Heap.h revision 33c8ae5bb1bb8052680108d999c608df8c72a613 
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 * Internal heap functions
18 */
19#ifndef DALVIK_ALLOC_HEAP_H_
20#define DALVIK_ALLOC_HEAP_H_
21
22struct GcSpec {
23  /* If true, only the application heap is threatened. */
24  bool isPartial;
25  /* If true, the trace is run concurrently with the mutator. */
26  bool isConcurrent;
27  /* Toggles for the soft reference clearing policy. */
28  bool doPreserve;
29  /* A name for this garbage collection mode. */
30  const char *reason;
31};
32
33/* Not enough space for an "ordinary" Object to be allocated. */
34extern const GcSpec *GC_FOR_MALLOC;
35
36/* Automatic GC triggered by exceeding a heap occupancy threshold. */
37extern const GcSpec *GC_CONCURRENT;
38
39/* Explicit GC via Runtime.gc(), VMRuntime.gc(), or SIGUSR1. */
40extern const GcSpec *GC_EXPLICIT;
41
42/* Final attempt to reclaim memory before throwing an OOM. */
43extern const GcSpec *GC_BEFORE_OOM;
44
45/*
46 * Initialize the GC heap.
47 *
48 * Returns true if successful, false otherwise.
49 */
50bool dvmHeapStartup(void);
51
52/*
53 * Initialization that needs to wait until after leaving zygote mode.
54 * This needs to be called before the first allocation or GC that
55 * happens after forking.
56 */
57bool dvmHeapStartupAfterZygote(void);
58
59/*
60 * Tear down the GC heap.
61 *
62 * Frees all memory allocated via dvmMalloc() as
63 * a side-effect.
64 */
65void dvmHeapShutdown(void);
66
67/*
68 * Stops any threads internal to the garbage collector.  Called before
69 * the heap itself is shutdown.
70 */
71void dvmHeapThreadShutdown(void);
72
73#if 0       // needs to be in Alloc.h so debug code can find it.
74/*
75 * Returns a number of bytes greater than or
76 * equal to the size of the named object in the heap.
77 *
78 * Specifically, it returns the size of the heap
79 * chunk which contains the object.
80 */
81size_t dvmObjectSizeInHeap(const Object *obj);
82#endif
83
84/*
85 * Run the garbage collector without doing any locking.
86 */
87void dvmCollectGarbageInternal(const GcSpec *spec);
88
89/*
90 * Blocks the calling thread until the garbage collector is inactive.
91 * The caller must hold the heap lock as this call releases and
92 * re-acquires the heap lock.  After returning, no garbage collection
93 * will be in progress and the heap lock will be held by the caller.
94 */
95bool dvmWaitForConcurrentGcToComplete(void);
96
97/*
98 * Returns true iff <obj> points to a valid allocated object.
99 */
100bool dvmIsValidObject(const Object* obj);
101
102#endif  // DALVIK_ALLOC_HEAP_H_
103