Clear background compilation queue and abort background compilation when stopping the background co…

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 1017 matching lines @@
           // installing code.
           // Mutator thread may not run code while we are creating the
           // instruction object, since the creation of instruction object
           // changes code page access permissions (makes them temporary not
           // executable).
           {
             SafepointOperationScope safepoint_scope(thread());
             // 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);
+            }
             FinalizeCompilation(&assembler, &graph_compiler, flow_graph);
           }
           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.
@@ skipping 539 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(QueueElement);
 };
 
 
 // Allocated in C-heap. Handles both input and output of background compilation.
 // It implements a FIFO queue, using Peek, Add, Remove operations.
 class BackgroundCompilationQueue {
  public:
   BackgroundCompilationQueue() : first_(NULL), last_(NULL) {}
   virtual ~BackgroundCompilationQueue() {
-    while (!IsEmpty()) {
-      QueueElement* e = Remove();
-      delete e;
-    }
-    ASSERT((first_ == NULL) && (last_ == NULL));
+    Clear();
   }
 
   void VisitObjectPointers(ObjectPointerVisitor* visitor) {
     ASSERT(visitor != NULL);
     QueueElement* p = first_;
     while (p != NULL) {
       visitor->VisitPointer(p->function_ptr());
       p = p->next();
     }
   }
@@ skipping 41 matching lines @@
     QueueElement* p = first_;
     while (p != NULL) {
       if (p->function() == obj.raw()) {
         return true;
       }
       p = p->next();
     }
     return false;
   }
 
+  void Clear() {
+    while (!IsEmpty()) {
+      QueueElement* e = Remove();
+      delete e;
+    }
+    ASSERT((first_ == NULL) && (last_ == NULL));
+  }
+
  private:
   QueueElement* first_;
   QueueElement* last_;
 
   DISALLOW_COPY_AND_ASSIGN(BackgroundCompilationQueue);
 };
 
 
 BackgroundCompiler::BackgroundCompiler(Isolate* isolate)
     : isolate_(isolate), running_(true), done_(new bool()),
@@ skipping 45 matching lines @@
         Isolate* isolate = thread->isolate();
         // We cannot aggregate stats if isolate is shutting down.
         if (isolate->HasMutatorThread()) {
           isolate->aggregate_compiler_stats()->Add(*thread->compiler_stats());
         }
         thread->compiler_stats()->Clear();
 #endif  // PRODUCT
 
         QueueElement* qelem = NULL;
         { MonitorLocker ml(queue_monitor_);
-          qelem = function_queue()->Remove();
-          function = function_queue()->PeekFunction();
+          if (function_queue()->IsEmpty()) {
+            // We are shutting down, queue was cleared.
+            function = Function::null();
+          } else {
+            qelem = function_queue()->Remove();
+            function = function_queue()->PeekFunction();
+          }
         }
-        delete qelem;
+        if (qelem != NULL) {
+          delete qelem;
+        }
       }
     }
     Thread::ExitIsolateAsHelper();
     {
       // Wait to be notified when the work queue is not empty.
       MonitorLocker ml(queue_monitor_);
       while (function_queue()->IsEmpty() && running_) {
         ml.Wait();
       }
     }
@@ skipping 29 matching lines @@
 void BackgroundCompiler::Stop(BackgroundCompiler* task) {
   ASSERT(Isolate::Current()->background_compiler() == task);
   ASSERT(task != NULL);
   BackgroundCompilationQueue* function_queue = task->function_queue();
 
   Monitor* queue_monitor = task->queue_monitor_;
   Monitor* done_monitor = task->done_monitor_;
   bool* task_done = task->done_;
   // Wake up compiler task and stop it.
   {
-    MonitorLocker ml(task->queue_monitor_);
+    MonitorLocker ml(queue_monitor);
     task->running_ = false;
+    function_queue->Clear();
     // 'task' will be deleted by thread pool.
     task = NULL;
     ml.Notify();   // Stop waiting for the queue.
   }
 
   {
     MonitorLocker ml_done(done_monitor);
     while (!(*task_done)) {
       ml_done.WaitWithSafepointCheck(Thread::Current());
     }
@@ skipping 148 matching lines @@
 }
 
 
 void BackgroundCompiler::EnsureInit(Thread* thread) {
   UNREACHABLE();
 }
 
 #endif  // DART_PRECOMPILED_RUNTIME
 
 }  // namespace dart