void RUDPCCCObject::on_timer(uint64_t now_ts)
{
uint32_t delay = core_max(rtt_ / 8, 50);
if (now_ts >= prev_on_ts_ + delay) //10个RTT决策一次
{
print_count_ ++;
if(print_count_ % 4 == 0)
{
RUDP_DEBUG("send window size = " << snd_cwnd_ << ",rtt = " << rtt_ << ",rtt_var = " << rtt_var_ << ",resend = " << resend_count_);
set_max_cwnd(rtt_);
}
if(slow_start_) //停止慢启动过程
{
if(print_count_ > 10)
{
slow_start_ = false;
RUDP_INFO("ccc stop slow_start, snd_cwnd = " << snd_cwnd_);
}
}
else
{
if (recv_count_ > (snd_cwnd_ * delay * 7 / (rtt_ * 8)))
{
snd_cwnd_ = (uint32_t)(snd_cwnd_ + core_max(8,(snd_cwnd_ / 8)));
snd_cwnd_ = core_min(max_cwnd_, snd_cwnd_);
loss_flag_ = false;
}
else if (recv_count_ < snd_cwnd_ * delay * 5 / (rtt_ * 8)){
snd_cwnd_ = (uint32_t)(snd_cwnd_ - (snd_cwnd_ / 16));
snd_cwnd_ = core_max(min_cwnd_, snd_cwnd_);
loss_flag_ = true;
}
else if (rtt_var_ > 30 && resend_count_ >= core_max(8, snd_cwnd_ * delay * 3 / (8 * rtt_))){
snd_cwnd_ = (uint32_t)(snd_cwnd_ - (snd_cwnd_ / 10));
snd_cwnd_ = core_max(min_cwnd_, snd_cwnd_);
loss_flag_ = true;
}
resend_count_ = 0;
}
recv_count_ = 0;
prev_on_ts_ = now_ts;
}
}
void RUDPCCCObject::set_rtt(uint32_t keep_live_rtt)
{
//提高高延迟网络的吞吐量（BDP）
if(max_cwnd_ == DEFAULT_CWND_SIZE)
set_max_cwnd(keep_live_rtt);
//计算rtt和rtt修正
if(rtt_first_)
{
rtt_first_ = false;
rtt_ = keep_live_rtt;
rtt_var_ = rtt_ / 2;
}
else //参考了tcp的rtt计算
{
rtt_var_ = (rtt_var_ * 3 + core_abs(rtt_, keep_live_rtt)) / 4;
rtt_ = (7 * rtt_ + keep_live_rtt) / 8;
}
rtt_ = core_max(5, rtt_);
rtt_var_ = core_max(3, rtt_var_);
}
bool ExprRep::withinKnownPrecision(const extLong& relPrec,
const extLong& absPrec) {
if (appComputed()) { // an approximate value has been evaluated.
if (appValue().isExact()) {
return true;
} else { // approximation has certain error.
// decide to which position it is required to compute correctly.
extLong required = core_max(-absPrec, appValue().lMSB()-relPrec);
// see whether the existing error is smaller than the requirement.
return (knownPrecision() <= required);
}
} else
return false;
}//withinKnownPrecision(a, r)
int32_t CEpollReactor::open_reactor(uint32_t number_of_handlers)
{
for(uint32_t i = 1; i < EPOLL_HEAP_SIZE; i ++)
{
handler_heap_[i] = 0;
free_set_.insert(i);
}
max_handler_num_ = core_max(number_of_handlers, max_handler_num_);
epfd_ = epoll_create(max_handler_num_);
if(epfd_ == -1)
{
return -1;
}
events_ = new epoll_event[2 * max_handler_num_];
return 0;
}
void DivRep::computeApproxValue(const extLong& relPrec,
const extLong& absPrec) {
if (lMSB() < EXTLONG_BIG && lMSB() > EXTLONG_SMALL) {
extLong rr = relPrec + EXTLONG_SEVEN; // These rules come from
extLong ra = uMSB() + absPrec + EXTLONG_EIGHT; // Koji's Master Thesis, page 65
extLong ra2 = core_max(ra, EXTLONG_TWO);
extLong r = core_min(rr, ra2);
extLong af = - first->lMSB() + r;
extLong as = - second->lMSB() + r;
extLong pr = relPrec + EXTLONG_SIX;
extLong pa = uMSB() + absPrec + EXTLONG_SEVEN;
extLong p = core_min(pr, pa); // Seems to be an error:
// p can be negative here!
// Also, this does not conform to
// Koji's thesis which has a default
// relative precision (p.65).
appValue() = first->getAppValue(r, af).div(second->getAppValue(r, as), p);
} else {
std::cerr << "lMSB = " << lMSB() << std::endl;
core_error("a huge lMSB in DivRep", __FILE__, __LINE__, false);
}
}
