fix race condition in linuxWaitFd

1 files changed, 4 insertions, 5 deletions

diff --git a/lib/std/event/loop.zig b/lib/std/event/loop.zig
index 492b7c1758..912f99e961 100644
--- a/lib/std/event/loop.zig
+++ b/lib/std/event/loop.zig
@@ -440,13 +440,11 @@ pub const Loop = struct {
                 .overlapped = ResumeNode.overlapped_init,
             },
         };
-        var need_to_delete = false;
+        var need_to_delete = true;
         defer if (need_to_delete) self.linuxRemoveFd(fd);
 
         suspend {
-            if (self.linuxAddFd(fd, &resume_node.base, flags)) |_| {
-                need_to_delete = true;
-            } else |err| switch (err) {
+            self.linuxAddFd(fd, &resume_node.base, flags) catch |err| switch (err) {
                 error.FileDescriptorNotRegistered => unreachable,
                 error.OperationCausesCircularLoop => unreachable,
                 error.FileDescriptorIncompatibleWithEpoll => unreachable,
@@ -456,6 +454,7 @@ pub const Loop = struct {
                 error.UserResourceLimitReached,
                 error.Unexpected,
                 => {
+                    need_to_delete = false;
                     // Fall back to a blocking poll(). Ideally this codepath is never hit, since
                     // epoll should be just fine. But this is better than incorrect behavior.
                     var poll_flags: i16 = 0;
@@ -479,7 +478,7 @@ pub const Loop = struct {
                     };
                     resume @frame();
                 },
-            }
+            };
         }
     }