1 /*
2  * Copyright (C) 2014 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 #ifndef ART_RUNTIME_GC_GC_CAUSE_H_
18 #define ART_RUNTIME_GC_GC_CAUSE_H_
19 
20 #include <iosfwd>
21 
22 namespace art {
23 namespace gc {
24 
25 // What caused the GC?
26 enum GcCause {
27   // Invalid GC cause used as a placeholder.
28   kGcCauseNone,
29   // GC triggered by a failed allocation. Thread doing allocation is blocked waiting for GC before
30   // retrying allocation.
31   kGcCauseForAlloc,
32   // A background GC trying to ensure there is free memory ahead of allocations.
33   kGcCauseBackground,
34   // An explicit System.gc() call.
35   kGcCauseExplicit,
36   // GC triggered for a native allocation when NativeAllocationGcWatermark is exceeded.
37   // (This may be a blocking GC depending on whether we run a non-concurrent collector).
38   kGcCauseForNativeAlloc,
39   // GC triggered for a collector transition.
40   kGcCauseCollectorTransition,
41   // Not a real GC cause, used when we disable moving GC (currently for GetPrimitiveArrayCritical).
42   kGcCauseDisableMovingGc,
43   // Not a real GC cause, used when we trim the heap.
44   kGcCauseTrim,
45   // Not a real GC cause, used to implement exclusion between GC and instrumentation.
46   kGcCauseInstrumentation,
47   // Not a real GC cause, used to add or remove app image spaces.
48   kGcCauseAddRemoveAppImageSpace,
49   // Not a real GC cause, used to implement exclusion between GC and debugger.
50   kGcCauseDebugger,
51   // GC triggered for background transition when both foreground and background collector are CMS.
52   kGcCauseHomogeneousSpaceCompact,
53   // Class linker cause, used to guard filling art methods with special values.
54   kGcCauseClassLinker,
55   // Not a real GC cause, used to implement exclusion between code cache metadata and GC.
56   kGcCauseJitCodeCache,
57   // Not a real GC cause, used to add or remove system-weak holders.
58   kGcCauseAddRemoveSystemWeakHolder,
59   // Not a real GC cause, used to prevent hprof running in the middle of GC.
60   kGcCauseHprof,
61   // Not a real GC cause, used to prevent GetObjectsAllocated running in the middle of GC.
62   kGcCauseGetObjectsAllocated,
63   // GC cause for the profile saver.
64   kGcCauseProfileSaver,
65   // GC cause for running an empty checkpoint.
66   kGcCauseRunEmptyCheckpoint,
67 };
68 
69 const char* PrettyCause(GcCause cause);
70 std::ostream& operator<<(std::ostream& os, const GcCause& gc_cause);
71 
72 }  // namespace gc
73 }  // namespace art
74 
75 #endif  // ART_RUNTIME_GC_GC_CAUSE_H_
76