Merge pull request #2029 from AntelopeIO/GH-2021-snapshot-ram-5.0

[5.0] P2P: Pause net_plugin during snapshot write
AntelopeIO · Jan 4, 2024 · 04774eb · 04774eb
2 parents 31f7bc4 + 8fe4f3c
commit 04774eb
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Showing 3 changed files with 22 additions and 1 deletion.
diff --git a/libraries/chain/controller.cpp b/libraries/chain/controller.cpp
@@ -251,6 +251,7 @@ struct controller_impl {
    named_thread_pool<chain>        thread_pool;
    deep_mind_handler*              deep_mind_logger = nullptr;
    bool                            okay_to_print_integrity_hash_on_stop = false;
+   std::atomic<bool>               writing_snapshot = false;
 
    thread_local static platform_timer timer; // a copy for main thread and each read-only thread
 #if defined(EOSIO_EOS_VM_RUNTIME_ENABLED) || defined(EOSIO_EOS_VM_JIT_RUNTIME_ENABLED)
@@ -3246,7 +3247,15 @@ fc::sha256 controller::calculate_integrity_hash() { try {
 
 void controller::write_snapshot( const snapshot_writer_ptr& snapshot ) {
    EOS_ASSERT( !my->pending, block_validate_exception, "cannot take a consistent snapshot with a pending block" );
-   return my->add_to_snapshot(snapshot);
+   my->writing_snapshot.store(true, std::memory_order_release);
+   fc::scoped_exit<std::function<void()>> e = [&] {
+      my->writing_snapshot.store(false, std::memory_order_release);
+   };
+   my->add_to_snapshot(snapshot);
+}
+
+bool controller::is_writing_snapshot() const {
+   return my->writing_snapshot.load(std::memory_order_acquire);
 }
 
 int64_t controller::set_proposed_producers( vector<producer_authority> producers ) {

diff --git a/libraries/chain/include/eosio/chain/controller.hpp b/libraries/chain/include/eosio/chain/controller.hpp
@@ -256,6 +256,8 @@ namespace eosio { namespace chain {
 
          fc::sha256 calculate_integrity_hash();
          void write_snapshot( const snapshot_writer_ptr& snapshot );
+         // thread-safe
+         bool is_writing_snapshot()const;
 
          bool sender_avoids_whitelist_blacklist_enforcement( account_name sender )const;
          void check_actor_list( const flat_set<account_name>& actors )const;

diff --git a/plugins/net_plugin/net_plugin.cpp b/plugins/net_plugin/net_plugin.cpp
@@ -537,6 +537,14 @@ namespace eosio {
       void start_expire_timer();
       void start_monitors();
 
+      // we currently pause on snapshot generation
+      void wait_if_paused() const {
+         controller& cc = chain_plug->chain();
+         while (cc.is_writing_snapshot()) {
+            std::this_thread::sleep_for(std::chrono::milliseconds(10));
+         }
+      }
+
       void expire();
       /** \name Peer Timestamps
        *  Time message handling
@@ -2897,6 +2905,8 @@ namespace eosio {
             return;
          }
 
+         my_impl->wait_if_paused();
+
          boost::asio::async_read( *socket,
             pending_message_buffer.get_buffer_sequence_for_boost_async_read(), completion_handler,
             boost::asio::bind_executor( strand,