Merge pull request #3611 from armanbilge/issue/3585

Treat non-positive sleep durations as `cede`s
typelevel · May 11, 2023 · 9236fb4 · 9236fb4
2 parents 56fb90f + b0f7f6a
commit 9236fb4
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Showing 2 changed files with 19 additions and 12 deletions.
diff --git a/core/shared/src/main/scala/cats/effect/IOFiber.scala b/core/shared/src/main/scala/cats/effect/IOFiber.scala
@@ -909,21 +909,24 @@ private final class IOFiber[A](
 
         case 19 =>
           val cur = cur0.asInstanceOf[Sleep]
+          val delay = cur.delay
 
-          val next = IO.async[Unit] { cb =>
-            IO {
-              val scheduler = runtime.scheduler
-              val delay = cur.delay
+          val next =
+            if (delay.length > 0)
+              IO.async[Unit] { cb =>
+                IO {
+                  val scheduler = runtime.scheduler
 
-              val cancel =
-                if (scheduler.isInstanceOf[WorkStealingThreadPool])
-                  scheduler.asInstanceOf[WorkStealingThreadPool].sleepInternal(delay, cb)
-                else
-                  scheduler.sleep(delay, () => cb(RightUnit))
+                  val cancel =
+                    if (scheduler.isInstanceOf[WorkStealingThreadPool])
+                      scheduler.asInstanceOf[WorkStealingThreadPool].sleepInternal(delay, cb)
+                    else
+                      scheduler.sleep(delay, () => cb(RightUnit))
 
-              Some(IO(cancel.run()))
-            }
-          }
+                  Some(IO(cancel.run()))
+                }
+              }
+            else IO.cede
 
           runLoop(next, nextCancelation, nextAutoCede)
 

diff --git a/tests/shared/src/test/scala/cats/effect/IOSpec.scala b/tests/shared/src/test/scala/cats/effect/IOSpec.scala
@@ -1734,6 +1734,10 @@ class IOSpec extends BaseSpec with Discipline with IOPlatformSpecification {
         affected must beTrue
       }
 
+      "round up negative sleeps" in real {
+        IO.sleep(-1.seconds).as(ok)
+      }
+
       "timeout" should {
         "succeed" in real {
           val op = IO.pure(true).timeout(100.millis)