finish the simple Round-Robin Pacemakerpacemaker-clean-up

2 files changed, 10 insertions, 282 deletions

diff --git a/include/hotstuff/hotstuff.h b/include/hotstuff/hotstuff.h
index ffc5e3d..291f9a7 100644
--- a/include/hotstuff/hotstuff.h
+++ b/include/hotstuff/hotstuff.h
@@ -27,7 +27,6 @@
 #include "salticidae/msg.h"
 #include "hotstuff/util.h"
 #include "hotstuff/consensus.h"
-#include "hotstuff/liveness.h"
 
 namespace hotstuff {
 
@@ -82,6 +81,7 @@ struct MsgRespBlock {
 using promise::promise_t;
 
 class HotStuffBase;
+using pacemaker_bt = BoxObj<class PaceMaker>;
 
 template<EntityType ent_type>
 class FetchContext: public promise_t {
@@ -140,6 +140,7 @@ class HotStuffBase: public HotStuffCore {
     size_t blk_size;
     /** libevent handle */
     EventContext ec;
+    salticidae::ThreadCall tcall;
     VeriPool vpool;
     std::vector<NetAddr> peers;
 
@@ -223,8 +224,10 @@ class HotStuffBase: public HotStuffCore {
                 bool ec_loop = false);
 
     size_t size() const { return peers.size(); }
-    PaceMaker &get_pace_maker() { return *pmaker; }
+    auto get_decision_waiting() const { return decision_waiting; }
+    PaceMaker *get_pace_maker() { return pmaker.get(); }
     void print_stat() const;
+    virtual void do_elected();
 //#ifdef HOTSTUFF_AUTOCLI
 //    virtual void do_demand_commands(size_t) {}
 //#endif
diff --git a/include/hotstuff/liveness.h b/include/hotstuff/liveness.h
index cdefdeb..1286c45 100644
--- a/include/hotstuff/liveness.h
+++ b/include/hotstuff/liveness.h
@@ -19,7 +19,7 @@
 #define _HOTSTUFF_LIVENESS_H
 
 #include "salticidae/util.h"
-#include "hotstuff/consensus.h"
+#include "hotstuff/hotstuff.h"
 
 namespace hotstuff {
 
@@ -224,280 +224,6 @@ class PaceMakerDummyFixed: public PaceMakerDummy {
 };
 
 /**
- * Simple long-standing proposer liveness gadget (with randomization).
- * There are three roles for each replica: proposer, candidate and follower.
- *
- * For a proposer, it proposes a new block and refrains itself from proposing
- * the next block unless it receives the QC for the previous block. It will
- * give up the leadership and turn into a candidate when it sees QC for a
- * higher block or being impeached.
- *
- * For a follower, it never proposes any block, but keeps a timer for the QC
- * for the block last proposed by the proposer (the proposer it believes to
- * be). When it times out without seeing such QC or the proposer is impeached,
- * the follower turns into a candidate.
- *
- * For a candidate, it periodically proposes empty blocks to synchronize the
- * preferred branch, with randomized timeout, and check for any new QC. Once it
- * sees such new QC, if the QC is given by itself, it becomes the proposer,
- * otherwise yields to the creator of the QC as a follower.
- *
- * CAUTIONS: This pace maker does not guarantee liveness when a Byzantine node
- * tries to contend with correct nodes and always proposes higher blocks to
- * grab the leadership. If you want to use this for your system, please make
- * sure you introduce mechanism to detect and ban such behavior, or use the
- * round-robin style pace maker instead.
- */
-class PMStickyProposer: virtual public PaceMaker {
-    enum {
-        PROPOSER,
-        FOLLOWER,
-        CANDIDATE
-    } role;
-    double qc_timeout;
-    double candidate_timeout;
-    EventContext ec;
-    /** QC timer or randomized timeout */
-    TimerEvent timer;
-    TimerEvent ev_imp;
-    block_t last_proposed;
-    /** the proposer it believes */
-    ReplicaID proposer;
-
-    /* extra state needed for a proposer */
-    std::queue<promise_t> pending_beats;
-    bool locked;
-
-    /* extra state needed for a candidate */
-    std::unordered_map<ReplicaID, promise_t> last_proposed_by;
-
-    promise_t pm_wait_receive_proposal;
-    promise_t pm_wait_propose;
-    promise_t pm_qc_finish;
-
-    void clear_promises() {
-        pm_wait_receive_proposal.reject();
-        pm_wait_propose.reject();
-        pm_qc_finish.reject();
-        for (auto &p: last_proposed_by)
-            p.second.reject();
-        last_proposed_by.clear();
-    }
-
-    /* helper functions for a follower */
-
-    void reg_follower_receive_proposal() {
-        pm_wait_receive_proposal.reject();
-        (pm_wait_receive_proposal = hsc->async_wait_receive_proposal())
-            .then(
-                salticidae::generic_bind(
-                    &PMStickyProposer::follower_receive_proposal, this, _1));
-    }
-
-    void follower_receive_proposal(const Proposal &prop) {
-        if (prop.proposer == proposer)
-        {
-            auto &qc_ref = prop.blk->get_qc_ref();
-            if (last_proposed && qc_ref != last_proposed)
-            {
-                HOTSTUFF_LOG_INFO("proposer misbehave");
-                to_candidate(); /* proposer misbehave */
-                return;
-            }
-            HOTSTUFF_LOG_PROTO("proposer emits new QC");
-            last_proposed = prop.blk;
-        }
-        reg_follower_receive_proposal();
-    }
-
-    /* helper functions for a proposer */
-
-    void proposer_schedule_next() {
-        if (!pending_beats.empty() && !locked)
-        {
-            auto pm = pending_beats.front();
-            pending_beats.pop();
-            pm_qc_finish.reject();
-            (pm_qc_finish = hsc->async_qc_finish(last_proposed))
-                .then([this, pm]() {
-                    timer.del();
-                    pm.resolve(proposer);
-                    timer.add(qc_timeout);
-                    HOTSTUFF_LOG_PROTO("QC timer reset");
-                });
-            locked = true;
-        }
-    }
-
-    void reg_proposer_propose() {
-        pm_wait_propose.reject();
-        (pm_wait_propose = hsc->async_wait_proposal()).then(
-            salticidae::generic_bind(
-                &PMStickyProposer::proposer_propose, this, _1));
-    }
-
-    void proposer_propose(const Proposal &prop) {
-        last_proposed = prop.blk;
-        locked = false;
-        proposer_schedule_next();
-        reg_proposer_propose();
-    }
-
-    void propose_elect_block() {
-        DataStream s;
-        /* FIXME: should extra data be the voter's id? */
-        s << hsc->get_id();
-        /* propose a block for leader election */
-        hsc->on_propose(std::vector<uint256_t>{},
-                get_parents(), std::move(s));
-    }
-
-    /* helper functions for a candidate */
-
-    void candidate_qc_timeout() {
-        pm_qc_finish.reject();
-        pm_wait_propose.reject();
-        (pm_wait_propose = hsc->async_wait_proposal()).then([this](const Proposal &prop) {
-            const auto &blk = prop.blk;
-            (pm_qc_finish = hsc->async_qc_finish(blk)).then([this, blk]() {
-                HOTSTUFF_LOG_INFO("collected QC for %s", std::string(*blk).c_str());
-                /* managed to collect a QC */
-                to_proposer();
-                propose_elect_block();
-            });
-        });
-        double t = salticidae::gen_rand_timeout(candidate_timeout);
-        timer.del();
-        timer.add(t);
-        HOTSTUFF_LOG_INFO("candidate next try in %.2fs", t);
-        propose_elect_block();
-    }
-
-    void reg_cp_receive_proposal() {
-        pm_wait_receive_proposal.reject();
-        (pm_wait_receive_proposal = hsc->async_wait_receive_proposal())
-            .then(
-                salticidae::generic_bind(
-                    &PMStickyProposer::cp_receive_proposal, this, _1));
-    }
-
-    void cp_receive_proposal(const Proposal &prop) {
-        auto _proposer = prop.proposer;
-        auto &p = last_proposed_by[_proposer];
-        HOTSTUFF_LOG_PROTO("got block %s from %d", std::string(*prop.blk).c_str(), _proposer);
-        p.reject();
-        (p = hsc->async_qc_finish(prop.blk)).then([this, blk=prop.blk, _proposer]() {
-            if (hsc->get_hqc() == blk)
-                to_follower(_proposer);
-        });
-        reg_cp_receive_proposal();
-    }
-
-    /* role transitions */
-
-    void to_follower(ReplicaID new_proposer) {
-        HOTSTUFF_LOG_INFO("new role: follower");
-        clear_promises();
-        role = FOLLOWER;
-        proposer = new_proposer;
-        last_proposed = nullptr;
-        hsc->set_vote_disabled(false);
-        timer.clear();
-        /* redirect all pending cmds to the new proposer */
-        while (!pending_beats.empty())
-        {
-            pending_beats.front().resolve(proposer);
-            pending_beats.pop();
-        }
-        reg_follower_receive_proposal();
-    }
-
-    void to_proposer() {
-        HOTSTUFF_LOG_INFO("new role: proposer");
-        clear_promises();
-        role = PROPOSER;
-        proposer = hsc->get_id();
-        last_proposed = nullptr;
-        hsc->set_vote_disabled(true);
-        timer = TimerEvent(ec, [this](TimerEvent &) {
-            /* proposer unable to get a QC in time */
-            to_candidate();
-        });
-        reg_cp_receive_proposal();
-        proposer_propose(Proposal(-1, hsc->get_genesis(), nullptr));
-    }
-
-    void to_candidate() {
-        HOTSTUFF_LOG_INFO("new role: candidate");
-        clear_promises();
-        role = CANDIDATE;
-        proposer = hsc->get_id();
-        last_proposed = nullptr;
-        hsc->set_vote_disabled(false);
-        timer = TimerEvent(ec, [this](TimerEvent &) {
-            candidate_qc_timeout();
-        });
-        candidate_timeout = qc_timeout;
-        reg_cp_receive_proposal();
-        candidate_qc_timeout();
-    }
-
-    protected:
-    void impeach() override {
-        if (role == CANDIDATE) return;
-        ev_imp = TimerEvent(ec, [this](TimerEvent &) {
-            to_candidate();
-        });
-        ev_imp.add(0);
-        HOTSTUFF_LOG_INFO("schedule to impeach the proposer");
-    }
-
-    public:
-    PMStickyProposer(double qc_timeout, const EventContext &ec):
-        qc_timeout(qc_timeout), ec(ec) {}
-
-    size_t get_pending_size() override { return pending_beats.size(); }
-
-    void init() { to_candidate(); }
-
-    ReplicaID get_proposer() override {
-        return proposer;
-    }
-
-    promise_t beat() override {
-        if (role != FOLLOWER)
-        {
-            promise_t pm;
-            pending_beats.push(pm);
-            if (role == PROPOSER)
-                proposer_schedule_next();
-            return std::move(pm);
-        }
-        else
-            return promise_t([proposer=proposer](promise_t &pm) {
-                pm.resolve(proposer);
-            });
-    }
-
-    promise_t beat_resp(ReplicaID last_proposer) override {
-        return promise_t([this, last_proposer](promise_t &pm) {
-            pm.resolve(last_proposer);
-        });
-    }
-};
-
-struct PaceMakerSticky: public PMHighTail, public PMStickyProposer {
-    PaceMakerSticky(int32_t parent_limit, double qc_timeout, EventContext eb):
-        PMHighTail(parent_limit), PMStickyProposer(qc_timeout, eb) {}
-
-    void init(HotStuffCore *hsc) override {
-        PaceMaker::init(hsc);
-        PMHighTail::init();
-        PMStickyProposer::init();
-    }
-};
-
-/**
  * Simple long-standing round-robin style proposer liveness gadget.
  */
 class PMRoundRobinProposer: virtual public PaceMaker {
@@ -610,15 +336,14 @@ class PMRoundRobinProposer: virtual public PaceMaker {
         locked = false;
         last_proposed = hsc->get_genesis();
         proposer_update_last_proposed();
+        if (proposer == hsc->get_id())
+            static_cast<hotstuff::HotStuffBase *>(hsc)->do_elected();
     }
 
     protected:
     void on_consensus(const block_t &blk) override {
-        if (!rotating)
-        {
-            timer.del();
-            exp_timeout = base_timeout;
-        }
+        timer.del();
+        exp_timeout = base_timeout;
         if (prop_blk[proposer] == blk)
             stop_rotate();
     }