incorporated feedback from AM

Author: fogus

src/main/clojure/clojure/core/async.clj

@@ -85,8 +85,9 @@ IOC and vthread code.
 
 (alias 'core 'clojure.core)
 
-(def go-becomes-ioc? (not (or (dispatch/vthreads-available-and-allowed?)
-                              (dispatch/target-vthreads?))))
+(def ^:private go-becomes-ioc?
+  (not (or (dispatch/vthreads-available-and-allowed?)
+           (dispatch/target-vthreads?))))
 
 (set! *warn-on-reflection* false)
 
@@ -515,6 +516,25 @@ IOC and vthread code.
   (let [ret (impl/take! port (fn-handler nop false))]
     (when ret @ret)))
 
+(defn- dynamic-require [& args]
+  (let [p (promise)
+        n *ns*
+        ll @#'clojure.core/*loaded-libs*]
+    (.start
+     (Thread.
+      (fn []
+        (try
+          (let [result (binding [*ns* n
+                                 clojure.core/*loaded-libs* ll]
+                         (apply require args))]
+            (deliver p result))
+          (catch Throwable t
+            (deliver p t))))))
+    (let [res @p]
+      (if res
+        (throw res)
+        res))))
+
 (defmacro go
   "Asynchronously executes the body, returning immediately to the
   calling thread. Additionally, any visible calls to <!, >! and alt!/alts!
@@ -531,11 +551,11 @@ IOC and vthread code.
   Returns a channel which will receive the result of the body when
   completed"
   [& body]
-  (let [rt-check-step (when clojure.core/*compile-files*
-                        `(dispatch/ensure-runtime-vthreads!))]
-    (if go-becomes-ioc?
-      (do (clojure.core.async.impl.dispatch/dynamic-require 'clojure.core.async.impl.go)
-          ((find-var 'clojure.core.async.impl.go/go-impl) &env body))
+  (if go-becomes-ioc?
+    (do (dynamic-require 'clojure.core.async.impl.go)
+        ((find-var 'clojure.core.async.impl.go/go-impl) &env body))
+    (let [rt-check-step (when clojure.core/*compile-files*
+                          `(dispatch/ensure-runtime-vthreads!))]
       `(do ~rt-check-step
            (thread-call (^:once fn* [] ~@body) :io)))))
 

src/main/clojure/clojure/core/async/impl/dispatch.clj

@@ -72,15 +72,15 @@
   [workload]
   (Executors/newCachedThreadPool (counted-thread-factory (str "async-" (name workload) "-%d") true)))
 
-(def virtual-threads-available?
+(def ^:private virtual-threads-available?
   (delay
     (try
       (Class/forName "java.lang.Thread$Builder$OfVirtual")
       true
       (catch ClassNotFoundException _
         false))))
 
-(defn vthreads-directive
+(defn- vthreads-directive
   "Retrieves the value of the sysprop clojure.core.async.vthreads."
   []
   (System/getProperty "clojure.core.async.vthreads"))
@@ -89,32 +89,14 @@
   (= (vthreads-directive) "target"))
 
 (defn vthreads-available-and-allowed? []
-  (and (not= (vthreads-directive) "avoid")
-       @virtual-threads-available?))
+  (and @virtual-threads-available?
+       (not= (vthreads-directive) "avoid")))
 
 (defn ensure-runtime-vthreads! []
   (when (not (vthreads-available-and-allowed?))
     (throw (ex-info "Code compiled to target virtual threads, but is running on a JVM without vthread support."
                     {:runtime-jvm-version (System/getProperty "java.version")}))))
 
-(defn dynamic-require [& args]
-  (let [p (promise)
-        n *ns*
-        ll @#'clojure.core/*loaded-libs*]
-    (.start
-     (Thread.
-      (fn []
-        (deliver p
-                 (binding [*ns* n
-                           clojure.core/*loaded-libs* ll]
-                   (try
-                     (apply require args)
-                     (catch Throwable t t)))))))
-    (let [res @p]
-      (if res
-        (throw res)
-        res))))
-
 (defn- make-io-executor
   []
   (if (vthreads-available-and-allowed?)

src/test/clojure/clojure/core/async_test.clj

@@ -193,15 +193,7 @@
       (io-thread (>!! c2 (clojure.string/upper-case (<!! c1))))
       (io-thread (>!! c3 (clojure.string/reverse (<!! c2))))
       (>!! c1 "loop")
-      (is (= "POOL" (<!! c3)))))
-  #_(testing "io-thread parking op should fail"
-    (let [c1 (chan)]
-      (io-thread
-       (try
-         (>! c1 :no)
-         (catch AssertionError _
-           (>!! c1 :yes))))
-      (is (= :yes (<!! c1))))))
+      (is (= "POOL" (<!! c3))))))
 
 (deftest ops-tests
   (testing "map<"