feature-gate

solana-labs · Jan 18, 2024 · d7f029a · d7f029a
1 parent fae78b2
commit d7f029a
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Showing 2 changed files with 32 additions and 9 deletions.
diff --git a/cost-model/src/cost_model.rs b/cost-model/src/cost_model.rs
@@ -18,7 +18,7 @@ use {
     solana_sdk::{
         borsh1::try_from_slice_unchecked,
         compute_budget::{self, ComputeBudgetInstruction},
-        feature_set::{include_loaded_accounts_data_size_in_fee_calculation, FeatureSet},
+        feature_set::{self, include_loaded_accounts_data_size_in_fee_calculation, FeatureSet},
         fee::FeeStructure,
         instruction::CompiledInstruction,
         program_utils::limited_deserialize,
@@ -44,7 +44,7 @@ impl CostModel {
             let mut tx_cost = UsageCostDetails::new_with_default_capacity();
 
             tx_cost.signature_cost = Self::get_signature_cost(transaction);
-            Self::get_write_lock_cost(&mut tx_cost, transaction);
+            Self::get_write_lock_cost(&mut tx_cost, transaction, feature_set);
             Self::get_transaction_cost(&mut tx_cost, transaction, feature_set);
             tx_cost.account_data_size = Self::calculate_account_data_size(transaction);
 
@@ -73,10 +73,19 @@ impl CostModel {
             .collect()
     }
 
-    fn get_write_lock_cost(tx_cost: &mut UsageCostDetails, transaction: &SanitizedTransaction) {
+    fn get_write_lock_cost(
+        tx_cost: &mut UsageCostDetails,
+        transaction: &SanitizedTransaction,
+        feature_set: &FeatureSet,
+    ) {
         tx_cost.writable_accounts = Self::get_writable_accounts(transaction);
-        tx_cost.write_lock_cost =
-            WRITE_LOCK_UNITS.saturating_mul(transaction.message().num_write_locks());
+        let num_write_locks =
+            if feature_set.is_active(&feature_set::cost_model_requested_write_lock_cost::id()) {
+                transaction.message().num_write_locks()
+            } else {
+                tx_cost.writable_accounts.len() as u64
+            };
+        tx_cost.write_lock_cost = WRITE_LOCK_UNITS.saturating_mul(num_write_locks);
     }
 
     fn get_transaction_cost(
@@ -339,10 +348,20 @@ mod tests {
             system_transaction::transfer(&mint_keypair, &system_program::id(), 2, start_hash),
         );
 
-        // Cost should be fore 2 write-locks, but only 1 is actually writable.
-        let tx_cost = CostModel::calculate_cost(&simple_transaction, &FeatureSet::all_enabled());
-        assert_eq!(2 * WRITE_LOCK_UNITS, tx_cost.write_lock_cost());
-        assert_eq!(1, tx_cost.writable_accounts().len());
+        // Feature not enabled - write lock is demoted and does not count towards cost
+        {
+            let tx_cost = CostModel::calculate_cost(&simple_transaction, &FeatureSet::default());
+            assert_eq!(WRITE_LOCK_UNITS, tx_cost.write_lock_cost());
+            assert_eq!(1, tx_cost.writable_accounts().len());
+        }
+
+        // Feature enabled - write lock is demoted but still counts towards cost
+        {
+            let tx_cost =
+                CostModel::calculate_cost(&simple_transaction, &FeatureSet::all_enabled());
+            assert_eq!(2 * WRITE_LOCK_UNITS, tx_cost.write_lock_cost());
+            assert_eq!(1, tx_cost.writable_accounts().len());
+        }
     }
 
     #[test]

diff --git a/sdk/src/feature_set.rs b/sdk/src/feature_set.rs
@@ -763,6 +763,9 @@ pub mod deprecate_executable_meta_update_in_bpf_loader {
 pub mod enable_zk_proof_from_account {
     solana_sdk::declare_id!("zkiTNuzBKxrCLMKehzuQeKZyLtX2yvFcEKMML8nExU8");
 }
+pub mod cost_model_requested_write_lock_cost {
+    solana_sdk::declare_id!("wLckV1a64ngtcKPRGU4S4grVTestXjmNjxBjaKZrAcn");
+}
 
 lazy_static! {
     /// Map of feature identifiers to user-visible description
@@ -950,6 +953,7 @@ lazy_static! {
         (disable_bpf_loader_instructions::id(), "disable bpf loader management instructions #34194"),
         (deprecate_executable_meta_update_in_bpf_loader::id(), "deprecate executable meta flag update in bpf loader #34194"),
         (enable_zk_proof_from_account::id(), "Enable zk token proof program to read proof from accounts instead of instruction data #34750"),
+        (cost_model_requested_write_lock_cost::id(), "cost model uses number of requested write locks #34819"),
         /*************** ADD NEW FEATURES HERE ***************/
     ]
     .iter()