My project has a CUDA memory pool which uses C++‘s std::queue. Allocating from the head of queue:
ptr = q.front();
q.pop();
While freeing memory insert it into the tail of queue:
q.push(ptr);
I changed the implementation from std::queue to std::deque. Both allocating and freeing all occur in the front of queue:
ptr = q.front();
q.pop_front();
......
q.push_front(ptr);
This modification helps me find a hidden bug which is releasing memory early. In origin code, the memory is inserted at the end of queue. So there is a interval between it is reused by other threads and current thread, and the work can still be done correctly as long as it is not reused by others. But after using std::deque, the memory is immediately used by other threads, which disclose the bug.