diff options
Diffstat (limited to 'src/base/circular_queue.hh')
| -rw-r--r-- | src/base/circular_queue.hh | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/src/base/circular_queue.hh b/src/base/circular_queue.hh index 5023661b9..f368ed0d1 100644 --- a/src/base/circular_queue.hh +++ b/src/base/circular_queue.hh @@ -106,10 +106,19 @@ class CircularQueue : private std::vector<T> static uint32_t moduloSub(uint32_t op1, uint32_t op2, uint32_t size) { - int ret = (uint32_t)(op1 - op2) % size; + int32_t ret = sub(op1, op2, size); return ret >= 0 ? ret : ret + size; } + static int32_t + sub(uint32_t op1, uint32_t op2, uint32_t size) + { + if (op1 > op2) + return (op1 - op2) % size; + else + return -((op2 - op1) % size); + } + void increase(uint32_t& v, size_t delta = 1) { v = moduloAdd(v, delta, _capacity); @@ -355,10 +364,10 @@ class CircularQueue : private std::vector<T> difference_type operator-(const iterator& that) { /* If a is already at the end, we can safely return 0. */ - auto ret = _cq->moduloSub(this->_idx, that._idx); + auto ret = _cq->sub(this->_idx, that._idx, _cq->capacity()); - if (ret == 0 && this->_round != that._round) { - ret += this->_round * _cq->capacity(); + if (this->_round != that._round) { + ret += ((this->_round - that._round) * _cq->capacity()); } return ret; } |