/*
* Copyright (c) 1998, 2019, Oracle and/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.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "code/codeBlob.hpp"
#include "code/codeCache.hpp"
#include "code/nmethod.hpp"
#include "code/scopeDesc.hpp"
#include "compiler/oopMap.hpp"
#include "gc/shared/collectedHeap.hpp"
#include "memory/allocation.inline.hpp"
#include "memory/iterator.hpp"
#include "memory/resourceArea.hpp"
#include "memory/universe.hpp"
#include "oops/compressedOops.hpp"
#include "runtime/frame.inline.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/signature.hpp"
#include "utilities/align.hpp"
#include "utilities/lockFreeStack.hpp"
#ifdef COMPILER1
#include "c1/c1_Defs.hpp"
#endif
#ifdef COMPILER2
#include "opto/optoreg.hpp"
#endif
// OopMapStream
OopMapStream::OopMapStream(OopMap* oop_map) {
_stream = new CompressedReadStream(oop_map->write_stream()->buffer());
_size = oop_map->omv_count();
_position = 0;
_valid_omv = false;
}
OopMapStream::OopMapStream(const ImmutableOopMap* oop_map) {
_stream = new CompressedReadStream(oop_map->data_addr());
_size = oop_map->count();
_position = 0;
_valid_omv = false;
}
void OopMapStream::find_next() {
if (_position++ < _size) {
_omv.read_from(_stream);
_valid_omv = true;
return;
}
_valid_omv = false;
}
// OopMap
// frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
// slots to hold 4-byte values like ints and floats in the LP64 build.
OopMap::OopMap(int frame_size, int arg_count) {
// OopMaps are usually quite so small, so pick a small initial size
set_write_stream(new CompressedWriteStream(32));
set_omv_count(0);
#ifdef ASSERT
_locs_length = VMRegImpl::stack2reg(0)->value() + frame_size + arg_count;
_locs_used = NEW_RESOURCE_ARRAY(OopMapValue::oop_types, _locs_length);
for(int i = 0; i < _locs_length; i++) _locs_used[i] = OopMapValue::unused_value;
#endif
}
OopMap::OopMap(OopMap::DeepCopyToken, OopMap* source) {
// This constructor does a deep copy
// of the source OopMap.
set_write_stream(new CompressedWriteStream(source->omv_count() * 2));
set_omv_count(0);
set_offset(source->offset());
#ifdef ASSERT
_locs_length = source->_locs_length;
_locs_used = NEW_RESOURCE_ARRAY(OopMapValue::oop_types, _locs_length);
for(int i = 0; i < _locs_length; i++) _locs_used[i] = OopMapValue::unused_value;
#endif
// We need to copy the entries too.
for (OopMapStream oms(source); !oms.is_done(); oms.next()) {
OopMapValue omv = oms.current();
omv.write_on(write_stream());
increment_count();
}
}
OopMap* OopMap::deep_copy() {
return new OopMap(_deep_copy_token, this);
}
void OopMap::copy_data_to(address addr) const {
memcpy(addr, write_stream()->buffer(), write_stream()->position());
}
int OopMap::heap_size() const {
int size = sizeof(OopMap);
int align = sizeof(void *) - 1;
size += write_stream()->position();
// Align to a reasonable ending point
size = ((size+align) & ~align);
return size;
}
// frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
// slots to hold 4-byte values like ints and floats in the LP64 build.
void OopMap::set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional) {
assert(reg->value() < _locs_length, "too big reg value for stack size");
assert( _locs_used[reg->value()] == OopMapValue::unused_value, "cannot insert twice" );
debug_only( _locs_used[reg->value()] = x; )
OopMapValue o(reg, x, optional);
o.write_on(write_stream());
increment_count();
}
void OopMap::set_oop(VMReg reg) {
set_xxx(reg, OopMapValue::oop_value, VMRegImpl::Bad());
}
void OopMap::set_narrowoop(VMReg reg) {
set_xxx(reg, OopMapValue::narrowoop_value, VMRegImpl::Bad());
}
void OopMap::set_callee_saved(VMReg reg, VMReg caller_machine_register ) {
set_xxx(reg, OopMapValue::callee_saved_value, caller_machine_register);
}
void OopMap::set_derived_oop(VMReg reg, VMReg derived_from_local_register ) {
if( reg == derived_from_local_register ) {
// Actually an oop, derived shares storage with base,
set_oop(reg);
} else {
set_xxx(reg, OopMapValue::derived_oop_value, derived_from_local_register);
}
}
// OopMapSet
OopMapSet::OopMapSet() {
set_om_size(MinOopMapAllocation);
set_om_count(0);
OopMap** temp = NEW_RESOURCE_ARRAY(OopMap*, om_size());
set_om_data(temp);
}
void OopMapSet::grow_om_data() {
int new_size = om_size() * 2;
OopMap** new_data = NEW_RESOURCE_ARRAY(OopMap*, new_size);
memcpy(new_data,om_data(),om_size() * sizeof(OopMap*));
set_om_size(new_size);
set_om_data(new_data);
}
void OopMapSet::add_gc_map(int pc_offset, OopMap *map ) {
assert(om_size() != -1,"Cannot grow a fixed OopMapSet");
if(om_count() >= om_size()) {
grow_om_data();
}
map->set_offset(pc_offset);
#ifdef ASSERT
if(om_count() > 0) {
OopMap* last = at(om_count()-1);
if (last->offset() == map->offset() ) {
fatal("OopMap inserted twice");
}
if(last->offset() > map->offset()) {
tty->print_cr( "WARNING, maps not sorted: pc[%d]=%d, pc[%d]=%d",
om_count(),last->offset(),om_count()+1,map->offset());
}
}
#endif // ASSERT
set(om_count(),map);
increment_count();
}
int OopMapSet::heap_size() const {
// The space we use
int size = sizeof(OopMap);
int align = sizeof(void *) - 1;
size = ((size+align) & ~align);
size += om_count() * sizeof(OopMap*);
// Now add in the space needed for the indivdiual OopMaps
for(int i=0; i < om_count(); i++) {
size += at(i)->heap_size();
}
// We don't need to align this, it will be naturally pointer aligned
return size;
}
OopMap* OopMapSet::singular_oop_map() {
guarantee(om_count() == 1, "Make sure we only have a single gc point");
return at(0);
}
OopMap* OopMapSet::find_map_at_offset(int pc_offset) const {
int i, len = om_count();
assert( len > 0, "must have pointer maps" );
// Scan through oopmaps. Stop when current offset is either equal or greater
// than the one we are looking for.
for( i = 0; i < len; i++) {
if( at(i)->offset() >= pc_offset )
break;
}
assert( i < len, "oopmap not found" );
OopMap* m = at(i);
assert( m->offset() == pc_offset, "oopmap not found" );
return m;
}
static void add_derived_oop(oop* base, oop* derived) {
#if !defined(TIERED) && !INCLUDE_JVMCI
COMPILER1_PRESENT(ShouldNotReachHere();)
#endif // !defined(TIERED) && !INCLUDE_JVMCI
#if COMPILER2_OR_JVMCI
DerivedPointerTable::add(derived, base);
#endif // COMPILER2_OR_JVMCI
}
#ifndef PRODUCT
static void trace_codeblob_maps(const frame *fr, const RegisterMap *reg_map) {
// Print oopmap and regmap
tty->print_cr("------ ");
CodeBlob* cb = fr->cb();
const ImmutableOopMapSet* maps = cb->oop_maps();
const ImmutableOopMap* map = cb->oop_map_for_return_address(fr->pc());
map->print();
if( cb->is_nmethod() ) {
nmethod* nm = (nmethod*)cb;
// native wrappers have no scope data, it is implied
if (nm->is_native_method()) {
tty->print("bci: 0 (native)");
} else {
ScopeDesc* scope = nm->scope_desc_at(fr->pc());
tty->print("bci: %d ",scope->bci());
}
}
tty->cr();
fr->print_on(tty);
tty->print(" ");
cb->print_value_on(tty); tty->cr();
reg_map->print();
tty->print_cr("------ ");
}
#endif // PRODUCT
void OopMapSet::oops_do(const frame *fr, const RegisterMap* reg_map, OopClosure* f) {
// add derived oops to a table
all_do(fr, reg_map, f, add_derived_oop, &do_nothing_cl);
}
void OopMapSet::all_do(const frame *fr, const RegisterMap *reg_map,
OopClosure* oop_fn, void derived_oop_fn(oop*, oop*),
OopClosure* value_fn) {
CodeBlob* cb = fr->cb();
assert(cb != NULL, "no codeblob");
NOT_PRODUCT(if (TraceCodeBlobStacks) trace_codeblob_maps(fr, reg_map);)
const ImmutableOopMapSet* maps = cb->oop_maps();
const ImmutableOopMap* map = cb->oop_map_for_return_address(fr->pc());
assert(map != NULL, "no ptr map found");
// handle derived pointers first (otherwise base pointer may be
// changed before derived pointer offset has been collected)
OopMapValue omv;
{
OopMapStream oms(map);
if (!oms.is_done()) {
#ifndef TIERED
COMPILER1_PRESENT(ShouldNotReachHere();)
#if INCLUDE_JVMCI
if (UseJVMCICompiler) {
ShouldNotReachHere();
}
#endif
#endif // !TIERED
do {
omv = oms.current();
if (omv.type() == OopMapValue::derived_oop_value) {
oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map);
guarantee(loc != NULL, "missing saved register");
oop *derived_loc = loc;
oop *base_loc = fr->oopmapreg_to_location(omv.content_reg(), reg_map);
// Ignore NULL oops and decoded NULL narrow oops which
// equal to CompressedOops::base() when a narrow oop
// implicit null check is used in compiled code.
// The narrow_oop_base could be NULL or be the address
// of the page below heap depending on compressed oops mode.
if (base_loc != NULL && *base_loc != NULL && !CompressedOops::is_base(*base_loc)) {
derived_oop_fn(base_loc, derived_loc);
}
}
oms.next();
} while (!oms.is_done());
}
}
{
// We want coop and oop oop_types
for (OopMapStream oms(map); !oms.is_done(); oms.next()) {
omv = oms.current();
oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map);
// It should be an error if no location can be found for a
// register mentioned as contained an oop of some kind. Maybe
// this was allowed previously because value_value items might
// be missing?
guarantee(loc != NULL, "missing saved register");
if ( omv.type() == OopMapValue::oop_value ) {
oop val = *loc;
if (val == NULL || CompressedOops::is_base(val)) {
// Ignore NULL oops and decoded NULL narrow oops which
// equal to CompressedOops::base() when a narrow oop
// implicit null check is used in compiled code.
// The narrow_oop_base could be NULL or be the address
// of the page below heap depending on compressed oops mode.
continue;
}
#ifdef ASSERT
if ((((uintptr_t)loc & (sizeof(*loc)-1)) != 0) ||
!Universe::heap()->is_in_or_null(*loc)) {
tty->print_cr("# Found non oop pointer. Dumping state at failure");
// try to dump out some helpful debugging information
trace_codeblob_maps(fr, reg_map);
omv.print();
tty->print_cr("register r");
omv.reg()->print();
tty->print_cr("loc = %p *loc = %p\n", loc, (address)*loc);
// do the real assert.
assert(Universe::heap()->is_in_or_null(*loc), "found non oop pointer");
}
#endif // ASSERT
oop_fn->do_oop(loc);
} else if ( omv.type() == OopMapValue::narrowoop_value ) {
narrowOop *nl = (narrowOop*)loc;
#ifndef VM_LITTLE_ENDIAN
VMReg vmReg = omv.reg();
// Don't do this on SPARC float registers as they can be individually addressed
if (!vmReg->is_stack() SPARC_ONLY(&& !vmReg->is_FloatRegister())) {
// compressed oops in registers only take up 4 bytes of an
// 8 byte register but they are in the wrong part of the
// word so adjust loc to point at the right place.
nl = (narrowOop*)((address)nl + 4);
}
#endif
oop_fn->do_oop(nl);
}
}
}
}
// Update callee-saved register info for the following frame
void OopMapSet::update_register_map(const frame *fr, RegisterMap *reg_map) {
ResourceMark rm;
CodeBlob* cb = fr->cb();
assert(cb != NULL, "no codeblob");
// Any reg might be saved by a safepoint handler (see generate_handler_blob).
assert( reg_map->_update_for_id == NULL || fr->is_older(reg_map->_update_for_id),
"already updated this map; do not 'update' it twice!" );
debug_only(reg_map->_update_for_id = fr->id());
// Check if caller must update oop argument
assert((reg_map->include_argument_oops() ||
!cb->caller_must_gc_arguments(reg_map->thread())),
"include_argument_oops should already be set");
// Scan through oopmap and find location of all callee-saved registers
// (we do not do update in place, since info could be overwritten)
address pc = fr->pc();
const ImmutableOopMap* map = cb->oop_map_for_return_address(pc);
assert(map != NULL, "no ptr map found");
DEBUG_ONLY(int nof_callee = 0;)
for (OopMapStream oms(map); !oms.is_done(); oms.next()) {
OopMapValue omv = oms.current();
if (omv.type() == OopMapValue::callee_saved_value) {
VMReg reg = omv.content_reg();
oop* loc = fr->oopmapreg_to_location(omv.reg(), reg_map);
reg_map->set_location(reg, (address) loc);
DEBUG_ONLY(nof_callee++;)
}
}
// Check that runtime stubs save all callee-saved registers
#ifdef COMPILER2
assert(cb->is_compiled_by_c1() || cb->is_compiled_by_jvmci() || !cb->is_runtime_stub() ||
(nof_callee >= SAVED_ON_ENTRY_REG_COUNT || nof_callee >= C_SAVED_ON_ENTRY_REG_COUNT),
"must save all");
#endif // COMPILER2
}
// Printing code is present in product build for -XX:+PrintAssembly.
static
void print_register_type(OopMapValue::oop_types x, VMReg optional,
outputStream* st) {
switch( x ) {
case OopMapValue::oop_value:
st->print("Oop");
break;
case OopMapValue::narrowoop_value:
st->print("NarrowOop");
break;
case OopMapValue::callee_saved_value:
st->print("Callers_");
optional->print_on(st);
break;
case OopMapValue::derived_oop_value:
st->print("Derived_oop_");
optional->print_on(st);
break;
default:
ShouldNotReachHere();
}
}
void OopMapValue::print_on(outputStream* st) const {
reg()->print_on(st);
st->print("=");
print_register_type(type(),content_reg(),st);
st->print(" ");
}
void OopMapValue::print() const { print_on(tty); }
void ImmutableOopMap::print_on(outputStream* st) const {
OopMapValue omv;
st->print("ImmutableOopMap {");
for(OopMapStream oms(this); !oms.is_done(); oms.next()) {
omv = oms.current();
omv.print_on(st);
}
st->print("}");
}
void ImmutableOopMap::print() const { print_on(tty); }
void OopMap::print_on(outputStream* st) const {
OopMapValue omv;
st->print("OopMap {");
for(OopMapStream oms((OopMap*)this); !oms.is_done(); oms.next()) {
omv = oms.current();
omv.print_on(st);
}
// Print hex offset in addition.
st->print("off=%d/0x%x}", (int) offset(), (int) offset());
}
void OopMap::print() const { print_on(tty); }
void ImmutableOopMapSet::print_on(outputStream* st) const {
const ImmutableOopMap* last = NULL;
const int len = count();
st->print_cr("ImmutableOopMapSet contains %d OopMaps", len);
for (int i = 0; i < len; i++) {
const ImmutableOopMapPair* pair = pair_at(i);
const ImmutableOopMap* map = pair->get_from(this);
if (map != last) {
st->cr();
map->print_on(st);
st->print(" pc offsets: ");
}
last = map;
st->print("%d ", pair->pc_offset());
}
st->cr();
}
void ImmutableOopMapSet::print() const { print_on(tty); }
void OopMapSet::print_on(outputStream* st) const {
const int len = om_count();
st->print_cr("OopMapSet contains %d OopMaps", len);
for( int i = 0; i < len; i++) {
OopMap* m = at(i);
st->print_cr("#%d ",i);
m->print_on(st);
st->cr();
}
st->cr();
}
void OopMapSet::print() const { print_on(tty); }
bool OopMap::equals(const OopMap* other) const {
if (other->_omv_count != _omv_count) {
return false;
}
if (other->write_stream()->position() != write_stream()->position()) {
return false;
}
if (memcmp(other->write_stream()->buffer(), write_stream()->buffer(), write_stream()->position()) != 0) {
return false;
}
return true;
}
const ImmutableOopMap* ImmutableOopMapSet::find_map_at_offset(int pc_offset) const {
ImmutableOopMapPair* pairs = get_pairs();
ImmutableOopMapPair* last = NULL;
for (int i = 0; i < _count; ++i) {
if (pairs[i].pc_offset() >= pc_offset) {
last = &pairs[i];
break;
}
}
// Heal Coverity issue: potential index out of bounds access.
guarantee(last != NULL, "last may not be null");
assert(last->pc_offset() == pc_offset, "oopmap not found");
return last->get_from(this);
}
const ImmutableOopMap* ImmutableOopMapPair::get_from(const ImmutableOopMapSet* set) const {
return set->oopmap_at_offset(_oopmap_offset);
}
ImmutableOopMap::ImmutableOopMap(const OopMap* oopmap) : _count(oopmap->count()) {
address addr = data_addr();
oopmap->copy_data_to(addr);
}
#ifdef ASSERT
int ImmutableOopMap::nr_of_bytes() const {
OopMapStream oms(this);
while (!oms.is_done()) {
oms.next();
}
return sizeof(ImmutableOopMap) + oms.stream_position();
}
#endif
ImmutableOopMapBuilder::ImmutableOopMapBuilder(const OopMapSet* set) : _set(set), _empty(NULL), _last(NULL), _empty_offset(-1), _last_offset(-1), _offset(0), _required(-1), _new_set(NULL) {
_mapping = NEW_RESOURCE_ARRAY(Mapping, _set->size());
}
int ImmutableOopMapBuilder::size_for(const OopMap* map) const {
return align_up((int)sizeof(ImmutableOopMap) + map->data_size(), 8);
}
int ImmutableOopMapBuilder::heap_size() {
int base = sizeof(ImmutableOopMapSet);
base = align_up(base, 8);
// all of ours pc / offset pairs
int pairs = _set->size() * sizeof(ImmutableOopMapPair);
pairs = align_up(pairs, 8);
for (int i = 0; i < _set->size(); ++i) {
int size = 0;
OopMap* map = _set->at(i);
if (is_empty(map)) {
/* only keep a single empty map in the set */
if (has_empty()) {
_mapping[i].set(Mapping::OOPMAP_EMPTY, _empty_offset, 0, map, _empty);
} else {
_empty_offset = _offset;
_empty = map;
size = size_for(map);
_mapping[i].set(Mapping::OOPMAP_NEW, _offset, size, map);
}
} else if (is_last_duplicate(map)) {
/* if this entry is identical to the previous one, just point it there */
_mapping[i].set(Mapping::OOPMAP_DUPLICATE, _last_offset, 0, map, _last);
} else {
/* not empty, not an identical copy of the previous entry */
size = size_for(map);
_mapping[i].set(Mapping::OOPMAP_NEW, _offset, size, map);
_last_offset = _offset;
_last = map;
}
assert(_mapping[i]._map == map, "check");
_offset += size;
}
int total = base + pairs + _offset;
DEBUG_ONLY(total += 8);
_required = total;
return total;
}
void ImmutableOopMapBuilder::fill_pair(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set) {
assert(offset < set->nr_of_bytes(), "check");
new ((address) pair) ImmutableOopMapPair(map->offset(), offset);
}
int ImmutableOopMapBuilder::fill_map(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set) {
fill_pair(pair, map, offset, set);
address addr = (address) pair->get_from(_new_set); // location of the ImmutableOopMap
new (addr) ImmutableOopMap(map);
return size_for(map);
}
void ImmutableOopMapBuilder::fill(ImmutableOopMapSet* set, int sz) {
ImmutableOopMapPair* pairs = set->get_pairs();
for (int i = 0; i < set->count(); ++i) {
const OopMap* map = _mapping[i]._map;
ImmutableOopMapPair* pair = NULL;
int size = 0;
if (_mapping[i]._kind == Mapping::OOPMAP_NEW) {
size = fill_map(&pairs[i], map, _mapping[i]._offset, set);
} else if (_mapping[i]._kind == Mapping::OOPMAP_DUPLICATE || _mapping[i]._kind == Mapping::OOPMAP_EMPTY) {
fill_pair(&pairs[i], map, _mapping[i]._offset, set);
}
const ImmutableOopMap* nv = set->find_map_at_offset(map->offset());
assert(memcmp(map->data(), nv->data_addr(), map->data_size()) == 0, "check identity");
}
}
#ifdef ASSERT
void ImmutableOopMapBuilder::verify(address buffer, int size, const ImmutableOopMapSet* set) {
for (int i = 0; i < 8; ++i) {
assert(buffer[size - 8 + i] == (unsigned char) 0xff, "overwritten memory check");
}
for (int i = 0; i < set->count(); ++i) {
const ImmutableOopMapPair* pair = set->pair_at(i);
assert(pair->oopmap_offset() < set->nr_of_bytes(), "check size");
const ImmutableOopMap* map = pair->get_from(set);
int nr_of_bytes = map->nr_of_bytes();
assert(pair->oopmap_offset() + nr_of_bytes <= set->nr_of_bytes(), "check size + size");
}
}
#endif
ImmutableOopMapSet* ImmutableOopMapBuilder::generate_into(address buffer) {
DEBUG_ONLY(memset(&buffer[_required-8], 0xff, 8));
_new_set = new (buffer) ImmutableOopMapSet(_set, _required);
fill(_new_set, _required);
DEBUG_ONLY(verify(buffer, _required, _new_set));
return _new_set;
}
ImmutableOopMapSet* ImmutableOopMapBuilder::build() {
_required = heap_size();
// We need to allocate a chunk big enough to hold the ImmutableOopMapSet and all of its ImmutableOopMaps
address buffer = NEW_C_HEAP_ARRAY(unsigned char, _required, mtCode);
return generate_into(buffer);
}
ImmutableOopMapSet* ImmutableOopMapSet::build_from(const OopMapSet* oopmap_set) {
ResourceMark mark;
ImmutableOopMapBuilder builder(oopmap_set);
return builder.build();
}
//------------------------------DerivedPointerTable---------------------------
#if COMPILER2_OR_JVMCI
class DerivedPointerTable::Entry : public CHeapObj<mtCompiler> {
oop* _location; // Location of derived pointer, also pointing to base
intptr_t _offset; // Offset from base pointer
Entry* volatile _next;
static Entry* volatile* next_ptr(Entry& entry) { return &entry._next; }
public:
Entry(oop* location, intptr_t offset) :
_location(location), _offset(offset), _next(NULL) {}
oop* location() const { return _location; }
intptr_t offset() const { return _offset; }
Entry* next() const { return _next; }
typedef LockFreeStack<Entry, &next_ptr> List;
static List* _list;
};
DerivedPointerTable::Entry::List* DerivedPointerTable::Entry::_list = NULL;
bool DerivedPointerTable::_active = false;
bool DerivedPointerTable::is_empty() {
return Entry::_list == NULL || Entry::_list->empty();
}
void DerivedPointerTable::clear() {
// The first time, we create the list. Otherwise it should be
// empty. If not, then we have probably forgotton to call
// update_pointers after last GC/Scavenge.
assert (!_active, "should not be active");
assert(is_empty(), "table not empty");
if (Entry::_list == NULL) {
void* mem = NEW_C_HEAP_OBJ(Entry::List, mtCompiler);
Entry::_list = ::new (mem) Entry::List();
}
_active = true;
}
// Returns value of location as an int
inline intptr_t value_of_loc(oop *pointer) {
return cast_from_oop<intptr_t>((*pointer));
}
void DerivedPointerTable::add(oop *derived_loc, oop *base_loc) {
assert(Universe::heap()->is_in_or_null(*base_loc), "not an oop");
assert(derived_loc != base_loc, "Base and derived in same location");
if (_active) {
assert(*derived_loc != (void*)base_loc, "location already added");
assert(Entry::_list != NULL, "list must exist");
intptr_t offset = value_of_loc(derived_loc) - value_of_loc(base_loc);
// This assert is invalid because derived pointers can be
// arbitrarily far away from their base.
// assert(offset >= -1000000, "wrong derived pointer info");
if (TraceDerivedPointers) {
tty->print_cr(
"Add derived pointer@" INTPTR_FORMAT
" - Derived: " INTPTR_FORMAT
" Base: " INTPTR_FORMAT " (@" INTPTR_FORMAT ") (Offset: " INTX_FORMAT ")",
p2i(derived_loc), p2i((address)*derived_loc), p2i((address)*base_loc), p2i(base_loc), offset
);
}
// Set derived oop location to point to base.
*derived_loc = (oop)base_loc;
Entry* entry = new Entry(derived_loc, offset);
Entry::_list->push(*entry);
}
}
void DerivedPointerTable::update_pointers() {
assert(Entry::_list != NULL, "list must exist");
Entry* entries = Entry::_list->pop_all();
while (entries != NULL) {
Entry* entry = entries;
entries = entry->next();
oop* derived_loc = entry->location();
intptr_t offset = entry->offset();
// The derived oop was setup to point to location of base
oop base = **(oop**)derived_loc;
assert(Universe::heap()->is_in_or_null(base), "must be an oop");
*derived_loc = (oop)(((address)base) + offset);
assert(value_of_loc(derived_loc) - value_of_loc(&base) == offset, "sanity check");
if (TraceDerivedPointers) {
tty->print_cr("Updating derived pointer@" INTPTR_FORMAT
" - Derived: " INTPTR_FORMAT " Base: " INTPTR_FORMAT " (Offset: " INTX_FORMAT ")",
p2i(derived_loc), p2i((address)*derived_loc), p2i((address)base), offset);
}
// Delete entry
delete entry;
}
assert(Entry::_list->empty(), "invariant");
_active = false;
}
#endif // COMPILER2_OR_JVMCI