50 lines
2.1 KiB
C
50 lines
2.1 KiB
C
// Copyright(c) 2006 to 2020 ZettaScale Technology and others
|
|
//
|
|
// This program and the accompanying materials are made available under the
|
|
// terms of the Eclipse Public License v. 2.0 which is available at
|
|
// http://www.eclipse.org/legal/epl-2.0, or the Eclipse Distribution License
|
|
// v. 1.0 which is available at
|
|
// http://www.eclipse.org/org/documents/edl-v10.php.
|
|
//
|
|
// SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
|
|
|
|
#ifndef DDSI_HBCONTROL_H
|
|
#define DDSI_HBCONTROL_H
|
|
|
|
#include "dds/features.h"
|
|
#include "dds/ddsrt/time.h"
|
|
|
|
#if defined (__cplusplus)
|
|
extern "C" {
|
|
#endif
|
|
|
|
/// @brief State information used in deciding when/what kind of a heartbeat to send (per writer)
|
|
///
|
|
/// Heartbeats inform readers of the range of sequence numbers available from the writer and serve the dual
|
|
/// purpose of (1) allowing the reader to detect message loss, and (2) allowing the reader to request a retransmit.
|
|
///
|
|
/// Because readers are not allowed to request a retransmit unless they received a heartbeat, we make an
|
|
/// effort to a embed heartbeat in an outgoing RTPS message (~ a packet) if a preceding RTPS message
|
|
/// also contained data from the writer. Its sole purpose is to allow it to request a retransmit.
|
|
struct ddsi_hbcontrol {
|
|
ddsrt_mtime_t t_of_last_write; ///< Time of most recent write
|
|
ddsrt_mtime_t t_of_last_hb; ///< Time of last heartbeat sent
|
|
ddsrt_mtime_t t_of_last_ackhb; ///< Time of last heartbeat sent that requires a response
|
|
ddsrt_mtime_t tsched; ///< Time at which next asynchronous heartbeat is scheduled
|
|
uint32_t hbs_since_last_write; ///< Number of heartbeats sent since last write
|
|
uint32_t last_packetid; ///< Last RTPS message id containing a heartbeat from this writer
|
|
};
|
|
|
|
/// @brief Encoding for possible ways of adding heartbeats to messages
|
|
enum ddsi_hbcontrol_ack_required {
|
|
DDSI_HBC_ACK_REQ_NO, ///< Heartbeat does not require a response (FINAL flag set)
|
|
DDSI_HBC_ACK_REQ_YES, ///< Heartbeat requires a response, may continue packing
|
|
DDSI_HBC_ACK_REQ_YES_AND_FLUSH ///< Heartbeat requires a response, must send immediately
|
|
};
|
|
|
|
#if defined (__cplusplus)
|
|
}
|
|
#endif
|
|
|
|
#endif /* DDSI_HBCONTROL_H */
|