1 /*
   2  * Copyright (c) 1997, 2013, 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 #include "precompiled.hpp"
  26 #include "memory/allocation.inline.hpp"
  27 #include "oops/constantPool.hpp"
  28 #include "oops/oop.inline.hpp"
  29 #include "runtime/handles.inline.hpp"
  30 #include "runtime/thread.inline.hpp"
  31 #ifdef TARGET_OS_FAMILY_linux
  32 # include "os_linux.inline.hpp"
  33 #endif
  34 #ifdef TARGET_OS_FAMILY_solaris
  35 # include "os_solaris.inline.hpp"
  36 #endif
  37 #ifdef TARGET_OS_FAMILY_windows
  38 # include "os_windows.inline.hpp"
  39 #endif
  40 #ifdef TARGET_OS_FAMILY_bsd
  41 # include "os_bsd.inline.hpp"
  42 #endif
  43 
  44 #ifdef ASSERT
  45 oop* HandleArea::allocate_handle(oop obj) {
  46   assert(_handle_mark_nesting > 1, "memory leak: allocating handle outside HandleMark");
  47   assert(_no_handle_mark_nesting == 0, "allocating handle inside NoHandleMark");
  48   assert(obj->is_oop(), "sanity check");
  49   return real_allocate_handle(obj);
  50 }
  51 
  52 Handle::Handle(Thread* thread, oop obj) {
  53   assert(thread == Thread::current(), "sanity check");
  54   if (obj == NULL) {
  55     _handle = NULL;
  56   } else {
  57     _handle = thread->handle_area()->allocate_handle(obj);
  58   }
  59 }
  60 
  61 #endif
  62 
  63 static uintx chunk_oops_do(OopClosure* f, Chunk* chunk, char* chunk_top) {
  64   oop* bottom = (oop*) chunk->bottom();
  65   oop* top    = (oop*) chunk_top;
  66   uintx handles_visited = top - bottom;
  67   assert(top >= bottom && top <= (oop*) chunk->top(), "just checking");
  68   // during GC phase 3, a handle may be a forward pointer that
  69   // is not yet valid, so loosen the assertion
  70   while (bottom < top) {
  71     // This test can be moved up but for now check every oop.
  72 
  73     assert((*bottom)->is_oop(), "handle should point to oop");
  74 
  75     f->do_oop(bottom++);
  76   }
  77   return handles_visited;
  78 }
  79 
  80 // Used for debugging handle allocation.
  81 NOT_PRODUCT(jint _nof_handlemarks  = 0;)
  82 
  83 void HandleArea::oops_do(OopClosure* f) {
  84   uintx handles_visited = 0;
  85   // First handle the current chunk. It is filled to the high water mark.
  86   handles_visited += chunk_oops_do(f, _chunk, _hwm);
  87   // Then handle all previous chunks. They are completely filled.
  88   Chunk* k = _first;
  89   while(k != _chunk) {
  90     handles_visited += chunk_oops_do(f, k, k->top());
  91     k = k->next();
  92   }
  93 
  94   // The thread local handle areas should not get very large
  95   if (TraceHandleAllocation && handles_visited > TotalHandleAllocationLimit) {
  96 #ifdef ASSERT
  97     warning("%d: Visited in HandleMark : %d",
  98       _nof_handlemarks, handles_visited);
  99 #else
 100     warning("Visited in HandleMark : %d", handles_visited);
 101 #endif
 102   }
 103   if (_prev != NULL) _prev->oops_do(f);
 104 }
 105 
 106 void HandleMark::initialize(Thread* thread) {
 107   _thread = thread;
 108   // Save area
 109   _area  = thread->handle_area();
 110   // Save current top
 111   _chunk = _area->_chunk;
 112   _hwm   = _area->_hwm;
 113   _max   = _area->_max;
 114   _size_in_bytes = _area->_size_in_bytes;
 115   debug_only(_area->_handle_mark_nesting++);
 116   assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks");
 117   debug_only(Atomic::inc(&_nof_handlemarks);)
 118 
 119   // Link this in the thread
 120   set_previous_handle_mark(thread->last_handle_mark());
 121   thread->set_last_handle_mark(this);
 122 }
 123 
 124 
 125 HandleMark::~HandleMark() {
 126   HandleArea* area = _area;   // help compilers with poor alias analysis
 127   assert(area == _thread->handle_area(), "sanity check");
 128   assert(area->_handle_mark_nesting > 0, "must stack allocate HandleMarks" );
 129   debug_only(area->_handle_mark_nesting--);
 130 
 131   // Debug code to trace the number of handles allocated per mark/
 132 #ifdef ASSERT
 133   if (TraceHandleAllocation) {
 134     size_t handles = 0;
 135     Chunk *c = _chunk->next();
 136     if (c == NULL) {
 137       handles = area->_hwm - _hwm; // no new chunk allocated
 138     } else {
 139       handles = _max - _hwm;      // add rest in first chunk
 140       while(c != NULL) {
 141         handles += c->length();
 142         c = c->next();
 143       }
 144       handles -= area->_max - area->_hwm; // adjust for last trunk not full
 145     }
 146     handles /= sizeof(void *); // Adjust for size of a handle
 147     if (handles > HandleAllocationLimit) {
 148       // Note: _nof_handlemarks is only set in debug mode
 149       warning("%d: Allocated in HandleMark : %d", _nof_handlemarks, handles);
 150     }
 151 
 152     tty->print_cr("Handles %d", handles);
 153   }
 154 #endif
 155 
 156   // Delete later chunks
 157   if( _chunk->next() ) {
 158     // reset arena size before delete chunks. Otherwise, the total
 159     // arena size could exceed total chunk size
 160     assert(area->size_in_bytes() > size_in_bytes(), "Sanity check");
 161     area->set_size_in_bytes(size_in_bytes());
 162     _chunk->next_chop();
 163   } else {
 164     assert(area->size_in_bytes() == size_in_bytes(), "Sanity check");
 165   }
 166   // Roll back arena to saved top markers
 167   area->_chunk = _chunk;
 168   area->_hwm = _hwm;
 169   area->_max = _max;
 170 #ifdef ASSERT
 171   // clear out first chunk (to detect allocation bugs)
 172   if (ZapVMHandleArea) {
 173     memset(_hwm, badHandleValue, _max - _hwm);
 174   }
 175   Atomic::dec(&_nof_handlemarks);
 176 #endif
 177 
 178   // Unlink this from the thread
 179   _thread->set_last_handle_mark(previous_handle_mark());
 180 }
 181 
 182 void* HandleMark::operator new(size_t size) throw() {
 183   return AllocateHeap(size, mtThread);
 184 }
 185 
 186 void* HandleMark::operator new [] (size_t size) throw() {
 187   return AllocateHeap(size, mtThread);
 188 }
 189 
 190 void HandleMark::operator delete(void* p) {
 191   FreeHeap(p, mtThread);
 192 }
 193 
 194 void HandleMark::operator delete[](void* p) {
 195   FreeHeap(p, mtThread);
 196 }
 197 
 198 #ifdef ASSERT
 199 
 200 NoHandleMark::NoHandleMark() {
 201   HandleArea* area = Thread::current()->handle_area();
 202   area->_no_handle_mark_nesting++;
 203   assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
 204 }
 205 
 206 
 207 NoHandleMark::~NoHandleMark() {
 208   HandleArea* area = Thread::current()->handle_area();
 209   assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
 210   area->_no_handle_mark_nesting--;
 211 }
 212 
 213 
 214 ResetNoHandleMark::ResetNoHandleMark() {
 215   HandleArea* area = Thread::current()->handle_area();
 216   _no_handle_mark_nesting = area->_no_handle_mark_nesting;
 217   area->_no_handle_mark_nesting = 0;
 218 }
 219 
 220 
 221 ResetNoHandleMark::~ResetNoHandleMark() {
 222   HandleArea* area = Thread::current()->handle_area();
 223   area->_no_handle_mark_nesting = _no_handle_mark_nesting;
 224 }
 225 
 226 #endif