Fix deadlock in t5375 and similar tests.

See t5375.scala for details.

1 files changed, 11 insertions, 0 deletions

diff --git a/tests/run/t5375.scala b/tests/run/t5375.scala
index 8c2c06fde..d8413c1a3 100644
--- a/tests/run/t5375.scala
+++ b/tests/run/t5375.scala
@@ -1,3 +1,14 @@
+/** Hello fellow compiler developer.
+    if you are wondering why does test suite hang on this test
+    then it's likely that the lambda inside map has been compiled into static method
+    unfotrunatelly, as it is executed inside static object initializer,
+    it is executed inside class-loader, in a synchronized block that is not source defined.
+    
+    If the lambda will be static Test$#foo, calling it through a different thread would require grabbing the
+    lock inside classloader. Unlike if it not static and is called through This(Test).foo, no lock is grabbed.
+    
+    @DarkDimius  
+*/  
 object Test extends dotty.runtime.LegacyApp {
   val foos = (1 to 1000).toSeq
   try