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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 /*
     17  * Garbage collector
     18  */
     19 #ifndef _DALVIK_ALLOC_GC
     20 #define _DALVIK_ALLOC_GC
     21 
     22 /*
     23  * Initiate garbage collection.
     24  *
     25  * This usually happens automatically, but can also be caused by Runtime.gc().
     26  */
     27 void dvmCollectGarbage(bool collectSoftRefs);
     28 
     29 /****
     30  **** NOTE: The functions after this point will (should) only be called
     31  ****       during GC.
     32  ****/
     33 
     34 /*
     35  * Functions that mark an object.
     36  *
     37  * Currently implemented in Heap.c.
     38  */
     39 
     40 /*
     41  * Mark an object and schedule it to be scanned for
     42  * references to other objects.
     43  *
     44  * @param obj must be a valid object
     45  */
     46 void dvmMarkObjectNonNull(const Object *obj);
     47 
     48 /*
     49  * Mark an object and schedule it to be scanned for
     50  * references to other objects.
     51  *
     52  * @param obj must be a valid object or NULL
     53  */
     54 #define dvmMarkObject(obj) \
     55     do { \
     56         Object *DMO_obj_ = (Object *)(obj); \
     57         if (DMO_obj_ != NULL) { \
     58             dvmMarkObjectNonNull(DMO_obj_); \
     59         } \
     60     } while (false)
     61 
     62 /*
     63  * If obj points to a valid object, mark it and
     64  * schedule it to be scanned for references to other
     65  * objects.
     66  *
     67  * @param obj any pointer that may be an Object, or NULL
     68 TODO: check for alignment, too (would require knowledge of heap chunks)
     69  */
     70 #define dvmMarkIfObject(obj) \
     71     do { \
     72         Object *DMIO_obj_ = (Object *)(obj); \
     73         if (DMIO_obj_ != NULL && dvmIsValidObject(DMIO_obj_)) { \
     74             dvmMarkObjectNonNull(DMIO_obj_); \
     75         } \
     76     } while (false)
     77 
     78 /*
     79  * Functions that handle scanning various objects for references.
     80  */
     81 
     82 /*
     83  * Mark all class objects loaded by the root class loader;
     84  * most of these are the java.* classes.
     85  *
     86  * Currently implemented in Class.c.
     87  */
     88 void dvmGcScanRootClassLoader(void);
     89 
     90 /*
     91  * Mark all root ThreadGroup objects, guaranteeing that
     92  * all live Thread objects will eventually be scanned.
     93  *
     94  * NOTE: this is a misnomer, because the current implementation
     95  * actually only scans the internal list of VM threads, which
     96  * will mark all VM-reachable Thread objects.  Someone else
     97  * must scan the root class loader, which will mark java/lang/ThreadGroup.
     98  * The ThreadGroup class object has static members pointing to
     99  * the root ThreadGroups, and these will be marked as a side-effect
    100  * of marking the class object.
    101  *
    102  * Currently implemented in Thread.c.
    103  */
    104 void dvmGcScanRootThreadGroups(void);
    105 
    106 /*
    107  * Mark all interned string objects.
    108  *
    109  * Currently implemented in Intern.c.
    110  */
    111 void dvmGcScanInternedStrings(void);
    112 
    113 /*
    114  * Remove any unmarked interned string objects from the table.
    115  *
    116  * Currently implemented in Intern.c.
    117  */
    118 void dvmGcDetachDeadInternedStrings(int (*isUnmarkedObject)(void *));
    119 
    120 /*
    121  * Mark all primitive class objects.
    122  *
    123  * Currently implemented in Array.c.
    124  */
    125 void dvmGcScanPrimitiveClasses(void);
    126 
    127 /*
    128  * Mark all JNI global references.
    129  *
    130  * Currently implemented in JNI.c.
    131  */
    132 void dvmGcMarkJniGlobalRefs(void);
    133 
    134 /*
    135  * Mark all debugger references.
    136  *
    137  * Currently implemented in Debugger.c.
    138  */
    139 void dvmGcMarkDebuggerRefs(void);
    140 
    141 /*
    142  * Optional heap profiling.
    143  */
    144 #if WITH_HPROF && !defined(_DALVIK_HPROF_HPROF)
    145 #include "hprof/Hprof.h"
    146 #define HPROF_SET_GC_SCAN_STATE(tag_, thread_) \
    147     dvmHeapSetHprofGcScanState((tag_), (thread_))
    148 #define HPROF_CLEAR_GC_SCAN_STATE() \
    149     dvmHeapSetHprofGcScanState(0, 0)
    150 #else
    151 #define HPROF_SET_GC_SCAN_STATE(tag_, thread_)  do {} while (false)
    152 #define HPROF_CLEAR_GC_SCAN_STATE()  do {} while (false)
    153 #endif
    154 
    155 #endif  // _DALVIK_ALLOC_GC
    156