1 /*

     2  * Copyright (c) 2005, 2015, 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 "gc/shared/collectedHeap.hpp"

    27 #include "gc/shared/gcLocker.inline.hpp"

    28 #include "memory/universe.hpp"

    29 #include "oops/oop.inline.hpp"

    30 #include "runtime/thread.hpp"

    31 #include "runtime/unhandledOops.hpp"

    32 #include "utilities/globalDefinitions.hpp"

    33 

    34 #ifdef CHECK_UNHANDLED_OOPS

    35 const int free_list_size = 256;

    36 

    37 

    38 UnhandledOops::UnhandledOops(Thread* thread) {

    39   _thread = thread;

    40   _oop_list = new (ResourceObj::C_HEAP, mtInternal)

    41                     GrowableArray<UnhandledOopEntry>(free_list_size, true);

    42   _level = 0;

    43 }

    44 

    45 UnhandledOops::~UnhandledOops() {

    46   delete _oop_list;

    47 }

    48 

    49 

    50 void UnhandledOops::dump_oops(UnhandledOops *list) {

    51   for (int k = 0; k < list->_oop_list->length(); k++) {

    52     UnhandledOopEntry entry = list->_oop_list->at(k);

    53     tty->print(" " INTPTR_FORMAT, p2i(entry._oop_ptr));

    54   }

    55   tty->cr();

    56 }

    57 

    58 // For debugging unhandled oop detector _in the debugger_

    59 // You don't want to turn it on in compiled code here.

    60 static bool unhandled_oop_print=0;

    61 

    62 void UnhandledOops::register_unhandled_oop(oop* op, address pc) {

    63   if (!_thread->is_in_stack((address)op))

    64     return;

    65 

    66   _level ++;

    67   if (unhandled_oop_print) {

    68     for (int i=0; i<_level; i++) tty->print(" ");

    69     tty->print_cr("r " INTPTR_FORMAT, p2i(op));

    70   }

    71   UnhandledOopEntry entry(op, pc);

    72   _oop_list->push(entry);

    73 }

    74 

    75 

    76 bool match_oop_entry(void *op, UnhandledOopEntry e) {

    77   return (e.oop_ptr() == op);

    78 }

    79 

    80 // Mark unhandled oop as okay for GC - the containing struct has an oops_do and

    81 // for some reason the oop has to be on the stack.

    82 // May not be called for the current thread, as in the case of

    83 // VM_GetOrSetLocal in jvmti.

    84 void UnhandledOops::allow_unhandled_oop(oop* op) {

    85   assert (CheckUnhandledOops, "should only be called with checking option");

    86 

    87   int i = _oop_list->find_from_end(op, match_oop_entry);

    88   assert(i!=-1, "safe for gc oop not in unhandled_oop_list");

    89 

    90   UnhandledOopEntry entry = _oop_list->at(i);

    91   assert(!entry._ok_for_gc, "duplicate entry");

    92   entry._ok_for_gc = true;

    93   _oop_list->at_put(i, entry);

    94 }

    95 

    96 

    97 // Called by the oop destructor to remove unhandled oop from the thread's

    98 // oop list.  All oops given are assumed to be on the list.  If not,

    99 // there's a bug in the unhandled oop detector.

   100 void UnhandledOops::unregister_unhandled_oop(oop* op) {

   101   if (!_thread->is_in_stack((address)op)) return;

   102 

   103   _level --;

   104   if (unhandled_oop_print) {

   105     for (int i=0; i<_level; i++) tty->print(" ");

   106     tty->print_cr("u " INTPTR_FORMAT, p2i(op));

   107   }

   108 

   109   int i = _oop_list->find_from_end(op, match_oop_entry);

   110   assert(i!=-1, "oop not in unhandled_oop_list");

   111   _oop_list->remove_at(i);

   112 }

   113 

   114 void UnhandledOops::clear_unhandled_oops() {

   115   assert (CheckUnhandledOops, "should only be called with checking option");

   116 

   117   for (int k = 0; k < _oop_list->length(); k++) {

   118     UnhandledOopEntry entry = _oop_list->at(k);

   119     // If an entry is on the unhandled oop list but isn't on the stack

   120     // anymore, it must not have gotten unregistered properly and it's a bug

   121     // in the unhandled oop generator.

   122     if(!_thread->is_in_stack((address)entry._oop_ptr)) {

   123       tty->print_cr("oop_ptr is " INTPTR_FORMAT, p2i(entry._oop_ptr));

   124       tty->print_cr("thread is " INTPTR_FORMAT " from pc " INTPTR_FORMAT,

   125                      p2i(_thread), p2i(entry._pc));

   126       assert(false, "heap is corrupted by the unhandled oop detector");

   127     }

   128     // Set unhandled oops to a pattern that will crash distinctively

   129     if (!entry._ok_for_gc) *(intptr_t*)(entry._oop_ptr) = BAD_OOP_ADDR;

   130   }

   131 }

   132 #endif // CHECK_UNHANDLED_OOPS