Adding a SetRAILMode API.

src/isolate.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/isolate.h"
 
 #include <stdlib.h>
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
@@ skipping 1854 matching lines @@
       global_handles_(NULL),
       eternal_handles_(NULL),
       thread_manager_(NULL),
       has_installed_extensions_(false),
       regexp_stack_(NULL),
       date_cache_(NULL),
       call_descriptor_data_(NULL),
       // TODO(bmeurer) Initialized lazily because it depends on flags; can
       // be fixed once the default isolate cleanup is done.
       random_number_generator_(NULL),
+      rail_mode_(PERFORMANCE_DEFAULT),
       serializer_enabled_(enable_serializer),
       has_fatal_error_(false),
       initialized_from_snapshot_(false),
       is_tail_call_elimination_enabled_(true),
       cpu_profiler_(NULL),
       heap_profiler_(NULL),
       function_entry_hook_(NULL),
       deferred_handles_head_(NULL),
       optimizing_compile_dispatcher_(NULL),
       stress_deopt_count_(0),
@@ skipping 1123 matching lines @@
     }
   }
   if (new_length == 0) {
     heap()->set_detached_contexts(heap()->empty_fixed_array());
   } else if (new_length < length) {
     heap()->RightTrimFixedArray<Heap::CONCURRENT_TO_SWEEPER>(
         *detached_contexts, length - new_length);
   }
 }
 
+void Isolate::SetRAILMode(RAILMode rail_mode) {
+  rail_mode_ = rail_mode;
+  if (FLAG_trace_rail) {
+    PrintIsolate(this, "RAIL mode: %s\n", RAILModeName(rail_mode_));
+  }
+}
 
 bool StackLimitCheck::JsHasOverflowed(uintptr_t gap) const {
   StackGuard* stack_guard = isolate_->stack_guard();
 #ifdef USE_SIMULATOR
   // The simulator uses a separate JS stack.
   Address jssp_address = Simulator::current(isolate_)->get_sp();
   uintptr_t jssp = reinterpret_cast<uintptr_t>(jssp_address);
   if (jssp - gap < stack_guard->real_jslimit()) return true;
 #endif  // USE_SIMULATOR
   return GetCurrentStackPosition() - gap < stack_guard->real_climit();
@@ skipping 29 matching lines @@
   // Then check whether this scope intercepts.
   if ((flag & intercept_mask_)) {
     intercepted_flags_ |= flag;
     return true;
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8