remove deadlock detection

Author: zetanumbers

Cargo.lock

@@ -4330,7 +4330,6 @@ version = "0.0.0"
 dependencies = [
  "hashbrown",
  "parking_lot",
- "rustc-rayon-core",
  "rustc_abi",
  "rustc_ast",
  "rustc_attr_data_structures",

compiler/rustc_interface/src/util.rs

@@ -19,7 +19,7 @@ use rustc_session::{EarlyDiagCtxt, Session, filesearch};
 use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::edition::Edition;
 use rustc_span::source_map::SourceMapInputs;
-use rustc_span::{SessionGlobals, Symbol, sym};
+use rustc_span::{Symbol, sym};
 use rustc_target::spec::Target;
 use tracing::info;
 
@@ -175,13 +175,7 @@ pub(crate) fn run_in_thread_pool_with_globals<
     sm_inputs: SourceMapInputs,
     f: F,
 ) -> R {
-    use std::process;
-
-    use rustc_data_structures::defer;
     use rustc_data_structures::sync::FromDyn;
-    use rustc_middle::ty::tls;
-    use rustc_query_impl::QueryCtxt;
-    use rustc_query_system::query::{QueryContext, break_query_cycles};
 
     let thread_stack_size = init_stack_size(thread_builder_diag);
 
@@ -203,7 +197,6 @@ pub(crate) fn run_in_thread_pool_with_globals<
     }
 
     let current_gcx = FromDyn::from(CurrentGcx::new());
-    let current_gcx2 = current_gcx.clone();
 
     let proxy = Proxy::new();
 
@@ -214,46 +207,6 @@ pub(crate) fn run_in_thread_pool_with_globals<
         .acquire_thread_handler(move || proxy_.acquire_thread())
         .release_thread_handler(move || proxy__.release_thread())
         .num_threads(threads)
-        .deadlock_handler(move || {
-            // On deadlock, creates a new thread and forwards information in thread
-            // locals to it. The new thread runs the deadlock handler.
-
-            let current_gcx2 = current_gcx2.clone();
-            let registry = rayon_core::Registry::current();
-            let session_globals = rustc_span::with_session_globals(|session_globals| {
-                session_globals as *const SessionGlobals as usize
-            });
-            thread::Builder::new()
-                .name("rustc query cycle handler".to_string())
-                .spawn(move || {
-                    let on_panic = defer(|| {
-                        eprintln!("internal compiler error: query cycle handler thread panicked, aborting process");
-                        // We need to abort here as we failed to resolve the deadlock,
-                        // otherwise the compiler could just hang,
-                        process::abort();
-                    });
-
-                    // Get a `GlobalCtxt` reference from `CurrentGcx` as we cannot rely on having a
-                    // `TyCtxt` TLS reference here.
-                    current_gcx2.access(|gcx| {
-                        tls::enter_context(&tls::ImplicitCtxt::new(gcx), || {
-                            tls::with(|tcx| {
-                                // Accessing session globals is sound as they outlive `GlobalCtxt`.
-                                // They are needed to hash query keys containing spans or symbols.
-                                let query_map = rustc_span::set_session_globals_then(unsafe { &*(session_globals as *const SessionGlobals) }, || {
-                                    // Ensure there was no errors collecting all active jobs.
-                                    // We need the complete map to ensure we find a cycle to break.
-                                    QueryCtxt::new(tcx).collect_active_jobs().ok().expect("failed to collect active queries in deadlock handler")
-                                });
-                                break_query_cycles(query_map, &registry);
-                            })
-                        })
-                    });
-
-                    on_panic.disable();
-                })
-                .unwrap();
-        })
         .stack_size(thread_stack_size);
 
     // We create the session globals on the main thread, then create the thread

compiler/rustc_query_system/Cargo.toml

@@ -6,7 +6,6 @@ edition = "2024"
 [dependencies]
 # tidy-alphabetical-start
 parking_lot = "0.12"
-rustc-rayon-core = { version = "0.5.0" }
 rustc_abi = { path = "../rustc_abi" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_attr_data_structures = { path = "../rustc_attr_data_structures" }