8175085: [REDO] G1 Needs pre barrier on dereference of weak JNI handles
Reviewed-by: kbarrett, dcubed, tschatzl
/*
* Copyright (c) 1997, 2016, 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
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* questions.
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*/
#include "precompiled.hpp"
#include "classfile/vmSymbols.hpp"
#include "code/vmreg.inline.hpp"
#include "interpreter/bytecode.hpp"
#include "interpreter/interpreter.hpp"
#include "memory/allocation.inline.hpp"
#include "memory/resourceArea.hpp"
#include "memory/universe.inline.hpp"
#include "oops/methodData.hpp"
#include "oops/oop.inline.hpp"
#include "prims/jvmtiThreadState.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/monitorChunk.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/vframe.hpp"
#include "runtime/vframeArray.hpp"
#include "runtime/vframe_hp.hpp"
#include "utilities/events.hpp"
#ifdef COMPILER2
#include "opto/runtime.hpp"
#endif
int vframeArrayElement:: bci(void) const { return (_bci == SynchronizationEntryBCI ? 0 : _bci); }
void vframeArrayElement::free_monitors(JavaThread* jt) {
if (_monitors != NULL) {
MonitorChunk* chunk = _monitors;
_monitors = NULL;
jt->remove_monitor_chunk(chunk);
delete chunk;
}
}
void vframeArrayElement::fill_in(compiledVFrame* vf, bool realloc_failures) {
// Copy the information from the compiled vframe to the
// interpreter frame we will be creating to replace vf
_method = vf->method();
_bci = vf->raw_bci();
_reexecute = vf->should_reexecute();
#ifdef ASSERT
_removed_monitors = false;
#endif
int index;
// Get the monitors off-stack
GrowableArray<MonitorInfo*>* list = vf->monitors();
if (list->is_empty()) {
_monitors = NULL;
} else {
// Allocate monitor chunk
_monitors = new MonitorChunk(list->length());
vf->thread()->add_monitor_chunk(_monitors);
// Migrate the BasicLocks from the stack to the monitor chunk
for (index = 0; index < list->length(); index++) {
MonitorInfo* monitor = list->at(index);
assert(!monitor->owner_is_scalar_replaced() || realloc_failures, "object should be reallocated already");
BasicObjectLock* dest = _monitors->at(index);
if (monitor->owner_is_scalar_replaced()) {
dest->set_obj(NULL);
} else {
assert(monitor->owner() == NULL || (!monitor->owner()->is_unlocked() && !monitor->owner()->has_bias_pattern()), "object must be null or locked, and unbiased");
dest->set_obj(monitor->owner());
monitor->lock()->move_to(monitor->owner(), dest->lock());
}
}
}
// Convert the vframe locals and expressions to off stack
// values. Because we will not gc all oops can be converted to
// intptr_t (i.e. a stack slot) and we are fine. This is
// good since we are inside a HandleMark and the oops in our
// collection would go away between packing them here and
// unpacking them in unpack_on_stack.
// First the locals go off-stack
// FIXME this seems silly it creates a StackValueCollection
// in order to get the size to then copy them and
// convert the types to intptr_t size slots. Seems like it
// could do it in place... Still uses less memory than the
// old way though
StackValueCollection *locs = vf->locals();
_locals = new StackValueCollection(locs->size());
for(index = 0; index < locs->size(); index++) {
StackValue* value = locs->at(index);
switch(value->type()) {
case T_OBJECT:
assert(!value->obj_is_scalar_replaced() || realloc_failures, "object should be reallocated already");
// preserve object type
_locals->add( new StackValue(cast_from_oop<intptr_t>((value->get_obj()())), T_OBJECT ));
break;
case T_CONFLICT:
// A dead local. Will be initialized to null/zero.
_locals->add( new StackValue());
break;
case T_INT:
_locals->add( new StackValue(value->get_int()));
break;
default:
ShouldNotReachHere();
}
}
// Now the expressions off-stack
// Same silliness as above
StackValueCollection *exprs = vf->expressions();
_expressions = new StackValueCollection(exprs->size());
for(index = 0; index < exprs->size(); index++) {
StackValue* value = exprs->at(index);
switch(value->type()) {
case T_OBJECT:
assert(!value->obj_is_scalar_replaced() || realloc_failures, "object should be reallocated already");
// preserve object type
_expressions->add( new StackValue(cast_from_oop<intptr_t>((value->get_obj()())), T_OBJECT ));
break;
case T_CONFLICT:
// A dead stack element. Will be initialized to null/zero.
// This can occur when the compiler emits a state in which stack
// elements are known to be dead (because of an imminent exception).
_expressions->add( new StackValue());
break;
case T_INT:
_expressions->add( new StackValue(value->get_int()));
break;
default:
ShouldNotReachHere();
}
}
}
int unpack_counter = 0;
void vframeArrayElement::unpack_on_stack(int caller_actual_parameters,
int callee_parameters,
int callee_locals,
frame* caller,
bool is_top_frame,
bool is_bottom_frame,
int exec_mode) {
JavaThread* thread = (JavaThread*) Thread::current();
bool realloc_failure_exception = thread->frames_to_pop_failed_realloc() > 0;
// Look at bci and decide on bcp and continuation pc
address bcp;
// C++ interpreter doesn't need a pc since it will figure out what to do when it
// begins execution
address pc;
bool use_next_mdp = false; // true if we should use the mdp associated with the next bci
// rather than the one associated with bcp
if (raw_bci() == SynchronizationEntryBCI) {
// We are deoptimizing while hanging in prologue code for synchronized method
bcp = method()->bcp_from(0); // first byte code
pc = Interpreter::deopt_entry(vtos, 0); // step = 0 since we don't skip current bytecode
} else if (should_reexecute()) { //reexecute this bytecode
assert(is_top_frame, "reexecute allowed only for the top frame");
bcp = method()->bcp_from(bci());
pc = Interpreter::deopt_reexecute_entry(method(), bcp);
} else {
bcp = method()->bcp_from(bci());
pc = Interpreter::deopt_continue_after_entry(method(), bcp, callee_parameters, is_top_frame);
use_next_mdp = true;
}
assert(Bytecodes::is_defined(*bcp), "must be a valid bytecode");
// Monitorenter and pending exceptions:
//
// For Compiler2, there should be no pending exception when deoptimizing at monitorenter
// because there is no safepoint at the null pointer check (it is either handled explicitly
// or prior to the monitorenter) and asynchronous exceptions are not made "pending" by the
// runtime interface for the slow case (see JRT_ENTRY_FOR_MONITORENTER). If an asynchronous
// exception was processed, the bytecode pointer would have to be extended one bytecode beyond
// the monitorenter to place it in the proper exception range.
//
// For Compiler1, deoptimization can occur while throwing a NullPointerException at monitorenter,
// in which case bcp should point to the monitorenter since it is within the exception's range.
//
// For realloc failure exception we just pop frames, skip the guarantee.
assert(*bcp != Bytecodes::_monitorenter || is_top_frame, "a _monitorenter must be a top frame");
assert(thread->deopt_compiled_method() != NULL, "compiled method should be known");
guarantee(realloc_failure_exception || !(thread->deopt_compiled_method()->is_compiled_by_c2() &&
*bcp == Bytecodes::_monitorenter &&
exec_mode == Deoptimization::Unpack_exception),
"shouldn't get exception during monitorenter");
int popframe_preserved_args_size_in_bytes = 0;
int popframe_preserved_args_size_in_words = 0;
if (is_top_frame) {
JvmtiThreadState *state = thread->jvmti_thread_state();
if (JvmtiExport::can_pop_frame() &&
(thread->has_pending_popframe() || thread->popframe_forcing_deopt_reexecution())) {
if (thread->has_pending_popframe()) {
// Pop top frame after deoptimization
#ifndef CC_INTERP
pc = Interpreter::remove_activation_preserving_args_entry();
#else
// Do an uncommon trap type entry. c++ interpreter will know
// to pop frame and preserve the args
pc = Interpreter::deopt_entry(vtos, 0);
use_next_mdp = false;
#endif
} else {
// Reexecute invoke in top frame
pc = Interpreter::deopt_entry(vtos, 0);
use_next_mdp = false;
popframe_preserved_args_size_in_bytes = in_bytes(thread->popframe_preserved_args_size());
// Note: the PopFrame-related extension of the expression stack size is done in
// Deoptimization::fetch_unroll_info_helper
popframe_preserved_args_size_in_words = in_words(thread->popframe_preserved_args_size_in_words());
}
} else if (!realloc_failure_exception && JvmtiExport::can_force_early_return() && state != NULL && state->is_earlyret_pending()) {
// Force early return from top frame after deoptimization
#ifndef CC_INTERP
pc = Interpreter::remove_activation_early_entry(state->earlyret_tos());
#endif
} else {
if (realloc_failure_exception && JvmtiExport::can_force_early_return() && state != NULL && state->is_earlyret_pending()) {
state->clr_earlyret_pending();
state->set_earlyret_oop(NULL);
state->clr_earlyret_value();
}
// Possibly override the previous pc computation of the top (youngest) frame
switch (exec_mode) {
case Deoptimization::Unpack_deopt:
// use what we've got
break;
case Deoptimization::Unpack_exception:
// exception is pending
pc = SharedRuntime::raw_exception_handler_for_return_address(thread, pc);
// [phh] We're going to end up in some handler or other, so it doesn't
// matter what mdp we point to. See exception_handler_for_exception()
// in interpreterRuntime.cpp.
break;
case Deoptimization::Unpack_uncommon_trap:
case Deoptimization::Unpack_reexecute:
// redo last byte code
pc = Interpreter::deopt_entry(vtos, 0);
use_next_mdp = false;
break;
default:
ShouldNotReachHere();
}
}
}
// Setup the interpreter frame
assert(method() != NULL, "method must exist");
int temps = expressions()->size();
int locks = monitors() == NULL ? 0 : monitors()->number_of_monitors();
Interpreter::layout_activation(method(),
temps + callee_parameters,
popframe_preserved_args_size_in_words,
locks,
caller_actual_parameters,
callee_parameters,
callee_locals,
caller,
iframe(),
is_top_frame,
is_bottom_frame);
// Update the pc in the frame object and overwrite the temporary pc
// we placed in the skeletal frame now that we finally know the
// exact interpreter address we should use.
_frame.patch_pc(thread, pc);
assert (!method()->is_synchronized() || locks > 0 || _removed_monitors || raw_bci() == SynchronizationEntryBCI, "synchronized methods must have monitors");
BasicObjectLock* top = iframe()->interpreter_frame_monitor_begin();
for (int index = 0; index < locks; index++) {
top = iframe()->previous_monitor_in_interpreter_frame(top);
BasicObjectLock* src = _monitors->at(index);
top->set_obj(src->obj());
src->lock()->move_to(src->obj(), top->lock());
}
if (ProfileInterpreter) {
iframe()->interpreter_frame_set_mdp(0); // clear out the mdp.
}
iframe()->interpreter_frame_set_bcp(bcp);
if (ProfileInterpreter) {
MethodData* mdo = method()->method_data();
if (mdo != NULL) {
int bci = iframe()->interpreter_frame_bci();
if (use_next_mdp) ++bci;
address mdp = mdo->bci_to_dp(bci);
iframe()->interpreter_frame_set_mdp(mdp);
}
}
if (PrintDeoptimizationDetails) {
tty->print_cr("Expressions size: %d", expressions()->size());
}
// Unpack expression stack
// If this is an intermediate frame (i.e. not top frame) then this
// only unpacks the part of the expression stack not used by callee
// as parameters. The callee parameters are unpacked as part of the
// callee locals.
int i;
for(i = 0; i < expressions()->size(); i++) {
StackValue *value = expressions()->at(i);
intptr_t* addr = iframe()->interpreter_frame_expression_stack_at(i);
switch(value->type()) {
case T_INT:
*addr = value->get_int();
#ifndef PRODUCT
if (PrintDeoptimizationDetails) {
tty->print_cr("Reconstructed expression %d (INT): %d", i, (int)(*addr));
}
#endif
break;
case T_OBJECT:
*addr = value->get_int(T_OBJECT);
#ifndef PRODUCT
if (PrintDeoptimizationDetails) {
tty->print("Reconstructed expression %d (OBJECT): ", i);
oop o = (oop)(address)(*addr);
if (o == NULL) {
tty->print_cr("NULL");
} else {
ResourceMark rm;
tty->print_raw_cr(o->klass()->name()->as_C_string());
}
}
#endif
break;
case T_CONFLICT:
// A dead stack slot. Initialize to null in case it is an oop.
*addr = NULL_WORD;
break;
default:
ShouldNotReachHere();
}
}
// Unpack the locals
for(i = 0; i < locals()->size(); i++) {
StackValue *value = locals()->at(i);
intptr_t* addr = iframe()->interpreter_frame_local_at(i);
switch(value->type()) {
case T_INT:
*addr = value->get_int();
#ifndef PRODUCT
if (PrintDeoptimizationDetails) {
tty->print_cr("Reconstructed local %d (INT): %d", i, (int)(*addr));
}
#endif
break;
case T_OBJECT:
*addr = value->get_int(T_OBJECT);
#ifndef PRODUCT
if (PrintDeoptimizationDetails) {
tty->print("Reconstructed local %d (OBJECT): ", i);
oop o = (oop)(address)(*addr);
if (o == NULL) {
tty->print_cr("NULL");
} else {
ResourceMark rm;
tty->print_raw_cr(o->klass()->name()->as_C_string());
}
}
#endif
break;
case T_CONFLICT:
// A dead location. If it is an oop then we need a NULL to prevent GC from following it
*addr = NULL_WORD;
break;
default:
ShouldNotReachHere();
}
}
if (is_top_frame && JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
// An interpreted frame was popped but it returns to a deoptimized
// frame. The incoming arguments to the interpreted activation
// were preserved in thread-local storage by the
// remove_activation_preserving_args_entry in the interpreter; now
// we put them back into the just-unpacked interpreter frame.
// Note that this assumes that the locals arena grows toward lower
// addresses.
if (popframe_preserved_args_size_in_words != 0) {
void* saved_args = thread->popframe_preserved_args();
assert(saved_args != NULL, "must have been saved by interpreter");
#ifdef ASSERT
assert(popframe_preserved_args_size_in_words <=
iframe()->interpreter_frame_expression_stack_size()*Interpreter::stackElementWords,
"expression stack size should have been extended");
#endif // ASSERT
int top_element = iframe()->interpreter_frame_expression_stack_size()-1;
intptr_t* base;
if (frame::interpreter_frame_expression_stack_direction() < 0) {
base = iframe()->interpreter_frame_expression_stack_at(top_element);
} else {
base = iframe()->interpreter_frame_expression_stack();
}
Copy::conjoint_jbytes(saved_args,
base,
popframe_preserved_args_size_in_bytes);
thread->popframe_free_preserved_args();
}
}
#ifndef PRODUCT
if (PrintDeoptimizationDetails) {
ttyLocker ttyl;
tty->print_cr("[%d Interpreted Frame]", ++unpack_counter);
iframe()->print_on(tty);
RegisterMap map(thread);
vframe* f = vframe::new_vframe(iframe(), &map, thread);
f->print();
tty->print_cr("locals size %d", locals()->size());
tty->print_cr("expression size %d", expressions()->size());
method()->print_value();
tty->cr();
// method()->print_codes();
} else if (TraceDeoptimization) {
tty->print(" ");
method()->print_value();
Bytecodes::Code code = Bytecodes::java_code_at(method(), bcp);
int bci = method()->bci_from(bcp);
tty->print(" - %s", Bytecodes::name(code));
tty->print(" @ bci %d ", bci);
tty->print_cr("sp = " PTR_FORMAT, p2i(iframe()->sp()));
}
#endif // PRODUCT
// The expression stack and locals are in the resource area don't leave
// a dangling pointer in the vframeArray we leave around for debug
// purposes
_locals = _expressions = NULL;
}
int vframeArrayElement::on_stack_size(int callee_parameters,
int callee_locals,
bool is_top_frame,
int popframe_extra_stack_expression_els) const {
assert(method()->max_locals() == locals()->size(), "just checking");
int locks = monitors() == NULL ? 0 : monitors()->number_of_monitors();
int temps = expressions()->size();
return Interpreter::size_activation(method()->max_stack(),
temps + callee_parameters,
popframe_extra_stack_expression_els,
locks,
callee_parameters,
callee_locals,
is_top_frame);
}
vframeArray* vframeArray::allocate(JavaThread* thread, int frame_size, GrowableArray<compiledVFrame*>* chunk,
RegisterMap *reg_map, frame sender, frame caller, frame self,
bool realloc_failures) {
// Allocate the vframeArray
vframeArray * result = (vframeArray*) AllocateHeap(sizeof(vframeArray) + // fixed part
sizeof(vframeArrayElement) * (chunk->length() - 1), // variable part
mtCompiler);
result->_frames = chunk->length();
result->_owner_thread = thread;
result->_sender = sender;
result->_caller = caller;
result->_original = self;
result->set_unroll_block(NULL); // initialize it
result->fill_in(thread, frame_size, chunk, reg_map, realloc_failures);
return result;
}
void vframeArray::fill_in(JavaThread* thread,
int frame_size,
GrowableArray<compiledVFrame*>* chunk,
const RegisterMap *reg_map,
bool realloc_failures) {
// Set owner first, it is used when adding monitor chunks
_frame_size = frame_size;
for(int i = 0; i < chunk->length(); i++) {
element(i)->fill_in(chunk->at(i), realloc_failures);
}
// Copy registers for callee-saved registers
if (reg_map != NULL) {
for(int i = 0; i < RegisterMap::reg_count; i++) {
#ifdef AMD64
// The register map has one entry for every int (32-bit value), so
// 64-bit physical registers have two entries in the map, one for
// each half. Ignore the high halves of 64-bit registers, just like
// frame::oopmapreg_to_location does.
//
// [phh] FIXME: this is a temporary hack! This code *should* work
// correctly w/o this hack, possibly by changing RegisterMap::pd_location
// in frame_amd64.cpp and the values of the phantom high half registers
// in amd64.ad.
// if (VMReg::Name(i) < SharedInfo::stack0 && is_even(i)) {
intptr_t* src = (intptr_t*) reg_map->location(VMRegImpl::as_VMReg(i));
_callee_registers[i] = src != NULL ? *src : NULL_WORD;
// } else {
// jint* src = (jint*) reg_map->location(VMReg::Name(i));
// _callee_registers[i] = src != NULL ? *src : NULL_WORD;
// }
#else
jint* src = (jint*) reg_map->location(VMRegImpl::as_VMReg(i));
_callee_registers[i] = src != NULL ? *src : NULL_WORD;
#endif
if (src == NULL) {
set_location_valid(i, false);
} else {
set_location_valid(i, true);
jint* dst = (jint*) register_location(i);
*dst = *src;
}
}
}
}
void vframeArray::unpack_to_stack(frame &unpack_frame, int exec_mode, int caller_actual_parameters) {
// stack picture
// unpack_frame
// [new interpreter frames ] (frames are skeletal but walkable)
// caller_frame
//
// This routine fills in the missing data for the skeletal interpreter frames
// in the above picture.
// Find the skeletal interpreter frames to unpack into
JavaThread* THREAD = JavaThread::current();
RegisterMap map(THREAD, false);
// Get the youngest frame we will unpack (last to be unpacked)
frame me = unpack_frame.sender(&map);
int index;
for (index = 0; index < frames(); index++ ) {
*element(index)->iframe() = me;
// Get the caller frame (possibly skeletal)
me = me.sender(&map);
}
// Do the unpacking of interpreter frames; the frame at index 0 represents the top activation, so it has no callee
// Unpack the frames from the oldest (frames() -1) to the youngest (0)
frame* caller_frame = &me;
for (index = frames() - 1; index >= 0 ; index--) {
vframeArrayElement* elem = element(index); // caller
int callee_parameters, callee_locals;
if (index == 0) {
callee_parameters = callee_locals = 0;
} else {
methodHandle caller = elem->method();
methodHandle callee = element(index - 1)->method();
Bytecode_invoke inv(caller, elem->bci());
// invokedynamic instructions don't have a class but obviously don't have a MemberName appendix.
// NOTE: Use machinery here that avoids resolving of any kind.
const bool has_member_arg =
!inv.is_invokedynamic() && MethodHandles::has_member_arg(inv.klass(), inv.name());
callee_parameters = callee->size_of_parameters() + (has_member_arg ? 1 : 0);
callee_locals = callee->max_locals();
}
elem->unpack_on_stack(caller_actual_parameters,
callee_parameters,
callee_locals,
caller_frame,
index == 0,
index == frames() - 1,
exec_mode);
if (index == frames() - 1) {
Deoptimization::unwind_callee_save_values(elem->iframe(), this);
}
caller_frame = elem->iframe();
caller_actual_parameters = callee_parameters;
}
deallocate_monitor_chunks();
}
void vframeArray::deallocate_monitor_chunks() {
JavaThread* jt = JavaThread::current();
for (int index = 0; index < frames(); index++ ) {
element(index)->free_monitors(jt);
}
}
#ifndef PRODUCT
bool vframeArray::structural_compare(JavaThread* thread, GrowableArray<compiledVFrame*>* chunk) {
if (owner_thread() != thread) return false;
int index = 0;
#if 0 // FIXME can't do this comparison
// Compare only within vframe array.
for (deoptimizedVFrame* vf = deoptimizedVFrame::cast(vframe_at(first_index())); vf; vf = vf->deoptimized_sender_or_null()) {
if (index >= chunk->length() || !vf->structural_compare(chunk->at(index))) return false;
index++;
}
if (index != chunk->length()) return false;
#endif
return true;
}
#endif
address vframeArray::register_location(int i) const {
assert(0 <= i && i < RegisterMap::reg_count, "index out of bounds");
return (address) & _callee_registers[i];
}
#ifndef PRODUCT
// Printing
// Note: we cannot have print_on as const, as we allocate inside the method
void vframeArray::print_on_2(outputStream* st) {
st->print_cr(" - sp: " INTPTR_FORMAT, p2i(sp()));
st->print(" - thread: ");
Thread::current()->print();
st->print_cr(" - frame size: %d", frame_size());
for (int index = 0; index < frames() ; index++ ) {
element(index)->print(st);
}
}
void vframeArrayElement::print(outputStream* st) {
st->print_cr(" - interpreter_frame -> sp: " INTPTR_FORMAT, p2i(iframe()->sp()));
}
void vframeArray::print_value_on(outputStream* st) const {
st->print_cr("vframeArray [%d] ", frames());
}
#endif