1 files changed, 96 insertions, 0 deletions
diff --git a/src/common/Finisher.cc b/src/common/Finisher.cc
new file mode 100644
index 000000000..974241f57
--- /dev/null
+++ b/src/common/Finisher.cc
@@ -0,0 +1,96 @@
+// -*- 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.
+      in_progress_queue.swap(finisher_queue);
+      finisher_running = true;
+      ul.unlock();
+      ldout(cct, 10) << "finisher_thread doing " << in_progress_queue << dendl;
+
+      if (logger) {
+	start = ceph_clock_now();
+	count = in_progress_queue.size();
+      }
+
+      // Now actually process the contexts.
+      for (auto p : in_progress_queue) {
+	p.first->complete(p.second);
+      }
+      ldout(cct, 10) << "finisher_thread done with " << in_progress_queue
+                     << dendl;
+      in_progress_queue.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;
+}
+