make TBB opt-in for packages on windows

jjallaire · jjallaire · commit 2394425533a7 · 2015-03-05T09:30:24.000-05:00
diff --git a/R/build.R b/R/build.R
@@ -16,7 +16,10 @@ RcppParallelLibs <- function() {
 # Inline plugin used by sourceCpp to link to the TBB library
 inlineCxxPlugin <- function() {
    list(
-      env = list(PKG_LIBS = tbbLdFlags()),
+      env = list(
+         PKG_CXXFLAGS = "-DRCPP_PARALLEL_USE_TBB=1",
+         PKG_LIBS = tbbLdFlags()
+      ),
       includes = "#include <RcppParallel.h>",
       LinkingTo = "RcppParallel",
       body = function( x ) x,
diff --git a/README.md b/README.md
@@ -49,9 +49,12 @@ importFrom(RcppParallel, RcppParallelLibs)
 ```
 
 Finally, for Windows builds you'll need the following in **src\\Makevars.win**
-to ensure that your package can link against the TBB DLL:
+to ensure that your package can use TBB (if you don't do
+this the TinyThread fallback implementation will be used):
+
+```make
+PKG_CXXFLAGS += -DRCPP_PARALLEL_USE_TBB=1
 
-```makefile
 PKG_LIBS += $(shell "${R_HOME}/bin${R_ARCH_BIN}/Rscript.exe" \
               -e "RcppParallel::RcppParallelLibs()")
 ```
diff --git a/inst/include/RcppParallel.h b/inst/include/RcppParallel.h
@@ -6,8 +6,11 @@
 #include "RcppParallel/TinyThread.h"
 
 // Use TBB only where it's known to compile and work correctly
+// (NOTE: Windows TBB is temporarily opt-in for packages for 
+// compatibility with CRAN packages not previously configured
+// to link to TBB in Makevars.win)
 #ifndef RCPP_PARALLEL_USE_TBB
-#if defined(_WIN32) || defined(__APPLE__) || defined(__gnu_linux__)
+#if defined(__APPLE__) || defined(__gnu_linux__)
 #define RCPP_PARALLEL_USE_TBB 1
 #include "RcppParallel/TBB.h"
 #else
diff --git a/src/options.cpp b/src/options.cpp
@@ -49,6 +49,10 @@ extern "C" SEXP defaultNumThreads() {
 
 #include <tthread/tinythread.h>
 
+extern "C" SEXP setThreadOptions(SEXP numThreadsSEXP, SEXP stackSizeSEXP) {
+   return R_NilValue;
+}
+
 extern "C" SEXP defaultNumThreads() {
    SEXP threadsSEXP = Rf_allocVector(INTSXP, 1);
    INTEGER(threadsSEXP)[0] = tthread::thread::hardware_concurrency();
