Merge pull request #4 from garbageslam/block-version-aware-with-oncecell

add once-cell for config in block-version-aware PR

consensus/enclave/api/src/error.rs

@@ -57,7 +57,10 @@ pub enum Error {
     FeeMap(FeeMapError),
 
     /// Enclave not initialized
-    NotInited,
+    NotInitialized,
+
+    /// Block Version Error: {0}
+    BlockVersion(String),
 }
 
 impl From<MessageCipherError> for Error {

consensus/enclave/impl/Cargo.toml

@@ -43,6 +43,7 @@ mc-util-from-random = { path = "../../../util/from-random" }
 mc-util-serial = { path = "../../../util/serial" }
 
 mbedtls = { version = "0.8.1", default-features = false, features = ["no_std_deps"] }
+once_cell = { version = "1.9", default-features = false, features = ["alloc", "race"] }
 prost = { version = "0.9", default-features = false, features = ["prost-derive"] }
 rand_core = { version = "0.6", default-features = false }
 

consensus/enclave/impl/src/lib.rs

@@ -17,7 +17,7 @@ mod identity;
 // Include autogenerated constants.rs
 include!(concat!(env!("OUT_DIR"), "/constants.rs"));
 
-use alloc::{collections::BTreeSet, format, string::String, vec::Vec};
+use alloc::{boxed::Box, collections::BTreeSet, format, string::String, vec::Vec};
 use core::convert::TryFrom;
 use identity::Ed25519Identity;
 use mc_account_keys::PublicAddress;
@@ -52,6 +52,9 @@ use mc_transaction_core::{
     validation::TransactionValidationError,
     Block, BlockContents, BlockSignature, TokenId,
 };
+// Race here refers to, this is thread-safe, first-one-wins behavior, without
+// blocking
+use once_cell::race::OnceBox;
 use prost::Message;
 use rand_core::{CryptoRng, RngCore};
 
@@ -114,7 +117,7 @@ pub struct SgxConsensusEnclave {
     /// This is configuration data that affects whether or not a transaction
     /// is valid. To ensure that it is uniform across the network, it's hash
     /// gets appended to responder id.
-    blockchain_config: Mutex<Option<BlockchainConfigWithDigest>>,
+    blockchain_config: OnceBox<BlockchainConfigWithDigest>,
 }
 
 impl SgxConsensusEnclave {
@@ -126,7 +129,7 @@ impl SgxConsensusEnclave {
                 &mut McRng::default(),
             )),
             logger,
-            blockchain_config: Mutex::new(None),
+            blockchain_config: Default::default(),
         }
     }
 
@@ -183,7 +186,9 @@ impl ConsensusEnclave for SgxConsensusEnclave {
         // Inject the fee map and block version into the peer ResponderId.
         let peer_self_id = blockchain_config.responder_id(peer_self_id);
 
-        *self.blockchain_config.lock().unwrap() = Some(blockchain_config);
+        self.blockchain_config
+            .set(Box::new(blockchain_config))
+            .expect("enclave already initialized");
 
         // Init AKE.
         self.ake.init(peer_self_id, client_self_id.clone())?;
@@ -217,9 +222,8 @@ impl ConsensusEnclave for SgxConsensusEnclave {
     fn get_minimum_fee(&self, token_id: &TokenId) -> Result<Option<u64>> {
         Ok(self
             .blockchain_config
-            .lock()?
-            .as_ref()
-            .ok_or(Error::NotInited)?
+            .get()
+            .ok_or(Error::NotInitialized)?
             .get_config()
             .fee_map
             .get_fee_for_token(token_id))
@@ -263,9 +267,8 @@ impl ConsensusEnclave for SgxConsensusEnclave {
         // Inject the blockchain config hash, passing off to the AKE
         let peer_id = self
             .blockchain_config
-            .lock()?
-            .as_ref()
-            .ok_or(Error::NotInited)?
+            .get()
+            .ok_or(Error::NotInitialized)?
             .responder_id(peer_id);
 
         Ok(self.ake.peer_init(&peer_id)?)
@@ -283,9 +286,8 @@ impl ConsensusEnclave for SgxConsensusEnclave {
         // Inject the blockchain config hash before passing off to the AKE
         let peer_id = self
             .blockchain_config
-            .lock()?
-            .as_ref()
-            .ok_or(Error::NotInited)?
+            .get()
+            .ok_or(Error::NotInitialized)?
             .responder_id(peer_id);
 
         Ok(self.ake.peer_connect(&peer_id, msg)?)
@@ -364,10 +366,10 @@ impl ConsensusEnclave for SgxConsensusEnclave {
         block_index: u64,
         proofs: Vec<TxOutMembershipProof>,
     ) -> Result<(WellFormedEncryptedTx, WellFormedTxContext)> {
-        let blockchain_config = self.blockchain_config.lock()?;
-        let config = blockchain_config
-            .as_ref()
-            .ok_or(Error::NotInited)?
+        let config = self
+            .blockchain_config
+            .get()
+            .ok_or(Error::NotInitialized)?
             .get_config();
 
         // Enforce that all membership proofs provided by the untrusted system for
@@ -453,14 +455,14 @@ impl ConsensusEnclave for SgxConsensusEnclave {
         encrypted_txs_with_proofs: &[(WellFormedEncryptedTx, Vec<TxOutMembershipProof>)],
         root_element: &TxOutMembershipElement,
     ) -> Result<(Block, BlockContents, BlockSignature)> {
-        let blockchain_config = self.blockchain_config.lock()?;
-        let config = blockchain_config
-            .as_ref()
-            .expect("enclave was not initialized")
+        let config = self
+            .blockchain_config
+            .get()
+            .ok_or(Error::NotInitialized)?
             .get_config();
 
         if parent_block.version > *config.block_version {
-            return Err(Error::FormBlock(format!("Block version cannot decrease: parent_block.version = {}, config.block_version = {}", parent_block.version, config.block_version)));
+            return Err(Error::BlockVersion(format!("Block version cannot decrease: parent_block.version = {}, config.block_version = {}", parent_block.version, config.block_version)));
         }
 
         // This implicitly converts Vec<Result<(Tx Vec<TxOutMembershipProof>),_>> into
@@ -1534,9 +1536,9 @@ mod tests {
 
             // Check if we get a form block error as expected
             match form_block_result {
-                Err(Error::FormBlock(_)) => {}
+                Err(Error::BlockVersion(_)) => {}
                 _ => panic!(
-                    "Expected a FormBlock error due to config.block_version being less than parent"
+                    "Expected a BlockVersion error due to config.block_version being less than parent"
                 ),
             }
         }