--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/jfr/utilities/jfrAllocation.hpp	Tue May 15 20:24:34 2018 +0200
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2014, 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_JFR_UTILITIES_JFRALLOCATION_HPP
+#define SHARE_VM_JFR_UTILITIES_JFRALLOCATION_HPP
+
+#include "memory/allocation.hpp"
+#include "services/memTracker.hpp"
+#include "utilities/exceptions.hpp"
+
+/*
+ * A subclass to the CHeapObj<mtTracing> allocator, useful for critical
+ * Jfr subsystems. Critical in this context means subsystems for which
+ * allocations are crucial to the bootstrap and initialization of Jfr.
+ * The default behaviour by a CHeapObj is to call vm_exit_out_of_memory()
+ * on allocation failure and this is problematic in combination with the
+ * Jfr on-demand, dynamic start at runtime, capability.
+ * We would not like a user dynamically starting Jfr to
+ * tear down the VM she is about to inspect as a side effect.
+ *
+ * This allocator uses the RETURN_NULL capabilities
+ * instead of calling vm_exit_out_of_memory() until Jfr is properly started.
+ * This allows for controlled behaviour on allocation failures during startup,
+ * which means we can take actions on failure, such as transactional rollback
+ * (deallocations and restorations).
+ * In addition, this allocator allows for easy hooking of memory
+ * allocations / deallocations for debugging purposes.
+ */
+
+class JfrCHeapObj : public CHeapObj<mtTracing> {
+ private:
+  static void on_memory_allocation(const void* allocation, size_t size);
+  static char* allocate_array_noinline(size_t elements, size_t element_size);
+
+ public:
+  NOINLINE void* operator new(size_t size) throw();
+  NOINLINE void* operator new (size_t size, const std::nothrow_t&  nothrow_constant) throw();
+  NOINLINE void* operator new [](size_t size) throw();
+  NOINLINE void* operator new [](size_t size, const std::nothrow_t&  nothrow_constant) throw();
+  void  operator delete(void* p, size_t size);
+  void  operator delete [] (void* p, size_t size);
+  static char* realloc_array(char* old, size_t size);
+  static void free(void* p, size_t size = 0);
+
+  template <class T>
+  static T* new_array(size_t size) {
+    T* const memory = (T*)allocate_array_noinline(size, sizeof(T));
+    on_memory_allocation(memory, sizeof(T) * size);
+    return memory;
+  }
+};
+
+#endif // SHARE_VM_JFR_UTILITIES_JFRALLOCATION_HPP