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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/Heap.h"
20 #include "alloc/HeapInternal.h" // for GcHeap
21 
22 /* dlmalloc uses one size_t per allocated chunk.
23  */
24 #define HEAP_SOURCE_CHUNK_OVERHEAD         (1 * sizeof (size_t))
25 #define HEAP_SOURCE_WORST_CHUNK_OVERHEAD   (32 * sizeof (size_t))
26 
27 /* The largest number of separate heaps we can handle.
28  */
29 #define HEAP_SOURCE_MAX_HEAP_COUNT 2
30 
31 /*
32  * Initializes the heap source; must be called before any other
33  * dvmHeapSource*() functions.
34  */
35 GcHeap *dvmHeapSourceStartup(size_t startSize, size_t absoluteMaxSize);
36 
37 /*
38  * If the HeapSource was created while in zygote mode, this
39  * will create a new heap for post-zygote allocations.
40  * Having a separate heap should maximize the number of pages
41  * that a given app_process shares with the zygote process.
42  */
43 bool dvmHeapSourceStartupAfterZygote(void);
44 
45 /*
46  * If the HeapSource was created while in zygote mode, this
47  * will create an additional zygote heap before the first fork().
48  * Having a separate heap should reduce the number of shared
49  * pages subsequently touched by the zygote process.
50  */
51 bool dvmHeapSourceStartupBeforeFork(void);
52 
53 /*
54  * Shutdown any threads internal to the heap source.  This should be
55  * called before the heap source itself is shutdown.
56  */
57 void dvmHeapSourceThreadShutdown(void);
58 
59 /*
60  * Tears down the heap source and frees any resources associated with it.
61  */
62 void dvmHeapSourceShutdown(GcHeap **gcHeap);
63 
64 /*
65  * Initializes a vector of object and mark bits to the object and mark
66  * bits of each heap.
67  */
68 void dvmHeapSourceGetObjectBitmaps(HeapBitmap liveBits[], HeapBitmap markBits[],
69                                    size_t numHeaps);
70 
71 /*
72  * Get the bitmap representing all live objects.
73  */
74 HeapBitmap *dvmHeapSourceGetLiveBits(void);
75 
76 /*
77  * Gets the begining of the allocation for the HeapSource.
78  */
79 void *dvmHeapSourceGetBase(void);
80 
81 /*
82  * Returns the requested value. If the per-heap stats are requested, fill
83  * them as well.
84  */
85 enum HeapSourceValueSpec {
86     HS_FOOTPRINT,
87     HS_ALLOWED_FOOTPRINT,
88     HS_BYTES_ALLOCATED,
89     HS_OBJECTS_ALLOCATED,
90     HS_EXTERNAL_BYTES_ALLOCATED,
91     HS_EXTERNAL_LIMIT
92 };
93 size_t dvmHeapSourceGetValue(enum HeapSourceValueSpec spec,
94                              size_t perHeapStats[], size_t arrayLen);
95 
96 /*
97  * Allocates <n> bytes of zeroed data.
98  */
99 void *dvmHeapSourceAlloc(size_t n);
100 
101 /*
102  * Allocates <n> bytes of zeroed data, growing up to absoluteMaxSize
103  * if necessary.
104  */
105 void *dvmHeapSourceAllocAndGrow(size_t n);
106 
107 /*
108  * Frees the first numPtrs objects in the ptrs list and returns the
109  * amount of reclaimed storage.  The list must contain addresses all
110  * in the same mspace, and must be in increasing order. This implies
111  * that there are no duplicates, and no entries are NULL.
112  */
113 size_t 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 true iff <ptr> is within the address space managed by heap source.
122  */
123 bool dvmHeapSourceContainsAddress(const void *ptr);
124 
125 /*
126  * Returns the value of the requested flag.
127  */
128 enum HeapSourcePtrFlag {
129     HS_CONTAINS,    // identical to dvmHeapSourceContains()
130     HS_ALLOCATED_IN_ZYGOTE
131 };
132 bool dvmHeapSourceGetPtrFlag(const void *ptr, enum HeapSourcePtrFlag flag);
133 
134 /*
135  * Returns the number of usable bytes in an allocated chunk; the size
136  * may be larger than the size passed to dvmHeapSourceAlloc().
137  */
138 size_t dvmHeapSourceChunkSize(const void *ptr);
139 
140 /*
141  * Returns the number of bytes that the heap source has allocated
142  * from the system using sbrk/mmap, etc.
143  */
144 size_t dvmHeapSourceFootprint(void);
145 
146 /*
147  * Gets the maximum number of bytes that the heap source is allowed
148  * to allocate from the system.
149  */
150 size_t dvmHeapSourceGetIdealFootprint(void);
151 
152 /*
153  * Given the current contents of the heap, increase the allowed
154  * heap footprint to match the target utilization ratio.  This
155  * should only be called immediately after a full mark/sweep.
156  */
157 void dvmHeapSourceGrowForUtilization(void);
158 
159 /*
160  * Return unused memory to the system if possible.  If <bytesTrimmed>
161  * is non-NULL, the number of bytes returned to the system is written to it.
162  */
163 void dvmHeapSourceTrim(size_t bytesTrimmed[], size_t arrayLen);
164 
165 /*
166  * Walks over the heap source and passes every allocated and
167  * free chunk to the callback.
168  */
169 void dvmHeapSourceWalk(void(*callback)(const void *chunkptr, size_t chunklen,
170                                       const void *userptr, size_t userlen,
171                                       void *arg),
172                        void *arg);
173 /*
174  * Gets the number of heaps available in the heap source.
175  */
176 size_t dvmHeapSourceGetNumHeaps(void);
177 
178 /*
179  * Exchanges the mark and object bitmaps.
180  */
181 void dvmHeapSourceSwapBitmaps(void);
182 
183 /*
184  * Zeroes the mark bitmap.
185  */
186 void dvmHeapSourceZeroMarkBitmap(void);
187 
188 /*
189  * Marks all objects inside the immune region of the heap. Addresses
190  * at or above this pointer are threatened, addresses below this
191  * pointer are immune.
192  */
193 void dvmMarkImmuneObjects(const char *immuneLimit);
194 
195 /*
196  * Returns a pointer that demarcates the threatened region of the
197  * heap.  Addresses at or above this pointer are threatened, addresses
198  * below this pointer are immune.
199  */
200 void *dvmHeapSourceGetImmuneLimit(GcMode mode);
201 
202 #endif  // _DALVIK_HEAP_SOURCE
203