Enable concurrent sweeping for non-concurrent GC.
Refactored the GarbageCollector to let all of the phases be run by
the collector's RunPhases virtual method. This lets the GC decide
which phases should be concurrent and reduces how much baked in GC
logic resides in GarbageCollector.
Enabled concurrent sweeping in the semi space and non concurrent
mark sweep GCs. Changed the semi-space collector to have a swap semi
spaces boolean which can be changed with a setter.
Fixed tests to pass with GSS collector, there was an error related to
the large object space limit.
Before (EvaluateAndApplyChanges):
GSS paused GC time 7.81s/7.81s, score: 3920
After (EvaluateAndApplyChanges):
GSS paused GC time 6.94s/7.71s, score: 3900
Benchmark score doesn't go up since the GC happens in the allocating
thread. There is a slight reduction in pause times experienced by
other threads (0.8s total).
Added options for pre sweeping GC heap verification and pre sweeping
rosalloc verification.
Bug: 14226004
Bug: 14250892
Bug: 14386356
Change-Id: Ib557d0590c1ed82a639d0f0281ba67cf8cae938c
diff --git a/runtime/gc/collector/mark_sweep.cc b/runtime/gc/collector/mark_sweep.cc
index 007eb23..9cd740e 100644
--- a/runtime/gc/collector/mark_sweep.cc
+++ b/runtime/gc/collector/mark_sweep.cc
@@ -130,9 +130,37 @@
// Always clear soft references if a non-sticky collection.
clear_soft_references_ = GetGcType() != collector::kGcTypeSticky;
}
- // Do any pre GC verification.
- timings_.NewSplit("PreGcVerification");
- heap_->PreGcVerification(this);
+}
+
+void MarkSweep::RunPhases() {
+ Thread* self = Thread::Current();
+ InitializePhase();
+ Locks::mutator_lock_->AssertNotHeld(self);
+ if (IsConcurrent()) {
+ GetHeap()->PreGcVerification(this);
+ {
+ ReaderMutexLock mu(self, *Locks::mutator_lock_);
+ MarkingPhase();
+ }
+ ScopedPause pause(this);
+ GetHeap()->PrePauseRosAllocVerification(this);
+ PausePhase();
+ RevokeAllThreadLocalBuffers();
+ } else {
+ ScopedPause pause(this);
+ GetHeap()->PreGcVerificationPaused(this);
+ MarkingPhase();
+ GetHeap()->PrePauseRosAllocVerification(this);
+ PausePhase();
+ RevokeAllThreadLocalBuffers();
+ }
+ {
+ // Sweeping always done concurrently, even for non concurrent mark sweep.
+ ReaderMutexLock mu(self, *Locks::mutator_lock_);
+ ReclaimPhase();
+ }
+ GetHeap()->PostGcVerification(this);
+ FinishPhase();
}
void MarkSweep::ProcessReferences(Thread* self) {
@@ -166,7 +194,7 @@
}
ProcessReferences(self);
{
- timings_.NewSplit("SwapStacks");
+ TimingLogger::ScopedSplit split("SwapStacks", &timings_);
WriterMutexLock mu(self, *Locks::heap_bitmap_lock_);
heap_->SwapStacks(self);
live_stack_freeze_size_ = heap_->GetLiveStack()->Size();
@@ -177,13 +205,11 @@
timings_.StartSplit("PreSweepingGcVerification");
heap_->PreSweepingGcVerification(this);
timings_.EndSplit();
- if (IsConcurrent()) {
- // Disallow new system weaks to prevent a race which occurs when someone adds a new system
- // weak before we sweep them. Since this new system weak may not be marked, the GC may
- // incorrectly sweep it. This also fixes a race where interning may attempt to return a strong
- // reference to a string that is about to be swept.
- Runtime::Current()->DisallowNewSystemWeaks();
- }
+ // Disallow new system weaks to prevent a race which occurs when someone adds a new system
+ // weak before we sweep them. Since this new system weak may not be marked, the GC may
+ // incorrectly sweep it. This also fixes a race where interning may attempt to return a strong
+ // reference to a string that is about to be swept.
+ Runtime::Current()->DisallowNewSystemWeaks();
}
void MarkSweep::PreCleanCards() {
@@ -265,9 +291,7 @@
TimingLogger::ScopedSplit split("ReclaimPhase", &timings_);
Thread* self = Thread::Current();
SweepSystemWeaks(self);
- if (IsConcurrent()) {
- Runtime::Current()->AllowNewSystemWeaks();
- }
+ Runtime::Current()->AllowNewSystemWeaks();
{
WriterMutexLock mu(self, *Locks::heap_bitmap_lock_);
@@ -1256,9 +1280,6 @@
void MarkSweep::FinishPhase() {
TimingLogger::ScopedSplit split("FinishPhase", &timings_);
- // Can't enqueue references if we hold the mutator lock.
- timings_.NewSplit("PostGcVerification");
- heap_->PostGcVerification(this);
if (kCountScannedTypes) {
VLOG(gc) << "MarkSweep scanned classes=" << class_count_ << " arrays=" << array_count_
<< " other=" << other_count_;