2 * Copyright (C) 2008 The Android Open Source Project
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
17 * Maintain a table of references. Used for internal local references,
18 * JNI locals, JNI globals, and GC heap references.
20 * None of the table functions are synchronized.
22 #ifndef _DALVIK_REFERENCETABLE
23 #define _DALVIK_REFERENCETABLE
28 * The expected common operations are adding a new entry and removing a
29 * recently-added entry (usually the most-recently-added entry).
31 * If "allocEntries" is not equal to "maxEntries", the table may expand when
32 * entries are added, which means the memory may move. If you want to keep
33 * pointers into "table" rather than offsets, use a fixed-size table.
35 * (This structure is still somewhat transparent; direct access to
36 * table/nextEntry is allowed.)
38 typedef struct ReferenceTable {
39 Object** table; /* top of the list */
40 Object** nextEntry; /* bottom of the list */
42 int allocEntries; /* #of entries we have space for */
43 int maxEntries; /* max #of entries allowed */
47 * Initialize a ReferenceTable.
49 * If "initialCount" != "maxCount", the table will expand as required.
51 * Returns "false" if table allocation fails.
53 bool dvmInitReferenceTable(ReferenceTable* pRef, int initialCount,
57 * Clears out the contents of a ReferenceTable, freeing allocated storage.
58 * Does not free "pRef".
60 * You must call dvmInitReferenceTable() before you can re-use this table.
62 void dvmClearReferenceTable(ReferenceTable* pRef);
65 * Return the #of entries currently stored in the ReferenceTable.
67 INLINE size_t dvmReferenceTableEntries(const ReferenceTable* pRef)
69 return pRef->nextEntry - pRef->table;
73 * Returns "true" if the table is full. The table is considered full if
74 * we would need to expand it to add another entry.
76 INLINE size_t dvmIsReferenceTableFull(const ReferenceTable* pRef)
78 return dvmReferenceTableEntries(pRef) == (size_t)pRef->allocEntries;
82 * Add a new entry. "obj" must be a valid non-NULL object reference
83 * (though it's okay if it's not fully-formed, e.g. the result from
84 * dvmMalloc doesn't have obj->clazz set).
86 * Returns "false" if the table is full.
88 bool dvmAddToReferenceTable(ReferenceTable* pRef, Object* obj);
91 * Determine if "obj" is present in "pRef". Stops searching when we hit "top".
92 * To include the entire table, pass in "pRef->table" as the top.
94 * Returns NULL if "obj" was not found.
96 Object** dvmFindInReferenceTable(const ReferenceTable* pRef, Object** top,
100 * Remove an existing entry.
102 * We stop searching for a match after examining the element at "top". This
103 * is useful when entries are associated with a stack frame.
105 * Returns "false" if the entry was not found.
107 bool dvmRemoveFromReferenceTable(ReferenceTable* pRef, Object** top,
111 * Dump the contents of a reference table to the log file.
113 void dvmDumpReferenceTable(const ReferenceTable* pRef, const char* descr);
115 #endif /*_DALVIK_REFERENCETABLE*/