Allow forcing value for FOLLY_FUTURE_USING_FIBER in folly-config.h

Summary:
Let clients choose whether to use fibers or not, but default
to the same autodetected setting as prior logic.

Reviewed By: yfeldblum

Differential Revision: D5585605

fbshipit-source-id: 9a4bf9f9bc23b4e15601f30c40602f21798c9685

diff --git a/folly/futures/Future-inl.h b/folly/futures/Future-inl.h
index 6ba9b241e942f40fdd6fabe82f70e5008cc10f03..e682dcab47c5f8f5ce5a13eaf6e12a9e584cd11c 100644 (file)
--- a/folly/futures/Future-inl.h
+++ b/folly/futures/Future-inl.h
@@ -28,12 +28,14 @@
 #include <folly/futures/Timekeeper.h>
 #include <folly/futures/detail/Core.h>
 
+#ifndef FOLLY_FUTURE_USING_FIBER
 #if FOLLY_MOBILE || defined(__APPLE__)
 #define FOLLY_FUTURE_USING_FIBER 0
 #else
 #define FOLLY_FUTURE_USING_FIBER 1
 #include <folly/fibers/Baton.h>
 #endif
+#endif
 
 namespace folly {