perf(core): use quanta::Instant for hot-path timing (#2384)

Replace std::time::Instant with quanta::Instant on per-packet, per-RPC,
and per-session paths. TSC-based, ~5ns vs ~25ns per now() call.

Reuses the existing `extern crate self as hotpath` alias so
`use hotpath::instant::Instant;` resolves to the same quanta type with
or without the hotpath feature. Leaves tokio::time::Instant and
smoltcp::time::Instant untouched.

easytier/src/peers/acl_filter.rs

@@ -1,6 +1,5 @@
 use std::net::{Ipv4Addr, Ipv6Addr};
 use std::sync::atomic::Ordering;
-use std::time::Instant;
 use std::{
     net::IpAddr,
     sync::{Arc, atomic::AtomicBool},
@@ -8,6 +7,7 @@ use std::{
 
 use arc_swap::ArcSwap;
 use dashmap::DashMap;
+use hotpath::instant::Instant;
 use pnet::packet::ipv6::Ipv6Packet;
 use pnet::packet::{
     Packet as _, ip::IpNextHeaderProtocols, ipv4::Ipv4Packet, tcp::TcpPacket, udp::UdpPacket,
@@ -402,9 +402,10 @@ mod tests {
     use std::{
         net::{IpAddr, Ipv4Addr, Ipv6Addr},
         sync::Arc,
-        time::Instant,
     };
 
+    use hotpath::instant::Instant;
+
     use crate::{
         common::acl_processor::PacketInfo,
         proto::acl::{Acl, ChainType, Protocol},

easytier/src/peers/peer_conn_ping.rs

@@ -6,6 +6,7 @@ use std::{
     time::Duration,
 };
 
+use hotpath::instant::Instant;
 use rand::{Rng, thread_rng};
 use tokio::{
     sync::broadcast,
@@ -177,7 +178,7 @@ impl PeerConnPinger {
         sink.send(req).await?;
         control_metrics.record_tx(req_len);
 
-        let now = std::time::Instant::now();
+        let now = Instant::now();
         // wait until we get a pong packet in ctrl_resp_receiver
         let resp = timeout(Duration::from_secs(2), async {
             loop {

easytier/src/peers/peer_manager.rs

@@ -2,12 +2,13 @@ use anyhow::Context;
 use async_trait::async_trait;
 use cidr::{Ipv4Cidr, Ipv6Cidr};
 use dashmap::DashMap;
+use hotpath::instant::Instant;
 use std::collections::BTreeSet;
 use std::{
     fmt::Debug,
     net::{IpAddr, Ipv4Addr, Ipv6Addr},
     sync::{Arc, Weak, atomic::AtomicBool},
-    time::{Duration, Instant, SystemTime},
+    time::{Duration, SystemTime},
 };
 
 #[cfg(feature = "hotpath")]
@@ -2204,12 +2205,9 @@ impl PeerManager {
 #[cfg(test)]
 mod tests {
     use base64::Engine;
-    use std::{
-        collections::HashMap,
-        fmt::Debug,
-        sync::Arc,
-        time::{Duration, Instant},
-    };
+    use std::{collections::HashMap, fmt::Debug, sync::Arc, time::Duration};
+
+    use hotpath::instant::Instant;
 
     use crate::{
         common::{

easytier/src/peers/peer_ospf_route.rs

@@ -6,13 +6,14 @@ use std::{
         Arc, Weak,
         atomic::{AtomicBool, AtomicU32, Ordering},
     },
-    time::{Duration, Instant, SystemTime},
+    time::{Duration, SystemTime},
 };
 
 use arc_swap::ArcSwap;
 use cidr::{IpCidr, Ipv4Cidr, Ipv6Cidr, Ipv6Inet};
 use crossbeam::atomic::AtomicCell;
 use dashmap::DashMap;
+use hotpath::instant::Instant;
 use ordered_hash_map::OrderedHashMap;
 use parking_lot::{RwLock, lock_api::RwLockUpgradableReadGuard};
 use petgraph::{
@@ -2170,9 +2171,9 @@ struct PeerRouteServiceImpl {
     interface_peers_generation: AtomicU64,
     applied_interface_peers_generation: AtomicU64,
 
-    last_update_my_foreign_network: AtomicCell<Option<std::time::Instant>>,
+    last_update_my_foreign_network: AtomicCell<Option<Instant>>,
 
-    peer_info_last_update: AtomicCell<std::time::Instant>,
+    peer_info_last_update: AtomicCell<Instant>,
 }
 
 impl Debug for PeerRouteServiceImpl {
@@ -2239,7 +2240,7 @@ impl PeerRouteServiceImpl {
 
             last_update_my_foreign_network: AtomicCell::new(None),
 
-            peer_info_last_update: AtomicCell::new(std::time::Instant::now()),
+            peer_info_last_update: AtomicCell::new(Instant::now()),
         }
     }
 
@@ -2435,7 +2436,7 @@ impl PeerRouteServiceImpl {
         }
 
         self.last_update_my_foreign_network
-            .store(Some(std::time::Instant::now()));
+            .store(Some(Instant::now()));
 
         let foreign_networks = self
             .interface
@@ -3156,12 +3157,12 @@ impl PeerRouteServiceImpl {
             "update_peer_info_last_update, my_peer_id: {:?}, prev: {:?}, new: {:?}",
             self.my_peer_id,
             self.peer_info_last_update.load(),
-            std::time::Instant::now()
+            Instant::now()
         );
-        self.peer_info_last_update.store(std::time::Instant::now());
+        self.peer_info_last_update.store(Instant::now());
     }
 
-    fn get_peer_info_last_update(&self) -> std::time::Instant {
+    fn get_peer_info_last_update(&self) -> Instant {
         self.peer_info_last_update.load()
     }
 

easytier/src/peers/relay_peer_map.rs

@@ -1,6 +1,7 @@
-use std::{sync::Arc, time::Instant};
+use std::sync::Arc;
 
 use dashmap::DashMap;
+use hotpath::instant::Instant;
 use prost::Message;
 use snow::params::NoiseParams;
 use tokio::sync::{Mutex, OwnedMutexGuard, oneshot};

easytier/src/peers/route_trait.rs

@@ -1,6 +1,7 @@
 use cidr::Ipv6Inet;
 use cidr::{Ipv4Cidr, Ipv6Cidr};
 use dashmap::DashMap;
+use hotpath::instant::Instant;
 use std::{
     collections::BTreeSet,
     net::{Ipv4Addr, Ipv6Addr},
@@ -157,7 +158,7 @@ pub trait Route {
 
     async fn get_peer_info(&self, peer_id: PeerId) -> Option<RoutePeerInfo>;
 
-    async fn get_peer_info_last_update_time(&self) -> std::time::Instant;
+    async fn get_peer_info_last_update_time(&self) -> Instant;
 
     fn get_peer_groups(&self, peer_id: PeerId) -> Arc<Vec<String>>;
 
@@ -226,7 +227,7 @@ impl Route for MockRoute {
         panic!("mock route")
     }
 
-    async fn get_peer_info_last_update_time(&self) -> std::time::Instant {
+    async fn get_peer_info_last_update_time(&self) -> Instant {
         panic!("mock route")
     }