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.
18 * Maintain a table of references. Used for internal local references,
19 * JNI locals, JNI globals, and GC heap references.
21 * None of the table functions are synchronized.
23 #ifndef _DALVIK_REFERENCETABLE
24 #define _DALVIK_REFERENCETABLE
33 * The expected common operations are adding a new entry and removing a
34 * recently-added entry (usually the most-recently-added entry).
36 * If "allocEntries" is not equal to "maxEntries", the table may expand when
37 * entries are added, which means the memory may move. If you want to keep
38 * pointers into "table" rather than offsets, use a fixed-size table.
40 * (This structure is still somewhat transparent; direct access to
41 * table/nextEntry is allowed.)
43 typedef struct ReferenceTable {
44 Object** nextEntry; /* top of the list */
45 Object** table; /* bottom of the list */
47 int allocEntries; /* #of entries we have space for */
48 int maxEntries; /* max #of entries allowed */
52 * Initialize a ReferenceTable.
54 * If "initialCount" != "maxCount", the table will expand as required.
56 * Returns "false" if table allocation fails.
58 bool dvmInitReferenceTable(ReferenceTable* pRef, int initialCount,
62 * Clears out the contents of a ReferenceTable, freeing allocated storage.
63 * Does not free "pRef".
65 * You must call dvmInitReferenceTable() before you can re-use this table.
67 void dvmClearReferenceTable(ReferenceTable* pRef);
70 * Return the #of entries currently stored in the ReferenceTable.
72 INLINE size_t dvmReferenceTableEntries(const ReferenceTable* pRef)
74 return pRef->nextEntry - pRef->table;
78 * Returns "true" if the table is full. The table is considered full if
79 * we would need to expand it to add another entry.
81 INLINE size_t dvmIsReferenceTableFull(const ReferenceTable* pRef)
83 return dvmReferenceTableEntries(pRef) == (size_t)pRef->allocEntries;
87 * Add a new entry. "obj" must be a valid non-NULL object reference
88 * (though it's okay if it's not fully-formed, e.g. the result from
89 * dvmMalloc doesn't have obj->clazz set).
91 * Returns "false" if the table is full.
93 bool dvmAddToReferenceTable(ReferenceTable* pRef, Object* obj);
96 * Determine if "obj" is present in "pRef". Stops searching when we hit
97 * "bottom". To include the entire table, pass in "pRef->table" as the
100 * Returns NULL if "obj" was not found.
102 Object** dvmFindInReferenceTable(const ReferenceTable* pRef, Object** bottom,
106 * Remove an existing entry.
108 * We stop searching for a match after examining the element at "bottom".
109 * This is useful when entries are associated with a stack frame.
111 * Returns "false" if the entry was not found.
113 bool dvmRemoveFromReferenceTable(ReferenceTable* pRef, Object** bottom,
117 * Dump the contents of a reference table to the log file.
119 * The caller should lock any external sync before calling.
121 void dvmDumpReferenceTable(const ReferenceTable* pRef, const char* descr);
124 * Internal function, shared with IndirectRefTable.
126 void dvmDumpReferenceTableContents(Object* const* refs, size_t count,
133 #endif /*_DALVIK_REFERENCETABLE*/