Only reload libraries when they may have been modified.

runtime/vm/isolate.h

 // 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.
 
 #ifndef VM_ISOLATE_H_
 #define VM_ISOLATE_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/atomic.h"
@@ skipping 239 matching lines @@
       const uint8_t* instructions_snapshot_buffer);
 
   void ScheduleMessageInterrupts();
 
   // Marks all libraries as loaded.
   void DoneLoading();
   void DoneFinalizing();
 
   // By default the reload context is deleted. This parameter allows
   // the caller to delete is separately if it is still needed.
-  void ReloadSources(bool dont_delete_reload_context = false);
+  void ReloadSources(bool force_reload,
+                     bool dont_delete_reload_context = false);
 
   bool MakeRunnable();
   void Run();
 
   MessageHandler* message_handler() const { return message_handler_; }
   void set_message_handler(MessageHandler* value) { message_handler_ = value; }
 
   bool is_runnable() const { return is_runnable_; }
   void set_is_runnable(bool value) {
     is_runnable_ = value;
@@ skipping 214 matching lines @@
   void DeleteReloadContext();
 
   bool HasAttemptedReload() const {
     return has_attempted_reload_;
   }
 
   bool CanReload() const;
 
   void ReportReloadError(const Error& error);
 
+  int64_t reload_timestamp() const {
+    return reload_timestamp_;
+  }
+
   uword user_tag() const {
     return user_tag_;
   }
   static intptr_t user_tag_offset() {
     return OFFSET_OF(Isolate, user_tag_);
   }
   static intptr_t current_tag_offset() {
     return OFFSET_OF(Isolate, current_tag_);
   }
   static intptr_t default_tag_offset() {
@@ skipping 319 matching lines @@
   // destroyed while there are child isolates in the midst of a spawn.
   Monitor* spawn_count_monitor_;
   intptr_t spawn_count_;
 
   // Has a reload ever been attempted?
   bool has_attempted_reload_;
   intptr_t no_reload_scope_depth_;  // we can only reload when this is 0.
   // Per-isolate copy of FLAG_reload_every.
   intptr_t reload_every_n_stack_overflow_checks_;
   IsolateReloadContext* reload_context_;
+  int64_t reload_timestamp_;
 
 #define ISOLATE_METRIC_VARIABLE(type, variable, name, unit)                    \
   type metric_##variable##_;
   ISOLATE_METRIC_LIST(ISOLATE_METRIC_VARIABLE);
 #undef ISOLATE_METRIC_VARIABLE
 
 
   static Dart_IsolateCreateCallback create_callback_;
   static Dart_IsolateShutdownCallback shutdown_callback_;
   static Dart_IsolateInterruptCallback vmstats_callback_;
@@ skipping 150 matching lines @@
   intptr_t* spawn_count_;
 
   Dart_IsolateFlags isolate_flags_;
   bool paused_;
   bool errors_are_fatal_;
 };
 
 }  // namespace dart
 
 #endif  // VM_ISOLATE_H_