Implement safepointing of threads

runtime/vm/compiler.cc

Index: runtime/vm/compiler.cc
diff --git a/runtime/vm/compiler.cc b/runtime/vm/compiler.cc
index be9c996a8ee88a12f439c6bb3fbe4041a12f7223..074a44e8064f6852f4f55d9903327aa3e68e6fa7 100644
--- a/runtime/vm/compiler.cc
+++ b/runtime/vm/compiler.cc
@@ -1050,21 +1050,17 @@ bool CompileParsedFunctionHelper::Compile(CompilationPipeline* pipeline) {
                                   compiler_timeline,
                                   "FinalizeCompilation");
         // This part of compilation must be at a safepoint.
-        if (!thread()->IsMutatorThread()) {
+        if (thread()->IsMutatorThread()) {
+          FinalizeCompilation(&assembler, &graph_compiler, flow_graph);
+        } else {
           // Stop mutator thread before creating the instruction object and
           // 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).
-          isolate()->thread_registry()->SafepointThreads();
-        }
-
-        FinalizeCompilation(&assembler, &graph_compiler, flow_graph);
-
-        if (!thread()->IsMutatorThread()) {
-          // Background compilation.
-          isolate()->thread_registry()->ResumeAllThreads();
+          SafepointOperationScope safepoint_scope(thread());
+          FinalizeCompilation(&assembler, &graph_compiler, flow_graph);
         }
       }
       // Mark that this isolate now has compiled code.
@@ -1894,9 +1890,7 @@ void BackgroundCompiler::Stop(BackgroundCompiler* task) {
   {
     MonitorLocker ml_done(done_monitor);
     while (!(*task_done)) {
-      // In case that the compiler is waiting for safepoint.
-      Isolate::Current()->thread_registry()->CheckSafepoint();
-      ml_done.Wait(1);
+      ml_done.WaitWithSafepointCheck(Thread::Current());
     }
   }
   delete task_done;