Improve hot reload test mode

runtime/vm/code_generator.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/code_generator.h"
 
 #include "vm/assembler.h"
 #include "vm/ast.h"
 #include "vm/code_patcher.h"
 #include "vm/compiler.h"
@@ skipping 1224 matching lines @@
         Instance::Handle(isolate->object_store()->stack_overflow());
     Exceptions::Throw(thread, exception);
     UNREACHABLE();
   }
 
   // The following code is used to stress test deoptimization and
   // debugger stack tracing.
   bool do_deopt = false;
   bool do_stacktrace = false;
   bool do_reload = false;
+  const intptr_t isolate_reload_every =
+      isolate->reload_every_n_stack_overflow_checks();
   if ((FLAG_deoptimize_every > 0) ||
       (FLAG_stacktrace_every > 0) ||
-      (FLAG_reload_every > 0)) {
+      (isolate_reload_every > 0)) {
     // TODO(turnidge): To make --deoptimize_every and
     // --stacktrace-every faster we could move this increment/test to
     // the generated code.
     int32_t count = thread->IncrementAndGetStackOverflowCount();
     if (FLAG_deoptimize_every > 0 &&
         (count % FLAG_deoptimize_every) == 0) {
       do_deopt = true;
     }
     if (FLAG_stacktrace_every > 0 &&
         (count % FLAG_stacktrace_every) == 0) {
       do_stacktrace = true;
     }
-    if ((FLAG_reload_every > 0) &&
-        (count % FLAG_reload_every) == 0) {
+    if ((isolate_reload_every > 0) &&
+        (count % isolate_reload_every) == 0) {
       do_reload = isolate->CanReload();
     }
   }
   if ((FLAG_deoptimize_filter != NULL) ||
       (FLAG_stacktrace_filter != NULL) ||
-      FLAG_reload_every_optimized) {
+       FLAG_reload_every_optimized) {
     DartFrameIterator iterator;
     StackFrame* frame = iterator.NextFrame();
     ASSERT(frame != NULL);
     const Code& code = Code::Handle(frame->LookupDartCode());
     ASSERT(!code.IsNull());
     const Function& function = Function::Handle(code.function());
     ASSERT(!function.IsNull());
     const char* function_name = function.ToFullyQualifiedCString();
     ASSERT(function_name != NULL);
     if (!code.is_optimized() && FLAG_reload_every_optimized) {
@@ skipping 12 matching lines @@
       OS::PrintErr("*** Computing stacktrace (%s)\n",
                    function.ToFullyQualifiedCString());
       do_stacktrace = true;
     }
   }
   if (do_deopt) {
     // TODO(turnidge): Consider using DeoptimizeAt instead.
     DeoptimizeFunctionsOnStack();
   }
   if (do_reload) {
-    if (FLAG_reload_every_back_off) {
-      FLAG_reload_every *= 2;
-    }
+    // Maybe adjust the rate of future reloads.
+    isolate->MaybeIncreaseReloadEveryNStackOverflowChecks();
+    // Issue a reload.
     NOT_IN_PRODUCT(isolate->ReloadSources();)
   }
   if (FLAG_support_debugger && do_stacktrace) {
     String& var_name = String::Handle();
     Instance& var_value = Instance::Handle();
     // Collecting the stack trace and accessing local variables
     // of frames may trigger parsing of functions to compute
     // variable descriptors of functions. Parsing may trigger
     // code execution, e.g. to compute compile-time constants. Thus,
     // disable FLAG_stacktrace_every during trace collection to prevent
@@ skipping 577 matching lines @@
   const intptr_t elm_size = old_data.ElementSizeInBytes();
   const TypedData& new_data =
       TypedData::Handle(TypedData::New(cid, new_size, Heap::kOld));
   TypedData::Copy(new_data, 0, old_data, 0, old_size * elm_size);
   typed_data_cell.SetAt(0, new_data);
   arguments.SetReturn(new_data);
 }
 
 
 }  // namespace dart