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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 #ifndef _DALVIK_HEAP_SOURCE
17 #define _DALVIK_HEAP_SOURCE
18 
19 #include "alloc/HeapInternal.h" // for GcHeap
20 
21 /* dlmalloc uses one size_t per allocated chunk.
22  */
23 #define HEAP_SOURCE_CHUNK_OVERHEAD         (1 * sizeof (size_t))
24 #define HEAP_SOURCE_WORST_CHUNK_OVERHEAD   (32 * sizeof (size_t))
25 
26 /* The largest number of separate heaps we can handle.
27  */
28 #define HEAP_SOURCE_MAX_HEAP_COUNT 3
29 
30 /*
31  * Initializes the heap source; must be called before any other
32  * dvmHeapSource*() functions.
33  */
34 GcHeap *dvmHeapSourceStartup(size_t startSize, size_t absoluteMaxSize);
35 
36 /*
37  * If the HeapSource was created while in zygote mode, this
38  * will create a new heap for post-zygote allocations.
39  * Having a separate heap should maximize the number of pages
40  * that a given app_process shares with the zygote process.
41  */
42 bool dvmHeapSourceStartupAfterZygote(void);
43 
44 /*
45  * If the HeapSource was created while in zygote mode, this
46  * will create an additional zygote heap before the first fork().
47  * Having a separate heap should reduce the number of shared
48  * pages subsequently touched by the zygote process.
49  */
50 bool dvmHeapSourceStartupBeforeFork(void);
51 
52 /*
53  * Tears down the heap source and frees any resources associated with it.
54  */
55 void dvmHeapSourceShutdown(GcHeap *gcHeap);
56 
57 /*
58  * Writes shallow copies of the currently-used bitmaps into outBitmaps,
59  * returning the number of bitmaps written.  Returns <0 if the array
60  * was not long enough.
61  */
62 ssize_t dvmHeapSourceGetObjectBitmaps(HeapBitmap outBitmaps[],
63         size_t maxBitmaps);
64 
65 /*
66  * Replaces the object location HeapBitmaps with the elements of
67  * <objectBitmaps>.  The elements of <objectBitmaps> are overwritten
68  * with shallow copies of the old bitmaps.
69  *
70  * Returns false if the number of bitmaps doesn't match the number
71  * of heaps.
72  */
73 bool dvmHeapSourceReplaceObjectBitmaps(HeapBitmap objectBitmaps[],
74         size_t nBitmaps);
75 
76 /*
77  * Returns the requested value. If the per-heap stats are requested, fill
78  * them as well.
79  */
80 enum HeapSourceValueSpec {
81     HS_FOOTPRINT,
82     HS_ALLOWED_FOOTPRINT,
83     HS_BYTES_ALLOCATED,
84     HS_OBJECTS_ALLOCATED,
85     HS_EXTERNAL_BYTES_ALLOCATED,
86     HS_EXTERNAL_LIMIT
87 };
88 size_t dvmHeapSourceGetValue(enum HeapSourceValueSpec spec,
89                              size_t perHeapStats[], size_t arrayLen);
90 
91 /*
92  * Allocates <n> bytes of zeroed data.
93  */
94 void *dvmHeapSourceAlloc(size_t n);
95 
96 /*
97  * Allocates <n> bytes of zeroed data, growing up to absoluteMaxSize
98  * if necessary.
99  */
100 void *dvmHeapSourceAllocAndGrow(size_t n);
101 
102 /*
103  * Frees the memory pointed to by <ptr>, which may be NULL.
104  */
105 void dvmHeapSourceFree(void *ptr);
106 
107 /*
108  * Frees the first numPtrs objects in the ptrs list. The list must
109  * contain addresses all in the same mspace, and must be in increasing
110  * order. This implies that there are no duplicates, and no entries
111  * are NULL.
112  */
113 void dvmHeapSourceFreeList(size_t numPtrs, void **ptrs);
114 
115 /*
116  * Returns true iff <ptr> was allocated from the heap source.
117  */
118 bool dvmHeapSourceContains(const void *ptr);
119 
120 /*
121  * Returns the value of the requested flag.
122  */
123 enum HeapSourcePtrFlag {
124     HS_CONTAINS,    // identical to dvmHeapSourceContains()
125     HS_ALLOCATED_IN_ZYGOTE
126 };
127 bool dvmHeapSourceGetPtrFlag(const void *ptr, enum HeapSourcePtrFlag flag);
128 
129 /*
130  * Returns the number of usable bytes in an allocated chunk; the size
131  * may be larger than the size passed to dvmHeapSourceAlloc().
132  */
133 size_t dvmHeapSourceChunkSize(const void *ptr);
134 
135 /*
136  * Returns the number of bytes that the heap source has allocated
137  * from the system using sbrk/mmap, etc.
138  */
139 size_t dvmHeapSourceFootprint(void);
140 
141 /*
142  * Gets the maximum number of bytes that the heap source is allowed
143  * to allocate from the system.
144  */
145 size_t dvmHeapSourceGetIdealFootprint(void);
146 
147 /*
148  * Given the current contents of the heap, increase the allowed
149  * heap footprint to match the target utilization ratio.  This
150  * should only be called immediately after a full mark/sweep.
151  */
152 void dvmHeapSourceGrowForUtilization(void);
153 
154 /*
155  * Return unused memory to the system if possible.  If <bytesTrimmed>
156  * is non-NULL, the number of bytes returned to the system is written to it.
157  */
158 void dvmHeapSourceTrim(size_t bytesTrimmed[], size_t arrayLen);
159 
160 /*
161  * Walks over the heap source and passes every allocated and
162  * free chunk to the callback.
163  */
164 void dvmHeapSourceWalk(void(*callback)(const void *chunkptr, size_t chunklen,
165                                       const void *userptr, size_t userlen,
166                                       void *arg),
167                        void *arg);
168 /*
169  * Gets the number of heaps available in the heap source.
170  */
171 size_t dvmHeapSourceGetNumHeaps(void);
172 
173 #endif  // _DALVIK_HEAP_SOURCE
174