Merge pull request #586 from evoskuil/master

Add bump event to prevent preconfirm stall with no downloads.

console/executor.cpp

@@ -93,7 +93,7 @@ const std::unordered_map<uint8_t, std::string> executor::fired_
 
     { events::block_archived,      "block_archived......" },
     { events::block_validated,     "block_validated....." },
-    { events::block_confirmable,   "block_confirmable..." },
+    { events::block_confirmed,     "block_confirmed....." },
     { events::block_unconfirmable, "block_unconfirmable." },
     { events::validate_bypassed,   "validate_bypassed..." },
     { events::confirm_bypassed,    "confirm_bypassed...." },
@@ -1013,7 +1013,7 @@ void executor::write_test()
         else if ((ec = query_.block_confirmable(link)))
         {
             // must set_strong before each (no push, verifies non-use).
-            console(format("Failure: block_confirmable, %1%") % ec.message());
+            console(format("Failure: block_confirmed, %1%") % ec.message());
             break;
         }
         ////if (!query_.set_txs_connected(link))

include/bitcoin/node/chase.hpp

@@ -29,10 +29,14 @@ enum class chase
     /// Work shuffling.
     /// -----------------------------------------------------------------------
 
-    /// Chaser is directed to start validating (height_t).
+    /// Chasers are directed to start operating (height_t).
     /// Issued by 'full_node' and handled by 'preconfirm'.
     start,
 
+    /// Chaser is directed to start when there are no downloads (height_t).
+    /// Issued by 'organize' and handled by 'preconfirm'.
+    bump,
+
     /// Channels (all) are directed to pause reading (channel_t).
     /// Issued by 'full_node' and handled by 'protocol'.
     pause,

include/bitcoin/node/chasers/chaser.hpp

@@ -97,6 +97,9 @@ class BCN_API chaser
     /// True if the current thread is on the chaser strand.
     bool stranded() const NOEXCEPT;
 
+    /// Top candidate is within configured span from current time.
+    bool is_current() const NOEXCEPT;
+
     /// Header timestamp is within configured span from current time.
     bool is_current(uint32_t timestamp) const NOEXCEPT;
 

include/bitcoin/node/events.hpp

@@ -36,7 +36,7 @@ enum events : uint8_t
     /// Blocks.
     block_archived,      // block checked
     block_validated,     // block checked, accepted, connected
-    block_confirmable,   // block checked, accepted, connected, confirmable
+    block_confirmed,   // block checked, accepted, connected, confirmable
     block_unconfirmable, // block invalid (after headers-first archive)
     validate_bypassed,   // block checked, accepted [assumed]
     confirm_bypassed,    // block checked, accepted, connected [assumed]

include/bitcoin/node/impl/chasers/chaser_organize.ipp

@@ -102,6 +102,7 @@ void CLASS::handle_event(const code&, chase event_, event_link value) NOEXCEPT
             break;
         }
         case chase::start:
+        case chase::bump:
         case chase::pause:
         case chase::resume:
         case chase::starved:
@@ -366,12 +367,18 @@ void CLASS::do_organize(typename Block::cptr& block_ptr,
 
     // Delay so headers can get current before block download starts.
     // Checking currency before notify also avoids excessive work backlog.
-
-    // If all headers are previously associated then no blocks will be fed to
-    // preconfirmation, resulting in a stall...
-
     if (is_block() || is_current(header.timestamp()))
+    {
+        // If at start the fork point is top of both chains, and next candidate
+        // is already downloaded, then new header will arrive and download will
+        // be skipped, resulting in stall until restart at which time the start
+        // event will advance through all downloaded candidates and progress on
+        // arrivals. This bumps preconfirmation for current strong headers.
+        notify(error::success, chase::bump, add1(branch_point));
+
+        // Start block downloads, which upon completion bumps preconfirmation.
         notify(error::success, chase_object(), branch_point);
+    }
 
     state_ = state;
     handler(error::success, height);

src/chasers/chaser.cpp

@@ -93,6 +93,11 @@ bool chaser::stranded() const NOEXCEPT
     return strand_.running_in_this_thread();
 }
 
+bool chaser::is_current() const NOEXCEPT
+{
+    return node_.is_current();
+}
+
 bool chaser::is_current(uint32_t timestamp) const NOEXCEPT
 {
     return node_.is_current(timestamp);

src/chasers/chaser_check.cpp

@@ -87,6 +87,7 @@ void chaser_check::handle_event(const code&, chase event_,
             break;
         }
         case chase::start:
+        case chase::bump:
         case chase::pause:
         case chase::resume:
         case chase::starved:
@@ -133,10 +134,8 @@ void chaser_check::do_add_headers(height_t branch_point) NOEXCEPT
     LOGN("Branch point (" << branch_point << ") unassociated ("
         << added << ").");
 
-    if (is_zero(added))
-        return;
-
-    notify(error::success, chase::download, added);
+    if (!is_zero(added))
+        notify(error::success, chase::download, added);
 }
 
 // purge headers
@@ -247,8 +246,7 @@ size_t chaser_check::count_map(const maps& table) const NOEXCEPT
         });
 }
 
-map_ptr chaser_check::make_map(size_t start,
-    size_t count) const NOEXCEPT
+map_ptr chaser_check::make_map(size_t start, size_t count) const NOEXCEPT
 {
     // Known malleated blocks are disassociated and therefore appear here.
     return std::make_shared<associations>(

src/chasers/chaser_confirm.cpp

@@ -66,6 +66,7 @@ void chaser_confirm::handle_event(const code&, chase event_,
             break;
         }
         case chase::start:
+        case chase::bump:
         case chase::pause:
         case chase::resume:
         case chase::starved:
@@ -179,21 +180,21 @@ void chaser_confirm::do_preconfirmed(height_t height) NOEXCEPT
                 // Advance and confirm.
                 notify(code, chase::confirmable, index);
                 fire(events::confirm_bypassed, index);
-
+        
                 if (!set_confirmed(link, index++))
                 {
                     fault(error::store_integrity);
                     return;
                 }
                 continue;
             }
-
+        
             if (code == error::store_integrity)
             {
                 fault(error::store_integrity);
                 return;
             }
-
+        
             if (query.is_malleable(link))
             {
                 notify(code, chase::malleated, link);
@@ -206,17 +207,17 @@ void chaser_confirm::do_preconfirmed(height_t height) NOEXCEPT
                     fault(error::store_integrity);
                     return;
                 }
-
+        
                 notify(code, chase::unconfirmable, link);
                 fire(events::block_unconfirmable, index);
             }
-
+        
             if (!roll_back(popped, fork_point, sub1(index)))
             {
                 fault(error::store_integrity);
                 return;
             }
-
+        
             LOGR("Unconfirmable block [" << index << "] " << code.message());
             return;
         }
@@ -235,7 +236,7 @@ void chaser_confirm::do_preconfirmed(height_t height) NOEXCEPT
         // ....................................................................
 
         notify(error::success, chase::confirmable, index);
-        fire(events::block_confirmable, index);
+        fire(events::block_confirmed, index);
 
         if (!set_confirmed(link, index++))
         {
@@ -258,11 +259,14 @@ code chaser_confirm::confirm(const header_link& link,
         ec == database::error::block_unconfirmable)
         return ec;
 
-    if (ec == database::error::block_preconfirmable)
-        return query.block_confirmable(link);
+    // TODO: fix block_confirmable.
+    return error::success;
 
-    // Should not get here without a known block state.
-    return error::store_integrity;
+    ////if (ec == database::error::block_preconfirmable)
+    ////    return query.block_confirmable(link);
+    ////
+    ////// Should not get here without a known block state.
+    ////return error::store_integrity;
 }
 
 // utility

src/chasers/chaser_preconfirm.cpp

@@ -56,11 +56,7 @@ void chaser_preconfirm::handle_event(const code&, chase event_,
     switch (event_)
     {
         case chase::start:
-        {
-            POST(do_checked, height_t{});
-            break;
-        }
-        case chase::header:
+        case chase::bump:
         {
             POST(do_checked, height_t{});
             break;
@@ -81,6 +77,7 @@ void chaser_preconfirm::handle_event(const code&, chase event_,
             break;
         }
         ////case chase::start:
+        ////case chase::bump:
         case chase::pause:
         case chase::resume:
         case chase::starved:
@@ -240,7 +237,8 @@ code chaser_preconfirm::validate(const header_link& link,
         {}              // work_required
     };
 
-    return ec = block.accept(ctx, subsidy_interval_blocks_, initial_subsidy_) ?
+    return
+        ec = block.accept(ctx, subsidy_interval_blocks_, initial_subsidy_) ?
         ec : block.connect(ctx);
 }
 

src/chasers/chaser_template.cpp

@@ -67,6 +67,7 @@ void chaser_template::handle_event(const code&, chase event_,
             break;
         }
         case chase::start:
+        case chase::bump:
         case chase::pause:
         case chase::resume:
         case chase::starved:

src/chasers/chaser_transaction.cpp

@@ -61,6 +61,8 @@ void chaser_transaction::handle_event(const code&, chase event_,
             // TODO: handle fault.
             break;
         }
+
+        case chase::bump:
         case chase::start:
         case chase::pause:
         case chase::resume:

src/protocols/protocol_block_in_31800.cpp

@@ -147,6 +147,7 @@ void protocol_block_in_31800::handle_event(const code&,
             break;
         }
         case chase::start:
+        case chase::bump:
         ////case chase::pause:
         ////case chase::resume:
         case chase::starved:

src/protocols/protocol_observer.cpp

@@ -65,6 +65,7 @@ void protocol_observer::handle_event(const code&, chase event_,
             break;
         }
         case chase::start:
+        case chase::bump:
         ////case chase::pause:
         ////case chase::resume:
         case chase::starved:

src/sessions/session_outbound.cpp

@@ -91,6 +91,7 @@ void session_outbound::handle_event(const code&,
             break;
         }
         case chase::start:
+        case chase::bump:
         case chase::pause:
         case chase::resume:
         ////case chase::starved: