Moves the top_ and end_ words of the Scavenger into mutator thread.

runtime/vm/isolate.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/isolate.h"
 
 #include "include/dart_api.h"
 #include "include/dart_native_api.h"
 #include "platform/assert.h"
 #include "platform/text_buffer.h"
@@ skipping 2640 matching lines @@
     // Now get a free Thread structure.
     thread = thread_registry()->GetFreeThreadLocked(this, is_mutator);
     ASSERT(thread != NULL);
 
     thread->ResetHighWatermark();
 
     // Set up other values and set the TLS value.
     thread->isolate_ = this;
     ASSERT(heap() != NULL);
     thread->heap_ = heap();
+
     thread->set_os_thread(os_thread);
     ASSERT(thread->execution_state() == Thread::kThreadInNative);
     thread->set_execution_state(Thread::kThreadInVM);
     thread->set_safepoint_state(0);
     thread->set_vm_tag(VMTag::kVMTagId);
     ASSERT(thread->no_safepoint_scope_depth() == 0);
     os_thread->set_thread(thread);
     if (is_mutator) {
       mutator_thread_ = thread;

[rmacnak, 2017/07/05 17:39:52]

// Grab an allocation area.

[danunez, 2017/07/05 18:12:55]

Done.

+      if (this != Dart::vm_isolate()) {

[rmacnak, 2017/07/05 17:39:52]

Is there a property of the heap we can check instead? Perhaps a zero-sized
new-space?

[danunez, 2017/07/05 18:12:55]

That should work. I'll give it a shot.

+        mutator_thread_->top_ = *(heap()->new_space()->TopAddress());

[rmacnak, 2017/07/05 17:39:52]

*top_address() -> top()

[danunez, 2017/07/05 18:12:55]

Done.

+        mutator_thread_->end_ = *(heap()->new_space()->EndAddress());
+      }
     }
     Thread::SetCurrent(thread);
     os_thread->EnableThreadInterrupts();
   }
   return thread;
 }
 
 
 void Isolate::UnscheduleThread(Thread* thread,
                                bool is_mutator,
@@ skipping 19 matching lines @@
   if (!bypass_safepoint) {
     // Ensure that the thread reports itself as being at a safepoint.
     thread->EnterSafepoint();
   }
   OSThread* os_thread = thread->os_thread();
   ASSERT(os_thread != NULL);
   os_thread->DisableThreadInterrupts();
   os_thread->set_thread(NULL);
   OSThread::SetCurrent(os_thread);
   if (is_mutator) {
+    if (this != Dart::vm_isolate()) {

[rmacnak, 2017/07/05 17:39:52]

// Release allocation area.

[danunez, 2017/07/05 18:12:55]

Done.

+      *(heap()->new_space()->TopAddress()) = mutator_thread_->top_;

[rmacnak, 2017/07/05 17:39:52]

*top_address() -> set_top()

[danunez, 2017/07/05 18:12:55]

Done.

+      *(heap()->new_space()->EndAddress()) = mutator_thread_->end_;
+    }
+    mutator_thread_->top_ = 0;
+    mutator_thread_->end_ = 0;
     mutator_thread_ = NULL;
   }
   thread->isolate_ = NULL;
   thread->heap_ = NULL;
   thread->set_os_thread(NULL);
   thread->set_execution_state(Thread::kThreadInNative);
   thread->set_safepoint_state(Thread::SetAtSafepoint(true, 0));
   thread->clear_pending_functions();
   ASSERT(thread->no_safepoint_scope_depth() == 0);
   // Return thread structure.
@@ skipping 227 matching lines @@
 void IsolateSpawnState::DecrementSpawnCount() {
   ASSERT(spawn_count_monitor_ != NULL);
   ASSERT(spawn_count_ != NULL);
   MonitorLocker ml(spawn_count_monitor_);
   ASSERT(*spawn_count_ > 0);
   *spawn_count_ = *spawn_count_ - 1;
   ml.Notify();
 }
 
 }  // namespace dart