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| #define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include "OnceAProcess.h"
#ifdef SANS_CRT
#include "TestSansCRT.h"
#define assert MY_ASSERT
#else
#include <assert.h>
#endif
/*
Do something once in a process
------------------------------ */
EXTERN_C LRESULT DoOnceAProcess(
LONG volatile * pbStartedDoing, /*[in/out] Ptr to a static variable. Must be initialized to (LONG)FALSE;*/
LONG volatile * pbDone, /*[in/out] Ptr to a static variable. Must be initialized to (LONG)FALSE;*/
ONCEAPROCESSCALLBACK proc, /*[in] Callback function, called once in the process. Must not be NULL.*/
LPARAM userData, /*[in/bypass] User parameter passed to the callback function.*/
LRESULT defReturnVal /*[in/bypass] Value to return if the function was NOT called.*/
) /*Returns the callback's return value, or defReturnVal.*/
{
static const LONG lTrue = TRUE;
static const LONG lFalse = FALSE;
LRESULT ret = defReturnVal;
if( ! *pbDone )
{
/* If not already started doing, do it.
Else, wait actively until done */
/* InterlockedCompareExchange() :
If *pbStartedDoing == lFalse, set it to lTrue; return the previous value of *pbStartedDoing. */
LONG alreadyStartedDoing = InterlockedCompareExchange(pbStartedDoing, lTrue, lFalse);
if(alreadyStartedDoing == lFalse)
{
ret = proc(userData);
*pbDone = lTrue;
}
else
{
while( ! (*pbDone) ) {}
}
}
/* Now, *pbDone can only be true:
Either it was already done, or it has just been done. */
assert(*pbDone);
return ret;
}
/* TLS slot initialization callback
-------------------------------- */
static LRESULT AllocTlsIndexToPtr(LPARAM parPdwTlsIndex)
{
HRESULT hrRet = S_OK;
DWORD * pdwTlsIndex = (DWORD*)parPdwTlsIndex;
DWORD tlsIndex;
assert(pdwTlsIndex!=NULL);
tlsIndex = TlsAlloc();
if(tlsIndex==TLS_OUT_OF_INDEXES)
{
/* Error: Get an error value from the Win32 error code. */
HRESULT hrError = HRESULT_FROM_WIN32(GetLastError());
if(SUCCEEDED(hrError))
hrError = E_UNEXPECTED;
assert(FAILED(hrError));
/* return it. */
hrRet = hrError;
}
*pdwTlsIndex = tlsIndex;
return (LRESULT)hrRet;
}
/* Allocate a Thread-Local Storage slot once in a process
------------------------------------------------------ */
EXTERN_C HRESULT AllocateTlsSlotOnce(
LONG volatile * pbStartedDoing, /*[in/out] Ptr to a static variable. Must be initialized to (LONG)FALSE;*/
LONG volatile * pbDone, /*[in/out] Ptr to a static variable. Must be initialized to (LONG)FALSE;*/
DWORD * pdwTlsIndex /*[out] Return the TLS slot here, leave untouched if already done.*/
) /*Returns S_FALSE if was already allocated.*/
{
assert(pbStartedDoing != NULL);
assert(pbDone != NULL);
assert(pdwTlsIndex != NULL);
return (HRESULT)DoOnceAProcess(pbStartedDoing, pbDone, AllocTlsIndexToPtr, (LPARAM)pdwTlsIndex, (LRESULT)S_FALSE);
}
/* Critical section initialization callback
---------------------------------------- */
static LRESULT InitializeCriticalSectionToPtr(LPARAM parPCrit)
{
HRESULT hrRet = S_OK;
LPCRITICAL_SECTION pCrit = (LPCRITICAL_SECTION)parPCrit;
assert(pCrit!=NULL);
#ifdef SANS_CRT
//No CRT means no exception handling : Just pray.
InitializeCriticalSection(pCrit);
#else
__try
{
InitializeCriticalSection(pCrit);
}
__except(EXCEPTION_EXECUTE_HANDLER)
{
if(GetExceptionCode()==STATUS_NO_MEMORY)
hrRet = E_OUTOFMEMORY;
else
hrRet = E_UNEXPECTED;
}
#endif
return (LRESULT)hrRet;
}
/* Initialize a global critical section once in a process
------------------------------------------------------ */
EXTERN_C HRESULT InitializeCriticalSectionOnce(
LONG volatile * pbStartedDoing, /*[in/out] Ptr to a static variable. Must be initialized to (LONG)FALSE;*/
LONG volatile * pbDone, /*[in/out] Ptr to a static variable. Must be initialized to (LONG)FALSE;*/
LPCRITICAL_SECTION pCrit /*[out] Ptr to the critical section to initialize.*/
) /*Returns S_FALSE if was already initialized.*/
{
assert(pbStartedDoing != NULL);
assert(pbDone != NULL);
assert(pCrit != NULL);
return (HRESULT)DoOnceAProcess(pbStartedDoing, pbDone, InitializeCriticalSectionToPtr, (LPARAM)pCrit, (LRESULT)S_FALSE);
} |
