From 22271cc84969a85dbeb93beb3686bfe1cdfcaf3a Mon Sep 17 00:00:00 2001
From: Daniel Spiewak <djspiewak@gmail.com>
Date: Fri, 3 Jan 2025 09:17:43 -0600
Subject: [PATCH] Split `epoll_wait` into blocking and non-blocking variants

---
 .../cats/effect/unsafe/EpollSystem.scala      | 21 +++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/core/native/src/main/scala/cats/effect/unsafe/EpollSystem.scala b/core/native/src/main/scala/cats/effect/unsafe/EpollSystem.scala
index fc8ce7880d..f35bf7a6c1 100644
--- a/core/native/src/main/scala/cats/effect/unsafe/EpollSystem.scala
+++ b/core/native/src/main/scala/cats/effect/unsafe/EpollSystem.scala
@@ -217,7 +217,11 @@ object EpollSystem extends PollingSystem {
       @tailrec
       def processEvents(timeout: Int): Unit = {
 
-        val triggeredEvents = epoll_wait(epfd, events, MaxEvents, timeout)
+        val triggeredEvents =
+          if (timeout >= 0)
+            awaiting.epoll_wait(epfd, events, MaxEvents, timeout)
+          else
+            immediate.epoll_wait(epfd, events, MaxEvents, timeout)
 
         if (triggeredEvents >= 0) {
           polled = true
@@ -317,9 +321,18 @@ object EpollSystem extends PollingSystem {
 
     def epoll_ctl(epfd: Int, op: Int, fd: Int, event: Ptr[epoll_event]): Int = extern
 
-    @blocking // TODO: create non-@blocking version
-    def epoll_wait(epfd: Int, events: Ptr[epoll_event], maxevents: Int, timeout: Int): Int =
-      extern
+    @extern
+    object awaiting {
+      @blocking
+      def epoll_wait(epfd: Int, events: Ptr[epoll_event], maxevents: Int, timeout: Int): Int =
+        extern
+    }
+
+    @extern
+    object immediate {
+      def epoll_wait(epfd: Int, events: Ptr[epoll_event], maxevents: Int, timeout: Int): Int =
+        extern
+    }
   }
 
   private object epollImplicits {