Add parallel phase feature test macro and simplify leave policy initialization logic (#2002)

Author: dnmokhov

include/oneapi/tbb/detail/_config.h

@@ -562,6 +562,14 @@
 #endif
 
 // Feature-test macros
+#if __TBB_PREVIEW_FLOW_GRAPH_RESOURCE_LIMITING
+#define TBB_HAS_FLOW_GRAPH_RESOURCE_LIMITING 202603
+#endif
+
+#if __TBB_PREVIEW_PARALLEL_PHASE
+#define TBB_HAS_PARALLEL_PHASE 202603
+#endif
+
 #if __TBB_PREVIEW_TASK_ARENA_CORE_TYPE_SELECTOR
 #define TBB_HAS_TASK_ARENA_CORE_TYPE_SELECTOR 202603
 #endif
@@ -570,8 +578,4 @@
 #define TBB_HAS_TASK_GROUP_WAIT_FOR_SINGLE_TASK 202603
 #endif
 
-#if __TBB_PREVIEW_FLOW_GRAPH_RESOURCE_LIMITING
-#define TBB_HAS_FLOW_GRAPH_RESOURCE_LIMITING 202603
-#endif
-
 #endif // __TBB_detail__config_H

src/tbb/arena.h

@@ -196,8 +196,8 @@ class thread_leave_manager {
         std::uintptr_t policy = FAST_LEAVE;
         if (lp == tbb::task_arena::leave_policy::automatic) {
             auto glp = tbb::task_arena::leave_policy(global_control::active_value(global_control::leave_policy));
-            if (glp == tbb::task_arena::leave_policy::automatic) {
-                policy = governor::hybrid_cpu() ? FAST_LEAVE : DELAYED_LEAVE;
+            if (glp == tbb::task_arena::leave_policy::automatic && !governor::hybrid_cpu()) {
+                policy = DELAYED_LEAVE;
             }
         }
         my_state.store(policy, std::memory_order_relaxed);

test/tbb/test_parallel_phase.cpp

@@ -427,3 +427,8 @@ TEST_CASE("Test parallel phase with this_task_arena") {
     WARN_MESSAGE(median1 < median2,
         "Expected one-time fast leave setting to slow workers to start new work");
 }
+
+//! \brief \ref interface
+TEST_CASE("Feature test macro") {
+    CHECK_MESSAGE(TBB_HAS_PARALLEL_PHASE == 202603, "Incorrect feature test macro");
+}