fix: remove deadlock condition between p2p and relayer threads that could arise when they both try to read the reward set. In short -- don't use a StacksDBTx<'a> to read chainstate when a StacksDBConn<'a> will do. Patch the relevant files to make it so the offending code can take a StacksDBIndexed trait impl instead of a transaction.

Author: jcnelson

stackslib/src/chainstate/nakamoto/coordinator/mod.rs

@@ -188,7 +188,7 @@ impl<'a, T: BlockEventDispatcher> OnChainRewardSetProvider<'a, T> {
         debug_log: bool,
     ) -> Result<RewardSet, Error> {
         let Some(reward_set_block) = NakamotoChainState::get_header_by_coinbase_height(
-            &mut chainstate.index_tx_begin(),
+            &mut chainstate.index_conn(),
             block_id,
             coinbase_height_of_calculation,
         )?

stackslib/src/chainstate/nakamoto/mod.rs

@@ -300,6 +300,13 @@ pub trait StacksDBIndexed {
     fn get(&mut self, tip: &StacksBlockId, key: &str) -> Result<Option<String>, DBError>;
     fn sqlite(&self) -> &Connection;
 
+    /// Get the ancestor block hash given a height
+    fn get_ancestor_block_id(
+        &mut self,
+        coinbase_height: u64,
+        tip_index_hash: &StacksBlockId,
+    ) -> Result<Option<StacksBlockId>, DBError>;
+
     /// Get the block ID for a specific coinbase height in the fork identified by `tip`
     fn get_nakamoto_block_id_at_coinbase_height(
         &mut self,
@@ -452,6 +459,14 @@ impl StacksDBIndexed for StacksDBConn<'_> {
     fn sqlite(&self) -> &Connection {
         self.conn()
     }
+
+    fn get_ancestor_block_id(
+        &mut self,
+        coinbase_height: u64,
+        tip_index_hash: &StacksBlockId,
+    ) -> Result<Option<StacksBlockId>, DBError> {
+        self.get_ancestor_block_hash(coinbase_height, tip_index_hash)
+    }
 }
 
 impl StacksDBIndexed for StacksDBTx<'_> {
@@ -462,6 +477,14 @@ impl StacksDBIndexed for StacksDBTx<'_> {
     fn sqlite(&self) -> &Connection {
         self.tx().deref()
     }
+
+    fn get_ancestor_block_id(
+        &mut self,
+        coinbase_height: u64,
+        tip_index_hash: &StacksBlockId,
+    ) -> Result<Option<StacksBlockId>, DBError> {
+        self.get_ancestor_block_hash(coinbase_height, tip_index_hash)
+    }
 }
 
 impl<'a> ChainstateTx<'a> {
@@ -2406,22 +2429,22 @@ impl NakamotoChainState {
     /// Return a Nakamoto StacksHeaderInfo at a given coinbase height in the fork identified by `tip_index_hash`.
     /// * For Stacks 2.x, this is the Stacks block's header
     /// * For Stacks 3.x (Nakamoto), this is the first block in the miner's tenure.
-    pub fn get_header_by_coinbase_height(
-        tx: &mut StacksDBTx,
+    pub fn get_header_by_coinbase_height<SDBI: StacksDBIndexed>(
+        conn: &mut SDBI,
         tip_index_hash: &StacksBlockId,
         coinbase_height: u64,
     ) -> Result<Option<StacksHeaderInfo>, ChainstateError> {
         // nakamoto block?
         if let Some(block_id) =
-            tx.get_nakamoto_block_id_at_coinbase_height(tip_index_hash, coinbase_height)?
+            conn.get_nakamoto_block_id_at_coinbase_height(tip_index_hash, coinbase_height)?
         {
-            return Self::get_block_header_nakamoto(tx.sqlite(), &block_id);
+            return Self::get_block_header_nakamoto(conn.sqlite(), &block_id);
         }
 
         // epcoh2 block?
-        let Some(ancestor_at_height) = tx
-            .get_ancestor_block_hash(coinbase_height, tip_index_hash)?
-            .map(|ancestor| Self::get_block_header(tx.tx(), &ancestor))
+        let Some(ancestor_at_height) = conn
+            .get_ancestor_block_id(coinbase_height, tip_index_hash)?
+            .map(|ancestor| Self::get_block_header(conn.sqlite(), &ancestor))
             .transpose()?
             .flatten()
         else {

stackslib/src/chainstate/nakamoto/tenure.rs

@@ -372,7 +372,7 @@ impl NakamotoChainState {
 
         let matured_coinbase_height = coinbase_height - MINER_REWARD_MATURITY;
         let matured_tenure_block_header = Self::get_header_by_coinbase_height(
-            chainstate_tx,
+            chainstate_tx.deref_mut(),
             &tip_index_hash,
             matured_coinbase_height,
         )?
@@ -964,7 +964,7 @@ impl NakamotoChainState {
 
         let total_coinbase = coinbase_at_block.saturating_add(accumulated_rewards);
         let parent_tenure_start_header: StacksHeaderInfo = Self::get_header_by_coinbase_height(
-            chainstate_tx,
+            chainstate_tx.deref_mut(),
             &block.header.parent_block_id,
             parent_coinbase_height,
         )?