diff --git a/src/accountant.rs b/src/accountant.rs
index 7f2e65fa9..bdad3cf6b 100644
--- a/src/accountant.rs
+++ b/src/accountant.rs
@@ -9,7 +9,7 @@ use plan::{Plan, Witness};
 use transaction::Transaction;
 use signature::{KeyPair, PublicKey, Signature};
 use mint::Mint;
-use historian::{reserve_signature, Historian};
+use historian::Historian;
 use recorder::Signal;
 use std::sync::mpsc::SendError;
 use std::collections::{HashMap, HashSet};
@@ -30,13 +30,7 @@ pub type Result<T> = result::Result<T, AccountingError>;
 /// Commit funds to the 'to' party.
 fn complete_transaction(balances: &mut HashMap<PublicKey, i64>, plan: &Plan) {
     if let Plan::Pay(ref payment) = *plan {
-        if balances.contains_key(&payment.to) {
-            if let Some(x) = balances.get_mut(&payment.to) {
-                *x += payment.tokens;
-            }
-        } else {
-            balances.insert(payment.to, payment.tokens);
-        }
+        *balances.entry(payment.to).or_insert(0) += payment.tokens;
     }
 }
 
@@ -122,7 +116,7 @@ impl Accountant {
         tr: &Transaction,
         allow_deposits: bool,
     ) -> Result<()> {
-        if !reserve_signature(&mut self.historian.signatures, &tr.sig) {
+        if !self.historian.reserve_signature(&tr.sig) {
             return Err(AccountingError::InvalidTransferSignature);
         }
 
@@ -133,7 +127,7 @@ impl Accountant {
         }
 
         let mut plan = tr.plan.clone();
-        plan.apply_witness(Witness::Timestamp(self.last_time));
+        plan.apply_witness(&Witness::Timestamp(self.last_time));
 
         if plan.is_complete() {
             complete_transaction(&mut self.balances, &plan);
@@ -146,7 +140,7 @@ impl Accountant {
 
     fn process_verified_sig(&mut self, from: PublicKey, tx_sig: Signature) -> Result<()> {
         if let Occupied(mut e) = self.pending.entry(tx_sig) {
-            e.get_mut().apply_witness(Witness::Signature(from));
+            e.get_mut().apply_witness(&Witness::Signature(from));
             if e.get().is_complete() {
                 complete_transaction(&mut self.balances, e.get());
                 e.remove_entry();
@@ -174,9 +168,9 @@ impl Accountant {
         // Check to see if any timelocked transactions can be completed.
         let mut completed = vec![];
         for (key, plan) in &mut self.pending {
-            plan.apply_witness(Witness::Timestamp(self.last_time));
+            plan.apply_witness(&Witness::Timestamp(self.last_time));
             if plan.is_complete() {
-                complete_transaction(&mut self.balances, &plan);
+                complete_transaction(&mut self.balances, plan);
                 completed.push(key.clone());
             }
         }
@@ -222,7 +216,7 @@ impl Accountant {
     }
 
     pub fn get_balance(self: &Self, pubkey: &PublicKey) -> Option<i64> {
-        self.balances.get(pubkey).map(|x| *x)
+        self.balances.get(pubkey).cloned()
     }
 }
 
diff --git a/src/accountant_skel.rs b/src/accountant_skel.rs
index 885f05a2b..6ff75b830 100644
--- a/src/accountant_skel.rs
+++ b/src/accountant_skel.rs
@@ -9,6 +9,7 @@ use result::Result;
 use streamer;
 use std::sync::{Arc, Mutex};
 use std::time::Duration;
+use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::mpsc::channel;
 use std::thread::{spawn, JoinHandle};
 use std::default::Default;
@@ -20,6 +21,7 @@ pub struct AccountantSkel {
     pub ledger: Vec<Entry>,
 }
 
+#[cfg_attr(feature = "cargo-clippy", allow(large_enum_variant))]
 #[derive(Serialize, Deserialize, Debug)]
 pub enum Request {
     Transaction(Transaction),
@@ -91,13 +93,13 @@ impl AccountantSkel {
         &mut self,
         r_reader: &streamer::Receiver,
         s_sender: &streamer::Sender,
-        recycler: streamer::Recycler,
+        recycler: &streamer::Recycler,
     ) -> Result<()> {
         let timer = Duration::new(1, 0);
         let msgs = r_reader.recv_timeout(timer)?;
         let msgs_ = msgs.clone();
         let msgs__ = msgs.clone();
-        let rsps = streamer::allocate(recycler.clone());
+        let rsps = streamer::allocate(recycler);
         let rsps_ = rsps.clone();
         let l = msgs__.read().unwrap().packets.len();
         rsps.write()
@@ -107,11 +109,11 @@ impl AccountantSkel {
         {
             let mut num = 0;
             let mut ursps = rsps.write().unwrap();
-            for packet in msgs.read().unwrap().packets.iter() {
+            for packet in &msgs.read().unwrap().packets {
                 let sz = packet.size;
                 let req = deserialize(&packet.data[0..sz])?;
                 if let Some(resp) = self.process_request(req) {
-                    let rsp = ursps.packets.get_mut(num).unwrap();
+                    let rsp = &mut ursps.packets[num];
                     let v = serialize(&resp)?;
                     let len = v.len();
                     rsp.data[0..len].copy_from_slice(&v);
@@ -131,7 +133,7 @@ impl AccountantSkel {
     pub fn serve(
         obj: Arc<Mutex<AccountantSkel>>,
         addr: &str,
-        exit: Arc<Mutex<bool>>,
+        exit: Arc<AtomicBool>,
     ) -> Result<[Arc<JoinHandle<()>>; 3]> {
         let read = UdpSocket::bind(addr)?;
         // make sure we are on the same interface
@@ -147,17 +149,14 @@ impl AccountantSkel {
         let t_sender = streamer::sender(write, exit.clone(), recycler.clone(), r_sender);
 
         let t_server = spawn(move || {
-            match Arc::try_unwrap(obj) {
-                Ok(me) => loop {
-                    let e = me.lock()
-                        .unwrap()
-                        .process(&r_reader, &s_sender, recycler.clone());
-                    if e.is_err() && *exit.lock().unwrap() {
+            if let Ok(me) = Arc::try_unwrap(obj) {
+                loop {
+                    let e = me.lock().unwrap().process(&r_reader, &s_sender, &recycler);
+                    if e.is_err() && exit.load(Ordering::Relaxed) {
                         break;
                     }
-                },
-                _ => (),
-            };
+                }
+            }
         });
         Ok([Arc::new(t_receiver), Arc::new(t_sender), Arc::new(t_server)])
     }
diff --git a/src/accountant_stub.rs b/src/accountant_stub.rs
index 0c4f1082c..7ca067866 100644
--- a/src/accountant_stub.rs
+++ b/src/accountant_stub.rs
@@ -127,6 +127,7 @@ mod tests {
     use mint::Mint;
     use signature::{KeyPair, KeyPairUtil};
     use std::sync::{Arc, Mutex};
+    use std::sync::atomic::{AtomicBool, Ordering};
 
     #[test]
     fn test_accountant_stub() {
@@ -135,7 +136,7 @@ mod tests {
         let alice = Mint::new(10_000);
         let acc = Accountant::new(&alice, Some(30));
         let bob_pubkey = KeyPair::new().pubkey();
-        let exit = Arc::new(Mutex::new(false));
+        let exit = Arc::new(AtomicBool::new(false));
         let acc = Arc::new(Mutex::new(AccountantSkel::new(acc)));
         let threads = AccountantSkel::serve(acc, addr, exit.clone()).unwrap();
         sleep(Duration::from_millis(30));
@@ -147,7 +148,7 @@ mod tests {
             .unwrap();
         acc.wait_on_signature(&sig, &last_id).unwrap();
         assert_eq!(acc.get_balance(&bob_pubkey).unwrap().unwrap(), 500);
-        *exit.lock().unwrap() = true;
+        exit.store(true, Ordering::Relaxed);
         for t in threads.iter() {
             match Arc::try_unwrap((*t).clone()) {
                 Ok(j) => j.join().expect("join"),
diff --git a/src/bin/client-demo.rs b/src/bin/client-demo.rs
index 18f4e6556..eec97db87 100644
--- a/src/bin/client-demo.rs
+++ b/src/bin/client-demo.rs
@@ -33,7 +33,7 @@ fn main() {
         })
         .collect();
     let duration = now.elapsed();
-    let ns = duration.as_secs() * 1_000_000_000 + duration.subsec_nanos() as u64;
+    let ns = duration.as_secs() * 1_000_000_000 + u64::from(duration.subsec_nanos());
     let bsps = txs as f64 / ns as f64;
     let nsps = ns as f64 / txs as f64;
     println!(
@@ -48,7 +48,7 @@ fn main() {
         assert!(tr.verify());
     }
     let duration = now.elapsed();
-    let ns = duration.as_secs() * 1_000_000_000 + duration.subsec_nanos() as u64;
+    let ns = duration.as_secs() * 1_000_000_000 + u64::from(duration.subsec_nanos());
     let bsvps = txs as f64 / ns as f64;
     let nspsv = ns as f64 / txs as f64;
     println!(
@@ -68,7 +68,7 @@ fn main() {
     acc.wait_on_signature(&sig, &last_id).unwrap();
 
     let duration = now.elapsed();
-    let ns = duration.as_secs() * 1_000_000_000 + duration.subsec_nanos() as u64;
+    let ns = duration.as_secs() * 1_000_000_000 + u64::from(duration.subsec_nanos());
     let tps = (txs * 1_000_000_000) as f64 / ns as f64;
     println!("Done. {} tps!", tps);
     let val = acc.get_balance(&mint_pubkey).unwrap().unwrap();
diff --git a/src/bin/genesis-demo.rs b/src/bin/genesis-demo.rs
index ca53378a9..c5fddfead 100644
--- a/src/bin/genesis-demo.rs
+++ b/src/bin/genesis-demo.rs
@@ -10,7 +10,7 @@ use silk::hash::Hash;
 use std::io::stdin;
 
 fn transfer(from: &KeyPair, (to, tokens): (PublicKey, i64), last_id: Hash) -> Event {
-    Event::Transaction(Transaction::new(&from, to, tokens, last_id))
+    Event::Transaction(Transaction::new(from, to, tokens, last_id))
 }
 
 fn main() {
diff --git a/src/bin/testnode.rs b/src/bin/testnode.rs
index 4fcc5ef48..b9204e7e5 100644
--- a/src/bin/testnode.rs
+++ b/src/bin/testnode.rs
@@ -5,6 +5,7 @@ use silk::accountant_skel::AccountantSkel;
 use silk::accountant::Accountant;
 use std::io::{self, BufRead};
 use std::sync::{Arc, Mutex};
+use std::sync::atomic::AtomicBool;
 
 fn main() {
     let addr = "127.0.0.1:8000";
@@ -14,7 +15,7 @@ fn main() {
         .lines()
         .map(|line| serde_json::from_str(&line.unwrap()).unwrap());
     let acc = Accountant::new_from_entries(entries, Some(1000));
-    let exit = Arc::new(Mutex::new(false));
+    let exit = Arc::new(AtomicBool::new(false));
     let skel = Arc::new(Mutex::new(AccountantSkel::new(acc)));
     eprintln!("Listening on {}", addr);
     let _threads = AccountantSkel::serve(skel, addr, exit.clone()).unwrap();
diff --git a/src/entry.rs b/src/entry.rs
index 36db0d841..56a612bb4 100644
--- a/src/entry.rs
+++ b/src/entry.rs
@@ -9,8 +9,8 @@ pub struct Entry {
 }
 
 impl Entry {
-    /// Creates a Entry from the number of hashes 'num_hashes' since the previous event
-    /// and that resulting 'id'.
+    /// Creates a Entry from the number of hashes `num_hashes` since the previous event
+    /// and that resulting `id`.
     pub fn new_tick(num_hashes: u64, id: &Hash) -> Self {
         Entry {
             num_hashes,
@@ -19,7 +19,7 @@ impl Entry {
         }
     }
 
-    /// Verifies self.id is the result of hashing a 'start_hash' 'self.num_hashes' times.
+    /// Verifies self.id is the result of hashing a `start_hash` `self.num_hashes` times.
     /// If the event is not a Tick, then hash that as well.
     pub fn verify(&self, start_hash: &Hash) -> bool {
         for event in &self.events {
@@ -31,7 +31,7 @@ impl Entry {
     }
 }
 
-/// Creates the hash 'num_hashes' after start_hash. If the event contains
+/// Creates the hash `num_hashes` after `start_hash`. If the event contains
 /// signature, the final hash will be a hash of both the previous ID and
 /// the signature.
 pub fn next_hash(start_hash: &Hash, num_hashes: u64, events: &[Event]) -> Hash {
@@ -56,7 +56,7 @@ pub fn next_hash(start_hash: &Hash, num_hashes: u64, events: &[Event]) -> Hash {
     id
 }
 
-/// Creates the next Entry 'num_hashes' after 'start_hash'.
+/// Creates the next Entry `num_hashes` after `start_hash`.
 pub fn create_entry(start_hash: &Hash, cur_hashes: u64, events: Vec<Event>) -> Entry {
     let num_hashes = cur_hashes + if events.is_empty() { 0 } else { 1 };
     let id = next_hash(start_hash, 0, &events);
@@ -67,7 +67,7 @@ pub fn create_entry(start_hash: &Hash, cur_hashes: u64, events: Vec<Event>) -> E
     }
 }
 
-/// Creates the next Tick Entry 'num_hashes' after 'start_hash'.
+/// Creates the next Tick Entry `num_hashes` after `start_hash`.
 pub fn create_entry_mut(start_hash: &mut Hash, cur_hashes: &mut u64, events: Vec<Event>) -> Entry {
     let entry = create_entry(start_hash, *cur_hashes, events);
     *start_hash = entry.id;
@@ -75,7 +75,7 @@ pub fn create_entry_mut(start_hash: &mut Hash, cur_hashes: &mut u64, events: Vec
     entry
 }
 
-/// Creates the next Tick Entry 'num_hashes' after 'start_hash'.
+/// Creates the next Tick Entry `num_hashes` after `start_hash`.
 pub fn next_tick(start_hash: &Hash, num_hashes: u64) -> Entry {
     Entry {
         num_hashes,
diff --git a/src/event.rs b/src/event.rs
index bfaa58c87..8afa18b21 100644
--- a/src/event.rs
+++ b/src/event.rs
@@ -35,8 +35,7 @@ impl Event {
     pub fn get_signature(&self) -> Option<Signature> {
         match *self {
             Event::Transaction(ref tr) => Some(tr.sig),
-            Event::Signature { .. } => None,
-            Event::Timestamp { .. } => None,
+            Event::Signature { .. } | Event::Timestamp { .. } => None,
         }
     }
 
diff --git a/src/historian.rs b/src/historian.rs
index a6a3b94de..a35f41d83 100644
--- a/src/historian.rs
+++ b/src/historian.rs
@@ -32,6 +32,14 @@ impl Historian {
         }
     }
 
+    pub fn reserve_signature(&mut self, sig: &Signature) -> bool {
+        if self.signatures.contains(sig) {
+            return false;
+        }
+        self.signatures.insert(*sig);
+        true
+    }
+
     /// A background thread that will continue tagging received Event messages and
     /// sending back Entry messages until either the receiver or sender channel is closed.
     fn create_recorder(
@@ -55,14 +63,6 @@ impl Historian {
     }
 }
 
-pub fn reserve_signature(sigs: &mut HashSet<Signature>, sig: &Signature) -> bool {
-    if sigs.contains(sig) {
-        return false;
-    }
-    sigs.insert(*sig);
-    true
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -112,10 +112,11 @@ mod tests {
 
     #[test]
     fn test_duplicate_event_signature() {
-        let mut sigs = HashSet::new();
+        let zero = Hash::default();
+        let mut hist = Historian::new(&zero, None);
         let sig = Signature::default();
-        assert!(reserve_signature(&mut sigs, &sig));
-        assert!(!reserve_signature(&mut sigs, &sig));
+        assert!(hist.reserve_signature(&sig));
+        assert!(!hist.reserve_signature(&sig));
     }
 
     #[test]
diff --git a/src/ledger.rs b/src/ledger.rs
index bb216ff30..d858d9179 100644
--- a/src/ledger.rs
+++ b/src/ledger.rs
@@ -1,14 +1,14 @@
 //! The `ledger` crate provides the foundational data structures for Proof-of-History,
 //! an ordered log of events in time.
 
-/// Each entry contains three pieces of data. The 'num_hashes' field is the number
-/// of hashes performed since the previous entry.  The 'id' field is the result
-/// of hashing 'id' from the previous entry 'num_hashes' times.  The 'event'
-/// field points to an Event that took place shortly after 'id' was generated.
+/// Each entry contains three pieces of data. The `num_hashes` field is the number
+/// of hashes performed since the previous entry.  The `id` field is the result
+/// of hashing `id` from the previous entry `num_hashes` times.  The `event`
+/// field points to an Event that took place shortly after `id` was generated.
 ///
-/// If you divide 'num_hashes' by the amount of time it takes to generate a new hash, you
+/// If you divide `num_hashes` by the amount of time it takes to generate a new hash, you
 /// get a duration estimate since the last event. Since processing power increases
-/// over time, one should expect the duration 'num_hashes' represents to decrease proportionally.
+/// over time, one should expect the duration `num_hashes` represents to decrease proportionally.
 /// Though processing power varies across nodes, the network gives priority to the
 /// fastest processor. Duration should therefore be estimated by assuming that the hash
 /// was generated by the fastest processor at the time the entry was recorded.
@@ -24,7 +24,7 @@ pub fn verify_slice(entries: &[Entry], start_hash: &Hash) -> bool {
     event_pairs.all(|(x0, x1)| x1.verify(&x0.id))
 }
 
-/// Create a vector of Ticks of length 'len' from 'start_hash' hash and 'num_hashes'.
+/// Create a vector of Ticks of length `len` from `start_hash` hash and `num_hashes`.
 pub fn next_ticks(start_hash: &Hash, num_hashes: u64, len: usize) -> Vec<Entry> {
     let mut id = *start_hash;
     let mut ticks = vec![];
diff --git a/src/plan.rs b/src/plan.rs
index e455218ea..f28ccec45 100644
--- a/src/plan.rs
+++ b/src/plan.rs
@@ -75,8 +75,9 @@ impl Plan {
 
     pub fn verify(&self, spendable_tokens: i64) -> bool {
         match *self {
-            Plan::Pay(ref payment) => payment.tokens == spendable_tokens,
-            Plan::After(_, ref payment) => payment.tokens == spendable_tokens,
+            Plan::Pay(ref payment) | Plan::After(_, ref payment) => {
+                payment.tokens == spendable_tokens
+            }
             Plan::Race(ref a, ref b) => {
                 a.1.tokens == spendable_tokens && b.1.tokens == spendable_tokens
             }
@@ -85,13 +86,13 @@ impl Plan {
 
     /// Apply a witness to the spending plan to see if the plan can be reduced.
     /// If so, modify the plan in-place.
-    pub fn apply_witness(&mut self, witness: Witness) {
+    pub fn apply_witness(&mut self, witness: &Witness) {
         let new_payment = match *self {
-            Plan::After(ref cond, ref payment) if cond.is_satisfied(&witness) => Some(payment),
-            Plan::Race((ref cond, ref payment), _) if cond.is_satisfied(&witness) => Some(payment),
-            Plan::Race(_, (ref cond, ref payment)) if cond.is_satisfied(&witness) => Some(payment),
+            Plan::After(ref cond, ref payment) if cond.is_satisfied(witness) => Some(payment),
+            Plan::Race((ref cond, ref payment), _) if cond.is_satisfied(witness) => Some(payment),
+            Plan::Race(_, (ref cond, ref payment)) if cond.is_satisfied(witness) => Some(payment),
             _ => None,
-        }.map(|x| x.clone());
+        }.cloned();
 
         if let Some(payment) = new_payment {
             mem::replace(self, Plan::Pay(payment));
@@ -135,7 +136,7 @@ mod tests {
         let to = PublicKey::default();
 
         let mut plan = Plan::new_authorized_payment(from, 42, to);
-        plan.apply_witness(Witness::Signature(from));
+        plan.apply_witness(&Witness::Signature(from));
         assert_eq!(plan, Plan::new_payment(42, to));
     }
 
@@ -145,7 +146,7 @@ mod tests {
         let to = PublicKey::default();
 
         let mut plan = Plan::new_future_payment(dt, 42, to);
-        plan.apply_witness(Witness::Timestamp(dt));
+        plan.apply_witness(&Witness::Timestamp(dt));
         assert_eq!(plan, Plan::new_payment(42, to));
     }
 
@@ -156,11 +157,11 @@ mod tests {
         let to = PublicKey::default();
 
         let mut plan = Plan::new_cancelable_future_payment(dt, from, 42, to);
-        plan.apply_witness(Witness::Timestamp(dt));
+        plan.apply_witness(&Witness::Timestamp(dt));
         assert_eq!(plan, Plan::new_payment(42, to));
 
         let mut plan = Plan::new_cancelable_future_payment(dt, from, 42, to);
-        plan.apply_witness(Witness::Signature(from));
+        plan.apply_witness(&Witness::Signature(from));
         assert_eq!(plan, Plan::new_payment(42, from));
     }
 }
diff --git a/src/recorder.rs b/src/recorder.rs
index 0a5a0bc14..a590cd878 100644
--- a/src/recorder.rs
+++ b/src/recorder.rs
@@ -12,6 +12,7 @@ use hash::{hash, Hash};
 use entry::{create_entry_mut, Entry};
 use event::Event;
 
+#[cfg_attr(feature = "cargo-clippy", allow(large_enum_variant))]
 pub enum Signal {
     Tick,
     Event(Event),
diff --git a/src/streamer.rs b/src/streamer.rs
index 56e5d2f90..54f631b7b 100644
--- a/src/streamer.rs
+++ b/src/streamer.rs
@@ -1,4 +1,5 @@
 use std::sync::{Arc, Mutex, RwLock};
+use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::mpsc;
 use std::fmt;
 use std::time::Duration;
@@ -64,16 +65,16 @@ impl Packet {
     }
 
     pub fn set_addr(&mut self, a: &SocketAddr) {
-        match a {
-            &SocketAddr::V4(v4) => {
+        match *a {
+            SocketAddr::V4(v4) => {
                 let ip = v4.ip().octets();
-                self.addr[0] = ip[0] as u16;
-                self.addr[1] = ip[1] as u16;
-                self.addr[2] = ip[2] as u16;
-                self.addr[3] = ip[3] as u16;
+                self.addr[0] = u16::from(ip[0]);
+                self.addr[1] = u16::from(ip[1]);
+                self.addr[2] = u16::from(ip[2]);
+                self.addr[3] = u16::from(ip[3]);
                 self.port = a.port();
             }
-            &SocketAddr::V6(v6) => {
+            SocketAddr::V6(v6) => {
                 self.addr = v6.ip().segments();
                 self.port = a.port();
                 self.v6 = true;
@@ -82,7 +83,7 @@ impl Packet {
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Default)]
 pub struct PacketData {
     pub packets: Vec<Packet>,
 }
@@ -101,7 +102,7 @@ impl PacketData {
     fn run_read_from(&mut self, socket: &UdpSocket) -> Result<usize> {
         self.packets.resize(BLOCK_SIZE, Packet::default());
         let mut i = 0;
-        for p in self.packets.iter_mut() {
+        for p in &mut self.packets {
             p.size = 0;
             match socket.recv_from(&mut p.data) {
                 Err(_) if i > 0 => {
@@ -130,7 +131,7 @@ impl PacketData {
         Ok(())
     }
     fn send_to(&self, socket: &UdpSocket, num: &mut usize) -> Result<()> {
-        for p in self.packets.iter() {
+        for p in &self.packets {
             let a = p.get_addr();
             socket.send_to(&p.data[0..p.size], &a)?;
             //TODO(anatoly): wtf do we do about errors?
@@ -140,35 +141,35 @@ impl PacketData {
     }
 }
 
-pub fn allocate(recycler: Recycler) -> SharedPacketData {
+pub fn allocate(recycler: &Recycler) -> SharedPacketData {
     let mut gc = recycler.lock().expect("lock");
     gc.pop()
         .unwrap_or_else(|| Arc::new(RwLock::new(PacketData::new())))
 }
 
-pub fn recycle(recycler: Recycler, msgs: SharedPacketData) {
+pub fn recycle(recycler: &Recycler, msgs: SharedPacketData) {
     let mut gc = recycler.lock().expect("lock");
     gc.push(msgs);
 }
 
 fn recv_loop(
     sock: &UdpSocket,
-    exit: Arc<Mutex<bool>>,
-    recycler: Recycler,
-    channel: Sender,
+    exit: &Arc<AtomicBool>,
+    recycler: &Recycler,
+    channel: &Sender,
 ) -> Result<()> {
     loop {
-        let msgs = allocate(recycler.clone());
+        let msgs = allocate(recycler);
         let msgs_ = msgs.clone();
         loop {
-            match msgs.write().unwrap().read_from(&sock) {
+            match msgs.write().unwrap().read_from(sock) {
                 Ok(()) => {
                     channel.send(msgs_)?;
                     break;
                 }
                 Err(_) => {
-                    if *exit.lock().unwrap() {
-                        recycle(recycler.clone(), msgs_);
+                    if exit.load(Ordering::Relaxed) {
+                        recycle(recycler, msgs_);
                         return Ok(());
                     }
                 }
@@ -179,19 +180,19 @@ fn recv_loop(
 
 pub fn receiver(
     sock: UdpSocket,
-    exit: Arc<Mutex<bool>>,
+    exit: Arc<AtomicBool>,
     recycler: Recycler,
     channel: Sender,
 ) -> Result<JoinHandle<()>> {
     let timer = Duration::new(1, 0);
     sock.set_read_timeout(Some(timer))?;
     Ok(spawn(move || {
-        let _ = recv_loop(&sock, exit, recycler, channel);
+        let _ = recv_loop(&sock, &exit, &recycler, &channel);
         ()
     }))
 }
 
-fn recv_send(sock: &UdpSocket, recycler: Recycler, r: &Receiver) -> Result<()> {
+fn recv_send(sock: &UdpSocket, recycler: &Recycler, r: &Receiver) -> Result<()> {
     let timer = Duration::new(1, 0);
     let msgs = r.recv_timeout(timer)?;
     let msgs_ = msgs.clone();
@@ -203,12 +204,12 @@ fn recv_send(sock: &UdpSocket, recycler: Recycler, r: &Receiver) -> Result<()> {
 
 pub fn sender(
     sock: UdpSocket,
-    exit: Arc<Mutex<bool>>,
+    exit: Arc<AtomicBool>,
     recycler: Recycler,
     r: Receiver,
 ) -> JoinHandle<()> {
     spawn(move || loop {
-        if recv_send(&sock, recycler.clone(), &r).is_err() && *exit.lock().unwrap() {
+        if recv_send(&sock, &recycler, &r).is_err() && exit.load(Ordering::Relaxed) {
             break;
         }
     })
@@ -228,16 +229,16 @@ mod bench {
     use result::Result;
     use streamer::{allocate, receiver, recycle, Packet, Receiver, Recycler, PACKET_SIZE};
 
-    fn producer(addr: &SocketAddr, recycler: Recycler, exit: Arc<Mutex<bool>>) -> JoinHandle<()> {
+    fn producer(addr: &SocketAddr, recycler: &Recycler, exit: Arc<AtomicBool>) -> JoinHandle<()> {
         let send = UdpSocket::bind("0.0.0.0:0").unwrap();
-        let msgs = allocate(recycler.clone());
+        let msgs = allocate(recycler);
         msgs.write().unwrap().packets.resize(10, Packet::default());
         for w in msgs.write().unwrap().packets.iter_mut() {
             w.size = PACKET_SIZE;
             w.set_addr(&addr);
         }
         spawn(move || loop {
-            if *exit.lock().unwrap() {
+            if exit.load(Ordering::Relaxed) {
                 return;
             }
             let mut num = 0;
@@ -247,13 +248,13 @@ mod bench {
     }
 
     fn sinc(
-        recycler: Recycler,
-        exit: Arc<Mutex<bool>>,
+        recycler: &Recycler,
+        exit: Arc<AtomicBool>,
         rvs: Arc<Mutex<usize>>,
         r: Receiver,
     ) -> JoinHandle<()> {
         spawn(move || loop {
-            if *exit.lock().unwrap() {
+            if exit.load(Ordering::Relaxed) {
                 return;
             }
             let timer = Duration::new(1, 0);
@@ -261,7 +262,7 @@ mod bench {
                 Ok(msgs) => {
                     let msgs_ = msgs.clone();
                     *rvs.lock().unwrap() += msgs.read().unwrap().packets.len();
-                    recycle(recycler.clone(), msgs_);
+                    recycle(recycler, msgs_);
                 }
                 _ => (),
             }
@@ -270,14 +271,14 @@ mod bench {
     fn run_streamer_bench() -> Result<()> {
         let read = UdpSocket::bind("127.0.0.1:0")?;
         let addr = read.local_addr()?;
-        let exit = Arc::new(Mutex::new(false));
+        let exit = Arc::new(AtomicBool::new(false));
         let recycler = Arc::new(Mutex::new(Vec::new()));
 
         let (s_reader, r_reader) = channel();
-        let t_reader = receiver(read, exit.clone(), recycler.clone(), s_reader)?;
-        let t_producer1 = producer(&addr, recycler.clone(), exit.clone());
-        let t_producer2 = producer(&addr, recycler.clone(), exit.clone());
-        let t_producer3 = producer(&addr, recycler.clone(), exit.clone());
+        let t_reader = receiver(read, exit.clone(), &recycler, s_reader)?;
+        let t_producer1 = producer(&addr, &recycler, exit.clone());
+        let t_producer2 = producer(&addr, &recycler, exit.clone());
+        let t_producer3 = producer(&addr, &recycler, exit.clone());
 
         let rvs = Arc::new(Mutex::new(0));
         let t_sinc = sinc(recycler.clone(), exit.clone(), rvs.clone(), r_reader);
@@ -291,7 +292,7 @@ mod bench {
         let ftime = (time as f64) / 10000000000f64;
         let fcount = (end_val - start_val) as f64;
         println!("performance: {:?}", fcount / ftime);
-        *exit.lock().unwrap() = true;
+        exit.store(true, Ordering::Relaxed);
         t_reader.join()?;
         t_producer1.join()?;
         t_producer2.join()?;
@@ -310,6 +311,7 @@ mod test {
     use std::sync::{Arc, Mutex};
     use std::net::UdpSocket;
     use std::time::Duration;
+    use std::sync::atomic::{AtomicBool, Ordering};
     use std::sync::mpsc::channel;
     use std::io::Write;
     use std::io;
@@ -339,7 +341,7 @@ mod test {
         let t_receiver = receiver(read, exit.clone(), recycler.clone(), s_reader).unwrap();
         let (s_sender, r_sender) = channel();
         let t_sender = sender(send, exit.clone(), recycler.clone(), r_sender);
-        let msgs = allocate(recycler.clone());
+        let msgs = allocate(&recycler);
         msgs.write().unwrap().packets.resize(10, Packet::default());
         for (i, w) in msgs.write().unwrap().packets.iter_mut().enumerate() {
             w.data[0] = i as u8;
@@ -351,7 +353,7 @@ mod test {
         let mut num = 0;
         get_msgs(r_reader, &mut num);
         assert_eq!(num, 10);
-        *exit.lock().unwrap() = true;
+        exit.store(true, Ordering::Relaxed);
         t_receiver.join().expect("join");
         t_sender.join().expect("join");
     }
@@ -364,13 +366,13 @@ mod test {
         let read = UdpSocket::bind("127.0.0.1:0").expect("bind");
         let addr = read.local_addr().unwrap();
         let send = UdpSocket::bind("127.0.0.1:0").expect("bind");
-        let exit = Arc::new(Mutex::new(false));
+        let exit = Arc::new(AtomicBool::new(false));
         let recycler = Arc::new(Mutex::new(Vec::new()));
         let (s_reader, r_reader) = channel();
         let t_receiver = receiver(read, exit.clone(), recycler.clone(), s_reader).unwrap();
         let (s_sender, r_sender) = channel();
         let t_sender = sender(send, exit.clone(), recycler.clone(), r_sender);
-        let msgs = allocate(recycler.clone());
+        let msgs = allocate(&recycler);
         msgs.write().unwrap().packets.resize(10, Packet::default());
         for (i, w) in msgs.write().unwrap().packets.iter_mut().enumerate() {
             w.data[0] = i as u8;
@@ -382,7 +384,7 @@ mod test {
         let mut num = 0;
         get_msgs(r_reader, &mut num);
         assert_eq!(num, 10);
-        *exit.lock().unwrap() = true;
+        exit.store(true, Ordering::Relaxed);
         t_receiver.join().expect("join");
         t_sender.join().expect("join");
     }