A' - L'a');
if (c2 >= L'A' && c2 <= L'Z')
c2 -= (WCHAR) (L'A' - L'a');
if (c1 != c2)
return (int) c1 - (int) c2;
} while (*lpString1++ && *lpString2++);
return 0;
}
int
WINAPI
lstrlenWInternal(
LPCWSTR lpString
)
{
int i = -1;
while (*(lpString+(++i)))
;
return i;
}
#endif // NOT UNICODE
#ifndef UNICODE
int WINAPIV wsprintfWInternal(LPWSTR wszOut, LPCWSTR pszFmt, ...)
{
char fmt[256]; // !!!
char ach[256]; // !!!
int i;
va_list va;
va_start(va, pszFmt);
WideCharToMultiByte(GetACP(), 0, pszFmt, -1, fmt, 256, NULL, NULL);
i = wvsprintf(ach, fmt, va);
va_end(va);
MultiByteToWideChar(CP_ACP, 0, ach, -1, wszOut, i+1);
return i;
}
#endif
// Helper function - convert int to WSTR
void WINAPI IntToWstr(int i, LPWSTR wstr)
{
#ifdef UNICODE
wsprintf(wstr, L"%d", i);
#else
TCHAR temp[32];
wsprintf(temp, "%d", i);
MultiByteToWideChar(CP_ACP, 0, temp, -1, wstr, 32);
#endif
} // IntToWstr
#if 0
void * memchrInternal(const void *pv, int c, size_t sz)
{
BYTE *pb = (BYTE *) pv;
while (sz--) {
if (*pb == c)
return (void *) pb;
pb++;
}
return NULL;
}
#endif
#define MEMORY_ALIGNMENT 4
#define MEMORY_ALIGNMENT_LOG2 2
#define MEMORY_ALIGNMENT_MASK MEMORY_ALIGNMENT - 1
void * __stdcall memmoveInternal(void * dst, const void * src, size_t count)
{
void * ret = dst;
#ifdef _X86_
if (dst <= src || (char *)dst >= ((char *)src + count)) {
/*
* Non-Overlapping Buffers
* copy from lower addresses to higher addresses
*/
_asm {
mov esi,src
mov edi,dst
mov ecx,count
cld
mov edx,ecx
and edx,MEMORY_ALIGNMENT_MASK
shr ecx,MEMORY_ALIGNMENT_LOG2
rep movsd
or ecx,edx
jz memmove_done
rep movsb
memmove_done:
}
}
else {
/*
* Overlapping Buffers
* copy from higher addresses to lower addresses
*/
_asm {
mov esi,src
mov edi,dst
mov ecx,count
std
add esi,ecx
add edi,ecx
dec esi
dec edi
rep movsb
cld
}
}
#else
MoveMemory(dst, src, count);
#endif
return ret;
}
/* Arithmetic functions to help with time format conversions
*/
/* Compute (a * b + d) / c */
LONGLONG WINAPI llMulDiv(LONGLONG a, LONGLONG b, LONGLONG c, LONGLONG d)
{
/* Compute the absolute values to avoid signed arithmetic problems */
ULARGE_INTEGER ua, ub;
DWORDLONG uc;
ua.QuadPart = (DWORDLONG)(a >= 0 ? a : -a);
ub.QuadPart = (DWORDLONG)(b >= 0 ? b : -b);
uc = (DWORDLONG)(c >= 0 ? c : -c);
BOOL bSign = (a < 0) ^ (b < 0);
/* Do long multiplication */
ULARGE_INTEGER p[2];
p[0].QuadPart = UInt32x32To64(ua.LowPart, ub.LowPart);
/* This next computation cannot overflow into p[1].HighPart because
the max number we can compute here is:
(2 ** 32 - 1) * (2 ** 32 - 1) + // ua.LowPart * ub.LowPart
(2 ** 32) * (2 ** 31) * (2 ** 32 - 1) * 2 // x.LowPart * y.HighPart * 2
== 2 ** 96 - 2 ** 64 + (2 ** 64 - 2 ** 33 + 1)
== 2 ** 96 - 2 ** 33 + 1
< 2 ** 96
*/
ULARGE_INTEGER x;
x.QuadPart = UInt32x32To64(ua.LowPart, ub.HighPart) +
UInt32x32To64(ua.HighPart, ub.LowPart) +
p[0].HighPart;
p[0].HighPart = x.LowPart;
p[1].QuadPart = UInt32x32To64(ua.HighPart, ub.HighPart) + x.HighPart;
if (d != 0) {
ULARGE_INTEGER ud[2];
if (bSign) {
ud[0].QuadPart = (DWORDLONG)(-d);
if (d > 0) {
/* -d < 0 */
ud[1].QuadPart = (DWORDLONG)(LONGLONG)-1;
} else {
ud[1].QuadPart = (DWORDLONG)0;
}
} else {
ud[0].QuadPart = (DWORDLONG)d;
if (d < 0) {
ud[1].QuadPart = (DWORDLONG)(LONGLONG)-1;
} else {
ud[1].QuadPart = (DWORDLONG)0;
}
}
/* Now do extended addition */
ULARGE_INTEGER uliTotal;
/* Add ls DWORDs */
uliTotal.QuadPart = (DWORDLONG)ud[0].LowPart + p[0].LowPart;
p[0].LowPart = uliTotal.LowPart;
/* Propagate carry */
uliTotal.LowPart = uliTotal.HighPart;
uliTotal.HighPart = 0;
/* Add 2nd most ls DWORDs */
uliTotal.QuadPart += (DWORDLONG)ud[0].HighPart + p[0].HighPart;
p[0].HighPart = uliTotal.LowPart;
/* Propagate carry */
uliTotal.LowPart = uliTotal.HighPart;
uliTotal.HighPart = 0;
/* Add MS DWORDLONGs - no carry expected */
p[1].QuadPart += ud[1].QuadPart + uliTotal.QuadPart;
/* Now see if we got a sign change from the addition */
if ((LONG)p[1].HighPart < 0) {
bSign = !bSign;
/* Negate the current value (ugh!) */
p[0].QuadPart = ~p[0].QuadPart;
p[1].QuadPart = ~p[1].QuadPart;
p[0].QuadPart += 1;
p[1].QuadPart += (p[0].QuadPart == 0);
}
}
/* Now for the division */
if (c < 0) {
bSign = !bSign;
}
/* This will catch c == 0 and overflow */
if (uc <= p[1].QuadPart) {
return bSign ? (LONGLONG)0x8000000000000000 :
(LONGLONG)0x7FFFFFFFFFFFFFFF;
}
DWORDLONG ullResult;
/* Do the division */
/* If the dividend is a DWORD_LONG use the compiler */
if (p[1].QuadPart == 0) {
ullResult = p[0].QuadPart / uc;
return bSign ? -(LONGLONG)ullResult : (LONGLONG)ullResult;
}
/* If the divisor is a DWORD then its simpler */
ULARGE_INTEGER ulic;
ulic.QuadPart = uc;
if (ulic.HighPart == 0) {
ULARGE_INTEGER uliDividend;
ULARGE_INTEGER uliResult;
DWORD dwDivisor = (DWORD)uc;
// ASSERT(p[1].HighPart == 0 && p[1].LowPart < dwDivisor);
uliDividend.HighPart = p[1].LowPart;
uliDividend.LowPart = p[0].HighPart;
#ifndef USE_LARGEINT
uliResult.HighPart = (DWORD)(uliDividend.QuadPart / dwDivisor);
p[0].HighPart = (DWORD)(uliDividend.QuadPart % dwDivisor);
uliResult.LowPart = 0;
uliResult.QuadPart = p[0].QuadPart / dwDivisor + uliResult.QuadPart;
#else
/* NOTE - this routine will take exceptions if
the result does not fit in a DWORD
*/
if (uliDividend.QuadPart >= (DWORDLONG)dwDivisor) {
uliResult.HighPart = EnlargedUnsignedDivide(
uliDividend,
dwDivisor,
&p[0].HighPart);
} else {
uliResult.HighPart = 0;
}
uliResult.LowPart = EnlargedUnsignedDivide(
p[0],
dwDivisor,
NULL);
#endif
return bSign ? -(LONGLONG)uliResult.QuadPart :
(LONGLONG)uliResult.QuadPart;
}
ullResult = 0;
/* OK - do long division */
for (int i = 0; i < 64; i++) {
ullResult <<= 1;
/* Shift 128 bit p left 1 */
p[1].QuadPart <<= 1;
if ((p[0].HighPart & 0x80000000) != 0) {
p[1].LowPart++;
}
p[0].QuadPart <<= 1;
/* Compare */
if (uc <= p[1].QuadPart) {
p[1].QuadPart -= uc;
ullResult += 1;
}
}
return bSign ? - (LONGLONG)ullResult : (LONGLONG)ullResult;
}
LONGLONG WINAPI Int64x32Div32(LONGLONG a, LONG b, LONG c, LONG d)
{
ULARGE_INTEGER ua;
DWORD ub;
DWORD uc;
/* Compute the absolute values to avoid signed arithmetic problems */
ua.QuadPart = (DWORDLONG)(a >= 0 ? a : -a);
ub = (DWORD)(b >= 0 ? b : -b);
uc = (DWORD)(c >= 0 ? c : -c);
BOOL bSign = (a < 0) ^ (b < 0);
/* Do long multiplication */
ULARGE_INTEGER p0;
DWORD p1;
p0.QuadPart = UInt32x32To64(ua.LowPart, ub);
if (ua.HighPart != 0) {
ULARGE_INTEGER x;
x.QuadPart = UInt32x32To64(ua.HighPart, ub) + p0.HighPart;
p0.HighPart = x.LowPart;
p1 = x.HighPart;
} else {
p1 = 0;
}
if (d != 0) {
ULARGE_INTEGER ud0;
DWORD ud1;
if (bSign) {
//
// Cast d to LONGLONG first otherwise -0x80000000 sign extends
// incorrectly
//
ud0.QuadPart = (DWORDLONG)(-(LONGLONG)d);
if (d > 0) {
/* -d < 0 */
ud1 = (DWORD)-1;
} else {
ud1 = (DWORD)0;
}
} else {
ud0.QuadPart = (DWORDLONG)d;
if (d < 0) {
ud1 = (DWORD)-1;
} else {
ud1 = (DWORD)0;
}
}
/* Now do extended addition */
ULARGE_INTEGER uliTotal;
/* Add ls DWORDs */
uliTotal.QuadPart = (DWORDLONG)ud0.LowPart + p0.LowPart;
p0.LowPart = uliTotal.LowPart;
/* Propagate carry */
uliTotal.LowPart = uliTotal.HighPart;
uliTotal.HighPart = 0;
/* Add 2nd most ls DWORDs */
uliTotal.QuadPart += (DWORDLONG)ud0.HighPart + p0.HighPart;
p0.HighPart = uliTotal.LowPart;
/* Add MS DWORDLONGs - no carry expected */
p1 += ud1 + uliTotal.HighPart;
/* Now see if we got a sign change from the addition */
if ((LONG)p1 < 0) {
bSign = !bSign;
/* Negate the current value (ugh!) */
p0.QuadPart = ~p0.QuadPart;
p1 = ~p1;
p0.QuadPart += 1;
p1 += (p0.QuadPart == 0);
}
}
/* Now for the division */
if (c < 0) {
bSign = !bSign;
}
/* This will catch c == 0 and overflow */
if (uc <= p1) {
return bSign ? (LONGLONG)0x8000000000000000 :
(LONGLONG)0x7FFFFFFFFFFFFFFF;
}
/* Do the division */
/* If the divisor is a DWORD then its simpler */
ULARGE_INTEGER uliDividend;
ULARGE_INTEGER uliResult;
DWORD dwDivisor = uc;
uliDividend.HighPart = p1;
uliDividend.LowPart = p0.HighPart;
/* NOTE - this routine will take exceptions if
the result does not fit in a DWORD
*/
if (uliDividend.QuadPart >= (DWORDLONG)dwDivisor) {
uliResult.HighPart = EnlargedUnsignedDivide(
uliDividend,
dwDivisor,
&p0.HighPart);
} else {
uliResult.HighPart = 0;
}
uliResult.LowPart = EnlargedUnsignedDivide(
p0,
dwDivisor,
NULL);
return bSign ? -(LONGLONG)uliResult.QuadPart :
(LONGLONG)uliResult.QuadPart;
}
#ifdef DEBUG
/******************************Public*Routine******************************\
* Debug CCritSec helpers
*
* We provide debug versions of the Constructor, destructor, Lock and Unlock
* routines. The debug code tracks who owns each critical section by
* maintaining a depth count.
*
* History:
*
\**************************************************************************/
CCritSec::CCritSec()
{
InitializeCriticalSection(&m_CritSec);
m_currentOwner = m_lockCount = 0;
m_fTrace = FALSE;
}
CCritSec::~CCritSec()
{
DeleteCriticalSection(&m_CritSec);
}
void CCritSec::Lock()
{
UINT tracelevel=3;
DWORD us = GetCurrentThreadId();
DWORD currentOwner = m_currentOwner;
if (currentOwner && (currentOwner != us)) {
// already owned, but not by us
if (m_fTrace) {
DbgLog((LOG_LOCKING, 2, TEXT("Thread %d about to wait for lock %x owned by %d"),
GetCurrentThreadId(), &m_CritSec, currentOwner));
tracelevel=2;
// if we saw the message about waiting for the critical
// section we ensure we see the message when we get the
// critical section
}
}
EnterCriticalSection(&m_CritSec);
if (0 == m_lockCount++) {
// we now own it for the first time. Set owner information
m_currentOwner = us;
//ASSERT(((PRTL_CRITICAL_SECTION)&m_CritSec)->OwningThread == (HANDLE)m_currentOwner);
// only valid on NT
if (m_fTrace) {
DbgLog((LOG_LOCKING, tracelevel, TEXT("Thread %d now owns lock %x"), m_currentOwner, &m_CritSec));
}
}
}
void CCritSec::Unlock() {
if (0 == --m_lockCount) {
// about to be unowned
if (m_fTrace) {
DbgLog((LOG_LOCKING, 3, TEXT("Thread %d releasing lock %x"), m_currentOwner, &m_CritSec));
//ASSERT(((PRTL_CRITICAL_SECTION)&m_CritSec)->OwningThread == (HANDLE)m_currentOwner);
// only valid on NT
}
m_currentOwner = 0;
}
LeaveCriticalSection(&m_CritSec);
}
void WINAPI DbgLockTrace(CCritSec * pcCrit, BOOL fTrace)
{
pcCrit->m_fTrace = fTrace;
}
BOOL WINAPI CritCheckIn(CCritSec * pcCrit)
{
return (GetCurrentThreadId() == pcCrit->m_currentOwner);
}
BOOL WINAPI CritCheckOut(CCritSec * pcCrit)
{
return (GetCurrentThreadId() != pcCrit->m_currentOwner);
}
#endif
typedef BSTR (STDAPICALLTYPE *LPSYSALLOCSTRING)(const OLECHAR FAR *);
// Dyna-link to SysAllocString to copy BSTR strings
STDAPI WriteBSTR(BSTR *pstrDest, LPCWSTR szSrc)
{
LPSYSALLOCSTRINGlpfnSysAllocString;
HINSTANCEhInst;
static const charszSysAllocString[] = "SysAllocString";
//
// Try to get the Ole32Aut.dll module handle.
//
hInst = LoadOLEAut32();
if (hInst == NULL) {
DWORD dwError = GetLastError();
return HRESULT_FROM_WIN32(dwError);
}
lpfnSysAllocString = (LPSYSALLOCSTRING)GetProcAddress(hInst,
szSysAllocString);
if (lpfnSysAllocString == NULL) {
DWORD dwError = GetLastError();
return HRESULT_FROM_WIN32(dwError);
}
*pstrDest = (*lpfnSysAllocString)(szSrc);
return S_OK;
}
// Free an OLE BSTR through the task allocator
STDAPI FreeBSTR(BSTR* pstr)
{
if (*pstr != NULL) {
// get pointer to string
DWORD* p = (DWORD*) (*pstr);
// back up to point at DWORD length
p--;
// set pointer to null
*pstr = NULL;
// and free this
CoTaskMemFree(p);
return S_OK;
} else {
return S_FALSE;
}
}
// Return a wide string - allocating memory for it
// Returns:
// S_OK - no error
// E_POINTER - ppszReturn == NULL
// E_OUTOFMEMORY - can't allocate memory for returned string
STDAPI AMGetWideString(LPCWSTR psz, LPWSTR *ppszReturn)
{
CheckPointer(ppszReturn, E_POINTER);
ValidateReadWritePtr(ppszReturn, sizeof(LPWSTR));
DWORD nameLen = sizeof(WCHAR) * (lstrlenW(psz)+1);
*ppszReturn = (LPWSTR)CoTaskMemAlloc(nameLen);
if (*ppszReturn == NULL) {
return E_OUTOFMEMORY;
}
CopyMemory(*ppszReturn, psz, nameLen);
return NOERROR;
}
// Waits for the HANDLE hObject. While waiting messages sent
// to windows on our thread by SendMessage will be processed.
// Using this function to do waits and mutual exclusion
// avoids some deadlocks in objects with windows.
// Return codes are the same as for WaitForSingleObject
DWORD WINAPI WaitDispatchingMessages(HANDLE hObject, DWORD dwWait, HWND hwnd, UINT uMsg)
{
BOOL bPeeked = FALSE;
DWORD dwResult;
DWORD dwStart;
DWORD dwThreadPriority;
if (dwWait != INFINITE && dwWait != 0) {
dwStart = GetTickCount();
}
for (; ; ) {
DWORD dwTimeOut = dwWait;
if (dwTimeOut > 10) {
dwTimeOut = 10;
}
dwResult = MsgWaitForMultipleObjects(
1,
&hObject,
FALSE,
dwTimeOut,
hwnd == NULL ? QS_SENDMESSAGE :
QS_SENDMESSAGE + QS_POSTMESSAGE);
if (dwResult == WAIT_OBJECT_0 + 1 ||
dwResult == WAIT_TIMEOUT && dwTimeOut != dwWait) {
MSG msg;
if (hwnd != NULL) {
while (PeekMessage(&msg, hwnd, uMsg, uMsg, PM_REMOVE)) {
DispatchMessage(&msg);
}
}
// Do this anyway - the previous peek doesn't flush out the
// messages
PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE);
if (dwWait != INFINITE && dwWait != 0) {
DWORD dwNow = GetTickCount();
// Working with differences handles wrap-around
DWORD dwDiff = dwNow - dwStart;
if (dwDiff > dwWait) {
dwWait = 0;
} else {
dwWait -= dwDiff;
}
dwStart = dwNow;
}
if (!bPeeked) {
// Raise our priority to prevent our message queue
// building up
dwThreadPriority = GetThreadPriority(GetCurrentThread());
if (dwThreadPriority < THREAD_PRIORITY_HIGHEST) {
SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_HIGHEST);
}
bPeeked = TRUE;
}
} else {
break;
}
}
if (bPeeked) {
SetThreadPriority(GetCurrentThread(), dwThreadPriority);
if (HIWORD(GetQueueStatus(QS_POSTMESSAGE)) & QS_POSTMESSAGE) {
// Send dummy message
PostThreadMessage(GetCurrentThreadId(), WM_NULL, 0, 0);
}
}
return dwResult;
}