use R_GetCCallable for execLaterNative

Author: shikokuchuo

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: nanonext
 Type: Package
 Title: NNG (Nanomsg Next Gen) Lightweight Messaging Library
-Version: 0.13.6.9013
+Version: 0.13.6.9014
 Description: R binding for NNG (Nanomsg Next Gen), a successor to ZeroMQ. NNG is
     a socket library implementing 'Scalability Protocols', a reliable,
     high-performance standard for common communications patterns including

NEWS.md

@@ -1,4 +1,4 @@
-# nanonext 0.13.6.9013 (development)
+# nanonext 0.13.6.9014 (development)
 
 #### New Features
 

src/init.c

@@ -52,6 +52,7 @@ SEXP nano_success;
 SEXP nano_unresolved;
 
 SEXP nano_precious;
+later_fun later2;
 
 static void RegisterSymbols(void) {
   nano_AioSymbol = Rf_install("aio");
@@ -195,6 +196,7 @@ static const R_ExternalMethodDef externalMethods[] = {
 void attribute_visible R_init_nanonext(DllInfo* dll) {
   RegisterSymbols();
   PreserveObjects();
+  later2 = (later_fun) R_GetCCallable("later", "execLaterNative");
   R_registerRoutines(dll, NULL, callMethods, NULL, externalMethods);
   R_useDynamicSymbols(dll, FALSE);
   R_forceSymbols(dll, TRUE);

src/later_shim.cpp

@@ -176,7 +176,8 @@ typedef struct nano_buf_s {
   size_t cur;
 } nano_buf;
 
-void later2(void (*func)(void *), void *data, double secs);
+typedef void (*later_fun)(void (*func)(void *), void *data, double secs);
+extern later_fun later2;
 
 SEXP nano_PreserveObject(SEXP);
 void nano_ReleaseObject(SEXP);