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// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab
#include "Finisher.h"
#define dout_subsys ceph_subsys_finisher
#undef dout_prefix
#define dout_prefix *_dout << "finisher(" << this << ") "
void Finisher::start()
{
ldout(cct, 10) << __func__ << dendl;
finisher_thread.create(thread_name.c_str());
}
void Finisher::stop()
{
ldout(cct, 10) << __func__ << dendl;
finisher_lock.lock();
finisher_stop = true;
// we don't have any new work to do, but we want the worker to wake up anyway
// to process the stop condition.
finisher_cond.notify_all();
finisher_lock.unlock();
finisher_thread.join(); // wait until the worker exits completely
ldout(cct, 10) << __func__ << " finish" << dendl;
}
void Finisher::wait_for_empty()
{
std::unique_lock ul(finisher_lock);
while (!finisher_queue.empty() || finisher_running) {
ldout(cct, 10) << "wait_for_empty waiting" << dendl;
finisher_empty_wait = true;
finisher_empty_cond.wait(ul);
}
ldout(cct, 10) << "wait_for_empty empty" << dendl;
finisher_empty_wait = false;
}
void *Finisher::finisher_thread_entry()
{
std::unique_lock ul(finisher_lock);
ldout(cct, 10) << "finisher_thread start" << dendl;
utime_t start;
uint64_t count = 0;
while (!finisher_stop) {
/// Every time we are woken up, we process the queue until it is empty.
while (!finisher_queue.empty()) {
// To reduce lock contention, we swap out the queue to process.
// This way other threads can submit new contexts to complete
// while we are working.
vector<pair<Context*,int>> ls;
ls.swap(finisher_queue);
finisher_running = true;
ul.unlock();
ldout(cct, 10) << "finisher_thread doing " << ls << dendl;
if (logger) {
start = ceph_clock_now();
count = ls.size();
}
// Now actually process the contexts.
for (auto p : ls) {
p.first->complete(p.second);
}
ldout(cct, 10) << "finisher_thread done with " << ls << dendl;
ls.clear();
if (logger) {
logger->dec(l_finisher_queue_len, count);
logger->tinc(l_finisher_complete_lat, ceph_clock_now() - start);
}
ul.lock();
finisher_running = false;
}
ldout(cct, 10) << "finisher_thread empty" << dendl;
if (unlikely(finisher_empty_wait))
finisher_empty_cond.notify_all();
if (finisher_stop)
break;
ldout(cct, 10) << "finisher_thread sleeping" << dendl;
finisher_cond.wait(ul);
}
// If we are exiting, we signal the thread waiting in stop(),
// otherwise it would never unblock
finisher_empty_cond.notify_all();
ldout(cct, 10) << "finisher_thread stop" << dendl;
finisher_stop = false;
return 0;
}
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