hazptr: rename start_hazptr_thread_pool_executor to enable_hazptr_thread_pool_executor

Summary: This makes the function name more accurate. The function does not start the thread pool executor. It only enables the construction and use of a thread pool executor by the default hazptr domain when needed.

Reviewed By: davidtgoldblatt

Differential Revision: D19852860

fbshipit-source-id: 5ae71d0fd2d2d20c9ca66f45d57e90085703b3fb

folly/init/Init.cpp

@@ -65,7 +65,7 @@ void init(int* argc, char*** argv, bool removeFlags) {
 #endif
   // Set the default hazard pointer domain to use a thread pool executor
   // for asynchronous reclamation
-  folly::start_hazptr_thread_pool_executor();
+  folly::enable_hazptr_thread_pool_executor();
 }
 
 Init::Init(int* argc, char*** argv, bool removeFlags) {

folly/synchronization/HazptrThreadPoolExecutor.cpp

@@ -35,7 +35,7 @@ folly::Executor* get_hazptr_tpe() {
 
 namespace folly {
 
-void start_hazptr_thread_pool_executor() {
+void enable_hazptr_thread_pool_executor() {
   if (FLAGS_folly_hazptr_use_executor) {
     default_hazptr_domain().set_executor(&get_hazptr_tpe);
   }

folly/synchronization/HazptrThreadPoolExecutor.h

@@ -20,6 +20,6 @@
 
 namespace folly {
 
-void start_hazptr_thread_pool_executor();
+void enable_hazptr_thread_pool_executor();
 
 } // namespace folly

folly/synchronization/test/HazptrTest.cpp

@@ -900,7 +900,7 @@ void recursive_destruction_test() {
 }
 
 void fork_test() {
-  folly::start_hazptr_thread_pool_executor();
+  folly::enable_hazptr_thread_pool_executor();
   auto trigger_reclamation = [] {
     hazptr_obj_cohort b;
     for (int i = 0; i < 2001; ++i) {