Java example source code file (oopMap.cpp)
The oopMap.cpp Java example source code
/*
* Copyright (c) 1998, 2013, 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_interface/collectedHeap.hpp"
#include "memory/allocation.inline.hpp"
#include "memory/resourceArea.hpp"
#include "runtime/frame.inline.hpp"
#include "runtime/signature.hpp"
#ifdef COMPILER1
#include "c1/c1_Defs.hpp"
#endif
// OopMapStream
OopMapStream::OopMapStream(OopMap* oop_map) {
if(oop_map->omv_data() == NULL) {
_stream = new CompressedReadStream(oop_map->write_stream()->buffer());
} else {
_stream = new CompressedReadStream(oop_map->omv_data());
}
_mask = OopMapValue::type_mask_in_place;
_size = oop_map->omv_count();
_position = 0;
_valid_omv = false;
}
OopMapStream::OopMapStream(OopMap* oop_map, int oop_types_mask) {
if(oop_map->omv_data() == NULL) {
_stream = new CompressedReadStream(oop_map->write_stream()->buffer());
} else {
_stream = new CompressedReadStream(oop_map->omv_data());
}
_mask = oop_types_mask;
_size = oop_map->omv_count();
_position = 0;
_valid_omv = false;
}
void OopMapStream::find_next() {
while(_position++ < _size) {
_omv.read_from(_stream);
if(((int)_omv.type() & _mask) > 0) {
_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_data(NULL);
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_data(NULL);
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_to(address addr) {
memcpy(addr,this,sizeof(OopMap));
memcpy(addr + sizeof(OopMap),write_stream()->buffer(),write_stream()->position());
OopMap* new_oop = (OopMap*)addr;
new_oop->set_omv_data_size(write_stream()->position());
new_oop->set_omv_data((unsigned char *)(addr + sizeof(OopMap)));
new_oop->set_write_stream(NULL);
}
int OopMap::heap_size() const {
int size = sizeof(OopMap);
int align = sizeof(void *) - 1;
if(write_stream() != NULL) {
size += write_stream()->position();
} else {
size += omv_data_size();
}
// 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);
if(x == OopMapValue::callee_saved_value) {
// This can never be a stack location, so we don't need to transform it.
assert(optional->is_reg(), "Trying to callee save a stack location");
o.set_content_reg(optional);
} else if(x == OopMapValue::derived_oop_value) {
o.set_content_reg(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_value(VMReg reg) {
// At this time, we only need value entries in our OopMap when ZapDeadCompiledLocals is active.
if (ZapDeadCompiledLocals)
set_xxx(reg, OopMapValue::value_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::copy_to(address addr) {
address temp = addr;
int align = sizeof(void *) - 1;
// Copy this
memcpy(addr,this,sizeof(OopMapSet));
temp += sizeof(OopMapSet);
temp = (address)((intptr_t)(temp + align) & ~align);
// Do the needed fixups to the new OopMapSet
OopMapSet* new_set = (OopMapSet*)addr;
new_set->set_om_data((OopMap**)temp);
// Allow enough space for the OopMap pointers
temp += (om_count() * sizeof(OopMap*));
for(int i=0; i < om_count(); i++) {
OopMap* map = at(i);
map->copy_to((address)temp);
new_set->set(i,(OopMap*)temp);
temp += map->heap_size();
}
// This "locks" the OopMapSet
new_set->set_om_size(-1);
}
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;
}
class DoNothingClosure: public OopClosure {
public:
void do_oop(oop* p) {}
void do_oop(narrowOop* p) {}
};
static DoNothingClosure do_nothing;
static void add_derived_oop(oop* base, oop* derived) {
#ifndef TIERED
COMPILER1_PRESENT(ShouldNotReachHere();)
#endif // TIERED
#ifdef COMPILER2
DerivedPointerTable::add(derived, base);
#endif // COMPILER2
}
#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();
OopMapSet* maps = cb->oop_maps();
OopMap* 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);
}
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);)
OopMapSet* maps = cb->oop_maps();
OopMap* 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,OopMapValue::derived_oop_value);
if (!oms.is_done()) {
#ifndef TIERED
COMPILER1_PRESENT(ShouldNotReachHere();)
#endif // !TIERED
// Protect the operation on the derived pointers. This
// protects the addition of derived pointers to the shared
// derived pointer table in DerivedPointerTable::add().
MutexLockerEx x(DerivedPointerTableGC_lock, Mutex::_no_safepoint_check_flag);
do {
omv = oms.current();
oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map);
if ( loc != NULL ) {
oop *base_loc = fr->oopmapreg_to_location(omv.content_reg(), reg_map);
oop *derived_loc = loc;
oop val = *base_loc;
if (val == (oop)NULL || Universe::is_narrow_oop_base(val)) {
// Ignore NULL oops and decoded NULL narrow oops which
// equal to Universe::narrow_oop_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.
} else
derived_oop_fn(base_loc, derived_loc);
}
oms.next();
} while (!oms.is_done());
}
}
// We want coop, value and oop oop_types
int mask = OopMapValue::oop_value | OopMapValue::value_value | OopMapValue::narrowoop_value;
{
for (OopMapStream oms(map,mask); !oms.is_done(); oms.next()) {
omv = oms.current();
oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map);
if ( loc != NULL ) {
if ( omv.type() == OopMapValue::oop_value ) {
oop val = *loc;
if (val == (oop)NULL || Universe::is_narrow_oop_base(val)) {
// Ignore NULL oops and decoded NULL narrow oops which
// equal to Universe::narrow_oop_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::value_value ) {
assert((*loc) == (oop)NULL || !Universe::is_narrow_oop_base(*loc),
"found invalid value pointer");
value_fn->do_oop(loc);
} else if ( omv.type() == OopMapValue::narrowoop_value ) {
narrowOop *nl = (narrowOop*)loc;
#ifndef VM_LITTLE_ENDIAN
if (!omv.reg()->is_stack()) {
// 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).
const int max_saved_on_entry_reg_count = ConcreteRegisterImpl::number_of_registers;
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");
int nof_callee = 0;
oop* locs[2*max_saved_on_entry_reg_count+1];
VMReg regs[2*max_saved_on_entry_reg_count+1];
// ("+1" because max_saved_on_entry_reg_count might be zero)
// 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();
OopMap* map = cb->oop_map_for_return_address(pc);
assert(map != NULL, " no ptr map found");
OopMapValue omv;
for(OopMapStream oms(map,OopMapValue::callee_saved_value); !oms.is_done(); oms.next()) {
omv = oms.current();
assert(nof_callee < 2*max_saved_on_entry_reg_count, "overflow");
regs[nof_callee] = omv.content_reg();
locs[nof_callee] = fr->oopmapreg_to_location(omv.reg(),reg_map);
nof_callee++;
}
// Check that runtime stubs save all callee-saved registers
#ifdef COMPILER2
assert(cb->is_compiled_by_c1() || !cb->is_runtime_stub() ||
(nof_callee >= SAVED_ON_ENTRY_REG_COUNT || nof_callee >= C_SAVED_ON_ENTRY_REG_COUNT),
"must save all");
#endif // COMPILER2
// Copy found callee-saved register to reg_map
for(int i = 0; i < nof_callee; i++) {
reg_map->set_location(regs[i], (address)locs[i]);
}
}
//=============================================================================
// Non-Product code
#ifndef PRODUCT
bool OopMap::has_derived_pointer() const {
#ifndef TIERED
COMPILER1_PRESENT(return false);
#endif // !TIERED
#ifdef COMPILER2
OopMapStream oms((OopMap*)this,OopMapValue::derived_oop_value);
return oms.is_done();
#else
return false;
#endif // COMPILER2
}
#endif //PRODUCT
// 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::value_value:
st->print("Value");
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 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);
}
st->print("off=%d}", (int) offset());
}
void OopMapSet::print_on(outputStream* st) const {
int i, len = om_count();
st->print_cr("OopMapSet contains %d OopMaps\n",len);
for( i = 0; i < len; i++) {
OopMap* m = at(i);
st->print_cr("#%d ",i);
m->print_on(st);
st->cr();
}
}
//------------------------------DerivedPointerTable---------------------------
#ifdef COMPILER2
class DerivedPointerEntry : public CHeapObj<mtCompiler> {
private:
oop* _location; // Location of derived pointer (also pointing to the base)
intptr_t _offset; // Offset from base pointer
public:
DerivedPointerEntry(oop* location, intptr_t offset) { _location = location; _offset = offset; }
oop* location() { return _location; }
intptr_t offset() { return _offset; }
};
GrowableArray<DerivedPointerEntry*>* DerivedPointerTable::_list = NULL;
bool DerivedPointerTable::_active = false;
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(_list == NULL || _list->length() == 0, "table not empty");
if (_list == NULL) {
_list = new (ResourceObj::C_HEAP, mtCompiler) GrowableArray<DerivedPointerEntry*>(10, true); // Allocated on C heap
}
_active = true;
}
// Returns value of location as an int
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 != (oop)base_loc, "location already added");
assert(_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: %d)",
derived_loc, (address)*derived_loc, (address)*base_loc, base_loc, offset
);
}
// Set derived oop location to point to base.
*derived_loc = (oop)base_loc;
assert_lock_strong(DerivedPointerTableGC_lock);
DerivedPointerEntry *entry = new DerivedPointerEntry(derived_loc, offset);
_list->append(entry);
}
}
void DerivedPointerTable::update_pointers() {
assert(_list != NULL, "list must exist");
for(int i = 0; i < _list->length(); i++) {
DerivedPointerEntry* entry = _list->at(i);
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: %d)",
derived_loc, (address)*derived_loc, (address)base, offset);
}
// Delete entry
delete entry;
_list->at_put(i, NULL);
}
// Clear list, so it is ready for next traversal (this is an invariant)
if (TraceDerivedPointers && !_list->is_empty()) {
tty->print_cr("--------------------------");
}
_list->clear();
_active = false;
}
#endif // COMPILER2
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