2 * Copyright (c) 2017 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 #ifndef __VOM_RPC_CMD_H__
17 #define __VOM_RPC_CMD_H__
21 #include "vom/cmd.hpp"
22 #include "vom/logger.hpp"
26 * A base class for all RPC commands to VPP.
27 * RPC commands are one of the sub-set of command types to VPP
28 * that modify/create state in VPP and thus return an error code.
29 * Commands are issued in one thread context, but read in another. The
30 * command has an associated std::promise that is met by the RX thread.
31 * this allows the sender, which waits on the promise's future, to
32 * experience a synchronous command.
34 * The command is templatised on the type of the HW::item to be set by
35 * the command, and the data returned in the promise,
37 template <typename HWITEM, typename DATA, typename MSG>
38 class rpc_cmd : public cmd
47 * Constructor taking the HW item that will be updated by the command
62 * return the HW item the command updates
64 HWITEM& item() { return m_hw_item; }
67 * return the const HW item the command updates
69 const HWITEM& item() const { return m_hw_item; }
72 * Fulfill the commands promise. Called from the RX thread
74 void fulfill(const DATA& d)
76 m_promise.set_value(d);
79 * we reset the promise after setting the value to reuse it
80 * when we run the retire command from the same cmd object
82 // m_promise = std::promise<DATA>();
86 * Wait on the commands promise. i.e. block on the completion
91 std::future_status status;
92 std::future<DATA> result;
94 result = m_promise.get_future();
95 status = result.wait_for(std::chrono::seconds(5));
97 if (status != std::future_status::ready) {
98 return (DATA(rc_t::TIMEOUT));
101 return (result.get());
105 * Called by the HW Command Q when it is disabled to indicate the
106 * command can be considered successful without issuing it to HW
108 virtual void succeeded() { m_hw_item.set(rc_t::OK); }
111 * call operator used as a callback by VAPI when the reply is available
113 virtual vapi_error_e operator()(MSG& reply)
115 int retval = reply.get_response().get_payload().retval;
116 VOM_LOG(log_level_t::DEBUG) << to_string() << " " << retval;
117 fulfill(rc_t::from_vpp_retval(retval));
123 * Retire/cancel a long running command
125 virtual void retire(connection& con) {}
129 * A reference to an object's HW::item that the command will update
134 * The promise that implements the synchronous issue
136 std::promise<DATA> m_promise;
141 * fd.io coding-style-patch-verification: ON
144 * eval: (c-set-style "mozilla")