1 files changed, 252 insertions, 0 deletions
diff --git a/src/test/direct_messenger/DirectMessenger.cc b/src/test/direct_messenger/DirectMessenger.cc
new file mode 100644
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+++ b/src/test/direct_messenger/DirectMessenger.cc
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+// -*- 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) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * 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 "DirectMessenger.h"
+#include "msg/DispatchStrategy.h"
+
+
+class DirectConnection : public Connection {
+  /// sent messages are dispatched here
+  DispatchStrategy *const dispatchers;
+
+  /// the connection that will be attached to outgoing messages, so that replies
+  /// can be dispatched back to the sender. the pointer is atomic for
+  /// thread-safety between mark_down() and send_message(). no reference is held
+  /// on this Connection to avoid cyclical refs. we don't need a reference
+  /// because its owning DirectMessenger will mark both connections down (and
+  /// clear this pointer) before dropping its own reference
+  std::atomic<Connection*> reply_connection{nullptr};
+
+ public:
+  DirectConnection(CephContext *cct, DirectMessenger *m,
+                   DispatchStrategy *dispatchers)
+    : Connection(cct, m),
+      dispatchers(dispatchers)
+  {}
+
+  /// sets the Connection that will receive replies to outgoing messages
+  void set_direct_reply_connection(ConnectionRef conn);
+
+  /// return true if a peer connection exists
+  bool is_connected() override;
+
+  /// pass the given message directly to our dispatchers
+  int send_message(Message *m) override;
+
+  /// release our pointer to the peer connection. later calls to is_connected()
+  /// will return false, and send_message() will fail with -ENOTCONN
+  void mark_down() override;
+
+  /// noop - keepalive messages are not needed within a process
+  void send_keepalive() override {}
+
+  /// noop - reconnect/recovery semantics are not needed within a process
+  void mark_disposable() override {}
+};
+
+void DirectConnection::set_direct_reply_connection(ConnectionRef conn)
+{
+  reply_connection.store(conn.get());
+}
+
+bool DirectConnection::is_connected()
+{
+  // true between calls to set_direct_reply_connection() and mark_down()
+  return reply_connection.load() != nullptr;
+}
+
+int DirectConnection::send_message(Message *m)
+{
+  // read reply_connection atomically and take a reference
+  ConnectionRef conn = reply_connection.load();
+  if (!conn) {
+    m->put();
+    return -ENOTCONN;
+  }
+  // attach reply_connection to the Message, so that calls to
+  // m->get_connection()->send_message() can be dispatched back to the sender
+  m->set_connection(conn);
+
+  dispatchers->ds_dispatch(m);
+  return 0;
+}
+
+void DirectConnection::mark_down()
+{
+  Connection *conn = reply_connection.load();
+  if (!conn) {
+    return; // already marked down
+  }
+  if (!reply_connection.compare_exchange_weak(conn, nullptr)) {
+    return; // lost the race to mark down
+  }
+  // called only once to avoid loops
+  conn->mark_down();
+}
+
+
+static ConnectionRef create_loopback(DirectMessenger *m,
+                                     entity_name_t name,
+                                     DispatchStrategy *dispatchers)
+{
+  auto loopback = boost::intrusive_ptr<DirectConnection>(
+      new DirectConnection(m->cct, m, dispatchers));
+  // loopback replies go to itself
+  loopback->set_direct_reply_connection(loopback);
+  loopback->set_peer_type(name.type());
+  loopback->set_features(CEPH_FEATURES_ALL);
+  return loopback;
+}
+
+DirectMessenger::DirectMessenger(CephContext *cct, entity_name_t name,
+                                 string mname, uint64_t nonce,
+                                 DispatchStrategy *dispatchers)
+  : SimplePolicyMessenger(cct, name, mname, nonce),
+    dispatchers(dispatchers),
+    loopback_connection(create_loopback(this, name, dispatchers))
+{
+  dispatchers->set_messenger(this);
+}
+
+DirectMessenger::~DirectMessenger()
+{
+}
+
+int DirectMessenger::set_direct_peer(DirectMessenger *peer)
+{
+  if (get_myinst() == peer->get_myinst()) {
+    return -EADDRINUSE; // must have a different entity instance
+  }
+  peer_inst = peer->get_myinst();
+
+  // allocate a Connection that dispatches to the peer messenger
+  auto direct_connection = boost::intrusive_ptr<DirectConnection>(
+      new DirectConnection(cct, peer, peer->dispatchers.get()));
+
+  direct_connection->set_peer_addr(peer_inst.addr);
+  direct_connection->set_peer_type(peer_inst.name.type());
+  direct_connection->set_features(CEPH_FEATURES_ALL);
+
+  // if set_direct_peer() was already called on the peer messenger, we can
+  // finish by attaching their connections. if not, the later call to
+  // peer->set_direct_peer() will attach their connection to ours
+  auto connection = peer->get_connection(get_myinst());
+  if (connection) {
+    auto p = static_cast<DirectConnection*>(connection.get());
+
+    p->set_direct_reply_connection(direct_connection);
+    direct_connection->set_direct_reply_connection(p);
+  }
+
+  peer_connection = std::move(direct_connection);
+  return 0;
+}
+
+int DirectMessenger::bind(const entity_addr_t &bind_addr)
+{
+  if (peer_connection) {
+    return -EINVAL; // can't change address after sharing it with the peer
+  }
+  set_myaddr(bind_addr);
+  loopback_connection->set_peer_addr(bind_addr);
+  return 0;
+}
+
+int DirectMessenger::client_bind(const entity_addr_t &bind_addr)
+{
+  // same as bind
+  return bind(bind_addr);
+}
+
+int DirectMessenger::start()
+{
+  if (!peer_connection) {
+    return -EINVAL; // did not connect to a peer
+  }
+  if (started) {
+    return -EINVAL; // already started
+  }
+
+  dispatchers->start();
+  return SimplePolicyMessenger::start();
+}
+
+int DirectMessenger::shutdown()
+{
+  if (!started) {
+    return -EINVAL; // not started
+  }
+
+  mark_down_all();
+  peer_connection.reset();
+  loopback_connection.reset();
+
+  dispatchers->shutdown();
+  SimplePolicyMessenger::shutdown();
+  sem.Put(); // signal wait()
+  return 0;
+}
+
+void DirectMessenger::wait()
+{
+  sem.Get(); // wait on signal from shutdown()
+  dispatchers->wait();
+}
+
+ConnectionRef DirectMessenger::get_connection(const entity_inst_t& dst)
+{
+  if (dst == peer_inst) {
+    return peer_connection;
+  }
+  if (dst == get_myinst()) {
+    return loopback_connection;
+  }
+  return nullptr;
+}
+
+ConnectionRef DirectMessenger::get_loopback_connection()
+{
+  return loopback_connection;
+}
+
+int DirectMessenger::send_message(Message *m, const entity_inst_t& dst)
+{
+  auto conn = get_connection(dst);
+  if (!conn) {
+    m->put();
+    return -ENOTCONN;
+  }
+  return conn->send_message(m);
+}
+
+void DirectMessenger::mark_down(const entity_addr_t& addr)
+{
+  ConnectionRef conn;
+  if (addr == peer_inst.addr) {
+    conn = peer_connection;
+  } else if (addr == get_myaddr_legacy()) {
+    conn = loopback_connection;
+  }
+  if (conn) {
+    conn->mark_down();
+  }
+}
+
+void DirectMessenger::mark_down_all()
+{
+  if (peer_connection) {
+    peer_connection->mark_down();
+  }
+  loopback_connection->mark_down();
+}