這個其實是一個線程安全的int mapper
void alThunkInit(void);
void alThunkExit(void);
ALuint alThunkAddEntry(ALvoid * ptr);
void alThunkRemoveEntry(ALuint index);
ALvoid *alThunkLookupEntry(ALuint index);
typedef struct {
ALvoid *ptr;
ALboolean InUse;
} ThunkEntry;
static ThunkEntry *g_ThunkArray;
static ALuint g_ThunkArraySize;
static CRITICAL_SECTION g_ThunkLock;
void alThunkInit(void)
{
InitializeCriticalSection(&g_ThunkLock);
g_ThunkArraySize = 1;
g_ThunkArray = calloc(1, g_ThunkArraySize * sizeof(ThunkEntry));
}
void alThunkExit(void)
{
free(g_ThunkArray);
g_ThunkArray = NULL;
g_ThunkArraySize = 0;
DeleteCriticalSection(&g_ThunkLock);
}
ALuint alThunkAddEntry(ALvoid *ptr)
{
ALuint index;
EnterCriticalSection(&g_ThunkLock);
for(index = 0;index < g_ThunkArraySize;index++)
{
if(g_ThunkArray[index].InUse == AL_FALSE)
break;
}
if(index == g_ThunkArraySize)
{
ThunkEntry *NewList;
NewList = realloc(g_ThunkArray, g_ThunkArraySize*2 * sizeof(ThunkEntry));
if(!NewList)
{
LeaveCriticalSection(&g_ThunkLock);
return 0;
}
memset(&NewList[g_ThunkArraySize], 0, g_ThunkArraySize*sizeof(ThunkEntry));
g_ThunkArraySize *= 2;
g_ThunkArray = NewList;
}
g_ThunkArray[index].ptr = ptr;
g_ThunkArray[index].InUse = AL_TRUE;
LeaveCriticalSection(&g_ThunkLock);
return index+1;
}
void alThunkRemoveEntry(ALuint index)
{
EnterCriticalSection(&g_ThunkLock);
if(index > 0 && index <= g_ThunkArraySize)
g_ThunkArray[index-1].InUse = AL_FALSE;
LeaveCriticalSection(&g_ThunkLock);
}
ALvoid *alThunkLookupEntry(ALuint index)
{
ALvoid *ptr = NULL;
EnterCriticalSection(&g_ThunkLock);
if(index > 0 && index <= g_ThunkArraySize)
ptr = g_ThunkArray[index-1].ptr;
LeaveCriticalSection(&g_ThunkLock);
return ptr;
}
用途比較廣