1 files changed, 82 insertions, 0 deletions
diff --git a/src/crimson/osd/scheduler/scheduler.h b/src/crimson/osd/scheduler/scheduler.h
new file mode 100644
index 000000000..a014991ab
--- /dev/null
+++ b/src/crimson/osd/scheduler/scheduler.h
@@ -0,0 +1,82 @@
+// -*- 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) 2019 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.
+ *
+ */
+
+#pragma once
+
+#include <seastar/core/future.hh>
+#include <ostream>
+
+#include "crimson/common/config_proxy.h"
+
+namespace crimson::osd::scheduler {
+
+enum class scheduler_class_t : uint8_t {
+  background_best_effort = 0,
+  background_recovery,
+  client,
+  repop,
+  immediate,
+};
+
+std::ostream &operator<<(std::ostream &, const scheduler_class_t &);
+
+using client_t = uint64_t;
+using cost_t = uint64_t;
+
+struct params_t {
+  cost_t cost = 1;
+  client_t owner;
+  scheduler_class_t klass;
+};
+
+struct item_t {
+  params_t params;
+  seastar::promise<> wake;
+};
+
+/**
+ * Base interface for classes responsible for choosing
+ * op processing order in the OSD.
+ */
+class Scheduler {
+public:
+  // Enqueue op for scheduling
+  virtual void enqueue(item_t &&item) = 0;
+
+  // Enqueue op for processing as though it were enqueued prior
+  // to other items already scheduled.
+  virtual void enqueue_front(item_t &&item) = 0;
+
+  // Returns true iff there are no ops scheduled
+  virtual bool empty() const = 0;
+
+  // Return next op to be processed
+  virtual item_t dequeue() = 0;
+
+  // Dump formatted representation for the queue
+  virtual void dump(ceph::Formatter &f) const = 0;
+
+  // Print human readable brief description with relevant parameters
+  virtual void print(std::ostream &out) const = 0;
+
+  // Destructor
+  virtual ~Scheduler() {};
+};
+
+std::ostream &operator<<(std::ostream &lhs, const Scheduler &);
+using SchedulerRef = std::unique_ptr<Scheduler>;
+
+SchedulerRef make_scheduler(ConfigProxy &);
+
+}