Add more safe points in compiler

runtime/vm/zone.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/zone.h"
 
 #include "platform/assert.h"
 #include "platform/utils.h"
 #include "vm/dart_api_state.h"
 #include "vm/flags.h"
@@ skipping 59 matching lines @@
     OUT_OF_MEMORY();
   }
   ASSERT(Utils::IsAligned(result->start(), Zone::kAlignment));
 #ifdef DEBUG
   // Zap the entire allocated segment (including the header).
   memset(result, kZapUninitializedByte, size);
 #endif
   result->next_ = next;
   result->size_ = size;
   Thread* current = Thread::Current();
+
   if (current != NULL) {
     current->IncrementMemoryUsage(size);
+    // In case the other thread is waiting to do a scavenge.
+    current->CheckForSafepoint();

[siva, 2017/03/23 18:05:01]

Why is this check needed here? We may run into issues when it is necessary to do
a new Zone inside a NoSafepointScope block.

[erikcorry, 2017/03/27 10:23:28]

Good catch.  This one was great for keeping down the wait time, but it's not
safe unless we make NoSafePointScope into a release-mode thing and check for it.
 Removed.

   } else if (ApiNativeScope::Current() != NULL) {
     // If there is no current thread, we might be inside of a native scope.
     ApiNativeScope::IncrementNativeScopeMemoryUsage(size);
   }
   return result;
 }
 
 // TODO(bkonyi): We need to account for the initial chunk size when a new zone
 // is created within a new thread or ApiNativeScope when calculating high
 // watermarks or memory consumption.
@@ skipping 236 matching lines @@
   ASSERT(thread()->zone() == &zone_);
   thread()->set_zone(zone_.previous_);
   if (FLAG_trace_zones) {
     OS::PrintErr("*** Deleting Stack zone 0x%" Px "(0x%" Px ")\n",
                  reinterpret_cast<intptr_t>(this),
                  reinterpret_cast<intptr_t>(&zone_));
   }
 }
 
 }  // namespace dart