jdk8-mips64-public/hotspot: src/share/vm/memory/resourceArea.hpp@7ae4e26cb1e0 (annotated)

src/share/vm/memory/resourceArea.hpp@7ae4e26cb1e0 (annotated)

src/share/vm/memory/resourceArea.hpp

Thu, 12 Oct 2017 21:27:07 +0800

author: aoqi
date: Thu, 12 Oct 2017 21:27:07 +0800
changeset 7535: 7ae4e26cb1e0
parent 7074: 833b0f92429a
parent 6876: 710a3c8b516e
child 9122: 024be04bb151
permissions: -rw-r--r--

merge

 /*
  * Copyright (c) 1997, 2014, 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.inline.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 = ThreadLocalStorage::thread();
     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 possibilty 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

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/memory/resourceArea.hpp@7ae4e26cb1e0 (annotated)

src/share/vm/memory/resourceArea.hpp