From 141adeb4933bf3ffe1d4a69f51f6055765fdae86 Mon Sep 17 00:00:00 2001
From: Mohsen Zohrevandi <mohsen.zohrevandi@fortanix.com>
Date: Tue, 21 Jul 2020 11:08:37 -0700
Subject: [PATCH] Fix sync_once_cell_does_not_leak_partially_constructed_boxes

Spinning multiple threads in this test causes a deadlock in
SGX where thread scheduling is not preemptive.
---
 src/libstd/lazy.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/libstd/lazy.rs b/src/libstd/lazy.rs
index 86e1cfae582e8..1705a4f77c555 100644
--- a/src/libstd/lazy.rs
+++ b/src/libstd/lazy.rs
@@ -827,6 +827,8 @@ mod tests {
                         tx.send(msg).unwrap();
                         break;
                     }
+                    #[cfg(target_env = "sgx")]
+                    crate::thread::yield_now();
                 }
             });
         }