path: root/include/hotstuff/liveness.h

#ifndef _HOTSTUFF_LIVENESS_H
#define _HOTSTUFF_LIVENESS_H

#include "salticidae/util.h"
#include "hotstuff/consensus.h"

namespace hotstuff {

using salticidae::_1;
using salticidae::_2;

/** Abstraction for liveness gadget (oracle). */
class PaceMaker {
    protected:
    HotStuffCore *hsc;
    public:
    virtual ~PaceMaker() = default;
    /** Initialize the PaceMaker. A derived class should also call the
     * default implementation to set `hsc`. */
    virtual void init(HotStuffCore *_hsc) { hsc = _hsc; }
    /** Get a promise resolved when the pace maker thinks it is a *good* time
     * to issue new commands. When promise is resolved, the replica should
     * propose the command. */
    virtual promise_t beat() = 0;
    /** Get the current proposer. */
    virtual ReplicaID get_proposer() = 0;
    /** Select the parent blocks for a new block.
     * @return Parent blocks. The block at index 0 is the direct parent, while
     * the others are uncles/aunts. The returned vector should be non-empty. */