gperftools中threadcache用鏈表存放cache內存,其中鏈表是這樣實現的:
inline void *SLL_Next(void *t) {
return *(reinterpret_cast<void**>(t));
}
inline void SLL_SetNext(void *t, void *n) {
*(reinterpret_cast<void**>(t)) = n;
}
inline void SLL_Push(void **list, void *element) {
SLL_SetNext(element, *list);
*list = element;
}
inline void *SLL_Pop(void **list) {
void *result = *list;
*list = SLL_Next(*list);
return result;
}
// Remove N elements from a linked list to which head points. head will be
// modified to point to the new head. start and end will point to the first
// and last nodes of the range. Note that end will point to NULL after this
// function is called.
inline void SLL_PopRange(void **head, int N, void **start, void **end) {
if (N == 0) {
*start = NULL;
*end = NULL;
return;
}
void *tmp = *head;
for (int i = 1; i < N; ++i) {
tmp = SLL_Next(tmp);
}
*start = *head;
*end = tmp;
*head = SLL_Next(tmp);
// Unlink range from list.
SLL_SetNext(tmp, NULL);
}
inline void SLL_PushRange(void **head, void *start, void *end) {
if (!start) return;
SLL_SetNext(end, *head);
*head = start;
}
inline size_t SLL_Size(void *head) {
int count = 0;
while (head) {
count++;
head = SLL_Next(head);
}
return count;
}
上面這段代碼可以用來管理自己的內存cache。
void *list8B;
SLL_Push(&l, reinterpret_cast<void*>malloc(8)); //add memory;
void *m = SLL_Pop(&list); //use cache;
SLL_Push(&l, m); //return memory;