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      1 /*
      2  * Copyright (C) 2008 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 /*
     18  * The VM wraps some additional data structures around the DexFile.  These
     19  * are defined here.
     20  */
     21 #ifndef _DALVIK_DVMDEX
     22 #define _DALVIK_DVMDEX
     23 
     24 #include "libdex/DexFile.h"
     25 
     26 /* extern */
     27 struct ClassObject;
     28 struct HashTable;
     29 struct InstField;
     30 struct Method;
     31 struct StringObject;
     32 
     33 
     34 /*
     35  * Some additional VM data structures that are associated with the DEX file.
     36  */
     37 typedef struct DvmDex {
     38     /* pointer to the DexFile we're associated with */
     39     DexFile*            pDexFile;
     40 
     41     /* clone of pDexFile->pHeader (it's used frequently enough) */
     42     const DexHeader*    pHeader;
     43 
     44     /* interned strings; parallel to "stringIds" */
     45     struct StringObject** pResStrings;
     46 
     47     /* resolved classes; parallel to "typeIds" */
     48     struct ClassObject** pResClasses;
     49 
     50     /* resolved methods; parallel to "methodIds" */
     51     struct Method**     pResMethods;
     52 
     53     /* resolved instance fields; parallel to "fieldIds" */
     54     /* (this holds both InstField and StaticField) */
     55     struct Field**      pResFields;
     56 
     57     /* interface method lookup cache */
     58     struct AtomicCache* pInterfaceCache;
     59 
     60     /* shared memory region with file contents */
     61     MemMapping          memMap;
     62 
     63     /* lock ensuring mutual exclusion during updates */
     64     pthread_mutex_t     modLock;
     65 } DvmDex;
     66 
     67 
     68 /*
     69  * Given a file descriptor for an open "optimized" DEX file, map it into
     70  * memory and parse the contents.
     71  *
     72  * On success, returns 0 and sets "*ppDvmDex" to a newly-allocated DvmDex.
     73  * On failure, returns a meaningful error code [currently just -1].
     74  */
     75 int dvmDexFileOpenFromFd(int fd, DvmDex** ppDvmDex);
     76 
     77 /*
     78  * Open a partial DEX file.  Only useful as part of the optimization process.
     79  */
     80 int dvmDexFileOpenPartial(const void* addr, int len, DvmDex** ppDvmDex);
     81 
     82 /*
     83  * Free a DvmDex structure, along with any associated structures.
     84  */
     85 void dvmDexFileFree(DvmDex* pDvmDex);
     86 
     87 
     88 /*
     89  * Change the 1- or 2-byte value at the specified address to a new value.  If
     90  * the location already has the new value, do nothing.
     91  *
     92  * This does not make any synchronization guarantees.  The caller must
     93  * ensure exclusivity vs. other callers.
     94  *
     95  * For the 2-byte call, the pointer should have 16-bit alignment.
     96  *
     97  * Returns "true" on success.
     98  */
     99 bool dvmDexChangeDex1(DvmDex* pDvmDex, u1* addr, u1 newVal);
    100 bool dvmDexChangeDex2(DvmDex* pDvmDex, u2* addr, u2 newVal);
    101 
    102 
    103 /*
    104  * Return the requested item if it has been resolved, or NULL if it hasn't.
    105  */
    106 INLINE struct StringObject* dvmDexGetResolvedString(const DvmDex* pDvmDex,
    107     u4 stringIdx)
    108 {
    109     assert(stringIdx < pDvmDex->pHeader->stringIdsSize);
    110     return pDvmDex->pResStrings[stringIdx];
    111 }
    112 INLINE struct ClassObject* dvmDexGetResolvedClass(const DvmDex* pDvmDex,
    113     u4 classIdx)
    114 {
    115     assert(classIdx < pDvmDex->pHeader->typeIdsSize);
    116     return pDvmDex->pResClasses[classIdx];
    117 }
    118 INLINE struct Method* dvmDexGetResolvedMethod(const DvmDex* pDvmDex,
    119     u4 methodIdx)
    120 {
    121     assert(methodIdx < pDvmDex->pHeader->methodIdsSize);
    122     return pDvmDex->pResMethods[methodIdx];
    123 }
    124 INLINE struct Field* dvmDexGetResolvedField(const DvmDex* pDvmDex,
    125     u4 fieldIdx)
    126 {
    127     assert(fieldIdx < pDvmDex->pHeader->fieldIdsSize);
    128     return pDvmDex->pResFields[fieldIdx];
    129 }
    130 
    131 /*
    132  * Update the resolved item table.  Resolution always produces the same
    133  * result, so we're not worried about atomicity here.
    134  */
    135 INLINE void dvmDexSetResolvedString(DvmDex* pDvmDex, u4 stringIdx,
    136     struct StringObject* str)
    137 {
    138     assert(stringIdx < pDvmDex->pHeader->stringIdsSize);
    139     pDvmDex->pResStrings[stringIdx] = str;
    140 }
    141 INLINE void dvmDexSetResolvedClass(DvmDex* pDvmDex, u4 classIdx,
    142     struct ClassObject* clazz)
    143 {
    144     assert(classIdx < pDvmDex->pHeader->typeIdsSize);
    145     pDvmDex->pResClasses[classIdx] = clazz;
    146 }
    147 INLINE void dvmDexSetResolvedMethod(DvmDex* pDvmDex, u4 methodIdx,
    148     struct Method* method)
    149 {
    150     assert(methodIdx < pDvmDex->pHeader->methodIdsSize);
    151     pDvmDex->pResMethods[methodIdx] = method;
    152 }
    153 INLINE void dvmDexSetResolvedField(DvmDex* pDvmDex, u4 fieldIdx,
    154     struct Field* field)
    155 {
    156     assert(fieldIdx < pDvmDex->pHeader->fieldIdsSize);
    157     pDvmDex->pResFields[fieldIdx] = field;
    158 }
    159 
    160 #endif /*_DALVIK_DVMDEX*/
    161