windows-nt/Source/XPSP1/NT/shell/ext/zaxxon/powertoy.cpp
2020-09-26 16:20:57 +08:00

132 lines
3.5 KiB
C++

/*****************************************************************************
*
* Powertoy.cpp - Powertoy bookkeeping
*
*****************************************************************************/
#include "priv.h"
#define DECL_CRTFREE
#include <crtfree.h>
/*****************************************************************************
*
* Dynamic Globals. There should be as few of these as possible.
*
* All access to dynamic globals must be thread-safe.
*
*****************************************************************************/
ULONG g_cRef = 0; /* Global reference count */
CRITICAL_SECTION g_csDll; /* The shared critical section */
HINSTANCE g_hinst = NULL;
#ifdef DEBUG
DWORD g_TlsMem = 0xffffffff;
#endif // DEBUG
/*****************************************************************************
*
* DllAddRef / DllRelease
*
* Maintain the DLL reference count.
*
*****************************************************************************/
void DllAddRef(void)
{
InterlockedIncrement((LPLONG)&g_cRef);
}
void DllRelease(void)
{
InterlockedDecrement((LPLONG)&g_cRef);
}
/*****************************************************************************
*
* DllGetClassObject
*
* OLE entry point. Produces an IClassFactory for the indicated GUID.
*
* The artificial refcount inside DllGetClassObject helps to
* avoid the race condition described in DllCanUnloadNow. It's
* not perfect, but it makes the race window much smaller.
*
*****************************************************************************/
STDAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, LPVOID * ppvObj)
{
HRESULT hres;
DllAddRef();
hres = CFactory_Create(rclsid, riid, ppvObj);
DllRelease();
return hres;
}
/*****************************************************************************
*
* DllCanUnloadNow
*
* OLE entry point. Fail iff there are outstanding refs.
*
* There is an unavoidable race condition between DllCanUnloadNow
* and the creation of a new IClassFactory: Between the time we
* return from DllCanUnloadNow() and the caller inspects the value,
* another thread in the same process may decide to call
* DllGetClassObject, thus suddenly creating an object in this DLL
* when there previously was none.
*
* It is the caller's responsibility to prepare for this possibility;
* there is nothing we can do about it.
*
*****************************************************************************/
STDMETHODIMP DllCanUnloadNow(void)
{
HRESULT hres;
ENTERCRITICAL;
hres = g_cRef ? S_FALSE : S_OK;
TraceMsg(TF_LIFE, "DllCanUnloadNow() returning hres=%#08lx. (S_OK means yes)", hres);
LEAVECRITICAL;
return hres;
}
/*****************************************************************************
*
* Entry32
*
* DLL entry point.
*
* On a thread detach, must check if the thread owns any
* global timeouts. If so, we must transfer the timeout to another
* thread or something.
*
*****************************************************************************/
STDAPI_(BOOL) DllMain(HINSTANCE hinst, DWORD dwReason, LPVOID lpReserved)
{
static s_hresOle = E_FAIL;
switch (dwReason)
{
case DLL_PROCESS_ATTACH:
InitializeCriticalSection(&g_csDll);
g_hinst = hinst;
DisableThreadLibraryCalls(hinst);
SHFusionInitializeFromModule(hinst);
break;
case DLL_PROCESS_DETACH:
SHFusionUninitialize();
DeleteCriticalSection(&g_csDll);
break;
}
return 1;
}