Make adding a pending deopt atomic.

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 1889 matching lines @@
 #endif  // !PRODUCT
   ASSERT(raw_class != NULL);
 #if !defined(DART_PRECOMPILER)
   // This is temporarily untrue during a class id remap.
   ASSERT(raw_class->ptr()->id_ == cid);
 #endif
   return raw_class;
 }
 
 
+void Isolate::AddPendingDeopt(uword fp, uword pc) {
+  // GrowableArray::Add is not atomic and may be interrupt by a profiler

[siva, 2016/10/10 04:10:26]

may be interrupted ...

+  // stack walk.
+  MallocGrowableArray<PendingLazyDeopt>* old_pending_deopts = pending_deopts_;
+  MallocGrowableArray<PendingLazyDeopt>* new_pending_deopts
+      = new MallocGrowableArray<PendingLazyDeopt>(
+          old_pending_deopts->length() + 1);
+  for (intptr_t i = 0; i < old_pending_deopts->length(); i++) {
+    ASSERT((*old_pending_deopts)[i].fp() != fp);
+    new_pending_deopts->Add((*old_pending_deopts)[i]);
+  }
+  PendingLazyDeopt deopt(fp, pc);
+  new_pending_deopts->Add(deopt);
+
+  pending_deopts_ = new_pending_deopts;
+  delete old_pending_deopts;
+}
+
+
+uword Isolate::FindPendingDeopt(uword fp) const {
+  for (intptr_t i = 0; i < pending_deopts_->length(); i++) {
+    if ((*pending_deopts_)[i].fp() == fp) {
+      return (*pending_deopts_)[i].pc();
+    }
+  }
+  FATAL("Missing pending deopt entry");
+  return 0;

[siva, 2016/10/10 04:10:26]

Can another thread be executing this code while AddPendingDeopt is happening?

+}
+
+
+void Isolate::ClearPendingDeoptsAtOrBelow(uword fp) const {
+  for (intptr_t i = pending_deopts_->length() - 1; i >= 0; i--) {
+    if ((*pending_deopts_)[i].fp() <= fp) {
+      pending_deopts_->RemoveAt(i);
+    }
+  }

[siva, 2016/10/10 04:10:26]

Same question about this function.

+}
+
+
 #ifndef PRODUCT
 static const char* ExceptionPauseInfoToServiceEnum(Dart_ExceptionPauseInfo pi) {
   switch (pi) {
     case kPauseOnAllExceptions:
       return "All";
     case kNoPauseOnExceptions:
       return "None";
     case kPauseOnUnhandledExceptions:
       return "Unhandled";
     default:
@@ skipping 987 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