Fix ASAN/TSAN failures
- trace system is now thread safe when run with TSAN
- fix a race in client_auth_filter.c
- allow timer manager to run in single threaded mode for fuzzers
diff --git a/src/core/lib/iomgr/iomgr.h b/src/core/lib/iomgr/iomgr.h
index 245a1e0..6e2e023 100644
--- a/src/core/lib/iomgr/iomgr.h
+++ b/src/core/lib/iomgr/iomgr.h
@@ -40,6 +40,9 @@
/** Initializes the iomgr. */
void grpc_iomgr_init(void);
+/** Starts any background threads for iomgr. */
+void grpc_iomgr_start(void);
+
/** Signals the intention to shutdown the iomgr. Expects to be able to flush
* exec_ctx. */
void grpc_iomgr_shutdown(grpc_exec_ctx *exec_ctx);