diff options
| -rw-r--r-- | src/librustc_trans/back/write.rs | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/src/librustc_trans/back/write.rs b/src/librustc_trans/back/write.rs index 0d5fe6c0ae9..94cae37761f 100644 --- a/src/librustc_trans/back/write.rs +++ b/src/librustc_trans/back/write.rs @@ -1356,6 +1356,16 @@ fn start_executing_work(sess: &Session, maybe_start_llvm_timer(&item, &mut llvm_start_time); main_thread_worker_state = MainThreadWorkerState::LLVMing; spawn_work(cgcx, item); + } else { + // There is no unstarted work, so let the main thread + // take over for a running worker. Otherwise the + // implicit token would just go to waste. + // We reduce the `running` counter by one. The + // `tokens.truncate()` below will take care of + // giving the Token back. + debug_assert!(running > 0); + running -= 1; + main_thread_worker_state = MainThreadWorkerState::LLVMing; } } MainThreadWorkerState::Translating => { |