Cleanup bench-exchange (#3919)

* bench-exchange changes

Generate new keypair for each bench-exchange
Add metrics
Tweak network sleep parameters for better reliability.

* Bench-exchange contract metrics

programs/exchange_api/src/exchange_processor.rs

@@ -4,6 +4,7 @@ use crate::exchange_instruction::*;
 use crate::exchange_state::*;
 use crate::id;
 use log::*;
+use solana_metrics::counter::Counter;
 use solana_sdk::account::KeyedAccount;
 use solana_sdk::instruction::InstructionError;
 use solana_sdk::pubkey::Pubkey;
@@ -256,6 +257,8 @@ impl ExchangeProcessor {
         // Trade holds the tokens in escrow
         account.tokens[from_token] -= info.tokens;
 
+        inc_new_counter_info!("exchange_processor-trades", 1);
+
         Self::serialize(
             &ExchangeState::Trade(TradeOrderInfo {
                 owner: *keyed_accounts[OWNER_INDEX].unsigned_key(),
@@ -386,6 +389,8 @@ impl ExchangeProcessor {
             Err(e)?
         }
 
+        inc_new_counter_info!("exchange_processor-swap", 1);
+
         Self::serialize(
             &ExchangeState::Swap(swap),
             &mut keyed_accounts[SWAP_ACCOUNT_INDEX].account.data,

programs/exchange_api/src/lib.rs

@@ -2,6 +2,9 @@ pub mod exchange_instruction;
 pub mod exchange_processor;
 pub mod exchange_state;
 
+#[macro_use]
+extern crate solana_metrics;
+
 use solana_sdk::pubkey::Pubkey;
 
 pub const EXCHANGE_PROGRAM_ID: [u8; 32] = [