1 /* 2 * Copyright (c) 2014, 2019, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_JFR_UTILITIES_JFRALLOCATION_HPP 26 #define SHARE_VM_JFR_UTILITIES_JFRALLOCATION_HPP 27 28 #include "memory/allocation.hpp" 29 #include "services/memTracker.hpp" 30 #include "utilities/exceptions.hpp" 31 32 /* 33 * A subclass to the CHeapObj<mtTracing> allocator, useful for critical 34 * Jfr subsystems. Critical in this context means subsystems for which 35 * allocations are crucial to the bootstrap and initialization of Jfr. 36 * The default behaviour by a CHeapObj is to call vm_exit_out_of_memory() 37 * on allocation failure and this is problematic in combination with the 38 * Jfr on-demand, dynamic start at runtime, capability. 39 * We would not like a user dynamically starting Jfr to 40 * tear down the VM she is about to inspect as a side effect. 41 * 42 * This allocator uses the RETURN_NULL capabilities 43 * instead of calling vm_exit_out_of_memory() until Jfr is properly started. 44 * This allows for controlled behaviour on allocation failures during startup, 45 * which means we can take actions on failure, such as transactional rollback 46 * (deallocations and restorations). 47 * In addition, this allocator allows for easy hooking of memory 48 * allocations / deallocations for debugging purposes. 49 */ 50 51 class JfrCHeapObj : public CHeapObj<mtTracing> { 52 private: 53 static void on_memory_allocation(const void* allocation, size_t size); 54 static char* allocate_array_noinline(size_t elements, size_t element_size); 55 56 public: 57 _NOINLINE_ void* operator new(size_t size) throw(); 58 _NOINLINE_ void* operator new (size_t size, const std::nothrow_t& nothrow_constant) throw(); 59 _NOINLINE_ void* operator new [](size_t size) throw(); 60 _NOINLINE_ void* operator new [](size_t size, const std::nothrow_t& nothrow_constant) throw(); 61 void operator delete(void* p, size_t size); 62 void operator delete [] (void* p, size_t size); 63 static char* realloc_array(char* old, size_t size); 64 static void free(void* p, size_t size = 0); 65 66 template <class T> 67 static T* new_array(size_t size) { 68 T* const memory = (T*)allocate_array_noinline(size, sizeof(T)); 69 on_memory_allocation(memory, sizeof(T) * size); 70 return memory; 71 } 72 }; 73 74 #endif // SHARE_VM_JFR_UTILITIES_JFRALLOCATION_HPP