Document refcounting

src/core/lib/iomgr/workqueue.h

@@ -54,12 +54,20 @@
    This has *already* been removed in a future commit. */
 void grpc_workqueue_flush(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue);
 
+/* Reference counting functions. Use the macro's always
+   (GRPC_WORKQUEUE_{REF,UNREF}).
+
+   Pass in a descriptive reason string for reffing/unreffing as the last
+   argument to each macro. When GRPC_WORKQUEUE_REFCOUNT_DEBUG is defined, that
+   string will be printed alongside the refcount. When it is not defined, the
+   string will be discarded at compilation time. */
+
 //#define GRPC_WORKQUEUE_REFCOUNT_DEBUG
 #ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
 #define GRPC_WORKQUEUE_REF(p, r) \
   (grpc_workqueue_ref((p), __FILE__, __LINE__, (r)), (p))
-#define GRPC_WORKQUEUE_UNREF(cl, p, r) \
-  grpc_workqueue_unref((cl), (p), __FILE__, __LINE__, (r))
+#define GRPC_WORKQUEUE_UNREF(exec_ctx, p, r) \
+  grpc_workqueue_unref((exec_ctx), (p), __FILE__, __LINE__, (r))
 void grpc_workqueue_ref(grpc_workqueue *workqueue, const char *file, int line,
                         const char *reason);
 void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,