1 /* 2 * Copyright (c) 1996, 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 #include "CmdIDList.h" 27 28 // How much space to allocate initially 29 static const UINT ARRAY_INITIAL_SIZE = 1024; 30 31 // Array expansion increment when need more free space 32 static const UINT ARRAY_SIZE_INCREMENT = 1024; 33 34 // It seems that Win95 can not handle ids greater than 2**16 35 static const UINT ARRAY_MAXIMUM_SIZE = 32768; 36 37 38 AwtCmdIDList::AwtCmdIDList() 39 { 40 m_capacity = ARRAY_INITIAL_SIZE; 41 m_first_free = -1; 42 m_array = (CmdIDEntry *)SAFE_SIZE_ARRAY_ALLOC(safe_Malloc, m_capacity, sizeof(AwtObject*)); 43 BuildFreeList(0); 44 } 45 46 AwtCmdIDList::~AwtCmdIDList() 47 { 48 free(m_array); 49 } 50 51 52 // Build a new free list from a newly allocated memory. This only 53 // happens after malloc/realloc, and new free entries are contiguous 54 // from first_index to m_capacity-1 55 INLINE void AwtCmdIDList::BuildFreeList(UINT first_index) 56 { 57 DASSERT(m_first_free == -1); 58 for (UINT i = first_index; i < m_capacity-1; ++i) 59 m_array[i].next_free_index = i+1; 60 m_array[m_capacity-1].next_free_index = -1; // nil 61 m_first_free = first_index; // head of the free list 62 } 63 64 65 jboolean AwtCmdIDList::isFreeIDAvailable() { 66 CriticalSection::Lock l(m_lock); 67 68 if (m_first_free == -1) { // out of free ids 69 if (m_capacity == ARRAY_MAXIMUM_SIZE) { 70 return JNI_FALSE; 71 } 72 } 73 return JNI_TRUE; 74 } 75 76 // Assign an id to the object. Recycle the first free entry from the 77 // head of the free list or allocate more memory for a new free list. 78 UINT AwtCmdIDList::Add(AwtObject* obj) 79 { 80 CriticalSection::Lock l(m_lock); 81 if (!isFreeIDAvailable()) { 82 throw std::bad_alloc(); // fatal error 83 } 84 85 if (m_first_free == -1) { // out of free ids 86 // snarf a bigger arena 87 UINT old_capacity = m_capacity; // will be the first free entry 88 m_capacity += ARRAY_SIZE_INCREMENT; 89 if (m_capacity > ARRAY_MAXIMUM_SIZE) 90 m_capacity = ARRAY_MAXIMUM_SIZE; 91 m_array = (CmdIDEntry *)SAFE_SIZE_ARRAY_REALLOC(safe_Realloc, m_array, 92 m_capacity, sizeof(CmdIDEntry*)); 93 BuildFreeList(old_capacity); 94 } 95 96 DASSERT(m_first_free != -1); 97 UINT newid = m_first_free; // use the entry from the head of the list 98 m_first_free = m_array[newid].next_free_index; // advance free pointer 99 m_array[newid].obj = obj; 100 101 return newid; 102 } 103 104 // Return the object associated with this id.. 105 AwtObject* AwtCmdIDList::Lookup(UINT id) 106 { 107 CriticalSection::Lock l(m_lock); 108 DASSERT(id < m_capacity); 109 if (m_array[id].next_free_index <= ARRAY_MAXIMUM_SIZE) { 110 return NULL; 111 } 112 return m_array[id].obj; 113 } 114 115 // Return this id to the head of the free list. 116 void AwtCmdIDList::Remove(UINT id) 117 { 118 CriticalSection::Lock l(m_lock); 119 DASSERT(id < m_capacity); 120 DASSERT(m_array[id].next_free_index > ARRAY_MAXIMUM_SIZE); // it's a pointer 121 m_array[id].next_free_index = m_first_free; 122 m_first_free = id; 123 }