From 9b303f3451064c8a0bc7060528b4c993ccc43461 Mon Sep 17 00:00:00 2001
From: Alexander Jung <104335080+AlexRamRam@users.noreply.github.com>
Date: Tue, 17 Oct 2023 21:20:10 -0400
Subject: [PATCH] Improve clarity of the final portion of evm_runner::exec()

Signed-off-by: Alexander Jung <104335080+AlexRamRam@users.noreply.github.com>
---
 src/parsec/agent/runners/evm/impl.cpp | 32 +++++++++++++++++----------
 src/parsec/agent/runners/evm/impl.hpp |  4 +++-
 2 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/src/parsec/agent/runners/evm/impl.cpp b/src/parsec/agent/runners/evm/impl.cpp
index 3669ea219..39e260128 100644
--- a/src/parsec/agent/runners/evm/impl.cpp
+++ b/src/parsec/agent/runners/evm/impl.cpp
@@ -585,31 +585,39 @@ namespace cbdc::parsec::agent::runner {
             m_log->trace("EVM output data:", out_buf.to_hex());
 
             m_log->trace("Result status: ", result.status_code);
-            auto fn = [this, gas_left = result.gas_left]() {
+
+            // finalize_fn() makes the final set of state updates and invokes
+            // the main result callback with the full set of accumulated state
+            // updates
+            auto finalize_fn = [this, gas_left = result.gas_left]() {
                 auto gas_used = m_msg.gas - gas_left;
                 m_host->finalize(gas_left, gas_used);
                 auto state_updates = m_host->get_state_updates();
                 m_result_callback(state_updates);
             };
-            lock_index_keys(fn);
+
+            const auto log_index_keys = m_host->get_log_index_keys();
+            if(log_index_keys.empty()) {
+                finalize_fn();
+            } else {
+                lock_index_keys_and_finalize(log_index_keys, finalize_fn);
+            }
         }
     }
 
-    void evm_runner::lock_index_keys(const std::function<void()>& callback) {
-        auto keys = m_host->get_log_index_keys();
-        if(keys.empty()) {
-            callback();
-            return;
-        }
+    void evm_runner::lock_index_keys_and_finalize(
+        const std::vector<cbdc::buffer>& keys,
+        const std::function<void()>& finalize_fn) {
         auto acquired = std::make_shared<std::atomic<size_t>>();
-        for(auto& key : keys) {
+        for(const auto& key : keys) {
             auto success = m_try_lock_callback(
                 key,
                 broker::lock_type::write,
-                [acquired, callback, key_count = keys.size()](
+                [acquired, finalize_fn, key_count = keys.size()](
                     const broker::interface::try_lock_return_type&) {
-                    if(++(*acquired) == key_count) {
-                        callback();
+                    const bool is_last_key = ++(*acquired) == key_count;
+                    if(is_last_key) {
+                        finalize_fn();
                     }
                 });
             if(!success) {
diff --git a/src/parsec/agent/runners/evm/impl.hpp b/src/parsec/agent/runners/evm/impl.hpp
index c75ea463b..ec6290dc4 100644
--- a/src/parsec/agent/runners/evm/impl.hpp
+++ b/src/parsec/agent/runners/evm/impl.hpp
@@ -111,7 +111,9 @@ namespace cbdc::parsec::agent::runner {
             const broker::interface::try_lock_return_type& res);
 
         void lock_ticket_number_key_and_continue_exec();
-        void lock_index_keys(const std::function<void()>& callback);
+        void
+        lock_index_keys_and_finalize(const std::vector<cbdc::buffer>& keys,
+                                     const std::function<void()>& finalize_fn);
         void schedule_exec();
 
         void schedule(const std::function<void()>& fn);