From 4bd31baa256bb8abb5b47bbebf2317e625d8aadb Mon Sep 17 00:00:00 2001
From: Tatsuya Kawano <tatsuya@hibaridb.org>
Date: Sat, 14 Sep 2024 12:04:19 +0800
Subject: [PATCH 1/4] Switch from `triomphe::Arc` to `MiniArc`, our own `Arc`
 implementation

`MiniArc` is like a `std::sync::Arc` but with a few differences:

- No `Weak` references.
- Uses `AtomicU32` instead of `AtomicUsize` for reference counting.
- Much smaller code size by having only the necessary methods for us.
---
 Cargo.toml                      |  6 +---
 src/common/concurrent.rs        | 50 ++++++++++++++---------------
 src/common/concurrent/deques.rs | 21 +++++++------
 src/common/timer_wheel.rs       | 26 +++++++--------
 src/future/base_cache.rs        | 56 ++++++++++++++++-----------------
 src/future/invalidator.rs       |  6 ++--
 src/future/key_lock.rs          | 14 ++++-----
 src/future/value_initializer.rs | 14 ++++-----
 src/sync/value_initializer.rs   | 10 +++---
 src/sync_base/base_cache.rs     | 56 ++++++++++++++++-----------------
 src/sync_base/invalidator.rs    |  6 ++--
 src/sync_base/key_lock.rs       | 14 ++++-----
 12 files changed, 138 insertions(+), 141 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index b363bc2a..fc21cdf9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -44,17 +44,13 @@ unstable-debug-counters = ["future", "once_cell"]
 crossbeam-channel = "0.5.5"
 crossbeam-epoch = "0.9.9"
 crossbeam-utils = "0.8"
+moka-arc = { git = "https://gitlab.com/moka-labs/moka-gh440-remove-triomphe/moka-arc.git" }
 parking_lot = "0.12"
 smallvec = "1.8"
 tagptr = "0.2"
 thiserror = "1.0"
 uuid = { version = "1.1", features = ["v4"] }
 
-# Opt-out serde and stable_deref_trait features
-# https://github.com/Manishearth/triomphe/pull/5
-# 0.1.12 requires Rust 1.76
-triomphe = { version = ">=0.1.3, <0.1.12", default-features = false }
-
 # Optional dependencies (enabled by default)
 quanta = { version = "0.12.2", optional = true }
 
diff --git a/src/common/concurrent.rs b/src/common/concurrent.rs
index 2f7e6d8e..95686327 100644
--- a/src/common/concurrent.rs
+++ b/src/common/concurrent.rs
@@ -3,7 +3,7 @@ use crate::common::{deque::DeqNode, time::Instant};
 use parking_lot::Mutex;
 use std::{fmt, ptr::NonNull, sync::Arc};
 use tagptr::TagNonNull;
-use triomphe::Arc as TrioArc;
+use moka_arc::MiniArc;
 
 pub(crate) mod constants;
 pub(crate) mod deques;
@@ -64,13 +64,13 @@ impl<K> Clone for KeyHash<K> {
 }
 
 pub(crate) struct KeyHashDate<K> {
-    entry_info: TrioArc<EntryInfo<K>>,
+    entry_info: MiniArc<EntryInfo<K>>,
 }
 
 impl<K> KeyHashDate<K> {
-    pub(crate) fn new(entry_info: &TrioArc<EntryInfo<K>>) -> Self {
+    pub(crate) fn new(entry_info: &MiniArc<EntryInfo<K>>) -> Self {
         Self {
-            entry_info: TrioArc::clone(entry_info),
+            entry_info: MiniArc::clone(entry_info),
         }
     }
 
@@ -101,11 +101,11 @@ impl<K> KeyHashDate<K> {
 
 pub(crate) struct KvEntry<K, V> {
     pub(crate) key: Arc<K>,
-    pub(crate) entry: TrioArc<ValueEntry<K, V>>,
+    pub(crate) entry: MiniArc<ValueEntry<K, V>>,
 }
 
 impl<K, V> KvEntry<K, V> {
-    pub(crate) fn new(key: Arc<K>, entry: TrioArc<ValueEntry<K, V>>) -> Self {
+    pub(crate) fn new(key: Arc<K>, entry: MiniArc<ValueEntry<K, V>>) -> Self {
         Self { key, entry }
     }
 }
@@ -114,7 +114,7 @@ impl<K, V> Clone for KvEntry<K, V> {
     fn clone(&self) -> Self {
         Self {
             key: Arc::clone(&self.key),
-            entry: TrioArc::clone(&self.entry),
+            entry: MiniArc::clone(&self.entry),
         }
     }
 }
@@ -177,33 +177,33 @@ impl<K> DeqNodes<K> {
 
 pub(crate) struct ValueEntry<K, V> {
     pub(crate) value: V,
-    info: TrioArc<EntryInfo<K>>,
-    nodes: TrioArc<Mutex<DeqNodes<K>>>,
+    info: MiniArc<EntryInfo<K>>,
+    nodes: MiniArc<Mutex<DeqNodes<K>>>,
 }
 
 impl<K, V> ValueEntry<K, V> {
-    pub(crate) fn new(value: V, entry_info: TrioArc<EntryInfo<K>>) -> Self {
+    pub(crate) fn new(value: V, entry_info: MiniArc<EntryInfo<K>>) -> Self {
         #[cfg(feature = "unstable-debug-counters")]
         self::debug_counters::InternalGlobalDebugCounters::value_entry_created();
 
         Self {
             value,
             info: entry_info,
-            nodes: TrioArc::new(Mutex::new(DeqNodes::default())),
+            nodes: MiniArc::new(Mutex::new(DeqNodes::default())),
         }
     }
 
-    pub(crate) fn new_from(value: V, entry_info: TrioArc<EntryInfo<K>>, other: &Self) -> Self {
+    pub(crate) fn new_from(value: V, entry_info: MiniArc<EntryInfo<K>>, other: &Self) -> Self {
         #[cfg(feature = "unstable-debug-counters")]
         self::debug_counters::InternalGlobalDebugCounters::value_entry_created();
         Self {
             value,
             info: entry_info,
-            nodes: TrioArc::clone(&other.nodes),
+            nodes: MiniArc::clone(&other.nodes),
         }
     }
 
-    pub(crate) fn entry_info(&self) -> &TrioArc<EntryInfo<K>> {
+    pub(crate) fn entry_info(&self) -> &MiniArc<EntryInfo<K>> {
         &self.info
     }
 
@@ -224,7 +224,7 @@ impl<K, V> ValueEntry<K, V> {
         self.info.policy_weight()
     }
 
-    pub(crate) fn deq_nodes(&self) -> &TrioArc<Mutex<DeqNodes<K>>> {
+    pub(crate) fn deq_nodes(&self) -> &MiniArc<Mutex<DeqNodes<K>>> {
         &self.nodes
     }
 
@@ -278,7 +278,7 @@ impl<K, V> Drop for ValueEntry<K, V> {
     }
 }
 
-impl<K, V> AccessTime for TrioArc<ValueEntry<K, V>> {
+impl<K, V> AccessTime for MiniArc<ValueEntry<K, V>> {
     #[inline]
     fn last_accessed(&self) -> Option<Instant> {
         self.info.last_accessed()
@@ -302,7 +302,7 @@ impl<K, V> AccessTime for TrioArc<ValueEntry<K, V>> {
 
 pub(crate) enum ReadOp<K, V> {
     Hit {
-        value_entry: TrioArc<ValueEntry<K, V>>,
+        value_entry: MiniArc<ValueEntry<K, V>>,
         is_expiry_modified: bool,
     },
     // u64 is the hash of the key.
@@ -312,7 +312,7 @@ pub(crate) enum ReadOp<K, V> {
 pub(crate) enum WriteOp<K, V> {
     Upsert {
         key_hash: KeyHash<K>,
-        value_entry: TrioArc<ValueEntry<K, V>>,
+        value_entry: MiniArc<ValueEntry<K, V>>,
         /// Entry generation after the operation.
         entry_gen: u16,
         old_weight: u32,
@@ -324,7 +324,7 @@ pub(crate) enum WriteOp<K, V> {
     },
 }
 
-/// Cloning a `WriteOp` is safe and cheap because it uses `Arc` and `TrioArc` pointers to
+/// Cloning a `WriteOp` is safe and cheap because it uses `Arc` and `MiniArc` pointers to
 /// the actual data.
 impl<K, V> Clone for WriteOp<K, V> {
     fn clone(&self) -> Self {
@@ -337,7 +337,7 @@ impl<K, V> Clone for WriteOp<K, V> {
                 new_weight,
             } => Self::Upsert {
                 key_hash: key_hash.clone(),
-                value_entry: TrioArc::clone(value_entry),
+                value_entry: MiniArc::clone(value_entry),
                 entry_gen: *entry_gen,
                 old_weight: *old_weight,
                 new_weight: *new_weight,
@@ -366,13 +366,13 @@ impl<K, V> WriteOp<K, V> {
     pub(crate) fn new_upsert(
         key: &Arc<K>,
         hash: u64,
-        value_entry: &TrioArc<ValueEntry<K, V>>,
+        value_entry: &MiniArc<ValueEntry<K, V>>,
         entry_generation: u16,
         old_weight: u32,
         new_weight: u32,
     ) -> Self {
         let key_hash = KeyHash::new(Arc::clone(key), hash);
-        let value_entry = TrioArc::clone(value_entry);
+        let value_entry = MiniArc::clone(value_entry);
         Self::Upsert {
             key_hash,
             value_entry,
@@ -384,15 +384,15 @@ impl<K, V> WriteOp<K, V> {
 }
 
 pub(crate) struct OldEntryInfo<K, V> {
-    pub(crate) entry: TrioArc<ValueEntry<K, V>>,
+    pub(crate) entry: MiniArc<ValueEntry<K, V>>,
     pub(crate) last_accessed: Option<Instant>,
     pub(crate) last_modified: Option<Instant>,
 }
 
 impl<K, V> OldEntryInfo<K, V> {
-    pub(crate) fn new(entry: &TrioArc<ValueEntry<K, V>>) -> Self {
+    pub(crate) fn new(entry: &MiniArc<ValueEntry<K, V>>) -> Self {
         Self {
-            entry: TrioArc::clone(entry),
+            entry: MiniArc::clone(entry),
             last_accessed: entry.last_accessed(),
             last_modified: entry.last_modified(),
         }
diff --git a/src/common/concurrent/deques.rs b/src/common/concurrent/deques.rs
index 424fc104..37245b1e 100644
--- a/src/common/concurrent/deques.rs
+++ b/src/common/concurrent/deques.rs
@@ -6,7 +6,8 @@ use crate::common::{
 
 use std::ptr::NonNull;
 use tagptr::TagNonNull;
-use triomphe::Arc as TrioArc;
+use moka_arc::MiniArc;
+
 pub(crate) struct Deques<K> {
     pub(crate) window: Deque<KeyHashDate<K>>, //    Not used yet.
     pub(crate) probation: Deque<KeyHashDate<K>>,
@@ -50,7 +51,7 @@ impl<K> Deques<K> {
         &mut self,
         region: CacheRegion,
         khd: KeyHashDate<K>,
-        entry: &TrioArc<ValueEntry<K, V>>,
+        entry: &MiniArc<ValueEntry<K, V>>,
     ) {
         let node = Box::new(DeqNode::new(khd));
         let node = match region {
@@ -66,14 +67,14 @@ impl<K> Deques<K> {
     pub(crate) fn push_back_wo<V>(
         &mut self,
         kd: KeyHashDate<K>,
-        entry: &TrioArc<ValueEntry<K, V>>,
+        entry: &MiniArc<ValueEntry<K, V>>,
     ) {
         let node = Box::new(DeqNode::new(kd));
         let node = self.write_order.push_back(node);
         entry.set_write_order_q_node(Some(node));
     }
 
-    pub(crate) fn move_to_back_ao<V>(&mut self, entry: &TrioArc<ValueEntry<K, V>>) {
+    pub(crate) fn move_to_back_ao<V>(&mut self, entry: &MiniArc<ValueEntry<K, V>>) {
         if let Some(tagged_node) = entry.access_order_q_node() {
             let (node, tag) = tagged_node.decompose();
             let p = unsafe { node.as_ref() };
@@ -95,7 +96,7 @@ impl<K> Deques<K> {
     pub(crate) fn move_to_back_ao_in_deque<V>(
         deq_name: &str,
         deq: &mut Deque<KeyHashDate<K>>,
-        entry: &TrioArc<ValueEntry<K, V>>,
+        entry: &MiniArc<ValueEntry<K, V>>,
     ) {
         if let Some(tagged_node) = entry.access_order_q_node() {
             let (node, tag) = tagged_node.decompose();
@@ -111,7 +112,7 @@ impl<K> Deques<K> {
         }
     }
 
-    pub(crate) fn move_to_back_wo<V>(&mut self, entry: &TrioArc<ValueEntry<K, V>>) {
+    pub(crate) fn move_to_back_wo<V>(&mut self, entry: &MiniArc<ValueEntry<K, V>>) {
         if let Some(node) = entry.write_order_q_node() {
             let p = unsafe { node.as_ref() };
             if self.write_order.contains(p) {
@@ -122,7 +123,7 @@ impl<K> Deques<K> {
 
     pub(crate) fn move_to_back_wo_in_deque<V>(
         deq: &mut Deque<KeyHashDate<K>>,
-        entry: &TrioArc<ValueEntry<K, V>>,
+        entry: &MiniArc<ValueEntry<K, V>>,
     ) {
         if let Some(node) = entry.write_order_q_node() {
             let p = unsafe { node.as_ref() };
@@ -132,7 +133,7 @@ impl<K> Deques<K> {
         }
     }
 
-    pub(crate) fn unlink_ao<V>(&mut self, entry: &TrioArc<ValueEntry<K, V>>) {
+    pub(crate) fn unlink_ao<V>(&mut self, entry: &MiniArc<ValueEntry<K, V>>) {
         if let Some(node) = entry.take_access_order_q_node() {
             self.unlink_node_ao(node);
         }
@@ -141,14 +142,14 @@ impl<K> Deques<K> {
     pub(crate) fn unlink_ao_from_deque<V>(
         deq_name: &str,
         deq: &mut Deque<KeyHashDate<K>>,
-        entry: &TrioArc<ValueEntry<K, V>>,
+        entry: &MiniArc<ValueEntry<K, V>>,
     ) {
         if let Some(node) = entry.take_access_order_q_node() {
             unsafe { Self::unlink_node_ao_from_deque(deq_name, deq, node) };
         }
     }
 
-    pub(crate) fn unlink_wo<V>(deq: &mut Deque<KeyHashDate<K>>, entry: &TrioArc<ValueEntry<K, V>>) {
+    pub(crate) fn unlink_wo<V>(deq: &mut Deque<KeyHashDate<K>>, entry: &MiniArc<ValueEntry<K, V>>) {
         if let Some(node) = entry.take_write_order_q_node() {
             Self::unlink_node_wo(deq, node);
         }
diff --git a/src/common/timer_wheel.rs b/src/common/timer_wheel.rs
index aa78affa..73add563 100644
--- a/src/common/timer_wheel.rs
+++ b/src/common/timer_wheel.rs
@@ -20,7 +20,7 @@ use super::{
 };
 
 use parking_lot::Mutex;
-use triomphe::Arc as TrioArc;
+use moka_arc::MiniArc;
 
 const BUCKET_COUNTS: &[u64] = &[
     64, // roughly seconds
@@ -69,16 +69,16 @@ pub(crate) enum TimerNode<K> {
         /// The position (level and index) of the timer wheel bucket.
         pos: Option<(u8, u8)>,
         /// An Arc pointer to the `EntryInfo` of the cache entry (`ValueEntry`).
-        entry_info: TrioArc<EntryInfo<K>>,
+        entry_info: MiniArc<EntryInfo<K>>,
         /// An Arc pointer to the `DeqNodes` of the cache entry (`ValueEntry`).
-        deq_nodes: TrioArc<Mutex<DeqNodes<K>>>,
+        deq_nodes: MiniArc<Mutex<DeqNodes<K>>>,
     },
 }
 
 impl<K> TimerNode<K> {
     fn new(
-        entry_info: TrioArc<EntryInfo<K>>,
-        deq_nodes: TrioArc<Mutex<DeqNodes<K>>>,
+        entry_info: MiniArc<EntryInfo<K>>,
+        deq_nodes: MiniArc<Mutex<DeqNodes<K>>>,
         level: usize,
         index: usize,
     ) -> Self {
@@ -118,7 +118,7 @@ impl<K> TimerNode<K> {
         matches!(self, Self::Sentinel)
     }
 
-    pub(crate) fn entry_info(&self) -> &TrioArc<EntryInfo<K>> {
+    pub(crate) fn entry_info(&self) -> &MiniArc<EntryInfo<K>> {
         if let Self::Entry { entry_info, .. } = &self {
             entry_info
         } else {
@@ -209,8 +209,8 @@ impl<K> TimerWheel<K> {
     /// Schedules a timer event for the node.
     pub(crate) fn schedule(
         &mut self,
-        entry_info: TrioArc<EntryInfo<K>>,
-        deq_nodes: TrioArc<Mutex<DeqNodes<K>>>,
+        entry_info: MiniArc<EntryInfo<K>>,
+        deq_nodes: MiniArc<Mutex<DeqNodes<K>>>,
     ) -> Option<NonNull<DeqNode<TimerNode<K>>>> {
         debug_assert!(self.is_enabled());
 
@@ -397,7 +397,7 @@ pub(crate) enum TimerEvent<K> {
     // from one wheel to another in a lower level of the hierarchy. (This variant
     // is mainly used for testing)
     #[cfg(test)]
-    Rescheduled(TrioArc<EntryInfo<K>>),
+    Rescheduled(MiniArc<EntryInfo<K>>),
     #[cfg(not(test))]
     Rescheduled(()),
     /// This timer node (containing a cache entry) has been removed from the timer.
@@ -517,7 +517,7 @@ impl<'iter, K> Iterator for TimerEventsIter<'iter, K> {
                     // Get the entry info before rescheduling (mutating) the node to
                     // avoid Stacked Borrows/Tree Borrows violations on `node_p`.
                     let entry_info =
-                        TrioArc::clone(unsafe { node_p.as_ref() }.element.entry_info());
+                        MiniArc::clone(unsafe { node_p.as_ref() }.element.entry_info());
 
                     match self.timer_wheel.schedule_existing_node(node_p) {
                         ReschedulingResult::Rescheduled => {
@@ -564,7 +564,7 @@ mod tests {
         time::{CheckedTimeOps, Clock, Instant, Mock},
     };
 
-    use triomphe::Arc as TrioArc;
+    use moka_arc::MiniArc;
 
     #[test]
     fn test_bucket_indices() {
@@ -654,10 +654,10 @@ mod tests {
             let hash = key as u64;
             let key_hash = KeyHash::new(Arc::new(key), hash);
             let policy_weight = 0;
-            let entry_info = TrioArc::new(EntryInfo::new(key_hash, now, policy_weight));
+            let entry_info = MiniArc::new(EntryInfo::new(key_hash, now, policy_weight));
             entry_info.set_expiration_time(Some(now.checked_add(ttl).unwrap()));
             let deq_nodes = Default::default();
-            let timer_node = timer.schedule(entry_info, TrioArc::clone(&deq_nodes));
+            let timer_node = timer.schedule(entry_info, MiniArc::clone(&deq_nodes));
             deq_nodes.lock().set_timer_node(timer_node);
         }
 
diff --git a/src/future/base_cache.rs b/src/future/base_cache.rs
index 0c9d0a5f..f302b66a 100644
--- a/src/future/base_cache.rs
+++ b/src/future/base_cache.rs
@@ -51,7 +51,7 @@ use std::{
     },
     time::{Duration, Instant as StdInstant},
 };
-use triomphe::Arc as TrioArc;
+use moka_arc::MiniArc;
 
 pub(crate) type HouseKeeperArc = Arc<Housekeeper>;
 
@@ -127,7 +127,7 @@ impl<K, V, S> BaseCache<K, V, S> {
     pub(crate) fn notify_invalidate(
         &self,
         key: &Arc<K>,
-        entry: &TrioArc<ValueEntry<K, V>>,
+        entry: &MiniArc<ValueEntry<K, V>>,
     ) -> BoxFuture<'static, ()>
     where
         K: Send + Sync + 'static,
@@ -335,7 +335,7 @@ where
                     let ent = Entry::new(maybe_key, entry.value.clone(), false, false);
                     let maybe_op = if record_read {
                         Some(ReadOp::Hit {
-                            value_entry: TrioArc::clone(entry),
+                            value_entry: MiniArc::clone(entry),
                             is_expiry_modified,
                         })
                     } else {
@@ -758,11 +758,11 @@ impl<K, V, S> BaseCache<K, V, S> {
         value: V,
         timestamp: Instant,
         policy_weight: u32,
-    ) -> (TrioArc<ValueEntry<K, V>>, u16) {
+    ) -> (MiniArc<ValueEntry<K, V>>, u16) {
         let key_hash = KeyHash::new(Arc::clone(key), hash);
-        let info = TrioArc::new(EntryInfo::new(key_hash, timestamp, policy_weight));
+        let info = MiniArc::new(EntryInfo::new(key_hash, timestamp, policy_weight));
         let gen: u16 = info.entry_gen();
-        (TrioArc::new(ValueEntry::new(value, info)), gen)
+        (MiniArc::new(ValueEntry::new(value, info)), gen)
     }
 
     #[inline]
@@ -772,15 +772,15 @@ impl<K, V, S> BaseCache<K, V, S> {
         timestamp: Instant,
         policy_weight: u32,
         other: &ValueEntry<K, V>,
-    ) -> (TrioArc<ValueEntry<K, V>>, u16) {
-        let info = TrioArc::clone(other.entry_info());
+    ) -> (MiniArc<ValueEntry<K, V>>, u16) {
+        let info = MiniArc::clone(other.entry_info());
         // To prevent this updated ValueEntry from being evicted by an expiration
         // policy, increment the entry generation.
         let gen = info.incr_entry_gen();
         info.set_last_accessed(timestamp);
         info.set_last_modified(timestamp);
         info.set_policy_weight(policy_weight);
-        (TrioArc::new(ValueEntry::new_from(value, info, other)), gen)
+        (MiniArc::new(ValueEntry::new_from(value, info, other)), gen)
     }
 
     fn expire_after_create(
@@ -901,7 +901,7 @@ impl<'a, K, V> EvictionState<'a, K, V> {
     async fn notify_entry_removal(
         &mut self,
         key: Arc<K>,
-        entry: &TrioArc<ValueEntry<K, V>>,
+        entry: &MiniArc<ValueEntry<K, V>>,
         cause: RemovalCause,
     ) where
         K: Send + Sync + 'static,
@@ -991,7 +991,7 @@ enum AdmissionResult<K> {
     Rejected,
 }
 
-type CacheStore<K, V, S> = crate::cht::SegmentedHashMap<Arc<K>, TrioArc<ValueEntry<K, V>>, S>;
+type CacheStore<K, V, S> = crate::cht::SegmentedHashMap<Arc<K>, MiniArc<ValueEntry<K, V>>, S>;
 
 struct Clocks {
     // Lock for this Clocks instance. Used when the `expiration_clock` is set.
@@ -1285,7 +1285,7 @@ where
     where
         K: Borrow<Q>,
         Q: Hash + Eq + ?Sized,
-        F: FnOnce(&Arc<K>, &TrioArc<ValueEntry<K, V>>) -> T,
+        F: FnOnce(&Arc<K>, &MiniArc<ValueEntry<K, V>>) -> T,
     {
         self.cache
             .get_key_value_and(hash, |k| (k as &K).borrow() == key, with_entry)
@@ -1296,7 +1296,7 @@ where
     where
         K: Borrow<Q>,
         Q: Hash + Eq + ?Sized,
-        F: FnOnce(&Arc<K>, &TrioArc<ValueEntry<K, V>>) -> Option<T>,
+        F: FnOnce(&Arc<K>, &MiniArc<ValueEntry<K, V>>) -> Option<T>,
     {
         self.cache
             .get_key_value_and_then(hash, |k| (k as &K).borrow() == key, with_entry)
@@ -1337,7 +1337,7 @@ where
 
     /// Returns `true` if the entry is invalidated by `invalidate_entries_if` method.
     #[inline]
-    fn is_invalidated_entry(&self, key: &Arc<K>, entry: &TrioArc<ValueEntry<K, V>>) -> bool
+    fn is_invalidated_entry(&self, key: &Arc<K>, entry: &MiniArc<ValueEntry<K, V>>) -> bool
     where
         V: Clone,
     {
@@ -1667,7 +1667,7 @@ where
     async fn handle_upsert(
         &self,
         kh: KeyHash<K>,
-        entry: TrioArc<ValueEntry<K, V>>,
+        entry: MiniArc<ValueEntry<K, V>>,
         gen: u16,
         old_weight: u32,
         new_weight: u32,
@@ -1717,7 +1717,7 @@ where
                     kh.hash,
                     |k| k == &kh.key,
                     |_, current_entry| {
-                        TrioArc::ptr_eq(entry.entry_info(), current_entry.entry_info())
+                        MiniArc::ptr_eq(entry.entry_info(), current_entry.entry_info())
                             && current_entry.entry_info().entry_gen() == gen
                     },
                 );
@@ -1822,7 +1822,7 @@ where
                     kh.hash,
                     |k| k == &key,
                     |_, current_entry| {
-                        TrioArc::ptr_eq(entry.entry_info(), current_entry.entry_info())
+                        MiniArc::ptr_eq(entry.entry_info(), current_entry.entry_info())
                             && current_entry.entry_info().entry_gen() == gen
                     },
                 );
@@ -1926,7 +1926,7 @@ where
 
     fn handle_admit(
         &self,
-        entry: &TrioArc<ValueEntry<K, V>>,
+        entry: &MiniArc<ValueEntry<K, V>>,
         policy_weight: u32,
         deqs: &mut Deques<K>,
         timer_wheel: &mut TimerWheel<K>,
@@ -1951,7 +1951,7 @@ where
     /// NOTE: This method may enable the timer wheel.
     fn update_timer_wheel(
         &self,
-        entry: &TrioArc<ValueEntry<K, V>>,
+        entry: &MiniArc<ValueEntry<K, V>>,
         timer_wheel: &mut TimerWheel<K>,
     ) {
         // Enable the timer wheel if needed.
@@ -1971,8 +1971,8 @@ where
             // expiration time and not registered to the timer wheel.
             (true, None) => {
                 let timer = timer_wheel.schedule(
-                    TrioArc::clone(entry.entry_info()),
-                    TrioArc::clone(entry.deq_nodes()),
+                    MiniArc::clone(entry.entry_info()),
+                    MiniArc::clone(entry.deq_nodes()),
                 );
                 entry.set_timer_node(timer);
             }
@@ -2000,7 +2000,7 @@ where
     fn handle_remove(
         deqs: &mut Deques<K>,
         timer_wheel: &mut TimerWheel<K>,
-        entry: TrioArc<ValueEntry<K, V>>,
+        entry: MiniArc<ValueEntry<K, V>>,
         gen: Option<u16>,
         counters: &mut EvictionCounters,
     ) {
@@ -2012,7 +2012,7 @@ where
 
     fn handle_remove_without_timer_wheel(
         deqs: &mut Deques<K>,
-        entry: TrioArc<ValueEntry<K, V>>,
+        entry: MiniArc<ValueEntry<K, V>>,
         gen: Option<u16>,
         counters: &mut EvictionCounters,
     ) {
@@ -2035,7 +2035,7 @@ where
         ao_deq: &mut Deque<KeyHashDate<K>>,
         wo_deq: &mut Deque<KeyHashDate<K>>,
         timer_wheel: &mut TimerWheel<K>,
-        entry: TrioArc<ValueEntry<K, V>>,
+        entry: MiniArc<ValueEntry<K, V>>,
         counters: &mut EvictionCounters,
     ) {
         if let Some(timer) = entry.take_timer_node() {
@@ -2576,7 +2576,7 @@ where
     pub(crate) async fn notify_single_removal(
         &self,
         key: Arc<K>,
-        entry: &TrioArc<ValueEntry<K, V>>,
+        entry: &MiniArc<ValueEntry<K, V>>,
         cause: RemovalCause,
     ) {
         if let Some(notifier) = &self.removal_notifier {
@@ -2588,7 +2588,7 @@ where
     fn notify_upsert(
         &self,
         key: Arc<K>,
-        entry: &TrioArc<ValueEntry<K, V>>,
+        entry: &MiniArc<ValueEntry<K, V>>,
         last_accessed: Option<Instant>,
         last_modified: Option<Instant>,
     ) -> BoxFuture<'static, ()> {
@@ -2629,7 +2629,7 @@ where
     fn notify_invalidate(
         &self,
         key: &Arc<K>,
-        entry: &TrioArc<ValueEntry<K, V>>,
+        entry: &MiniArc<ValueEntry<K, V>>,
     ) -> BoxFuture<'static, ()> {
         use futures_util::future::FutureExt;
 
@@ -2715,7 +2715,7 @@ where
 
 /// Returns `true` if this entry is expired by its per-entry TTL.
 #[inline]
-fn is_expired_by_per_entry_ttl<K>(entry_info: &TrioArc<EntryInfo<K>>, now: Instant) -> bool {
+fn is_expired_by_per_entry_ttl<K>(entry_info: &MiniArc<EntryInfo<K>>, now: Instant) -> bool {
     if let Some(ts) = entry_info.expiration_time() {
         ts <= now
     } else {
diff --git a/src/future/invalidator.rs b/src/future/invalidator.rs
index 4c159f6c..27e8f1e2 100644
--- a/src/future/invalidator.rs
+++ b/src/future/invalidator.rs
@@ -16,7 +16,7 @@ use std::{
         Arc,
     },
 };
-use triomphe::Arc as TrioArc;
+use moka_arc::MiniArc;
 use uuid::Uuid;
 
 pub(crate) type PredicateFun<K, V> = Arc<dyn Fn(&K, &V) -> bool + Send + Sync + 'static>;
@@ -141,7 +141,7 @@ impl<K, V, S> Invalidator<K, V, S> {
 
     // This method will be called by the get method of Cache.
     #[inline]
-    pub(crate) fn apply_predicates(&self, key: &Arc<K>, entry: &TrioArc<ValueEntry<K, V>>) -> bool
+    pub(crate) fn apply_predicates(&self, key: &Arc<K>, entry: &MiniArc<ValueEntry<K, V>>) -> bool
     where
         K: Hash + Eq + Send + Sync + 'static,
         V: Clone + Send + Sync + 'static,
@@ -296,7 +296,7 @@ where
         key: &Arc<K>,
         hash: u64,
         ts: Instant,
-    ) -> Option<TrioArc<ValueEntry<K, V>>>
+    ) -> Option<MiniArc<ValueEntry<K, V>>>
     where
         K: Send + Sync + 'static,
         V: Clone + Send + Sync + 'static,
diff --git a/src/future/key_lock.rs b/src/future/key_lock.rs
index fc06ff2f..6449aa10 100644
--- a/src/future/key_lock.rs
+++ b/src/future/key_lock.rs
@@ -6,11 +6,11 @@ use std::{
 use crate::cht::SegmentedHashMap;
 
 use async_lock::{Mutex, MutexGuard};
-use triomphe::Arc as TrioArc;
+use moka_arc::MiniArc;
 
 const LOCK_MAP_NUM_SEGMENTS: usize = 64;
 
-type LockMap<K, S> = SegmentedHashMap<Arc<K>, TrioArc<Mutex<()>>, S>;
+type LockMap<K, S> = SegmentedHashMap<Arc<K>, MiniArc<Mutex<()>>, S>;
 
 // We need the `where` clause here because of the Drop impl.
 pub(crate) struct KeyLock<'a, K, S>
@@ -21,7 +21,7 @@ where
     map: &'a LockMap<K, S>,
     key: Arc<K>,
     hash: u64,
-    lock: TrioArc<Mutex<()>>,
+    lock: MiniArc<Mutex<()>>,
 }
 
 impl<'a, K, S> Drop for KeyLock<'a, K, S>
@@ -30,11 +30,11 @@ where
     S: BuildHasher,
 {
     fn drop(&mut self) {
-        if TrioArc::count(&self.lock) <= 2 {
+        if MiniArc::count(&self.lock) <= 2 {
             self.map.remove_if(
                 self.hash,
                 |k| k == &self.key,
-                |_k, v| TrioArc::count(v) <= 2,
+                |_k, v| MiniArc::count(v) <= 2,
             );
         }
     }
@@ -45,7 +45,7 @@ where
     K: Eq + Hash,
     S: BuildHasher,
 {
-    fn new(map: &'a LockMap<K, S>, key: &Arc<K>, hash: u64, lock: TrioArc<Mutex<()>>) -> Self {
+    fn new(map: &'a LockMap<K, S>, key: &Arc<K>, hash: u64, lock: MiniArc<Mutex<()>>) -> Self {
         Self {
             map,
             key: Arc::clone(key),
@@ -76,7 +76,7 @@ where
 
     pub(crate) fn key_lock(&self, key: &Arc<K>) -> KeyLock<'_, K, S> {
         let hash = self.locks.hash(key);
-        let kl = TrioArc::new(Mutex::new(()));
+        let kl = MiniArc::new(Mutex::new(()));
         match self
             .locks
             .insert_if_not_present(Arc::clone(key), hash, kl.clone())
diff --git a/src/future/value_initializer.rs b/src/future/value_initializer.rs
index 63b7a341..53d40929 100644
--- a/src/future/value_initializer.rs
+++ b/src/future/value_initializer.rs
@@ -8,7 +8,7 @@ use std::{
     pin::Pin,
     sync::Arc,
 };
-use triomphe::Arc as TrioArc;
+use moka_arc::MiniArc;
 
 use crate::{
     ops::compute::{CompResult, Op},
@@ -49,7 +49,7 @@ impl<V> fmt::Debug for WaiterValue<V> {
     }
 }
 
-type Waiter<V> = TrioArc<RwLock<WaiterValue<V>>>;
+type Waiter<V> = MiniArc<RwLock<WaiterValue<V>>>;
 type WaiterMap<K, V, S> = crate::cht::SegmentedHashMap<(Arc<K>, TypeId), Waiter<V>, S>;
 
 struct WaiterGuard<'a, K, V, S>
@@ -116,7 +116,7 @@ pub(crate) struct ValueInitializer<K, V, S> {
     // try_get_with method. We use the type ID as a part of the key to ensure that we
     // can always downcast the trait object ErrorObject (in Waiter<V>) into its
     // concrete type.
-    waiters: TrioArc<WaiterMap<K, V, S>>,
+    waiters: MiniArc<WaiterMap<K, V, S>>,
 }
 
 impl<K, V, S> ValueInitializer<K, V, S>
@@ -127,7 +127,7 @@ where
 {
     pub(crate) fn with_hasher(hasher: S) -> Self {
         Self {
-            waiters: TrioArc::new(crate::cht::SegmentedHashMap::with_num_segments_and_hasher(
+            waiters: MiniArc::new(crate::cht::SegmentedHashMap::with_num_segments_and_hasher(
                 WAITER_MAP_NUM_SEGMENTS,
                 hasher,
             )),
@@ -172,7 +172,7 @@ where
 
         let (w_key, w_hash) = waiter_key_hash(&self.waiters, c_key, type_id);
 
-        let waiter = TrioArc::new(RwLock::new(WaiterValue::Computing));
+        let waiter = MiniArc::new(RwLock::new(WaiterValue::Computing));
         // NOTE: We have to acquire a write lock before `try_insert_waiter`,
         // so that any concurrent attempt will get our lock and wait on it.
         let lock = waiter.write().await;
@@ -281,7 +281,7 @@ where
 
         let type_id = TypeId::of::<ComputeNone>();
         let (w_key, w_hash) = waiter_key_hash(&self.waiters, &c_key, type_id);
-        let waiter = TrioArc::new(RwLock::new(WaiterValue::Computing));
+        let waiter = MiniArc::new(RwLock::new(WaiterValue::Computing));
         // NOTE: We have to acquire a write lock before `try_insert_waiter`,
         // so that any concurrent attempt will get our lock and wait on it.
         let lock = waiter.write().await;
@@ -482,7 +482,7 @@ where
     (Arc<K>, TypeId): Eq + Hash,
     S: BuildHasher,
 {
-    let waiter = TrioArc::clone(waiter);
+    let waiter = MiniArc::clone(waiter);
     waiter_map.insert_if_not_present(w_key, w_hash, waiter)
 }
 
diff --git a/src/sync/value_initializer.rs b/src/sync/value_initializer.rs
index f66aa9ef..90528f46 100644
--- a/src/sync/value_initializer.rs
+++ b/src/sync/value_initializer.rs
@@ -5,7 +5,7 @@ use std::{
     hash::{BuildHasher, Hash},
     sync::Arc,
 };
-use triomphe::Arc as TrioArc;
+use moka_arc::MiniArc;
 
 use crate::{
     ops::compute::{CompResult, Op},
@@ -38,7 +38,7 @@ impl<V> fmt::Debug for WaiterValue<V> {
     }
 }
 
-type Waiter<V> = TrioArc<RwLock<WaiterValue<V>>>;
+type Waiter<V> = MiniArc<RwLock<WaiterValue<V>>>;
 
 pub(crate) enum InitResult<V, E> {
     Initialized(V),
@@ -96,7 +96,7 @@ where
 
         let (w_key, w_hash) = self.waiter_key_hash(key, type_id);
 
-        let waiter = TrioArc::new(RwLock::new(WaiterValue::Computing));
+        let waiter = MiniArc::new(RwLock::new(WaiterValue::Computing));
         let mut lock = waiter.write();
 
         loop {
@@ -194,7 +194,7 @@ where
 
         let type_id = TypeId::of::<ComputeNone>();
         let (w_key, w_hash) = self.waiter_key_hash(&c_key, type_id);
-        let waiter = TrioArc::new(RwLock::new(WaiterValue::Computing));
+        let waiter = MiniArc::new(RwLock::new(WaiterValue::Computing));
         // NOTE: We have to acquire a write lock before `try_insert_waiter`,
         // so that any concurrent attempt will get our lock and wait on it.
         let mut lock = waiter.write();
@@ -370,7 +370,7 @@ where
         w_hash: u64,
         waiter: &Waiter<V>,
     ) -> Option<Waiter<V>> {
-        let waiter = TrioArc::clone(waiter);
+        let waiter = MiniArc::clone(waiter);
         self.waiters.insert_if_not_present(w_key, w_hash, waiter)
     }
 
diff --git a/src/sync_base/base_cache.rs b/src/sync_base/base_cache.rs
index fe951d29..d262cd59 100644
--- a/src/sync_base/base_cache.rs
+++ b/src/sync_base/base_cache.rs
@@ -45,7 +45,7 @@ use std::{
     },
     time::{Duration, Instant as StdInstant},
 };
-use triomphe::Arc as TrioArc;
+use moka_arc::MiniArc;
 
 pub(crate) type HouseKeeperArc = Arc<Housekeeper>;
 
@@ -109,7 +109,7 @@ impl<K, V, S> BaseCache<K, V, S> {
         self.inner.current_time_from_expiration_clock()
     }
 
-    pub(crate) fn notify_invalidate(&self, key: &Arc<K>, entry: &TrioArc<ValueEntry<K, V>>)
+    pub(crate) fn notify_invalidate(&self, key: &Arc<K>, entry: &MiniArc<ValueEntry<K, V>>)
     where
         K: Send + Sync + 'static,
         V: Clone + Send + Sync + 'static,
@@ -306,7 +306,7 @@ where
                 } else {
                     // Valid entry.
                     let maybe_key = if need_key { Some(Arc::clone(k)) } else { None };
-                    Some((maybe_key, TrioArc::clone(entry)))
+                    Some((maybe_key, MiniArc::clone(entry)))
                 }
             });
 
@@ -630,11 +630,11 @@ impl<K, V, S> BaseCache<K, V, S> {
         value: V,
         timestamp: Instant,
         policy_weight: u32,
-    ) -> (TrioArc<ValueEntry<K, V>>, u16) {
+    ) -> (MiniArc<ValueEntry<K, V>>, u16) {
         let key_hash = KeyHash::new(Arc::clone(key), hash);
-        let info = TrioArc::new(EntryInfo::new(key_hash, timestamp, policy_weight));
+        let info = MiniArc::new(EntryInfo::new(key_hash, timestamp, policy_weight));
         let gen: u16 = info.entry_gen();
-        (TrioArc::new(ValueEntry::new(value, info)), gen)
+        (MiniArc::new(ValueEntry::new(value, info)), gen)
     }
 
     #[inline]
@@ -644,15 +644,15 @@ impl<K, V, S> BaseCache<K, V, S> {
         timestamp: Instant,
         policy_weight: u32,
         other: &ValueEntry<K, V>,
-    ) -> (TrioArc<ValueEntry<K, V>>, u16) {
-        let info = TrioArc::clone(other.entry_info());
+    ) -> (MiniArc<ValueEntry<K, V>>, u16) {
+        let info = MiniArc::clone(other.entry_info());
         // To prevent this updated ValueEntry from being evicted by an expiration
         // policy, increment the entry generation.
         let gen = info.incr_entry_gen();
         info.set_last_accessed(timestamp);
         info.set_last_modified(timestamp);
         info.set_policy_weight(policy_weight);
-        (TrioArc::new(ValueEntry::new_from(value, info, other)), gen)
+        (MiniArc::new(ValueEntry::new_from(value, info, other)), gen)
     }
 
     fn expire_after_create(
@@ -773,7 +773,7 @@ impl<'a, K, V> EvictionState<'a, K, V> {
     fn notify_entry_removal(
         &mut self,
         key: Arc<K>,
-        entry: &TrioArc<ValueEntry<K, V>>,
+        entry: &MiniArc<ValueEntry<K, V>>,
         cause: RemovalCause,
     ) where
         K: Send + Sync + 'static,
@@ -863,7 +863,7 @@ enum AdmissionResult<K> {
     Rejected,
 }
 
-type CacheStore<K, V, S> = crate::cht::SegmentedHashMap<Arc<K>, TrioArc<ValueEntry<K, V>>, S>;
+type CacheStore<K, V, S> = crate::cht::SegmentedHashMap<Arc<K>, MiniArc<ValueEntry<K, V>>, S>;
 
 struct Clocks {
     has_expiration_clock: AtomicBool,
@@ -1140,7 +1140,7 @@ where
     where
         K: Borrow<Q>,
         Q: Hash + Eq + ?Sized,
-        F: FnOnce(&Arc<K>, &TrioArc<ValueEntry<K, V>>) -> T,
+        F: FnOnce(&Arc<K>, &MiniArc<ValueEntry<K, V>>) -> T,
     {
         self.cache
             .get_key_value_and(hash, |k| (k as &K).borrow() == key, with_entry)
@@ -1151,7 +1151,7 @@ where
     where
         K: Borrow<Q>,
         Q: Hash + Eq + ?Sized,
-        F: FnOnce(&Arc<K>, &TrioArc<ValueEntry<K, V>>) -> Option<T>,
+        F: FnOnce(&Arc<K>, &MiniArc<ValueEntry<K, V>>) -> Option<T>,
     {
         self.cache
             .get_key_value_and_then(hash, |k| (k as &K).borrow() == key, with_entry)
@@ -1192,7 +1192,7 @@ where
 
     /// Returns `true` if the entry is invalidated by `invalidate_entries_if` method.
     #[inline]
-    fn is_invalidated_entry(&self, key: &Arc<K>, entry: &TrioArc<ValueEntry<K, V>>) -> bool
+    fn is_invalidated_entry(&self, key: &Arc<K>, entry: &MiniArc<ValueEntry<K, V>>) -> bool
     where
         V: Clone,
     {
@@ -1515,7 +1515,7 @@ where
     fn handle_upsert(
         &self,
         kh: KeyHash<K>,
-        entry: TrioArc<ValueEntry<K, V>>,
+        entry: MiniArc<ValueEntry<K, V>>,
         gen: u16,
         old_weight: u32,
         new_weight: u32,
@@ -1561,7 +1561,7 @@ where
                     kh.hash,
                     |k| k == &kh.key,
                     |_, current_entry| {
-                        TrioArc::ptr_eq(entry.entry_info(), current_entry.entry_info())
+                        MiniArc::ptr_eq(entry.entry_info(), current_entry.entry_info())
                             && current_entry.entry_info().entry_gen() == gen
                     },
                 );
@@ -1658,7 +1658,7 @@ where
                     kh.hash,
                     |k| k == &key,
                     |_, current_entry| {
-                        TrioArc::ptr_eq(entry.entry_info(), current_entry.entry_info())
+                        MiniArc::ptr_eq(entry.entry_info(), current_entry.entry_info())
                             && current_entry.entry_info().entry_gen() == gen
                     },
                 );
@@ -1760,7 +1760,7 @@ where
 
     fn handle_admit(
         &self,
-        entry: &TrioArc<ValueEntry<K, V>>,
+        entry: &MiniArc<ValueEntry<K, V>>,
         policy_weight: u32,
         deqs: &mut Deques<K>,
         timer_wheel: &mut TimerWheel<K>,
@@ -1785,7 +1785,7 @@ where
     /// NOTE: This method may enable the timer wheel.
     fn update_timer_wheel(
         &self,
-        entry: &TrioArc<ValueEntry<K, V>>,
+        entry: &MiniArc<ValueEntry<K, V>>,
         timer_wheel: &mut TimerWheel<K>,
     ) {
         // Enable the timer wheel if needed.
@@ -1805,8 +1805,8 @@ where
             // expiration time and not registered to the timer wheel.
             (true, None) => {
                 let timer = timer_wheel.schedule(
-                    TrioArc::clone(entry.entry_info()),
-                    TrioArc::clone(entry.deq_nodes()),
+                    MiniArc::clone(entry.entry_info()),
+                    MiniArc::clone(entry.deq_nodes()),
                 );
                 entry.set_timer_node(timer);
             }
@@ -1834,7 +1834,7 @@ where
     fn handle_remove(
         deqs: &mut Deques<K>,
         timer_wheel: &mut TimerWheel<K>,
-        entry: TrioArc<ValueEntry<K, V>>,
+        entry: MiniArc<ValueEntry<K, V>>,
         gen: Option<u16>,
         counters: &mut EvictionCounters,
     ) {
@@ -1846,7 +1846,7 @@ where
 
     fn handle_remove_without_timer_wheel(
         deqs: &mut Deques<K>,
-        entry: TrioArc<ValueEntry<K, V>>,
+        entry: MiniArc<ValueEntry<K, V>>,
         gen: Option<u16>,
         counters: &mut EvictionCounters,
     ) {
@@ -1869,7 +1869,7 @@ where
         ao_deq: &mut Deque<KeyHashDate<K>>,
         wo_deq: &mut Deque<KeyHashDate<K>>,
         timer_wheel: &mut TimerWheel<K>,
-        entry: TrioArc<ValueEntry<K, V>>,
+        entry: MiniArc<ValueEntry<K, V>>,
         counters: &mut EvictionCounters,
     ) {
         if let Some(timer) = entry.take_timer_node() {
@@ -2368,7 +2368,7 @@ where
     pub(crate) fn notify_single_removal(
         &self,
         key: Arc<K>,
-        entry: &TrioArc<ValueEntry<K, V>>,
+        entry: &MiniArc<ValueEntry<K, V>>,
         cause: RemovalCause,
     ) {
         if let Some(notifier) = &self.removal_notifier {
@@ -2380,7 +2380,7 @@ where
     fn notify_upsert(
         &self,
         key: Arc<K>,
-        entry: &TrioArc<ValueEntry<K, V>>,
+        entry: &MiniArc<ValueEntry<K, V>>,
         last_accessed: Option<Instant>,
         last_modified: Option<Instant>,
     ) {
@@ -2407,7 +2407,7 @@ where
     }
 
     #[inline]
-    fn notify_invalidate(&self, key: &Arc<K>, entry: &TrioArc<ValueEntry<K, V>>) {
+    fn notify_invalidate(&self, key: &Arc<K>, entry: &MiniArc<ValueEntry<K, V>>) {
         let now = self.current_time_from_expiration_clock();
         let exp = &self.expiration_policy;
 
@@ -2480,7 +2480,7 @@ where
 
 /// Returns `true` if this entry is expired by its per-entry TTL.
 #[inline]
-fn is_expired_by_per_entry_ttl<K>(entry_info: &TrioArc<EntryInfo<K>>, now: Instant) -> bool {
+fn is_expired_by_per_entry_ttl<K>(entry_info: &MiniArc<EntryInfo<K>>, now: Instant) -> bool {
     if let Some(ts) = entry_info.expiration_time() {
         ts <= now
     } else {
diff --git a/src/sync_base/invalidator.rs b/src/sync_base/invalidator.rs
index dfb62c42..f281f709 100644
--- a/src/sync_base/invalidator.rs
+++ b/src/sync_base/invalidator.rs
@@ -16,7 +16,7 @@ use std::{
         Arc,
     },
 };
-use triomphe::Arc as TrioArc;
+use moka_arc::MiniArc;
 use uuid::Uuid;
 
 pub(crate) type PredicateFun<K, V> = Arc<dyn Fn(&K, &V) -> bool + Send + Sync + 'static>;
@@ -141,7 +141,7 @@ impl<K, V, S> Invalidator<K, V, S> {
 
     // This method will be called by the get method of Cache.
     #[inline]
-    pub(crate) fn apply_predicates(&self, key: &Arc<K>, entry: &TrioArc<ValueEntry<K, V>>) -> bool
+    pub(crate) fn apply_predicates(&self, key: &Arc<K>, entry: &MiniArc<ValueEntry<K, V>>) -> bool
     where
         K: Hash + Eq + Send + Sync + 'static,
         V: Clone + Send + Sync + 'static,
@@ -296,7 +296,7 @@ where
         key: &Arc<K>,
         hash: u64,
         ts: Instant,
-    ) -> Option<TrioArc<ValueEntry<K, V>>>
+    ) -> Option<MiniArc<ValueEntry<K, V>>>
     where
         K: Send + Sync + 'static,
         V: Clone + Send + Sync + 'static,
diff --git a/src/sync_base/key_lock.rs b/src/sync_base/key_lock.rs
index abc96873..fc5ad402 100644
--- a/src/sync_base/key_lock.rs
+++ b/src/sync_base/key_lock.rs
@@ -6,11 +6,11 @@ use std::{
 use crate::cht::SegmentedHashMap;
 
 use parking_lot::{Mutex, MutexGuard};
-use triomphe::Arc as TrioArc;
+use moka_arc::MiniArc;
 
 const LOCK_MAP_NUM_SEGMENTS: usize = 64;
 
-type LockMap<K, S> = SegmentedHashMap<Arc<K>, TrioArc<Mutex<()>>, S>;
+type LockMap<K, S> = SegmentedHashMap<Arc<K>, MiniArc<Mutex<()>>, S>;
 
 // We need the `where` clause here because of the Drop impl.
 pub(crate) struct KeyLock<'a, K, S>
@@ -21,7 +21,7 @@ where
     map: &'a LockMap<K, S>,
     key: Arc<K>,
     hash: u64,
-    lock: TrioArc<Mutex<()>>,
+    lock: MiniArc<Mutex<()>>,
 }
 
 impl<'a, K, S> Drop for KeyLock<'a, K, S>
@@ -30,11 +30,11 @@ where
     S: BuildHasher,
 {
     fn drop(&mut self) {
-        if TrioArc::count(&self.lock) <= 2 {
+        if MiniArc::count(&self.lock) <= 2 {
             self.map.remove_if(
                 self.hash,
                 |k| k == &self.key,
-                |_k, v| TrioArc::count(v) <= 2,
+                |_k, v| MiniArc::count(v) <= 2,
             );
         }
     }
@@ -45,7 +45,7 @@ where
     K: Eq + Hash,
     S: BuildHasher,
 {
-    fn new(map: &'a LockMap<K, S>, key: &Arc<K>, hash: u64, lock: TrioArc<Mutex<()>>) -> Self {
+    fn new(map: &'a LockMap<K, S>, key: &Arc<K>, hash: u64, lock: MiniArc<Mutex<()>>) -> Self {
         Self {
             map,
             key: Arc::clone(key),
@@ -76,7 +76,7 @@ where
 
     pub(crate) fn key_lock(&self, key: &Arc<K>) -> KeyLock<'_, K, S> {
         let hash = self.locks.hash(key);
-        let kl = TrioArc::new(Mutex::new(()));
+        let kl = MiniArc::new(Mutex::new(()));
         match self
             .locks
             .insert_if_not_present(Arc::clone(key), hash, kl.clone())

From 2e463d3d8f7d0dbee4abb96b322f56110974538a Mon Sep 17 00:00:00 2001
From: Tatsuya Kawano <tatsuya@hibaridb.org>
Date: Sat, 14 Sep 2024 12:15:30 +0800
Subject: [PATCH 2/4] Apply cargo fmt

---
 src/common/concurrent.rs        | 2 +-
 src/common/concurrent/deques.rs | 2 +-
 src/common/timer_wheel.rs       | 2 +-
 src/future/base_cache.rs        | 2 +-
 src/future/invalidator.rs       | 2 +-
 src/future/value_initializer.rs | 2 +-
 src/sync/value_initializer.rs   | 2 +-
 src/sync_base/base_cache.rs     | 2 +-
 src/sync_base/invalidator.rs    | 2 +-
 src/sync_base/key_lock.rs       | 2 +-
 10 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/common/concurrent.rs b/src/common/concurrent.rs
index 95686327..366edf50 100644
--- a/src/common/concurrent.rs
+++ b/src/common/concurrent.rs
@@ -1,9 +1,9 @@
 use crate::common::{deque::DeqNode, time::Instant};
 
+use moka_arc::MiniArc;
 use parking_lot::Mutex;
 use std::{fmt, ptr::NonNull, sync::Arc};
 use tagptr::TagNonNull;
-use moka_arc::MiniArc;
 
 pub(crate) mod constants;
 pub(crate) mod deques;
diff --git a/src/common/concurrent/deques.rs b/src/common/concurrent/deques.rs
index 37245b1e..8a14c7e4 100644
--- a/src/common/concurrent/deques.rs
+++ b/src/common/concurrent/deques.rs
@@ -4,9 +4,9 @@ use crate::common::{
     CacheRegion,
 };
 
+use moka_arc::MiniArc;
 use std::ptr::NonNull;
 use tagptr::TagNonNull;
-use moka_arc::MiniArc;
 
 pub(crate) struct Deques<K> {
     pub(crate) window: Deque<KeyHashDate<K>>, //    Not used yet.
diff --git a/src/common/timer_wheel.rs b/src/common/timer_wheel.rs
index 73add563..9598bbbf 100644
--- a/src/common/timer_wheel.rs
+++ b/src/common/timer_wheel.rs
@@ -19,8 +19,8 @@ use super::{
     time::{CheckedTimeOps, Instant},
 };
 
-use parking_lot::Mutex;
 use moka_arc::MiniArc;
+use parking_lot::Mutex;
 
 const BUCKET_COUNTS: &[u64] = &[
     64, // roughly seconds
diff --git a/src/future/base_cache.rs b/src/future/base_cache.rs
index f302b66a..d6cc3ccc 100644
--- a/src/future/base_cache.rs
+++ b/src/future/base_cache.rs
@@ -39,6 +39,7 @@ use async_lock::{Mutex, MutexGuard, RwLock};
 use crossbeam_channel::{Receiver, Sender, TrySendError};
 use crossbeam_utils::atomic::AtomicCell;
 use futures_util::future::BoxFuture;
+use moka_arc::MiniArc;
 use parking_lot::RwLock as SyncRwLock;
 use smallvec::SmallVec;
 use std::{
@@ -51,7 +52,6 @@ use std::{
     },
     time::{Duration, Instant as StdInstant},
 };
-use moka_arc::MiniArc;
 
 pub(crate) type HouseKeeperArc = Arc<Housekeeper>;
 
diff --git a/src/future/invalidator.rs b/src/future/invalidator.rs
index 27e8f1e2..7bc4eb68 100644
--- a/src/future/invalidator.rs
+++ b/src/future/invalidator.rs
@@ -9,6 +9,7 @@ use crate::{
 };
 
 use async_lock::{Mutex, MutexGuard};
+use moka_arc::MiniArc;
 use std::{
     hash::{BuildHasher, Hash},
     sync::{
@@ -16,7 +17,6 @@ use std::{
         Arc,
     },
 };
-use moka_arc::MiniArc;
 use uuid::Uuid;
 
 pub(crate) type PredicateFun<K, V> = Arc<dyn Fn(&K, &V) -> bool + Send + Sync + 'static>;
diff --git a/src/future/value_initializer.rs b/src/future/value_initializer.rs
index 53d40929..c56eeacc 100644
--- a/src/future/value_initializer.rs
+++ b/src/future/value_initializer.rs
@@ -1,5 +1,6 @@
 use async_lock::{RwLock, RwLockWriteGuard};
 use futures_util::FutureExt;
+use moka_arc::MiniArc;
 use std::{
     any::{Any, TypeId},
     fmt,
@@ -8,7 +9,6 @@ use std::{
     pin::Pin,
     sync::Arc,
 };
-use moka_arc::MiniArc;
 
 use crate::{
     ops::compute::{CompResult, Op},
diff --git a/src/sync/value_initializer.rs b/src/sync/value_initializer.rs
index 90528f46..66034972 100644
--- a/src/sync/value_initializer.rs
+++ b/src/sync/value_initializer.rs
@@ -1,3 +1,4 @@
+use moka_arc::MiniArc;
 use parking_lot::RwLock;
 use std::{
     any::{Any, TypeId},
@@ -5,7 +6,6 @@ use std::{
     hash::{BuildHasher, Hash},
     sync::Arc,
 };
-use moka_arc::MiniArc;
 
 use crate::{
     ops::compute::{CompResult, Op},
diff --git a/src/sync_base/base_cache.rs b/src/sync_base/base_cache.rs
index d262cd59..1d3a6281 100644
--- a/src/sync_base/base_cache.rs
+++ b/src/sync_base/base_cache.rs
@@ -32,6 +32,7 @@ use crate::{
 
 use crossbeam_channel::{Receiver, Sender, TrySendError};
 use crossbeam_utils::atomic::AtomicCell;
+use moka_arc::MiniArc;
 use parking_lot::{Mutex, RwLock};
 use smallvec::SmallVec;
 use std::{
@@ -45,7 +46,6 @@ use std::{
     },
     time::{Duration, Instant as StdInstant},
 };
-use moka_arc::MiniArc;
 
 pub(crate) type HouseKeeperArc = Arc<Housekeeper>;
 
diff --git a/src/sync_base/invalidator.rs b/src/sync_base/invalidator.rs
index f281f709..f51435a6 100644
--- a/src/sync_base/invalidator.rs
+++ b/src/sync_base/invalidator.rs
@@ -8,6 +8,7 @@ use crate::{
     PredicateError,
 };
 
+use moka_arc::MiniArc;
 use parking_lot::{Mutex, MutexGuard};
 use std::{
     hash::{BuildHasher, Hash},
@@ -16,7 +17,6 @@ use std::{
         Arc,
     },
 };
-use moka_arc::MiniArc;
 use uuid::Uuid;
 
 pub(crate) type PredicateFun<K, V> = Arc<dyn Fn(&K, &V) -> bool + Send + Sync + 'static>;
diff --git a/src/sync_base/key_lock.rs b/src/sync_base/key_lock.rs
index fc5ad402..c58c6eed 100644
--- a/src/sync_base/key_lock.rs
+++ b/src/sync_base/key_lock.rs
@@ -5,8 +5,8 @@ use std::{
 
 use crate::cht::SegmentedHashMap;
 
-use parking_lot::{Mutex, MutexGuard};
 use moka_arc::MiniArc;
+use parking_lot::{Mutex, MutexGuard};
 
 const LOCK_MAP_NUM_SEGMENTS: usize = 64;
 

From 0ef051ce222f4b9c5cca1689bbe4ec6fef057112 Mon Sep 17 00:00:00 2001
From: Tatsuya Kawano <tatsuya@hibaridb.org>
Date: Mon, 16 Sep 2024 09:05:24 +0800
Subject: [PATCH 3/4] Bump the version to v0.12.9

---
 Cargo.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Cargo.toml b/Cargo.toml
index fc21cdf9..336c54f9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "moka"
-version = "0.12.8"
+version = "0.12.9"
 edition = "2021"
 # Rust 1.65 was released on Nov 3, 2022.
 rust-version = "1.65"

From 14651ee287ee7b22a4ccba33eb70c5875e62b3b3 Mon Sep 17 00:00:00 2001
From: Tatsuya Kawano <tatsuya@hibaridb.org>
Date: Mon, 16 Sep 2024 10:12:29 +0800
Subject: [PATCH 4/4] Bring `MiniArc`, our own `Arc` implementation, from a
 separate crate into `moka`

Also enable Miri and Loom tests on the CI (GitHub Actions).
---
 .github/workflows/Loom.yml      |  50 +++++
 .github/workflows/Miri.yml      |   8 +
 .vscode/settings.json           |   3 +
 Cargo.toml                      |   7 +-
 src/common/concurrent.rs        |   4 +-
 src/common/concurrent/arc.rs    | 330 ++++++++++++++++++++++++++++++++
 src/common/concurrent/deques.rs |   3 +-
 src/common/timer_wheel.rs       |   7 +-
 src/future/base_cache.rs        |   2 +-
 src/future/invalidator.rs       |   3 +-
 src/future/key_lock.rs          |   3 +-
 src/future/value_initializer.rs |   2 +-
 src/sync/value_initializer.rs   |   2 +-
 src/sync_base/base_cache.rs     |   2 +-
 src/sync_base/invalidator.rs    |   3 +-
 src/sync_base/key_lock.rs       |   3 +-
 16 files changed, 410 insertions(+), 22 deletions(-)
 create mode 100644 .github/workflows/Loom.yml
 create mode 100644 src/common/concurrent/arc.rs

diff --git a/.github/workflows/Loom.yml b/.github/workflows/Loom.yml
new file mode 100644
index 00000000..ea3152f5
--- /dev/null
+++ b/.github/workflows/Loom.yml
@@ -0,0 +1,50 @@
+name: CI
+
+on:
+  push:
+    paths-ignore:
+      - '.devcontainer/**'
+      - '.gitpod.yml'
+      - '.vscode/**'
+      - 'tests/**'
+  pull_request:
+    paths-ignore:
+      - '.devcontainer/**'
+      - '.gitpod.yml'
+      - '.vscode/**'
+      - 'tests/**'
+  schedule:
+    # Run against the last commit on the default branch on Friday at 8pm (UTC?)
+    - cron: '0 20 * * 5'
+
+jobs:
+  pre_job:
+    runs-on: ubuntu-latest
+    outputs:
+      should_skip: ${{ steps.skip_check.outputs.should_skip }}
+    steps:
+      - id: skip_check
+        # https://github.com/marketplace/actions/skip-duplicate-actions
+        uses: fkirc/skip-duplicate-actions@v5
+        with:
+          concurrent_skipping: 'same_content'
+          do_not_skip: '["pull_request", "workflow_dispatch", "schedule"]'
+
+  test:
+    needs: pre_job
+    if: needs.pre_job.outputs.should_skip != 'true'
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout Moka
+        uses: actions/checkout@v4
+
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: stable
+
+      - name: Run tests in concurrent::arc module
+        run: cargo test --release --lib --features 'future, sync' common::concurrent::arc::loom_tests
+        env:
+          RUSTFLAGS: '--cfg moka_loom'
diff --git a/.github/workflows/Miri.yml b/.github/workflows/Miri.yml
index 3ca29c3c..4faa1fe0 100644
--- a/.github/workflows/Miri.yml
+++ b/.github/workflows/Miri.yml
@@ -47,6 +47,11 @@ jobs:
 
       - run: cargo miri setup
 
+      - name: Run Miri test on arc module using tree borrows
+        run: cargo miri test arc --features 'sync, future'
+        env:
+          MIRIFLAGS: '-Zmiri-tree-borrows'
+
       - name: Run Miri test on deque module using tree borrows
         run: cargo miri test deque --features 'sync, future'
         env:
@@ -57,6 +62,9 @@ jobs:
         env:
           MIRIFLAGS: '-Zmiri-tree-borrows'
 
+      - name: Run Miri test on arc module using stacked borrows
+        run: cargo miri test arc --features 'sync, future'
+
       - name: Run Miri test on deque module using stacked borrows
         run: cargo miri test deque --features 'sync, future'
 
diff --git a/.vscode/settings.json b/.vscode/settings.json
index c9ae44b0..5093b96c 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -32,10 +32,13 @@
         "ENHANCEME",
         "Eytan",
         "getrandom",
+        "Goregaokar",
         "hashbrown",
         "Hasher",
         "kani",
         "Kawano",
+        "Manish",
+        "Manishearth",
         "mapref",
         "Miri",
         "Moka",
diff --git a/Cargo.toml b/Cargo.toml
index 336c54f9..81107fa3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -44,7 +44,6 @@ unstable-debug-counters = ["future", "once_cell"]
 crossbeam-channel = "0.5.5"
 crossbeam-epoch = "0.9.9"
 crossbeam-utils = "0.8"
-moka-arc = { git = "https://gitlab.com/moka-labs/moka-gh440-remove-triomphe/moka-arc.git" }
 parking_lot = "0.12"
 smallvec = "1.8"
 tagptr = "0.2"
@@ -77,6 +76,11 @@ paste = "1.0.9"
 reqwest = { version = "0.11.11", default-features = false, features = ["rustls-tls"] }
 tokio = { version = "1.19", features = ["fs", "io-util", "macros", "rt-multi-thread", "sync", "time" ] }
 
+# We cannot use `cfg(loom)` here because an indirect dependency `concurrent-queue`
+# uses it.
+[target.'cfg(moka_loom)'.dependencies]
+loom = "0.7"
+
 [target.'cfg(trybuild)'.dev-dependencies]
 trybuild = "1.0"
 
@@ -88,6 +92,7 @@ unexpected_cfgs = { level = "warn", check-cfg = [
     "cfg(armv5te)",
     "cfg(beta_clippy)",
     "cfg(kani)",
+    "cfg(moka_loom)",
     "cfg(mips)",
     "cfg(rustver)",
     "cfg(skip_large_mem_tests)",
diff --git a/src/common/concurrent.rs b/src/common/concurrent.rs
index 366edf50..f8ba44c8 100644
--- a/src/common/concurrent.rs
+++ b/src/common/concurrent.rs
@@ -1,10 +1,10 @@
-use crate::common::{deque::DeqNode, time::Instant};
+use crate::common::{concurrent::arc::MiniArc, deque::DeqNode, time::Instant};
 
-use moka_arc::MiniArc;
 use parking_lot::Mutex;
 use std::{fmt, ptr::NonNull, sync::Arc};
 use tagptr::TagNonNull;
 
+pub(crate) mod arc;
 pub(crate) mod constants;
 pub(crate) mod deques;
 pub(crate) mod entry_info;
diff --git a/src/common/concurrent/arc.rs b/src/common/concurrent/arc.rs
new file mode 100644
index 00000000..d0d8e7d9
--- /dev/null
+++ b/src/common/concurrent/arc.rs
@@ -0,0 +1,330 @@
+// This module's source code was written by us, the `moka` developers, referring to
+// the following book and code:
+//
+// - Chapter 6. Building Our Own "Arc" of the Rust Atomics and Locks book.
+//     - Rust Atomics and Locks by Mara Bos (O’Reilly). Copyright 2023 Mara Bos,
+//       ISBN: 978-1-098-11944-7
+//     - https://marabos.nl/atomics/
+// - The `triomphe` crate v0.1.13 and v0.1.11 by Manish Goregaokar (Manishearth)
+//     -  MIT or Apache-2.0 License
+//     - https://github.com/Manishearth/triomphe
+// - `std::sync::Arc` in the Rust Standard Library (1.81.0).
+//     -  MIT or Apache-2.0 License
+
+use std::{
+    fmt,
+    hash::{Hash, Hasher},
+    ops::Deref,
+    ptr::NonNull,
+};
+
+#[cfg(not(moka_loom))]
+use std::sync::atomic::{self, AtomicU32};
+
+#[cfg(moka_loom)]
+use loom::sync::atomic::{self, AtomicU32};
+
+/// A thread-safe reference-counting pointer. `MiniArc` is similar to
+/// `std::sync::Arc`, Atomically Reference Counted shared pointer, but with a few
+/// differences:
+///
+/// - Smaller memory overhead:
+///     - `MiniArc` does not support weak references, so it does not need to store a
+///       weak reference count.
+///     - `MiniArc` uses `AtomicU32` for the reference count, while `std::sync::Arc`
+///       uses `AtomicUsize`. On a 64-bit system, `AtomicU32` is half the size of
+///       `AtomicUsize`.
+///         - Note: Depending on the value type `T`, the Rust compiler may add
+///           padding to the internal struct of `MiniArc<T>`, so the actual memory
+///           overhead may vary.
+/// - Smaller code size:
+///     - Only about 100 lines of code.
+///         - This is because `MiniArc` provides only the methods needed for the
+///           `moka` and `mini-moka` crates.
+///     - Smaller code size means less chance of bugs.
+pub(crate) struct MiniArc<T: ?Sized> {
+    ptr: NonNull<ArcData<T>>,
+}
+
+struct ArcData<T: ?Sized> {
+    ref_count: AtomicU32,
+    data: T,
+}
+
+/// A soft limit on the amount of references that may be made to an `MiniArc`.
+///
+/// Going above this limit will abort your program (although not necessarily)
+/// at _exactly_ `MAX_REFCOUNT + 1` references.
+const MAX_REFCOUNT: u32 = (i32::MAX) as u32;
+
+unsafe impl<T: ?Sized + Send + Sync> Send for MiniArc<T> {}
+unsafe impl<T: ?Sized + Send + Sync> Sync for MiniArc<T> {}
+
+impl<T> MiniArc<T> {
+    pub(crate) fn new(data: T) -> MiniArc<T> {
+        MiniArc {
+            ptr: NonNull::from(Box::leak(Box::new(ArcData {
+                ref_count: AtomicU32::new(1),
+                data,
+            }))),
+        }
+    }
+}
+
+impl<T: ?Sized> MiniArc<T> {
+    /// Gets the number of [`MiniArc`] pointers to this allocation
+    pub(crate) fn count(this: &Self) -> u32 {
+        use atomic::Ordering::Acquire;
+
+        this.data().ref_count.load(Acquire)
+    }
+
+    /// Returns `true` if the two `MiniArc`s point to the same allocation in a
+    /// vein similar to [`ptr::eq`].
+    ///
+    /// # Safety
+    ///
+    /// This function is unreliable when `T` is a `dyn Trait`. Currently
+    /// coercing `MiniArc<SomeTime>` to `MiniArc<dyn Trait>` is not possible, so
+    /// this is not a problem in practice. However, if this coercion becomes
+    /// possible in the future, this function may return incorrect results when
+    /// comparing `MiniArc<dyn Trait>` instances.
+    ///
+    /// To fix this, we must rise the minimum supported Rust version (MSRV) to
+    /// 1.76 and use `std::ptr::addr_eq` internally instead of `eq` (`==`).
+    /// `addr_eq` compares the _addresses_ of the pointers for equality,
+    /// ignoring any metadata in fat pointers.
+    ///
+    /// See the following `triomphe` issue for more information:
+    /// https://github.com/Manishearth/triomphe/pull/84
+    ///
+    /// Note that `triomphe` has a feature called `unsize`, which enables the
+    /// coercion by using the `unsize` crate. `MiniArc` does not have such a
+    /// feature, so we are safe for now.
+    #[inline]
+    #[allow(ambiguous_wide_pointer_comparisons)] // Remove when MSRV is 1.76 or newer.
+    pub(crate) fn ptr_eq(this: &Self, other: &Self) -> bool {
+        // `addr_eq` requires Rust 1.76 or newer.
+        // ptr::addr_eq(this.ptr.as_ptr(), other.ptr.as_ptr())
+        this.ptr.as_ptr() == other.ptr.as_ptr()
+    }
+
+    #[inline]
+    fn data(&self) -> &ArcData<T> {
+        unsafe { self.ptr.as_ref() }
+    }
+}
+
+impl<T: ?Sized> Deref for MiniArc<T> {
+    type Target = T;
+
+    fn deref(&self) -> &T {
+        &self.data().data
+    }
+}
+
+impl<T: ?Sized> Clone for MiniArc<T> {
+    fn clone(&self) -> Self {
+        use atomic::Ordering::Relaxed;
+
+        if self.data().ref_count.fetch_add(1, Relaxed) > MAX_REFCOUNT {
+            std::process::abort();
+        }
+
+        MiniArc { ptr: self.ptr }
+    }
+}
+
+impl<T: ?Sized> Drop for MiniArc<T> {
+    fn drop(&mut self) {
+        use std::sync::atomic::Ordering::{Acquire, Release};
+
+        if self.data().ref_count.fetch_sub(1, Release) == 1 {
+            atomic::fence(Acquire);
+            unsafe {
+                drop(Box::from_raw(self.ptr.as_ptr()));
+            }
+        }
+    }
+}
+
+impl<T: Default> Default for MiniArc<T> {
+    /// Creates a new `MiniArc<T>`, with the `Default` value for `T`.
+    fn default() -> MiniArc<T> {
+        MiniArc::new(Default::default())
+    }
+}
+
+impl<T: ?Sized + PartialEq> PartialEq for MiniArc<T> {
+    fn eq(&self, other: &MiniArc<T>) -> bool {
+        // TODO: pointer equality is incorrect if `T` is not `Eq`.
+        // See: https://github.com/Manishearth/triomphe/pull/88
+        Self::ptr_eq(self, other) || *(*self) == *(*other)
+    }
+
+    #[allow(clippy::partialeq_ne_impl)]
+    fn ne(&self, other: &MiniArc<T>) -> bool {
+        !Self::ptr_eq(self, other) && *(*self) != *(*other)
+    }
+}
+
+impl<T: ?Sized + Eq> Eq for MiniArc<T> {}
+
+impl<T: ?Sized + fmt::Display> fmt::Display for MiniArc<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(&**self, f)
+    }
+}
+
+impl<T: ?Sized + fmt::Debug> fmt::Debug for MiniArc<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(&**self, f)
+    }
+}
+
+impl<T: ?Sized> fmt::Pointer for MiniArc<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Pointer::fmt(&self.ptr.as_ptr(), f)
+    }
+}
+
+impl<T: ?Sized + Hash> Hash for MiniArc<T> {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        (**self).hash(state)
+    }
+}
+
+#[cfg(all(test, not(moka_loom)))]
+mod tests {
+    use std::sync::atomic::{AtomicUsize, Ordering::Relaxed};
+
+    use super::*;
+
+    #[test]
+    fn test_drop() {
+        static NUM_DROPS: AtomicUsize = AtomicUsize::new(0);
+
+        struct DetectDrop;
+
+        impl Drop for DetectDrop {
+            fn drop(&mut self) {
+                NUM_DROPS.fetch_add(1, Relaxed);
+            }
+        }
+
+        // Create two MiniArcs sharing an object containing a string
+        // and a DetectDrop, to detect when it is dropped.
+        let x = MiniArc::new(("hello", DetectDrop));
+        let y = x.clone();
+
+        // Send x to another thread, and use it there.
+        let t = std::thread::spawn(move || {
+            assert_eq!(x.0, "hello");
+        });
+
+        // In parallel, y should still be usable here.
+        assert_eq!(y.0, "hello");
+        assert!(MiniArc::count(&y) >= 1);
+
+        // Wait for the thread to finish.
+        t.join().unwrap();
+
+        // One MiniArc, x, should be dropped by now.
+        // We still have y, so the object should not have been dropped yet.
+        assert_eq!(NUM_DROPS.load(Relaxed), 0);
+        assert_eq!(MiniArc::count(&y), 1);
+
+        // Drop the remaining `MiniArc`.
+        drop(y);
+
+        // Now that `y` is dropped too,
+        // the object should have been dropped.
+        assert_eq!(NUM_DROPS.load(Relaxed), 1);
+    }
+
+    #[test]
+    fn test_eq() {
+        let w = MiniArc::new(6502);
+        let x = w.clone();
+        let y = MiniArc::new(6502);
+        let z = MiniArc::new(8086);
+
+        assert_eq!(w, x);
+        assert_eq!(x, w);
+        assert_eq!(w, y);
+        assert_eq!(y, w);
+        assert_ne!(y, z);
+        assert_ne!(z, y);
+    }
+
+    #[test]
+    fn test_partial_eq_bug() {
+        let float = f32::NAN;
+        assert_ne!(float, float);
+        let arc = MiniArc::new(f32::NAN);
+        // TODO: this is a bug.
+        // See: https://github.com/Manishearth/triomphe/pull/88
+        assert_eq!(arc, arc);
+    }
+
+    #[allow(dead_code)]
+    const fn is_partial_eq<T: ?Sized + PartialEq>() {}
+
+    #[allow(dead_code)]
+    const fn is_eq<T: ?Sized + Eq>() {}
+
+    // compile-time check that PartialEq/Eq is correctly derived
+    const _: () = is_partial_eq::<MiniArc<i32>>();
+    const _: () = is_eq::<MiniArc<i32>>();
+}
+
+#[cfg(all(test, moka_loom))]
+mod loom_tests {
+    use super::*;
+
+    #[test]
+    fn test_drop() {
+        use loom::sync::atomic::{AtomicUsize, Ordering::Relaxed};
+
+        struct DetectDrop(loom::sync::Arc<AtomicUsize>);
+
+        impl Drop for DetectDrop {
+            fn drop(&mut self) {
+                self.0.fetch_add(1, Relaxed);
+            }
+        }
+
+        loom::model(move || {
+            let num_drops = loom::sync::Arc::new(AtomicUsize::new(0));
+
+            // Create two MiniArcs sharing an object containing a string
+            // and a DetectDrop, to detect when it is dropped.
+            let x = MiniArc::new(("hello", DetectDrop(loom::sync::Arc::clone(&num_drops))));
+            let y = x.clone();
+
+            // Send x to another thread, and use it there.
+            let t = loom::thread::spawn(move || {
+                assert_eq!(x.0, "hello");
+            });
+
+            // In parallel, y should still be usable here.
+            assert_eq!(y.0, "hello");
+            assert!(MiniArc::count(&y) >= 1);
+
+            // Wait for the thread to finish.
+            t.join().unwrap();
+
+            // One MiniArc, x, should be dropped by now.
+            // We still have y, so the object should not have been dropped yet.
+            assert_eq!(num_drops.load(Relaxed), 0);
+            assert_eq!(MiniArc::count(&y), 1);
+
+            // Drop the remaining `MiniArc`.
+            drop(y);
+
+            // Now that `y` is dropped too,
+            // the object should have been dropped.
+            assert_eq!(num_drops.load(Relaxed), 1);
+        });
+    }
+}
diff --git a/src/common/concurrent/deques.rs b/src/common/concurrent/deques.rs
index 8a14c7e4..94d235bb 100644
--- a/src/common/concurrent/deques.rs
+++ b/src/common/concurrent/deques.rs
@@ -1,10 +1,9 @@
-use super::{KeyHashDate, ValueEntry};
+use super::{arc::MiniArc, KeyHashDate, ValueEntry};
 use crate::common::{
     deque::{DeqNode, Deque},
     CacheRegion,
 };
 
-use moka_arc::MiniArc;
 use std::ptr::NonNull;
 use tagptr::TagNonNull;
 
diff --git a/src/common/timer_wheel.rs b/src/common/timer_wheel.rs
index 9598bbbf..0b74b9df 100644
--- a/src/common/timer_wheel.rs
+++ b/src/common/timer_wheel.rs
@@ -14,12 +14,11 @@
 use std::{ptr::NonNull, time::Duration};
 
 use super::{
-    concurrent::{entry_info::EntryInfo, DeqNodes},
+    concurrent::{arc::MiniArc, entry_info::EntryInfo, DeqNodes},
     deque::{DeqNode, Deque},
     time::{CheckedTimeOps, Instant},
 };
 
-use moka_arc::MiniArc;
 use parking_lot::Mutex;
 
 const BUCKET_COUNTS: &[u64] = &[
@@ -560,12 +559,10 @@ mod tests {
 
     use super::{TimerEvent, TimerWheel, SPANS};
     use crate::common::{
-        concurrent::{entry_info::EntryInfo, KeyHash},
+        concurrent::{arc::MiniArc, entry_info::EntryInfo, KeyHash},
         time::{CheckedTimeOps, Clock, Instant, Mock},
     };
 
-    use moka_arc::MiniArc;
-
     #[test]
     fn test_bucket_indices() {
         fn bi(timer: &TimerWheel<()>, now: Instant, dur: Duration) -> (usize, usize) {
diff --git a/src/future/base_cache.rs b/src/future/base_cache.rs
index d6cc3ccc..6815004e 100644
--- a/src/future/base_cache.rs
+++ b/src/future/base_cache.rs
@@ -10,6 +10,7 @@ use crate::{
     common::{
         self,
         concurrent::{
+            arc::MiniArc,
             atomic_time::AtomicInstant,
             constants::{
                 READ_LOG_CH_SIZE, READ_LOG_FLUSH_POINT, WRITE_LOG_CH_SIZE, WRITE_LOG_FLUSH_POINT,
@@ -39,7 +40,6 @@ use async_lock::{Mutex, MutexGuard, RwLock};
 use crossbeam_channel::{Receiver, Sender, TrySendError};
 use crossbeam_utils::atomic::AtomicCell;
 use futures_util::future::BoxFuture;
-use moka_arc::MiniArc;
 use parking_lot::RwLock as SyncRwLock;
 use smallvec::SmallVec;
 use std::{
diff --git a/src/future/invalidator.rs b/src/future/invalidator.rs
index 7bc4eb68..5c48cd12 100644
--- a/src/future/invalidator.rs
+++ b/src/future/invalidator.rs
@@ -1,7 +1,7 @@
 use super::{base_cache::Inner, PredicateId, PredicateIdStr};
 use crate::{
     common::{
-        concurrent::{AccessTime, KvEntry, ValueEntry},
+        concurrent::{arc::MiniArc, AccessTime, KvEntry, ValueEntry},
         time::Instant,
     },
     notification::RemovalCause,
@@ -9,7 +9,6 @@ use crate::{
 };
 
 use async_lock::{Mutex, MutexGuard};
-use moka_arc::MiniArc;
 use std::{
     hash::{BuildHasher, Hash},
     sync::{
diff --git a/src/future/key_lock.rs b/src/future/key_lock.rs
index 6449aa10..08f73b8f 100644
--- a/src/future/key_lock.rs
+++ b/src/future/key_lock.rs
@@ -3,10 +3,9 @@ use std::{
     sync::Arc,
 };
 
-use crate::cht::SegmentedHashMap;
+use crate::{cht::SegmentedHashMap, common::concurrent::arc::MiniArc};
 
 use async_lock::{Mutex, MutexGuard};
-use moka_arc::MiniArc;
 
 const LOCK_MAP_NUM_SEGMENTS: usize = 64;
 
diff --git a/src/future/value_initializer.rs b/src/future/value_initializer.rs
index c56eeacc..fb9e87be 100644
--- a/src/future/value_initializer.rs
+++ b/src/future/value_initializer.rs
@@ -1,6 +1,5 @@
 use async_lock::{RwLock, RwLockWriteGuard};
 use futures_util::FutureExt;
-use moka_arc::MiniArc;
 use std::{
     any::{Any, TypeId},
     fmt,
@@ -11,6 +10,7 @@ use std::{
 };
 
 use crate::{
+    common::concurrent::arc::MiniArc,
     ops::compute::{CompResult, Op},
     Entry,
 };
diff --git a/src/sync/value_initializer.rs b/src/sync/value_initializer.rs
index 66034972..cf29b14a 100644
--- a/src/sync/value_initializer.rs
+++ b/src/sync/value_initializer.rs
@@ -1,4 +1,3 @@
-use moka_arc::MiniArc;
 use parking_lot::RwLock;
 use std::{
     any::{Any, TypeId},
@@ -8,6 +7,7 @@ use std::{
 };
 
 use crate::{
+    common::concurrent::arc::MiniArc,
     ops::compute::{CompResult, Op},
     Entry,
 };
diff --git a/src/sync_base/base_cache.rs b/src/sync_base/base_cache.rs
index 1d3a6281..4f8dee7a 100644
--- a/src/sync_base/base_cache.rs
+++ b/src/sync_base/base_cache.rs
@@ -9,6 +9,7 @@ use crate::{
     common::{
         self,
         concurrent::{
+            arc::MiniArc,
             atomic_time::AtomicInstant,
             constants::{
                 READ_LOG_CH_SIZE, READ_LOG_FLUSH_POINT, WRITE_LOG_CH_SIZE, WRITE_LOG_FLUSH_POINT,
@@ -32,7 +33,6 @@ use crate::{
 
 use crossbeam_channel::{Receiver, Sender, TrySendError};
 use crossbeam_utils::atomic::AtomicCell;
-use moka_arc::MiniArc;
 use parking_lot::{Mutex, RwLock};
 use smallvec::SmallVec;
 use std::{
diff --git a/src/sync_base/invalidator.rs b/src/sync_base/invalidator.rs
index f51435a6..f5ff7dc4 100644
--- a/src/sync_base/invalidator.rs
+++ b/src/sync_base/invalidator.rs
@@ -1,14 +1,13 @@
 use super::{base_cache::Inner, PredicateId, PredicateIdStr};
 use crate::{
     common::{
-        concurrent::{AccessTime, KvEntry, ValueEntry},
+        concurrent::{arc::MiniArc, AccessTime, KvEntry, ValueEntry},
         time::Instant,
     },
     notification::RemovalCause,
     PredicateError,
 };
 
-use moka_arc::MiniArc;
 use parking_lot::{Mutex, MutexGuard};
 use std::{
     hash::{BuildHasher, Hash},
diff --git a/src/sync_base/key_lock.rs b/src/sync_base/key_lock.rs
index c58c6eed..ae470401 100644
--- a/src/sync_base/key_lock.rs
+++ b/src/sync_base/key_lock.rs
@@ -3,9 +3,8 @@ use std::{
     sync::Arc,
 };
 
-use crate::cht::SegmentedHashMap;
+use crate::{cht::SegmentedHashMap, common::concurrent::arc::MiniArc};
 
-use moka_arc::MiniArc;
 use parking_lot::{Mutex, MutexGuard};
 
 const LOCK_MAP_NUM_SEGMENTS: usize = 64;