8234740: Harmonize parameter order in Atomic - cmpxchg
Reviewed-by: rehn, dholmes
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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#ifndef SHARE_GC_Z_ZBARRIER_INLINE_HPP
#define SHARE_GC_Z_ZBARRIER_INLINE_HPP
#include "classfile/javaClasses.hpp"
#include "gc/z/zAddress.inline.hpp"
#include "gc/z/zBarrier.hpp"
#include "gc/z/zOop.inline.hpp"
#include "gc/z/zResurrection.inline.hpp"
#include "oops/oop.hpp"
#include "runtime/atomic.hpp"
inline void ZBarrier::self_heal(volatile oop* p, uintptr_t addr, uintptr_t heal_addr) {
if (heal_addr == 0) {
// Never heal with null since it interacts badly with reference processing.
// A mutator clearing an oop would be similar to calling Reference.clear(),
// which would make the reference non-discoverable or silently dropped
// by the reference processor.
return;
}
for (;;) {
if (addr == heal_addr) {
// Already healed
return;
}
// Heal
const uintptr_t prev_addr = Atomic::cmpxchg((volatile uintptr_t*)p, addr, heal_addr);
if (prev_addr == addr) {
// Success
return;
}
if (ZAddress::is_good_or_null(prev_addr)) {
// No need to heal
return;
}
// The oop location was healed by another barrier, but it is still not
// good or null. Re-apply healing to make sure the oop is not left with
// weaker (remapped or finalizable) metadata bits than what this barrier
// tried to apply.
assert(ZAddress::offset(prev_addr) == ZAddress::offset(heal_addr), "Invalid offset");
addr = prev_addr;
}
}
template <ZBarrierFastPath fast_path, ZBarrierSlowPath slow_path>
inline oop ZBarrier::barrier(volatile oop* p, oop o) {
uintptr_t addr = ZOop::to_address(o);
// Fast path
if (fast_path(addr)) {
return ZOop::from_address(addr);
}
// Slow path
const uintptr_t good_addr = slow_path(addr);
if (p != NULL) {
self_heal(p, addr, good_addr);
}
return ZOop::from_address(good_addr);
}
template <ZBarrierFastPath fast_path, ZBarrierSlowPath slow_path>
inline oop ZBarrier::weak_barrier(volatile oop* p, oop o) {
const uintptr_t addr = ZOop::to_address(o);
// Fast path
if (fast_path(addr)) {
// Return the good address instead of the weak good address
// to ensure that the currently active heap view is used.
return ZOop::from_address(ZAddress::good_or_null(addr));
}
// Slow path
const uintptr_t good_addr = slow_path(addr);
if (p != NULL) {
// The slow path returns a good/marked address or null, but we never mark
// oops in a weak load barrier so we always heal with the remapped address.
self_heal(p, addr, ZAddress::remapped_or_null(good_addr));
}
return ZOop::from_address(good_addr);
}
template <ZBarrierFastPath fast_path, ZBarrierSlowPath slow_path>
inline void ZBarrier::root_barrier(oop* p, oop o) {
const uintptr_t addr = ZOop::to_address(o);
// Fast path
if (fast_path(addr)) {
return;
}
// Slow path
const uintptr_t good_addr = slow_path(addr);
// Non-atomic healing helps speed up root scanning. This is safe to do
// since we are always healing roots in a safepoint, or under a lock,
// which ensures we are never racing with mutators modifying roots while
// we are healing them. It's also safe in case multiple GC threads try
// to heal the same root if it is aligned, since they would always heal
// the root in the same way and it does not matter in which order it
// happens. For misaligned oops, there needs to be mutual exclusion.
*p = ZOop::from_address(good_addr);
}
inline bool ZBarrier::is_null_fast_path(uintptr_t addr) {
return ZAddress::is_null(addr);
}
inline bool ZBarrier::is_good_or_null_fast_path(uintptr_t addr) {
return ZAddress::is_good_or_null(addr);
}
inline bool ZBarrier::is_weak_good_or_null_fast_path(uintptr_t addr) {
return ZAddress::is_weak_good_or_null(addr);
}
//
// Load barrier
//
inline oop ZBarrier::load_barrier_on_oop(oop o) {
return load_barrier_on_oop_field_preloaded((oop*)NULL, o);
}
inline oop ZBarrier::load_barrier_on_oop_field(volatile oop* p) {
const oop o = *p;
return load_barrier_on_oop_field_preloaded(p, o);
}
inline oop ZBarrier::load_barrier_on_oop_field_preloaded(volatile oop* p, oop o) {
return barrier<is_good_or_null_fast_path, load_barrier_on_oop_slow_path>(p, o);
}
inline void ZBarrier::load_barrier_on_oop_array(volatile oop* p, size_t length) {
for (volatile const oop* const end = p + length; p < end; p++) {
load_barrier_on_oop_field(p);
}
}
// ON_WEAK barriers should only ever be applied to j.l.r.Reference.referents.
inline void verify_on_weak(volatile oop* referent_addr) {
#ifdef ASSERT
if (referent_addr != NULL) {
uintptr_t base = (uintptr_t)referent_addr - java_lang_ref_Reference::referent_offset;
oop obj = cast_to_oop(base);
assert(oopDesc::is_oop(obj), "Verification failed for: ref " PTR_FORMAT " obj: " PTR_FORMAT, (uintptr_t)referent_addr, base);
assert(java_lang_ref_Reference::is_referent_field(obj, java_lang_ref_Reference::referent_offset), "Sanity");
}
#endif
}
inline oop ZBarrier::load_barrier_on_weak_oop_field_preloaded(volatile oop* p, oop o) {
verify_on_weak(p);
if (ZResurrection::is_blocked()) {
return barrier<is_good_or_null_fast_path, weak_load_barrier_on_weak_oop_slow_path>(p, o);
}
return load_barrier_on_oop_field_preloaded(p, o);
}
inline oop ZBarrier::load_barrier_on_phantom_oop_field_preloaded(volatile oop* p, oop o) {
if (ZResurrection::is_blocked()) {
return barrier<is_good_or_null_fast_path, weak_load_barrier_on_phantom_oop_slow_path>(p, o);
}
return load_barrier_on_oop_field_preloaded(p, o);
}
inline void ZBarrier::load_barrier_on_root_oop_field(oop* p) {
const oop o = *p;
root_barrier<is_good_or_null_fast_path, load_barrier_on_oop_slow_path>(p, o);
}
//
// Weak load barrier
//
inline oop ZBarrier::weak_load_barrier_on_oop_field(volatile oop* p) {
assert(!ZResurrection::is_blocked(), "Should not be called during resurrection blocked phase");
const oop o = *p;
return weak_load_barrier_on_oop_field_preloaded(p, o);
}
inline oop ZBarrier::weak_load_barrier_on_oop_field_preloaded(volatile oop* p, oop o) {
return weak_barrier<is_weak_good_or_null_fast_path, weak_load_barrier_on_oop_slow_path>(p, o);
}
inline oop ZBarrier::weak_load_barrier_on_weak_oop(oop o) {
return weak_load_barrier_on_weak_oop_field_preloaded((oop*)NULL, o);
}
inline oop ZBarrier::weak_load_barrier_on_weak_oop_field(volatile oop* p) {
const oop o = *p;
return weak_load_barrier_on_weak_oop_field_preloaded(p, o);
}
inline oop ZBarrier::weak_load_barrier_on_weak_oop_field_preloaded(volatile oop* p, oop o) {
verify_on_weak(p);
if (ZResurrection::is_blocked()) {
return barrier<is_good_or_null_fast_path, weak_load_barrier_on_weak_oop_slow_path>(p, o);
}
return weak_load_barrier_on_oop_field_preloaded(p, o);
}
inline oop ZBarrier::weak_load_barrier_on_phantom_oop(oop o) {
return weak_load_barrier_on_phantom_oop_field_preloaded((oop*)NULL, o);
}
inline oop ZBarrier::weak_load_barrier_on_phantom_oop_field(volatile oop* p) {
const oop o = *p;
return weak_load_barrier_on_phantom_oop_field_preloaded(p, o);
}
inline oop ZBarrier::weak_load_barrier_on_phantom_oop_field_preloaded(volatile oop* p, oop o) {
if (ZResurrection::is_blocked()) {
return barrier<is_good_or_null_fast_path, weak_load_barrier_on_phantom_oop_slow_path>(p, o);
}
return weak_load_barrier_on_oop_field_preloaded(p, o);
}
//
// Is alive barrier
//
inline bool ZBarrier::is_alive_barrier_on_weak_oop(oop o) {
// Check if oop is logically non-null. This operation
// is only valid when resurrection is blocked.
assert(ZResurrection::is_blocked(), "Invalid phase");
return weak_load_barrier_on_weak_oop(o) != NULL;
}
inline bool ZBarrier::is_alive_barrier_on_phantom_oop(oop o) {
// Check if oop is logically non-null. This operation
// is only valid when resurrection is blocked.
assert(ZResurrection::is_blocked(), "Invalid phase");
return weak_load_barrier_on_phantom_oop(o) != NULL;
}
//
// Keep alive barrier
//
inline void ZBarrier::keep_alive_barrier_on_weak_oop_field(volatile oop* p) {
// This operation is only valid when resurrection is blocked.
assert(ZResurrection::is_blocked(), "Invalid phase");
const oop o = *p;
barrier<is_good_or_null_fast_path, keep_alive_barrier_on_weak_oop_slow_path>(p, o);
}
inline void ZBarrier::keep_alive_barrier_on_phantom_oop_field(volatile oop* p) {
// This operation is only valid when resurrection is blocked.
assert(ZResurrection::is_blocked(), "Invalid phase");
const oop o = *p;
barrier<is_good_or_null_fast_path, keep_alive_barrier_on_phantom_oop_slow_path>(p, o);
}
inline void ZBarrier::keep_alive_barrier_on_phantom_root_oop_field(oop* p) {
// This operation is only valid when resurrection is blocked.
assert(ZResurrection::is_blocked(), "Invalid phase");
const oop o = *p;
root_barrier<is_good_or_null_fast_path, keep_alive_barrier_on_phantom_oop_slow_path>(p, o);
}
//
// Mark barrier
//
inline void ZBarrier::mark_barrier_on_oop_field(volatile oop* p, bool finalizable) {
// The fast path only checks for null since the GC worker
// threads doing marking wants to mark through good oops.
const oop o = *p;
if (finalizable) {
barrier<is_null_fast_path, mark_barrier_on_finalizable_oop_slow_path>(p, o);
} else {
barrier<is_null_fast_path, mark_barrier_on_oop_slow_path>(p, o);
}
}
inline void ZBarrier::mark_barrier_on_oop_array(volatile oop* p, size_t length, bool finalizable) {
for (volatile const oop* const end = p + length; p < end; p++) {
mark_barrier_on_oop_field(p, finalizable);
}
}
inline void ZBarrier::mark_barrier_on_root_oop_field(oop* p) {
const oop o = *p;
root_barrier<is_good_or_null_fast_path, mark_barrier_on_root_oop_slow_path>(p, o);
}
inline void ZBarrier::mark_barrier_on_invisible_root_oop_field(oop* p) {
const oop o = *p;
root_barrier<is_good_or_null_fast_path, mark_barrier_on_invisible_root_oop_slow_path>(p, o);
}
//
// Relocate barrier
//
inline void ZBarrier::relocate_barrier_on_root_oop_field(oop* p) {
const oop o = *p;
root_barrier<is_good_or_null_fast_path, relocate_barrier_on_root_oop_slow_path>(p, o);
}
#endif // SHARE_GC_Z_ZBARRIER_INLINE_HPP