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/*
* Copyright (c) 2018, 2022, Red Hat, Inc. All rights reserved.
+ * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
#include "gc/shared/plab.hpp"
#include "gc/shared/gcThreadLocalData.hpp"
#include "gc/shared/gc_globals.hpp"
#include "gc/shenandoah/shenandoahBarrierSet.hpp"
#include "gc/shenandoah/shenandoahCodeRoots.hpp"
+ #include "gc/shenandoah/shenandoahGenerationalHeap.hpp"
+ #include "gc/shenandoah/shenandoahEvacTracker.hpp"
#include "gc/shenandoah/shenandoahSATBMarkQueueSet.hpp"
+ #include "gc/shenandoah/mode/shenandoahMode.hpp"
#include "runtime/javaThread.hpp"
#include "utilities/debug.hpp"
#include "utilities/sizes.hpp"
class ShenandoahThreadLocalData {
private:
char _gc_state;
// Evacuation OOM state
uint8_t _oom_scope_nesting_level;
bool _oom_during_evac;
+
SATBMarkQueue _satb_mark_queue;
+
+ // Thread-local allocation buffer for object evacuations.
+ // In generational mode, it is exclusive to the young generation.
PLAB* _gclab;
size_t _gclab_size;
+
double _paced_time;
- ShenandoahThreadLocalData() :
- _gc_state(0),
- _oom_scope_nesting_level(0),
- _oom_during_evac(false),
- _satb_mark_queue(&ShenandoahBarrierSet::satb_mark_queue_set()),
- _gclab(nullptr),
- _gclab_size(0),
- _paced_time(0) {
- }
+ // Thread-local allocation buffer only used in generational mode.
+ // Used both by mutator threads and by GC worker threads
+ // for evacuations within the old generation and
+ // for promotions from the young generation into the old generation.
+ PLAB* _plab;
- ~ShenandoahThreadLocalData() {
- if (_gclab != nullptr) {
- delete _gclab;
- }
- }
+ // Heuristics will grow the desired size of plabs.
+ size_t _plab_desired_size;
+
+ // Once the plab has been allocated, and we know the actual size, we record it here.
+ size_t _plab_actual_size;
+
+ // As the plab is used for promotions, this value is incremented. When the plab is
+ // retired, the difference between 'actual_size' and 'promoted' will be returned to
+ // the old generation's promotion reserve (i.e., it will be 'unexpended').
+ size_t _plab_promoted;
+
+ // If false, no more promotion by this thread during this evacuation phase.
+ bool _plab_allows_promotion;
+
+ // If true, evacuations may attempt to allocate a smaller plab if the original size fails.
+ bool _plab_retries_enabled;
+
+ ShenandoahEvacuationStats* _evacuation_stats;
+
+ ShenandoahThreadLocalData();
+ ~ShenandoahThreadLocalData();
static ShenandoahThreadLocalData* data(Thread* thread) {
assert(UseShenandoahGC, "Sanity");
return thread->gc_data<ShenandoahThreadLocalData>();
}
static void initialize_gclab(Thread* thread) {
assert (thread->is_Java_thread() || thread->is_Worker_thread(), "Only Java and GC worker threads are allowed to get GCLABs");
assert(data(thread)->_gclab == nullptr, "Only initialize once");
data(thread)->_gclab = new PLAB(PLAB::min_size());
data(thread)->_gclab_size = 0;
+
+ if (ShenandoahHeap::heap()->mode()->is_generational()) {
+ data(thread)->_plab = new PLAB(align_up(PLAB::min_size(), CardTable::card_size_in_words()));
+ data(thread)->_plab_desired_size = 0;
+ }
}
static PLAB* gclab(Thread* thread) {
return data(thread)->_gclab;
}
static void set_gclab_size(Thread* thread, size_t v) {
data(thread)->_gclab_size = v;
}
+ static void begin_evacuation(Thread* thread, size_t bytes) {
+ data(thread)->_evacuation_stats->begin_evacuation(bytes);
+ }
+
+ static void end_evacuation(Thread* thread, size_t bytes) {
+ data(thread)->_evacuation_stats->end_evacuation(bytes);
+ }
+
+ static void record_age(Thread* thread, size_t bytes, uint age) {
+ data(thread)->_evacuation_stats->record_age(bytes, age);
+ }
+
+ static ShenandoahEvacuationStats* evacuation_stats(Thread* thread) {
+ return data(thread)->_evacuation_stats;
+ }
+
+ static PLAB* plab(Thread* thread) {
+ return data(thread)->_plab;
+ }
+
+ static size_t plab_size(Thread* thread) {
+ return data(thread)->_plab_desired_size;
+ }
+
+ static void set_plab_size(Thread* thread, size_t v) {
+ data(thread)->_plab_desired_size = v;
+ }
+
+ static void enable_plab_retries(Thread* thread) {
+ data(thread)->_plab_retries_enabled = true;
+ }
+
+ static void disable_plab_retries(Thread* thread) {
+ data(thread)->_plab_retries_enabled = false;
+ }
+
+ static bool plab_retries_enabled(Thread* thread) {
+ return data(thread)->_plab_retries_enabled;
+ }
+
+ static void enable_plab_promotions(Thread* thread) {
+ data(thread)->_plab_allows_promotion = true;
+ }
+
+ static void disable_plab_promotions(Thread* thread) {
+ data(thread)->_plab_allows_promotion = false;
+ }
+
+ static bool allow_plab_promotions(Thread* thread) {
+ return data(thread)->_plab_allows_promotion;
+ }
+
+ static void reset_plab_promoted(Thread* thread) {
+ data(thread)->_plab_promoted = 0;
+ }
+
+ static void add_to_plab_promoted(Thread* thread, size_t increment) {
+ data(thread)->_plab_promoted += increment;
+ }
+
+ static void subtract_from_plab_promoted(Thread* thread, size_t increment) {
+ assert(data(thread)->_plab_promoted >= increment, "Cannot subtract more than remaining promoted");
+ data(thread)->_plab_promoted -= increment;
+ }
+
+ static size_t get_plab_promoted(Thread* thread) {
+ return data(thread)->_plab_promoted;
+ }
+
+ static void set_plab_actual_size(Thread* thread, size_t value) {
+ data(thread)->_plab_actual_size = value;
+ }
+
+ static size_t get_plab_actual_size(Thread* thread) {
+ return data(thread)->_plab_actual_size;
+ }
+
static void add_paced_time(Thread* thread, double v) {
data(thread)->_paced_time += v;
}
static double paced_time(Thread* thread) {
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