1 files changed, 83 insertions, 0 deletions
diff --git a/src/crimson/osd/osdmap_gate.h b/src/crimson/osd/osdmap_gate.h
new file mode 100644
index 000000000..d76c4b82f
--- /dev/null
+++ b/src/crimson/osd/osdmap_gate.h
@@ -0,0 +1,83 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#pragma once
+
+#include <functional>
+#include <map>
+#include <optional>
+
+#include <seastar/core/future.hh>
+#include <seastar/core/shared_future.hh>
+
+#include "include/types.h"
+#include "crimson/osd/osd_operation.h"
+
+namespace ceph {
+  class Formatter;
+}
+
+namespace crimson::osd {
+
+class ShardServices;
+
+enum class OSDMapGateType {
+  OSD,
+  PG,
+};
+
+template <OSDMapGateType OSDMapGateTypeV>
+class OSDMapGate {
+public:
+  struct OSDMapBlocker : BlockerT<OSDMapBlocker> {
+    const char * type_name;
+    epoch_t epoch;
+
+    OSDMapBlocker(std::pair<const char *, epoch_t> args)
+      : type_name(args.first), epoch(args.second) {}
+
+    OSDMapBlocker(const OSDMapBlocker &) = delete;
+    OSDMapBlocker(OSDMapBlocker &&) = delete;
+    OSDMapBlocker &operator=(const OSDMapBlocker &) = delete;
+    OSDMapBlocker &operator=(OSDMapBlocker &&) = delete;
+
+    seastar::shared_promise<epoch_t> promise;
+
+    void dump_detail(Formatter *f) const final;
+  };
+  using Blocker = OSDMapBlocker;
+
+private:
+  // order the promises in ascending order of the waited osdmap epoch,
+  // so we can access all the waiters expecting a map whose epoch is less
+  // than or equal to a given epoch
+  using waiting_peering_t = std::map<epoch_t,
+				     OSDMapBlocker>;
+  const char *blocker_type;
+  waiting_peering_t waiting_peering;
+  epoch_t current = 0;
+  bool stopping = false;
+public:
+  OSDMapGate(const char *blocker_type)
+    : blocker_type(blocker_type) {}
+
+  /**
+   * wait_for_map
+   *
+   * Wait for an osdmap whose epoch is greater or equal to given epoch.
+   * If shard_services is non-null, request map if not present.
+   */
+  seastar::future<epoch_t>
+  wait_for_map(
+    typename OSDMapBlocker::BlockingEvent::TriggerI&& trigger,
+    epoch_t epoch,
+    ShardServices *shard_services=nullptr
+  );
+  void got_map(epoch_t epoch);
+  seastar::future<> stop();
+};
+
+using OSD_OSDMapGate = OSDMapGate<OSDMapGateType::OSD>;
+using PG_OSDMapGate = OSDMapGate<OSDMapGateType::PG>;
+
+}