Update

vendor/tailscale.com/util/eventbus/client.go

@@ -1,4 +1,4 @@
-// Copyright (c) Tailscale Inc & AUTHORS
+// Copyright (c) Tailscale Inc & contributors
 // SPDX-License-Identifier: BSD-3-Clause
 
 package eventbus
@@ -146,7 +146,10 @@ func Subscribe[T any](c *Client) *Subscriber[T] {
 
 	r := c.subscribeStateLocked()
 	s := newSubscriber[T](r, logfForCaller(c.logger()))
-	r.addSubscriber(s)
+	// Register the non-generic core with the bus rather than the typed facade,
+	// mirroring SubscribeFunc and Publish: this keeps the bus's outputs map
+	// and subscriber-interface itab out of per-T cost.
+	r.addSubscriber(s.core)
 	return s
 }
 
@@ -169,7 +172,11 @@ func SubscribeFunc[T any](c *Client, f func(T)) *SubscriberFunc[T] {
 
 	r := c.subscribeStateLocked()
 	s := newSubscriberFunc[T](r, f, logfForCaller(c.logger()))
-	r.addSubscriber(s)
+	// Register the non-generic core, not the typed facade. Doing
+	// so means the bus's outputs map and the subscriber interface
+	// itab are not parameterized by T, eliminating per-T itab and
+	// dictionary cost.
+	r.addSubscriber(s.core)
 	return s
 }
 
@@ -177,6 +184,11 @@ func SubscribeFunc[T any](c *Client, f func(T)) *SubscriberFunc[T] {
 // It panics if c is closed.
 func Publish[T any](c *Client) *Publisher[T] {
 	p := newPublisher[T](c)
-	c.addPublisher(p)
+	// Register the non-generic core with the client so the
+	// per-Client publisher set, the publisher interface itab, and
+	// the publisher equality function are not parameterized by T.
+	// This eliminates per-T itab/dictionary/eq cost for every new
+	// event type passed through Publish[T].
+	c.addPublisher(p.core)
 	return p
 }