1 /*

     2  * Copyright (c) 2017, 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 "classfile/protectionDomainCache.hpp"

    27 #include "classfile/systemDictionary.hpp"

    28 #include "memory/iterator.hpp"

    29 #include "memory/resourceArea.hpp"

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

    31 #include "utilities/hashtable.inline.hpp"

    32 

    33 unsigned int ProtectionDomainCacheTable::compute_hash(Handle protection_domain) {

    34   // Identity hash can safepoint, so keep protection domain in a Handle.

    35   return (unsigned int)(protection_domain->identity_hash());

    36 }

    37 

    38 int ProtectionDomainCacheTable::index_for(Handle protection_domain) {

    39   return hash_to_index(compute_hash(protection_domain));

    40 }

    41 

    42 ProtectionDomainCacheTable::ProtectionDomainCacheTable(int table_size)

    43   : Hashtable<oop, mtClass>(table_size, sizeof(ProtectionDomainCacheEntry))

    44 {

    45 }

    46 

    47 void ProtectionDomainCacheTable::unlink(BoolObjectClosure* is_alive) {

    48   assert(SafepointSynchronize::is_at_safepoint(), "must be");

    49   for (int i = 0; i < table_size(); ++i) {

    50     ProtectionDomainCacheEntry** p = bucket_addr(i);

    51     ProtectionDomainCacheEntry* entry = bucket(i);

    52     while (entry != NULL) {

    53       if (is_alive->do_object_b(entry->literal())) {

    54         p = entry->next_addr();

    55       } else {

    56         if (log_is_enabled(Debug, protectiondomain)) {

    57           outputStream* log = Log(protectiondomain)::debug_stream();

    58           log->print("protection domain unlinked: ");

    59           entry->literal()->print_value_on(log);

    60           log->cr();

    61         }

    62         *p = entry->next();

    63         free_entry(entry);

    64       }

    65       entry = *p;

    66     }

    67   }

    68 }

    69 

    70 void ProtectionDomainCacheTable::oops_do(OopClosure* f) {

    71   for (int index = 0; index < table_size(); index++) {

    72     for (ProtectionDomainCacheEntry* probe = bucket(index);

    73                                      probe != NULL;

    74                                      probe = probe->next()) {

    75       probe->oops_do(f);

    76     }

    77   }

    78 }

    79 

    80 #ifndef PRODUCT

    81 void ProtectionDomainCacheTable::print() {

    82   tty->print_cr("Protection domain cache table (table_size=%d, classes=%d)",

    83                 table_size(), number_of_entries());

    84   for (int index = 0; index < table_size(); index++) {

    85     for (ProtectionDomainCacheEntry* probe = bucket(index);

    86                                      probe != NULL;

    87                                      probe = probe->next()) {

    88       probe->print();

    89     }

    90   }

    91 }

    92 

    93 void ProtectionDomainCacheEntry::print() {

    94   tty->print_cr("entry " PTR_FORMAT " value " PTR_FORMAT " next " PTR_FORMAT,

    95                 p2i(this), p2i(literal()), p2i(next()));

    96 }

    97 #endif

    98 

    99 void ProtectionDomainCacheTable::verify() {

   100   verify_table<ProtectionDomainCacheEntry>("Protection Domain Table");

   101 }

   102 

   103 void ProtectionDomainCacheEntry::verify() {

   104   guarantee(literal()->is_oop(), "must be an oop");

   105 }

   106 

   107 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::get(Handle protection_domain) {

   108   unsigned int hash = compute_hash(protection_domain);

   109   int index = hash_to_index(hash);

   110 

   111   ProtectionDomainCacheEntry* entry = find_entry(index, protection_domain);

   112   if (entry == NULL) {

   113     entry = add_entry(index, hash, protection_domain);

   114   }

   115   return entry;

   116 }

   117 

   118 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::find_entry(int index, Handle protection_domain) {

   119   for (ProtectionDomainCacheEntry* e = bucket(index); e != NULL; e = e->next()) {

   120     if (e->protection_domain() == protection_domain()) {

   121       return e;

   122     }

   123   }

   124 

   125   return NULL;

   126 }

   127 

   128 ProtectionDomainCacheEntry* ProtectionDomainCacheTable::add_entry(int index, unsigned int hash, Handle protection_domain) {

   129   assert_locked_or_safepoint(SystemDictionary_lock);

   130   assert(index == index_for(protection_domain), "incorrect index?");

   131   assert(find_entry(index, protection_domain) == NULL, "no double entry");

   132 

   133   ProtectionDomainCacheEntry* p = new_entry(hash, protection_domain);

   134   Hashtable<oop, mtClass>::add_entry(index, p);

   135   return p;

   136 }