Add accessor to estimate a FiberManager's run queue size

Summary: Add accessor to estimate a FiberManager's run queue size

Reviewed By: @sarangbh

Differential Revision: D2293367

diff --git a/folly/experimental/fibers/FiberManager.h b/folly/experimental/fibers/FiberManager.h
index 9c2ae7567fbd693e0fee9f17d9931ee3a9000f37..6f19b87ee2dd4add01fc11ba76ca68b67303dee2 100644 (file)
--- a/folly/experimental/fibers/FiberManager.h
+++ b/folly/experimental/fibers/FiberManager.h
@@ -252,6 +252,14 @@ class FiberManager : public ::folly::Executor {
    */
   void setObserver(ExecutionObserver* observer);
 
+  /**
+   * Returns an estimate of the number of fibers which are waiting to run (does
+   * not include fibers or tasks scheduled remotely).
+   */
+  size_t runQueueSize() const {
+    return readyFibers_.size() + yieldedFibers_.size();
+  }
+
   static FiberManager& getFiberManager();
   static FiberManager* getFiberManagerUnsafe();