1 files changed, 26 insertions, 0 deletions
diff --git a/compiler/rustc_middle/src/ty/query/job.rs b/compiler/rustc_middle/src/ty/query/job.rs
new file mode 100644
index 00000000000..bd2e7747b7d
--- /dev/null
+++ b/compiler/rustc_middle/src/ty/query/job.rs
@@ -0,0 +1,26 @@
+use crate::ty::tls;
+
+use rustc_query_system::query::deadlock;
+use rustc_rayon_core as rayon_core;
+use std::thread;
+
+/// Creates a new thread and forwards information in thread locals to it.
+/// The new thread runs the deadlock handler.
+/// Must only be called when a deadlock is about to happen.
+pub unsafe fn handle_deadlock() {
+    let registry = rayon_core::Registry::current();
+
+    let context = tls::get_tlv();
+    assert!(context != 0);
+    rustc_data_structures::sync::assert_sync::<tls::ImplicitCtxt<'_, '_>>();
+    let icx: &tls::ImplicitCtxt<'_, '_> = &*(context as *const tls::ImplicitCtxt<'_, '_>);
+
+    let session_globals = rustc_span::SESSION_GLOBALS.with(|sg| sg as *const _);
+    let session_globals = &*session_globals;
+    thread::spawn(move || {
+        tls::enter_context(icx, |_| {
+            rustc_span::SESSION_GLOBALS
+                .set(session_globals, || tls::with(|tcx| deadlock(tcx, &registry)))
+        })
+    });
+}