Increase thread stack size on Mac in debug mode.

runtime/platform/thread_macos.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 "platform/thread.h"
 
 #include <sys/errno.h>
 
 #include "platform/assert.h"
 
@@ skipping 54 matching lines @@
 
 int Thread::Start(ThreadStartFunction function, uword parameter) {
   pthread_attr_t attr;
   int result = pthread_attr_init(&attr);
   RETURN_ON_PTHREAD_FAILURE(result);
 
   result = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
   RETURN_ON_PTHREAD_FAILURE(result);
 
 #ifdef DEBUG
-  const int kStackSize = (256 * KB);
+  const int kStackSize = (512 * KB);
 #else
   const int kStackSize = (128 * KB);
 #endif
   result = pthread_attr_setstacksize(&attr, kStackSize);
   RETURN_ON_PTHREAD_FAILURE(result);
 
   ThreadStartData* data = new ThreadStartData(function, parameter);
 
   pthread_t tid;
   result = pthread_create(&tid, &attr, ThreadStart, data);
@@ skipping 164 matching lines @@
 }
 
 
 void Monitor::NotifyAll() {
   // TODO(iposva): Do we need to track lock owners?
   int result = pthread_cond_broadcast(data_.cond());
   VALIDATE_PTHREAD_RESULT(result);
 }
 
 }  // namespace dart