| /* |
| * Copyright (c) 1997, 2015, 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_MEMORY_RESOURCEAREA_HPP |
| #define SHARE_VM_MEMORY_RESOURCEAREA_HPP |
| |
| #include "memory/allocation.hpp" |
| #include "runtime/thread.hpp" |
| |
| // The resource area holds temporary data structures in the VM. |
| // The actual allocation areas are thread local. Typical usage: |
| // |
| // ... |
| // { |
| // ResourceMark rm; |
| // int foo[] = NEW_RESOURCE_ARRAY(int, 64); |
| // ... |
| // } |
| // ... |
| |
| //------------------------------ResourceArea----------------------------------- |
| // A ResourceArea is an Arena that supports safe usage of ResourceMark. |
| class ResourceArea: public Arena { |
| friend class ResourceMark; |
| friend class DeoptResourceMark; |
| friend class VMStructs; |
| debug_only(int _nesting;) // current # of nested ResourceMarks |
| debug_only(static int _warned;) // to suppress multiple warnings |
| |
| public: |
| ResourceArea() : Arena(mtThread) { |
| debug_only(_nesting = 0;) |
| } |
| |
| ResourceArea(size_t init_size) : Arena(mtThread, init_size) { |
| debug_only(_nesting = 0;); |
| } |
| |
| char* allocate_bytes(size_t size, AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM) { |
| #ifdef ASSERT |
| if (_nesting < 1 && !_warned++) |
| fatal("memory leak: allocating without ResourceMark"); |
| if (UseMallocOnly) { |
| // use malloc, but save pointer in res. area for later freeing |
| char** save = (char**)internal_malloc_4(sizeof(char*)); |
| return (*save = (char*)os::malloc(size, mtThread, CURRENT_PC)); |
| } |
| #endif |
| return (char*)Amalloc(size, alloc_failmode); |
| } |
| |
| debug_only(int nesting() const { return _nesting; }); |
| }; |
| |
| |
| //------------------------------ResourceMark----------------------------------- |
| // A resource mark releases all resources allocated after it was constructed |
| // when the destructor is called. Typically used as a local variable. |
| class ResourceMark: public StackObj { |
| protected: |
| ResourceArea *_area; // Resource area to stack allocate |
| Chunk *_chunk; // saved arena chunk |
| char *_hwm, *_max; |
| size_t _size_in_bytes; |
| #ifdef ASSERT |
| Thread* _thread; |
| ResourceMark* _previous_resource_mark; |
| #endif //ASSERT |
| |
| void initialize(Thread *thread) { |
| _area = thread->resource_area(); |
| _chunk = _area->_chunk; |
| _hwm = _area->_hwm; |
| _max= _area->_max; |
| _size_in_bytes = _area->size_in_bytes(); |
| debug_only(_area->_nesting++;) |
| assert( _area->_nesting > 0, "must stack allocate RMs" ); |
| #ifdef ASSERT |
| _thread = thread; |
| _previous_resource_mark = thread->current_resource_mark(); |
| thread->set_current_resource_mark(this); |
| #endif // ASSERT |
| } |
| public: |
| |
| #ifndef ASSERT |
| ResourceMark(Thread *thread) { |
| assert(thread == Thread::current(), "not the current thread"); |
| initialize(thread); |
| } |
| #else |
| ResourceMark(Thread *thread); |
| #endif // ASSERT |
| |
| ResourceMark() { initialize(Thread::current()); } |
| |
| ResourceMark( ResourceArea *r ) : |
| _area(r), _chunk(r->_chunk), _hwm(r->_hwm), _max(r->_max) { |
| _size_in_bytes = r->_size_in_bytes; |
| debug_only(_area->_nesting++;) |
| assert( _area->_nesting > 0, "must stack allocate RMs" ); |
| #ifdef ASSERT |
| Thread* thread = Thread::current_or_null(); |
| if (thread != NULL) { |
| _thread = thread; |
| _previous_resource_mark = thread->current_resource_mark(); |
| thread->set_current_resource_mark(this); |
| } else { |
| _thread = NULL; |
| _previous_resource_mark = NULL; |
| } |
| #endif // ASSERT |
| } |
| |
| void reset_to_mark() { |
| if (UseMallocOnly) free_malloced_objects(); |
| |
| if( _chunk->next() ) { // Delete later chunks |
| // reset arena size before delete chunks. Otherwise, the total |
| // arena size could exceed total chunk size |
| assert(_area->size_in_bytes() > size_in_bytes(), "Sanity check"); |
| _area->set_size_in_bytes(size_in_bytes()); |
| _chunk->next_chop(); |
| } else { |
| assert(_area->size_in_bytes() == size_in_bytes(), "Sanity check"); |
| } |
| _area->_chunk = _chunk; // Roll back arena to saved chunk |
| _area->_hwm = _hwm; |
| _area->_max = _max; |
| |
| // clear out this chunk (to detect allocation bugs) |
| if (ZapResourceArea) memset(_hwm, badResourceValue, _max - _hwm); |
| } |
| |
| ~ResourceMark() { |
| assert( _area->_nesting > 0, "must stack allocate RMs" ); |
| debug_only(_area->_nesting--;) |
| reset_to_mark(); |
| #ifdef ASSERT |
| if (_thread != NULL) { |
| _thread->set_current_resource_mark(_previous_resource_mark); |
| } |
| #endif // ASSERT |
| } |
| |
| |
| private: |
| void free_malloced_objects() PRODUCT_RETURN; |
| size_t size_in_bytes() { return _size_in_bytes; } |
| }; |
| |
| //------------------------------DeoptResourceMark----------------------------------- |
| // A deopt resource mark releases all resources allocated after it was constructed |
| // when the destructor is called. Typically used as a local variable. It differs |
| // from a typical resource more in that it is C-Heap allocated so that deoptimization |
| // can use data structures that are arena based but are not amenable to vanilla |
| // ResourceMarks because deoptimization can not use a stack allocated mark. During |
| // deoptimization we go thru the following steps: |
| // |
| // 0: start in assembly stub and call either uncommon_trap/fetch_unroll_info |
| // 1: create the vframeArray (contains pointers to Resource allocated structures) |
| // This allocates the DeoptResourceMark. |
| // 2: return to assembly stub and remove stub frame and deoptee frame and create |
| // the new skeletal frames. |
| // 3: push new stub frame and call unpack_frames |
| // 4: retrieve information from the vframeArray to populate the skeletal frames |
| // 5: release the DeoptResourceMark |
| // 6: return to stub and eventually to interpreter |
| // |
| // With old style eager deoptimization the vframeArray was created by the vmThread there |
| // was no way for the vframeArray to contain resource allocated objects and so |
| // a complex set of data structures to simulate an array of vframes in CHeap memory |
| // was used. With new style lazy deoptimization the vframeArray is created in the |
| // the thread that will use it and we can use a much simpler scheme for the vframeArray |
| // leveraging existing data structures if we simply create a way to manage this one |
| // special need for a ResourceMark. If ResourceMark simply inherited from CHeapObj |
| // then existing ResourceMarks would work fine since no one use new to allocate them |
| // and they would be stack allocated. This leaves open the possibility of accidental |
| // misuse so we simple duplicate the ResourceMark functionality here. |
| |
| class DeoptResourceMark: public CHeapObj<mtInternal> { |
| protected: |
| ResourceArea *_area; // Resource area to stack allocate |
| Chunk *_chunk; // saved arena chunk |
| char *_hwm, *_max; |
| size_t _size_in_bytes; |
| |
| void initialize(Thread *thread) { |
| _area = thread->resource_area(); |
| _chunk = _area->_chunk; |
| _hwm = _area->_hwm; |
| _max= _area->_max; |
| _size_in_bytes = _area->size_in_bytes(); |
| debug_only(_area->_nesting++;) |
| assert( _area->_nesting > 0, "must stack allocate RMs" ); |
| } |
| |
| public: |
| |
| #ifndef ASSERT |
| DeoptResourceMark(Thread *thread) { |
| assert(thread == Thread::current(), "not the current thread"); |
| initialize(thread); |
| } |
| #else |
| DeoptResourceMark(Thread *thread); |
| #endif // ASSERT |
| |
| DeoptResourceMark() { initialize(Thread::current()); } |
| |
| DeoptResourceMark( ResourceArea *r ) : |
| _area(r), _chunk(r->_chunk), _hwm(r->_hwm), _max(r->_max) { |
| _size_in_bytes = _area->size_in_bytes(); |
| debug_only(_area->_nesting++;) |
| assert( _area->_nesting > 0, "must stack allocate RMs" ); |
| } |
| |
| void reset_to_mark() { |
| if (UseMallocOnly) free_malloced_objects(); |
| |
| if( _chunk->next() ) { // Delete later chunks |
| // reset arena size before delete chunks. Otherwise, the total |
| // arena size could exceed total chunk size |
| assert(_area->size_in_bytes() > size_in_bytes(), "Sanity check"); |
| _area->set_size_in_bytes(size_in_bytes()); |
| _chunk->next_chop(); |
| } else { |
| assert(_area->size_in_bytes() == size_in_bytes(), "Sanity check"); |
| } |
| _area->_chunk = _chunk; // Roll back arena to saved chunk |
| _area->_hwm = _hwm; |
| _area->_max = _max; |
| |
| // clear out this chunk (to detect allocation bugs) |
| if (ZapResourceArea) memset(_hwm, badResourceValue, _max - _hwm); |
| } |
| |
| ~DeoptResourceMark() { |
| assert( _area->_nesting > 0, "must stack allocate RMs" ); |
| debug_only(_area->_nesting--;) |
| reset_to_mark(); |
| } |
| |
| |
| private: |
| void free_malloced_objects() PRODUCT_RETURN; |
| size_t size_in_bytes() { return _size_in_bytes; }; |
| }; |
| |
| #endif // SHARE_VM_MEMORY_RESOURCEAREA_HPP |