1 files changed, 157 insertions, 0 deletions
diff --git a/src/rgw/rgw_aio_throttle.cc b/src/rgw/rgw_aio_throttle.cc
new file mode 100644
index 00000000..79d095d2
--- /dev/null
+++ b/src/rgw/rgw_aio_throttle.cc
@@ -0,0 +1,157 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2018 Red Hat, Inc.
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation. See file COPYING.
+ *
+ */
+
+#include "include/rados/librados.hpp"
+
+#include "rgw_aio_throttle.h"
+#include "rgw_rados.h"
+
+namespace rgw {
+
+void AioThrottle::aio_cb(void *cb, void *arg)
+{
+  Pending& p = *static_cast<Pending*>(arg);
+  p.result = p.completion->get_return_value();
+  p.parent->put(p);
+}
+
+bool AioThrottle::waiter_ready() const
+{
+  switch (waiter) {
+  case Wait::Available: return is_available();
+  case Wait::Completion: return has_completion();
+  case Wait::Drained: return is_drained();
+  default: return false;
+  }
+}
+
+AioResultList AioThrottle::submit(RGWSI_RADOS::Obj& obj,
+                                  librados::ObjectWriteOperation *op,
+                                  uint64_t cost, uint64_t id)
+{
+  auto p = std::make_unique<Pending>();
+  p->obj = obj;
+  p->id = id;
+  p->cost = cost;
+
+  if (cost > window) {
+    p->result = -EDEADLK; // would never succeed
+    std::unique_lock lock{mutex};
+    completed.push_back(*p);
+  } else {
+    get(*p);
+    p->result = obj.aio_operate(p->completion, op);
+    if (p->result < 0) {
+      put(*p);
+    }
+  }
+  p.release();
+  std::unique_lock lock{mutex};
+  return std::move(completed);
+}
+
+AioResultList AioThrottle::submit(RGWSI_RADOS::Obj& obj,
+                                  librados::ObjectReadOperation *op,
+                                  uint64_t cost, uint64_t id)
+{
+  auto p = std::make_unique<Pending>();
+  p->obj = obj;
+  p->id = id;
+  p->cost = cost;
+
+  if (cost > window) {
+    p->result = -EDEADLK; // would never succeed
+    std::unique_lock lock{mutex};
+    completed.push_back(*p);
+  } else {
+    get(*p);
+    p->result = obj.aio_operate(p->completion, op, &p->data);
+    if (p->result < 0) {
+      put(*p);
+    }
+  }
+  p.release();
+  std::unique_lock lock{mutex};
+  return std::move(completed);
+}
+
+void AioThrottle::get(Pending& p)
+{
+  std::unique_lock lock{mutex};
+
+  // wait for the write size to become available
+  pending_size += p.cost;
+  if (!is_available()) {
+    ceph_assert(waiter == Wait::None);
+    waiter = Wait::Available;
+    cond.wait(lock, [this] { return is_available(); });
+    waiter = Wait::None;
+  }
+
+  // register the pending write and attach a completion
+  p.parent = this;
+  p.completion = librados::Rados::aio_create_completion(&p, nullptr, aio_cb);
+  pending.push_back(p);
+}
+
+void AioThrottle::put(Pending& p)
+{
+  p.completion->release();
+  p.completion = nullptr;
+
+  std::scoped_lock lock{mutex};
+
+  // move from pending to completed
+  pending.erase(pending.iterator_to(p));
+  completed.push_back(p);
+
+  pending_size -= p.cost;
+
+  if (waiter_ready()) {
+    cond.notify_one();
+  }
+}
+
+AioResultList AioThrottle::poll()
+{
+  std::unique_lock lock{mutex};
+  return std::move(completed);
+}
+
+AioResultList AioThrottle::wait()
+{
+  std::unique_lock lock{mutex};
+  if (completed.empty() && !pending.empty()) {
+    ceph_assert(waiter == Wait::None);
+    waiter = Wait::Completion;
+    cond.wait(lock, [this] { return has_completion(); });
+    waiter = Wait::None;
+  }
+  return std::move(completed);
+}
+
+AioResultList AioThrottle::drain()
+{
+  std::unique_lock lock{mutex};
+  if (!pending.empty()) {
+    ceph_assert(waiter == Wait::None);
+    waiter = Wait::Drained;
+    cond.wait(lock, [this] { return is_drained(); });
+    waiter = Wait::None;
+  }
+  return std::move(completed);
+}
+
+} // namespace rgw