rt: coalesce thread-locals used by the runtime (#1925)

Previously, thread-locals used by the various drivers were situated
with the driver code. This resulted in state being spread out and many
thread-locals being required to run a runtime.

This PR coalesces the thread-locals into a single struct.

1 files changed, 3 insertions, 1 deletions

diff --git a/tokio/src/task/spawn.rs b/tokio/src/task/spawn.rs
index 4d18ee23..c4589308 100644
--- a/tokio/src/task/spawn.rs
+++ b/tokio/src/task/spawn.rs
@@ -123,6 +123,8 @@ doc_rt_core! {
         T: Future + Send + 'static,
         T::Output: Send + 'static,
     {
-        runtime::spawn(task)
+        let spawn_handle = runtime::context::ThreadContext::spawn_handle()
+        .expect("must be called from the context of Tokio runtime configured with either `basic_scheduler` or `threaded_scheduler`");
+        spawn_handle.spawn(task)
     }
 }