GC Experiment: move GC call from background compiler thread to the mutator thread

runtime/vm/compiler.cc

 // Copyright (c) 2012, 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/compiler.h"
 
 #include "vm/assembler.h"
 
 #include "vm/ast_printer.h"
 #include "vm/block_scheduler.h"
@@ skipping 1055 matching lines @@
             // Do not Garbage collect during this stage and instead allow the
             // heap to grow.
             NoHeapGrowthControlScope no_growth_control;
             if (!isolate()->background_compiler()->is_running()) {
               // The background compiler is being stopped.
               Compiler::AbortBackgroundCompilation(Thread::kNoDeoptId,
                   "Background compilation is being stopped");
             }
             FinalizeCompilation(&assembler, &graph_compiler, flow_graph);
           }
-          if (isolate()->heap()->NeedsGarbageCollection()) {
-            isolate()->heap()->CollectAllGarbage();
-          }
+          // TODO(srdjan): Enable this and remove the one from
+          // 'BackgroundCompiler::CompileOptimize'
+          // if (isolate()->heap()->NeedsGarbageCollection()) {
+          //   isolate()->heap()->CollectAllGarbage();
+          // }
         }
       }
       // Mark that this isolate now has compiled code.
       isolate()->set_has_compiled_code(true);
       // Exit the loop and the function with the correct result value.
       is_compiled = true;
       done = true;
     } else {
       // We bailed out or we encountered an error.
       const Error& error = Error::Handle(thread()->sticky_error());
@@ skipping 716 matching lines @@
     // Notify that the thread is done.
     MonitorLocker ml_done(done_monitor_);
     *done_ = true;
     ml_done.Notify();
   }
 }
 
 
 void BackgroundCompiler::CompileOptimized(const Function& function) {
   ASSERT(Thread::Current()->IsMutatorThread());
-  MonitorLocker ml(queue_monitor_);
-  ASSERT(running_);
-  if (function_queue()->ContainsObj(function)) {
-    return;
+  // TODO(srdjan): Checking different strategy for collecting garbage
+  // accumulated by background compiler.
+  if (isolate_->heap()->NeedsGarbageCollection()) {
+    isolate_->heap()->CollectAllGarbage();
   }
-  QueueElement* elem = new QueueElement(function);
-  function_queue()->Add(elem);
-  ml.Notify();
+  {
+    MonitorLocker ml(queue_monitor_);
+    ASSERT(running_);
+    if (function_queue()->ContainsObj(function)) {
+      return;
+    }
+    QueueElement* elem = new QueueElement(function);
+    function_queue()->Add(elem);
+    ml.Notify();
+  }
 }
 
 
 void BackgroundCompiler::VisitPointers(ObjectPointerVisitor* visitor) {
   function_queue_->VisitObjectPointers(visitor);
 }
 
 
 void BackgroundCompiler::Stop(Isolate* isolate) {
   BackgroundCompiler* task = isolate->background_compiler();
@@ skipping 169 matching lines @@
 }
 
 
 void BackgroundCompiler::EnsureInit(Thread* thread) {
   UNREACHABLE();
 }
 
 #endif  // DART_PRECOMPILED_RUNTIME
 
 }  // namespace dart