GH-1837 Do not start a speculative block that will immediately be res…

…tarted
AntelopeIO · Oct 31, 2023 · 4a9dd03 · 4a9dd03
1 parent 4fb6c11
commit 4a9dd03
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Showing 2 changed files with 16 additions and 2 deletions.
diff --git a/plugins/producer_plugin/producer_plugin.cpp b/plugins/producer_plugin/producer_plugin.cpp
@@ -1829,8 +1829,6 @@ producer_plugin_impl::start_block_result producer_plugin_impl::start_block() {
       last_start_block_time = now;
    }
 
-   // create speculative blocks at regular intervals, so we create blocks with "current" block time
-   _pending_block_deadline = block_timing_util::calculate_producing_block_deadline(_produce_block_cpu_effort, block_time);
    if (in_producing_mode()) {
       uint32_t production_round_index = block_timestamp_type(block_time).slot % chain::config::producer_repetitions;
       if (production_round_index == 0) {
@@ -1844,6 +1842,15 @@ producer_plugin_impl::start_block_result producer_plugin_impl::start_block() {
       }
    }
 
+   // create speculative blocks at regular intervals, so we create blocks with "current" block time
+   _pending_block_deadline = block_timing_util::calculate_producing_block_deadline(_produce_block_cpu_effort, block_time);
+   if (in_speculating_mode()) { // if we are producing, then produce block even if deadline has pasted
+      // speculative block, no reason to start a block that will immediately be re-started, set deadline in the future
+      // a block should come in during this time, if not then just keep creating the block every produce_block_cpu_effort
+      if (now + fc::milliseconds(config::block_interval_ms/10) > _pending_block_deadline) {
+         _pending_block_deadline = now + _produce_block_cpu_effort;
+      }
+   }
    const auto& preprocess_deadline = _pending_block_deadline;
 
    fc_dlog(_log, "Starting block #${n} at ${time} producer ${p}", ("n", pending_block_num)("time", now)("p", scheduled_producer.producer_name));

diff --git a/plugins/producer_plugin/test/test_block_timing_util.cpp b/plugins/producer_plugin/test/test_block_timing_util.cpp
@@ -114,6 +114,13 @@ BOOST_AUTO_TEST_CASE(test_calculate_block_deadline) {
       // 29.962500 + (450000/12) = 30.425
       BOOST_CHECK_EQUAL(block_deadline, fc::time_point::from_iso_string("2023-10-29T13:40:30.425"));
    }
+   {
+      // Real scenario that caused multiple start blocks
+      auto default_cpu_effort = fc::microseconds(block_interval.count() - (450000/12)); // 462,500
+      auto block_time = eosio::chain::block_timestamp_type(fc::time_point::from_iso_string("2023-10-31T13:37:35.000"));
+      fc::time_point block_deadline = calculate_producing_block_deadline(default_cpu_effort, block_time);
+      BOOST_CHECK_EQUAL(block_deadline.to_iso_string(), fc::time_point::from_iso_string("2023-10-31T13:37:34.587").to_iso_string());
+   }
 }
 
 BOOST_AUTO_TEST_CASE(test_calculate_producer_wake_up_time) {