Avoid possibly lengthy destruction of wasm instances on shutdown

libraries/chain/include/eosio/chain/wasm_interface.hpp

@@ -79,6 +79,9 @@ namespace eosio { namespace chain {
          wasm_interface(vm_type vm, const chainbase::database& db);
          ~wasm_interface();
 
+         //call before dtor to skip what can be minutes of dtor overhead with some runtimes; can cause leaks
+         void indicate_shutting_down();
+
          //validates code -- does a WASM validation pass and checks the wasm against EOSIO specific constraints
          static void validate(const controller& control, const bytes& code);
 

libraries/chain/include/eosio/chain/wasm_interface_private.hpp

@@ -46,6 +46,14 @@ namespace eosio { namespace chain {
             EOS_THROW(wasm_exception, "wasm_interface_impl fall through");
       }
 
+      ~wasm_interface_impl() {
+         if(is_shutting_down)
+            for(wasm_cache_index::iterator it = wasm_instantiation_cache.begin(); it != wasm_instantiation_cache.end(); ++it)
+               wasm_instantiation_cache.modify(it, [](wasm_cache_entry& e) {
+                  e.module.release();
+               });
+      }
+
       std::vector<uint8_t> parse_initial_memory(const Module& module) {
          std::vector<uint8_t> mem_image;
 
@@ -136,6 +144,7 @@ namespace eosio { namespace chain {
          return it->module;
       }
 
+      bool is_shutting_down = false;
       std::unique_ptr<wasm_runtime_interface> runtime_interface;
 
       typedef boost::multi_index_container<

libraries/chain/wasm_interface.cpp

@@ -57,6 +57,10 @@ namespace eosio { namespace chain {
       //Hard: Kick off instantiation in a separate thread at this location
 	 }
 
+   void wasm_interface::indicate_shutting_down() {
+      my->is_shutting_down = true;
+   }
+
    void wasm_interface::code_block_num_last_used(const digest_type& code_hash, const uint8_t& vm_type, const uint8_t& vm_version, const uint32_t& block_num) {
       my->code_block_num_last_used(code_hash, vm_type, vm_version, block_num);
    }

plugins/chain_plugin/chain_plugin.cpp

@@ -996,6 +996,8 @@ void chain_plugin::plugin_shutdown() {
    my->irreversible_block_connection.reset();
    my->accepted_transaction_connection.reset();
    my->applied_transaction_connection.reset();
+   if(app().is_quiting())
+      my->chain->get_wasm_interface().indicate_shutting_down();
    my->chain.reset();
 }