jdk8-mips64-public/hotspot: src/share/vm/utilities/hashtable.cpp@36c186bcc085 (annotated)

src/share/vm/utilities/hashtable.cpp@36c186bcc085 (annotated)

src/share/vm/utilities/hashtable.cpp

Mon, 03 Jan 2011 14:09:11 -0500

author: coleenp
date: Mon, 03 Jan 2011 14:09:11 -0500
changeset 2418: 36c186bcc085
parent 2314: f95d63e2154a
child 2497: 3582bf76420e
permissions: -rw-r--r--

6302804: Hotspot VM dies ungraceful death when C heap is exhausted in various places.
Summary: enhance the error reporting mechanism to help user to fix the problem rather than making it look like a VM error.
Reviewed-by: kvn, kamg

 /*
  * Copyright (c) 2003, 2010, 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.
  *
  */
 #include "precompiled.hpp"
 #include "memory/allocation.inline.hpp"
 #include "memory/resourceArea.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/safepoint.hpp"
 #include "utilities/dtrace.hpp"
 #include "utilities/hashtable.hpp"
 #include "utilities/hashtable.inline.hpp"
 HS_DTRACE_PROBE_DECL4(hs_private, hashtable__new_entry,
   void*, unsigned int, oop, void*);
 // This is a generic hashtable, designed to be used for the symbol
 // and string tables.
 //
 // It is implemented as an open hash table with a fixed number of buckets.
 //
 // %note:
 //  - HashtableEntrys are allocated in blocks to reduce the space overhead.
 BasicHashtableEntry* BasicHashtable::new_entry(unsigned int hashValue) {
   BasicHashtableEntry* entry;
   if (_free_list) {
     entry = _free_list;
     _free_list = _free_list->next();
   } else {
     if (_first_free_entry + _entry_size >= _end_block) {
       int block_size = MIN2(512, MAX2((int)_table_size / 2, (int)_number_of_entries));
       int len = _entry_size * block_size;
       len = 1 << log2_intptr(len); // round down to power of 2
       assert(len >= _entry_size, "");
       _first_free_entry = NEW_C_HEAP_ARRAY(char, len);
       _end_block = _first_free_entry + len;
     }
     entry = (BasicHashtableEntry*)_first_free_entry;
     _first_free_entry += _entry_size;
   }
   assert(_entry_size % HeapWordSize == 0, "");
   entry->set_hash(hashValue);
   return entry;
 }
 HashtableEntry* Hashtable::new_entry(unsigned int hashValue, oop obj) {
   HashtableEntry* entry;
   entry = (HashtableEntry*)BasicHashtable::new_entry(hashValue);
   entry->set_literal(obj);   // clears literal string field
   HS_DTRACE_PROBE4(hs_private, hashtable__new_entry,
     this, hashValue, obj, entry);
   return entry;
 }
 // GC support
 void Hashtable::unlink(BoolObjectClosure* is_alive) {
   // Readers of the table are unlocked, so we should only be removing
   // entries at a safepoint.
   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
   for (int i = 0; i < table_size(); ++i) {
     for (HashtableEntry** p = bucket_addr(i); *p != NULL; ) {
       HashtableEntry* entry = *p;
       if (entry->is_shared()) {
         break;
       }
       assert(entry->literal() != NULL, "just checking");
       if (is_alive->do_object_b(entry->literal())) {
         p = entry->next_addr();
       } else {
         *p = entry->next();
         free_entry(entry);
       }
     }
   }
 }
 void Hashtable::oops_do(OopClosure* f) {
   for (int i = 0; i < table_size(); ++i) {
     HashtableEntry** p = bucket_addr(i);
     HashtableEntry* entry = bucket(i);
     while (entry != NULL) {
       f->do_oop(entry->literal_addr());
       // Did the closure remove the literal from the table?
       if (entry->literal() == NULL) {
         assert(!entry->is_shared(), "immutable hashtable entry?");
         *p = entry->next();
         free_entry(entry);
       } else {
         p = entry->next_addr();
       }
       entry = (HashtableEntry*)HashtableEntry::make_ptr(*p);
     }
   }
 }
 // Reverse the order of elements in the hash buckets.
 void BasicHashtable::reverse() {
   for (int i = 0; i < _table_size; ++i) {
     BasicHashtableEntry* new_list = NULL;
     BasicHashtableEntry* p = bucket(i);
     while (p != NULL) {
       BasicHashtableEntry* next = p->next();
       p->set_next(new_list);
       new_list = p;
       p = next;
     }
     *bucket_addr(i) = new_list;
   }
 }
 // Copy the table to the shared space.
 void BasicHashtable::copy_table(char** top, char* end) {
   // Dump the hash table entries.
   intptr_t *plen = (intptr_t*)(*top);
   *top += sizeof(*plen);
   int i;
   for (i = 0; i < _table_size; ++i) {
     for (BasicHashtableEntry** p = _buckets[i].entry_addr();
                               *p != NULL;
                                p = (*p)->next_addr()) {
       if (*top + entry_size() > end) {
         warning("\nThe shared miscellaneous data space is not large "
                 "enough to \npreload requested classes.  Use "
                 "-XX:SharedMiscDataSize= to increase \nthe initial "
                 "size of the miscellaneous data space.\n");
         exit(2);
       }
       *p = (BasicHashtableEntry*)memcpy(*top, *p, entry_size());
       *top += entry_size();
     }
   }
   *plen = (char*)(*top) - (char*)plen - sizeof(*plen);
   // Set the shared bit.
   for (i = 0; i < _table_size; ++i) {
     for (BasicHashtableEntry* p = bucket(i); p != NULL; p = p->next()) {
       p->set_shared();
     }
   }
 }
 // Reverse the order of elements in the hash buckets.
 void Hashtable::reverse(void* boundary) {
   for (int i = 0; i < table_size(); ++i) {
     HashtableEntry* high_list = NULL;
     HashtableEntry* low_list = NULL;
     HashtableEntry* last_low_entry = NULL;
     HashtableEntry* p = bucket(i);
     while (p != NULL) {
       HashtableEntry* next = p->next();
       if ((void*)p->literal() >= boundary) {
         p->set_next(high_list);
         high_list = p;
       } else {
         p->set_next(low_list);
         low_list = p;
         if (last_low_entry == NULL) {
           last_low_entry = p;
         }
       }
       p = next;
     }
     if (low_list != NULL) {
       *bucket_addr(i) = low_list;
       last_low_entry->set_next(high_list);
     } else {
       *bucket_addr(i) = high_list;
     }
   }
 }
 // Dump the hash table buckets.
 void BasicHashtable::copy_buckets(char** top, char* end) {
   intptr_t len = _table_size * sizeof(HashtableBucket);
   *(intptr_t*)(*top) = len;
   *top += sizeof(intptr_t);
   *(intptr_t*)(*top) = _number_of_entries;
   *top += sizeof(intptr_t);
   if (*top + len > end) {
     warning("\nThe shared miscellaneous data space is not large "
             "enough to \npreload requested classes.  Use "
             "-XX:SharedMiscDataSize= to increase \nthe initial "
             "size of the miscellaneous data space.\n");
     exit(2);
   }
   _buckets = (HashtableBucket*)memcpy(*top, _buckets, len);
   *top += len;
 }
 #ifndef PRODUCT
 void Hashtable::print() {
   ResourceMark rm;
   for (int i = 0; i < table_size(); i++) {
     HashtableEntry* entry = bucket(i);
     while(entry != NULL) {
       tty->print("%d : ", i);
       entry->literal()->print();
       tty->cr();
       entry = entry->next();
     }
   }
 }
 void BasicHashtable::verify() {
   int count = 0;
   for (int i = 0; i < table_size(); i++) {
     for (BasicHashtableEntry* p = bucket(i); p != NULL; p = p->next()) {
       ++count;
     }
   }
   assert(count == number_of_entries(), "number of hashtable entries incorrect");
 }
 #endif // PRODUCT
 #ifdef ASSERT
 void BasicHashtable::verify_lookup_length(double load) {
   if ((double)_lookup_length / (double)_lookup_count > load * 2.0) {
     warning("Performance bug: SystemDictionary lookup_count=%d "
             "lookup_length=%d average=%lf load=%f",
             _lookup_count, _lookup_length,
             (double) _lookup_length / _lookup_count, load);
   }
 }
 #endif

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/utilities/hashtable.cpp@36c186bcc085 (annotated)

src/share/vm/utilities/hashtable.cpp