From 606fc5dfb501e23485582a860453c2acfb0eb046 Mon Sep 17 00:00:00 2001
From: Dmitriy Khaustov aka xDimon <khaustov.dm@gmail.com>
Date: Thu, 5 Oct 2023 16:41:43 +0300
Subject: [PATCH] fix: dispute deadlock

Signed-off-by: Dmitriy Khaustov aka xDimon <khaustov.dm@gmail.com>
---
 .../impl/dispute_coordinator_impl.cpp         | 51 +++++++++++++++----
 1 file changed, 40 insertions(+), 11 deletions(-)

diff --git a/core/dispute_coordinator/impl/dispute_coordinator_impl.cpp b/core/dispute_coordinator/impl/dispute_coordinator_impl.cpp
index 2f1bf3fb78..d5e2501b76 100644
--- a/core/dispute_coordinator/impl/dispute_coordinator_impl.cpp
+++ b/core/dispute_coordinator/impl/dispute_coordinator_impl.cpp
@@ -1877,7 +1877,8 @@ namespace kagome::dispute {
 
     [[maybe_unused]] auto &valid_import = res.value();
 
-    return cb(outcome::success());
+    main_thread_context_->io_context()->post(
+        [cb(std::move(cb))] { cb(outcome::success()); });
   }
 
   void DisputeCoordinatorImpl::getRecentDisputes(
@@ -1911,7 +1912,10 @@ namespace kagome::dispute {
           return {std::get<0>(p.first), std::get<1>(p.first), p.second};
         });
 
-    cb(std::move(output));
+    main_thread_context_->io_context()->post(
+        [cb(std::move(cb)), output(std::move(output))] {
+          cb(std::move(output));
+        });
   }
 
   void DisputeCoordinatorImpl::getActiveDisputes(
@@ -1920,14 +1924,21 @@ namespace kagome::dispute {
 
     // Return error if session information is missing.
     if (error_.has_value()) {
-      return cb(SessionObtainingError::SessionsUnavailable);
+      main_thread_context_->io_context()->post([cb(std::move(cb))] {
+        cb(SessionObtainingError::SessionsUnavailable);
+      });
+      return;
     }
 
     SL_TRACE(log_, "DisputeCoordinatorMessage::ActiveDisputes");
 
     auto recent_disputes_res = storage_->load_recent_disputes();
     if (recent_disputes_res.has_error()) {
-      return cb(recent_disputes_res.as_failure());
+      main_thread_context_->io_context()->post(
+          [cb(std::move(cb)), failure(recent_disputes_res.as_failure())] {
+            cb(failure);
+          });
+      return;
     }
     auto recent_disputes =
         recent_disputes_res.value().value_or(RecentDisputes{});
@@ -1962,7 +1973,10 @@ namespace kagome::dispute {
       }
     }
 
-    cb(std::move(output));
+    main_thread_context_->io_context()->post(
+        [cb(std::move(cb)), output(std::move(output))] {
+          cb(std::move(output));
+        });
   }
 
   void DisputeCoordinatorImpl::queryCandidateVotes(
@@ -1971,7 +1985,10 @@ namespace kagome::dispute {
 
     // Return error if session information is missing.
     if (error_.has_value()) {
-      return cb(SessionObtainingError::SessionsUnavailable);
+      main_thread_context_->io_context()->post([cb(std::move(cb))] {
+        cb(SessionObtainingError::SessionsUnavailable);
+      });
+      return;
     }
 
     SL_TRACE(log_, "DisputeCoordinatorMessage::QueryCandidateVotes");
@@ -1981,7 +1998,10 @@ namespace kagome::dispute {
     for (auto &[session, candidate_hash] : query) {
       auto state_res = storage_->load_candidate_votes(session, candidate_hash);
       if (state_res.has_error()) {
-        cb(state_res.as_failure());
+        main_thread_context_->io_context()->post(
+            [cb(std::move(cb)), failure(state_res.as_failure())] {
+              cb(failure);
+            });
         return;
       }
       auto &state_opt = state_res.value();
@@ -1993,7 +2013,10 @@ namespace kagome::dispute {
       }
     }
 
-    cb(std::move(output));
+    main_thread_context_->io_context()->post(
+        [cb(std::move(cb)), output(std::move(output))] {
+          cb(std::move(output));
+        });
   }
 
   void DisputeCoordinatorImpl::issueLocalStatement(
@@ -2031,7 +2054,10 @@ namespace kagome::dispute {
 
     // Return error if session information is missing.
     if (error_.has_value()) {
-      return cb(SessionObtainingError::SessionsUnavailable);
+      main_thread_context_->io_context()->post([cb(std::move(cb))] {
+        cb(SessionObtainingError::SessionsUnavailable);
+      });
+      return;
     }
 
     SL_TRACE(log_, "DisputeCoordinatorMessage::DetermineUndisputedChain");
@@ -2040,7 +2066,9 @@ namespace kagome::dispute {
         determine_undisputed_chain(base.number, base.hash, block_descriptions);
 
     if (res.has_error()) {
-      return cb(res.as_failure());
+      main_thread_context_->io_context()->post(
+          [cb(std::move(cb)), failure(res.as_failure())] { cb(failure); });
+      return;
     }
     auto &undisputed_chain = res.value();
 
@@ -2060,7 +2088,8 @@ namespace kagome::dispute {
       metric_disputes_finality_lag_->set(0);
     }
 
-    cb(std::move(undisputed_chain));
+    main_thread_context_->io_context()->post(
+        [cb(std::move(cb)), undisputed_chain] { cb(undisputed_chain); });
   }
 
   // https://github.com/paritytech/polkadot/blob/40974fb99c86f5c341105b7db53c7aa0df707d66/node/core/dispute-coordinator/src/initialized.rs#L1272