nghttp2/src/shrpx_connect_blocker.cc

71 lines
2.3 KiB
C++

/*
* nghttp2 - HTTP/2 C Library
*
* Copyright (c) 2014 Tatsuhiro Tsujikawa
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "shrpx_connect_blocker.h"
namespace shrpx {
namespace {
void connect_blocker_cb(struct ev_loop *loop, ev_timer *w, int revents) {
if (LOG_ENABLED(INFO)) {
LOG(INFO) << "Unblock";
}
}
} // namespace
ConnectBlocker::ConnectBlocker(std::mt19937 &gen, struct ev_loop *loop)
: gen_(gen), loop_(loop), fail_count_(0) {
ev_timer_init(&timer_, connect_blocker_cb, 0., 0.);
}
ConnectBlocker::~ConnectBlocker() { ev_timer_stop(loop_, &timer_); }
bool ConnectBlocker::blocked() const { return ev_is_active(&timer_); }
void ConnectBlocker::on_success() { fail_count_ = 0; }
namespace {
constexpr size_t MAX_BACKOFF_EXP = 10;
} // namespace
void ConnectBlocker::on_failure() {
if (ev_is_active(&timer_)) {
return;
}
++fail_count_;
auto max_backoff = (1 << std::min(MAX_BACKOFF_EXP, fail_count_)) - 1;
auto dist = std::uniform_int_distribution<>(0, max_backoff);
auto backoff = dist(gen_);
LOG(WARN) << "Could not connect " << fail_count_
<< " times in a row; sleep for " << backoff << " seconds";
ev_timer_set(&timer_, backoff, 0.);
ev_timer_start(loop_, &timer_);
}
} // namespace shrpx