ART GC
2017-07-31 本文已影响0人
dexteryu
Java堆
- Image Space: 存放一些预加载的类
- Zygote Space: 对应Davlik的Zygote堆
- Allocation Space: 对应Dalvik的Active堆
- Large Object Space: 用来分配一些大对象
GC的类型
- kGcCauseForAlloc: 内存不够的情况下引起的GC
- kGcCauseBackground: 内存达到一定的阀值的时候引发的GC
- kGcCauseExplicit: System.gc显示调用的GC
// heap.cc: CollectGarbageInternal
collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type,
GcCause gc_cause,
bool clear_soft_references) {
collector->Run(gc_cause, clear_soft_references || runtime->IsZygote());
RequestTrim(self);
// Grow the heap so that we know when to perform the next GC.
GrowForUtilization(collector, bytes_allocated_before_gc);
Dbg::GcDidFinish();
return gc_type;
}
Foreground GC和Background GC切换
// ActivityThread.scheduleLaunchActivity
public final void scheduleLaunchActivity(Intent intent, IBinder token, int ident) {
updateProcessState(procState, false);
sendMessage(H.LAUNCH_ACTIVITY, r);
}
// heap.cc: UpdateProcessState
void Heap::UpdateProcessState(ProcessState old_process_state, ProcessState new_process_state) {
if (old_process_state != new_process_state) {
const bool jank_perceptible = new_process_state == kProcessStateJankPerceptible;
if (jank_perceptible) {
RequestCollectorTransition(foreground_collector_type_, 0);
} else {
RequestCollectorTransition(background_collector_type_,
kIsDebugBuild ? 0 : kCollectorTransitionWait);
}
}
}
