diff -r fd16c54261b3 -r 489c9b5090e2 hotspot/src/share/vm/runtime/deoptimization.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/hotspot/src/share/vm/runtime/deoptimization.cpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,1789 @@ +/* + * Copyright 1997-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +#include "incls/_precompiled.incl" +#include "incls/_deoptimization.cpp.incl" + +bool DeoptimizationMarker::_is_active = false; + +Deoptimization::UnrollBlock::UnrollBlock(int size_of_deoptimized_frame, + int caller_adjustment, + int number_of_frames, + intptr_t* frame_sizes, + address* frame_pcs, + BasicType return_type) { + _size_of_deoptimized_frame = size_of_deoptimized_frame; + _caller_adjustment = caller_adjustment; + _number_of_frames = number_of_frames; + _frame_sizes = frame_sizes; + _frame_pcs = frame_pcs; + _register_block = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2); + _return_type = return_type; + // PD (x86 only) + _counter_temp = 0; + _initial_fp = 0; + _unpack_kind = 0; + _sender_sp_temp = 0; + + _total_frame_sizes = size_of_frames(); +} + + +Deoptimization::UnrollBlock::~UnrollBlock() { + FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes); + FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs); + FREE_C_HEAP_ARRAY(intptr_t, _register_block); +} + + +intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const { + assert(register_number < RegisterMap::reg_count, "checking register number"); + return &_register_block[register_number * 2]; +} + + + +int Deoptimization::UnrollBlock::size_of_frames() const { + // Acount first for the adjustment of the initial frame + int result = _caller_adjustment; + for (int index = 0; index < number_of_frames(); index++) { + result += frame_sizes()[index]; + } + return result; +} + + +void Deoptimization::UnrollBlock::print() { + ttyLocker ttyl; + tty->print_cr("UnrollBlock"); + tty->print_cr(" size_of_deoptimized_frame = %d", _size_of_deoptimized_frame); + tty->print( " frame_sizes: "); + for (int index = 0; index < number_of_frames(); index++) { + tty->print("%d ", frame_sizes()[index]); + } + tty->cr(); +} + + +// In order to make fetch_unroll_info work properly with escape +// analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and +// ResetNoHandleMark and HandleMark were removed from it. The actual reallocation +// of previously eliminated objects occurs in realloc_objects, which is +// called from the method fetch_unroll_info_helper below. +JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread)) + // It is actually ok to allocate handles in a leaf method. It causes no safepoints, + // but makes the entry a little slower. There is however a little dance we have to + // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro + + // fetch_unroll_info() is called at the beginning of the deoptimization + // handler. Note this fact before we start generating temporary frames + // that can confuse an asynchronous stack walker. This counter is + // decremented at the end of unpack_frames(). + thread->inc_in_deopt_handler(); + + return fetch_unroll_info_helper(thread); +JRT_END + + +// This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap) +Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread) { + + // Note: there is a safepoint safety issue here. No matter whether we enter + // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once + // the vframeArray is created. + // + + // Allocate our special deoptimization ResourceMark + DeoptResourceMark* dmark = new DeoptResourceMark(thread); + assert(thread->deopt_mark() == NULL, "Pending deopt!"); + thread->set_deopt_mark(dmark); + + frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect + RegisterMap map(thread, true); + RegisterMap dummy_map(thread, false); + // Now get the deoptee with a valid map + frame deoptee = stub_frame.sender(&map); + + // Create a growable array of VFrames where each VFrame represents an inlined + // Java frame. This storage is allocated with the usual system arena. + assert(deoptee.is_compiled_frame(), "Wrong frame type"); + GrowableArray* chunk = new GrowableArray(10); + vframe* vf = vframe::new_vframe(&deoptee, &map, thread); + while (!vf->is_top()) { + assert(vf->is_compiled_frame(), "Wrong frame type"); + chunk->push(compiledVFrame::cast(vf)); + vf = vf->sender(); + } + assert(vf->is_compiled_frame(), "Wrong frame type"); + chunk->push(compiledVFrame::cast(vf)); + +#ifdef COMPILER2 + // Reallocate the non-escaping objects and restore their fields. Then + // relock objects if synchronization on them was eliminated. + if (DoEscapeAnalysis && EliminateAllocations) { + GrowableArray* objects = chunk->at(0)->scope()->objects(); + bool reallocated = false; + if (objects != NULL) { + JRT_BLOCK + reallocated = realloc_objects(thread, &deoptee, objects, THREAD); + JRT_END + } + if (reallocated) { + reassign_fields(&deoptee, &map, objects); +#ifndef PRODUCT + if (TraceDeoptimization) { + ttyLocker ttyl; + tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread); + print_objects(objects); + } +#endif + } + for (int i = 0; i < chunk->length(); i++) { + GrowableArray* monitors = chunk->at(i)->scope()->monitors(); + if (monitors != NULL) { + relock_objects(&deoptee, &map, monitors); +#ifndef PRODUCT + if (TraceDeoptimization) { + ttyLocker ttyl; + tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread); + for (int j = 0; i < monitors->length(); i++) { + MonitorValue* mv = monitors->at(i); + if (mv->eliminated()) { + StackValue* owner = StackValue::create_stack_value(&deoptee, &map, mv->owner()); + tty->print_cr(" object <" INTPTR_FORMAT "> locked", owner->get_obj()()); + } + } + } +#endif + } + } + } +#endif // COMPILER2 + // Ensure that no safepoint is taken after pointers have been stored + // in fields of rematerialized objects. If a safepoint occurs from here on + // out the java state residing in the vframeArray will be missed. + No_Safepoint_Verifier no_safepoint; + + vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk); + + assert(thread->vframe_array_head() == NULL, "Pending deopt!");; + thread->set_vframe_array_head(array); + + // Now that the vframeArray has been created if we have any deferred local writes + // added by jvmti then we can free up that structure as the data is now in the + // vframeArray + + if (thread->deferred_locals() != NULL) { + GrowableArray* list = thread->deferred_locals(); + int i = 0; + do { + // Because of inlining we could have multiple vframes for a single frame + // and several of the vframes could have deferred writes. Find them all. + if (list->at(i)->id() == array->original().id()) { + jvmtiDeferredLocalVariableSet* dlv = list->at(i); + list->remove_at(i); + // individual jvmtiDeferredLocalVariableSet are CHeapObj's + delete dlv; + } else { + i++; + } + } while ( i < list->length() ); + if (list->length() == 0) { + thread->set_deferred_locals(NULL); + // free the list and elements back to C heap. + delete list; + } + + } + + // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info. + CodeBlob* cb = stub_frame.cb(); + // Verify we have the right vframeArray + assert(cb->frame_size() >= 0, "Unexpected frame size"); + intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size(); + +#ifdef ASSERT + assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking"); + Events::log("fetch unroll sp " INTPTR_FORMAT, unpack_sp); +#endif + // This is a guarantee instead of an assert because if vframe doesn't match + // we will unpack the wrong deoptimized frame and wind up in strange places + // where it will be very difficult to figure out what went wrong. Better + // to die an early death here than some very obscure death later when the + // trail is cold. + // Note: on ia64 this guarantee can be fooled by frames with no memory stack + // in that it will fail to detect a problem when there is one. This needs + // more work in tiger timeframe. + guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack"); + + int number_of_frames = array->frames(); + + // Compute the vframes' sizes. Note that frame_sizes[] entries are ordered from outermost to innermost + // virtual activation, which is the reverse of the elements in the vframes array. + intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames); + // +1 because we always have an interpreter return address for the final slot. + address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1); + int callee_parameters = 0; + int callee_locals = 0; + int popframe_extra_args = 0; + // Create an interpreter return address for the stub to use as its return + // address so the skeletal frames are perfectly walkable + frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0); + + // PopFrame requires that the preserved incoming arguments from the recently-popped topmost + // activation be put back on the expression stack of the caller for reexecution + if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) { + popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words()); + } + + // + // frame_sizes/frame_pcs[0] oldest frame (int or c2i) + // frame_sizes/frame_pcs[1] next oldest frame (int) + // frame_sizes/frame_pcs[n] youngest frame (int) + // + // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame + // owns the space for the return address to it's caller). Confusing ain't it. + // + // The vframe array can address vframes with indices running from + // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame. + // When we create the skeletal frames we need the oldest frame to be in the zero slot + // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk. + // so things look a little strange in this loop. + // + for (int index = 0; index < array->frames(); index++ ) { + // frame[number_of_frames - 1 ] = on_stack_size(youngest) + // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest)) + // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest))) + frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters, + callee_locals, + index == 0, + popframe_extra_args); + // This pc doesn't have to be perfect just good enough to identify the frame + // as interpreted so the skeleton frame will be walkable + // The correct pc will be set when the skeleton frame is completely filled out + // The final pc we store in the loop is wrong and will be overwritten below + frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset; + + callee_parameters = array->element(index)->method()->size_of_parameters(); + callee_locals = array->element(index)->method()->max_locals(); + popframe_extra_args = 0; + } + + // Compute whether the root vframe returns a float or double value. + BasicType return_type; + { + HandleMark hm; + methodHandle method(thread, array->element(0)->method()); + Bytecode_invoke* invoke = Bytecode_invoke_at_check(method, array->element(0)->bci()); + return_type = (invoke != NULL) ? invoke->result_type(thread) : T_ILLEGAL; + } + + // Compute information for handling adapters and adjusting the frame size of the caller. + int caller_adjustment = 0; + + // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized + // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather + // than simply use array->sender.pc(). This requires us to walk the current set of frames + // + frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame + deopt_sender = deopt_sender.sender(&dummy_map); // Now deoptee caller + + // Compute the amount the oldest interpreter frame will have to adjust + // its caller's stack by. If the caller is a compiled frame then + // we pretend that the callee has no parameters so that the + // extension counts for the full amount of locals and not just + // locals-parms. This is because without a c2i adapter the parm + // area as created by the compiled frame will not be usable by + // the interpreter. (Depending on the calling convention there + // may not even be enough space). + + // QQQ I'd rather see this pushed down into last_frame_adjust + // and have it take the sender (aka caller). + + if (deopt_sender.is_compiled_frame()) { + caller_adjustment = last_frame_adjust(0, callee_locals); + } else if (callee_locals > callee_parameters) { + // The caller frame may need extending to accommodate + // non-parameter locals of the first unpacked interpreted frame. + // Compute that adjustment. + caller_adjustment = last_frame_adjust(callee_parameters, callee_locals); + } + + + // If the sender is deoptimized the we must retrieve the address of the handler + // since the frame will "magically" show the original pc before the deopt + // and we'd undo the deopt. + + frame_pcs[0] = deopt_sender.raw_pc(); + + assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc"); + + UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord, + caller_adjustment * BytesPerWord, + number_of_frames, + frame_sizes, + frame_pcs, + return_type); +#if defined(IA32) || defined(AMD64) + // We need a way to pass fp to the unpacking code so the skeletal frames + // come out correct. This is only needed for x86 because of c2 using ebp + // as an allocatable register. So this update is useless (and harmless) + // on the other platforms. It would be nice to do this in a different + // way but even the old style deoptimization had a problem with deriving + // this value. NEEDS_CLEANUP + // Note: now that c1 is using c2's deopt blob we must do this on all + // x86 based platforms + intptr_t** fp_addr = (intptr_t**) (((address)info) + info->initial_fp_offset_in_bytes()); + *fp_addr = array->sender().fp(); // was adapter_caller +#endif /* IA32 || AMD64 */ + + if (array->frames() > 1) { + if (VerifyStack && TraceDeoptimization) { + tty->print_cr("Deoptimizing method containing inlining"); + } + } + + array->set_unroll_block(info); + return info; +} + +// Called to cleanup deoptimization data structures in normal case +// after unpacking to stack and when stack overflow error occurs +void Deoptimization::cleanup_deopt_info(JavaThread *thread, + vframeArray *array) { + + // Get array if coming from exception + if (array == NULL) { + array = thread->vframe_array_head(); + } + thread->set_vframe_array_head(NULL); + + // Free the previous UnrollBlock + vframeArray* old_array = thread->vframe_array_last(); + thread->set_vframe_array_last(array); + + if (old_array != NULL) { + UnrollBlock* old_info = old_array->unroll_block(); + old_array->set_unroll_block(NULL); + delete old_info; + delete old_array; + } + + // Deallocate any resource creating in this routine and any ResourceObjs allocated + // inside the vframeArray (StackValueCollections) + + delete thread->deopt_mark(); + thread->set_deopt_mark(NULL); + + + if (JvmtiExport::can_pop_frame()) { +#ifndef CC_INTERP + // Regardless of whether we entered this routine with the pending + // popframe condition bit set, we should always clear it now + thread->clear_popframe_condition(); +#else + // C++ interpeter will clear has_pending_popframe when it enters + // with method_resume. For deopt_resume2 we clear it now. + if (thread->popframe_forcing_deopt_reexecution()) + thread->clear_popframe_condition(); +#endif /* CC_INTERP */ + } + + // unpack_frames() is called at the end of the deoptimization handler + // and (in C2) at the end of the uncommon trap handler. Note this fact + // so that an asynchronous stack walker can work again. This counter is + // incremented at the beginning of fetch_unroll_info() and (in C2) at + // the beginning of uncommon_trap(). + thread->dec_in_deopt_handler(); +} + + +// Return BasicType of value being returned +JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode)) + + // We are already active int he special DeoptResourceMark any ResourceObj's we + // allocate will be freed at the end of the routine. + + // It is actually ok to allocate handles in a leaf method. It causes no safepoints, + // but makes the entry a little slower. There is however a little dance we have to + // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro + ResetNoHandleMark rnhm; // No-op in release/product versions + HandleMark hm; + + frame stub_frame = thread->last_frame(); + + // Since the frame to unpack is the top frame of this thread, the vframe_array_head + // must point to the vframeArray for the unpack frame. + vframeArray* array = thread->vframe_array_head(); + +#ifndef PRODUCT + if (TraceDeoptimization) { + tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode); + } +#endif + + UnrollBlock* info = array->unroll_block(); + + // Unpack the interpreter frames and any adapter frame (c2 only) we might create. + array->unpack_to_stack(stub_frame, exec_mode); + + BasicType bt = info->return_type(); + + // If we have an exception pending, claim that the return type is an oop + // so the deopt_blob does not overwrite the exception_oop. + + if (exec_mode == Unpack_exception) + bt = T_OBJECT; + + // Cleanup thread deopt data + cleanup_deopt_info(thread, array); + +#ifndef PRODUCT + if (VerifyStack) { + ResourceMark res_mark; + + // Verify that the just-unpacked frames match the interpreter's + // notions of expression stack and locals + vframeArray* cur_array = thread->vframe_array_last(); + RegisterMap rm(thread, false); + rm.set_include_argument_oops(false); + bool is_top_frame = true; + int callee_size_of_parameters = 0; + int callee_max_locals = 0; + for (int i = 0; i < cur_array->frames(); i++) { + vframeArrayElement* el = cur_array->element(i); + frame* iframe = el->iframe(); + guarantee(iframe->is_interpreted_frame(), "Wrong frame type"); + + // Get the oop map for this bci + InterpreterOopMap mask; + int cur_invoke_parameter_size = 0; + bool try_next_mask = false; + int next_mask_expression_stack_size = -1; + int top_frame_expression_stack_adjustment = 0; + methodHandle mh(thread, iframe->interpreter_frame_method()); + OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask); + BytecodeStream str(mh); + str.set_start(iframe->interpreter_frame_bci()); + int max_bci = mh->code_size(); + // Get to the next bytecode if possible + assert(str.bci() < max_bci, "bci in interpreter frame out of bounds"); + // Check to see if we can grab the number of outgoing arguments + // at an uncommon trap for an invoke (where the compiler + // generates debug info before the invoke has executed) + Bytecodes::Code cur_code = str.next(); + if (cur_code == Bytecodes::_invokevirtual || + cur_code == Bytecodes::_invokespecial || + cur_code == Bytecodes::_invokestatic || + cur_code == Bytecodes::_invokeinterface) { + Bytecode_invoke* invoke = Bytecode_invoke_at(mh, iframe->interpreter_frame_bci()); + symbolHandle signature(thread, invoke->signature()); + ArgumentSizeComputer asc(signature); + cur_invoke_parameter_size = asc.size(); + if (cur_code != Bytecodes::_invokestatic) { + // Add in receiver + ++cur_invoke_parameter_size; + } + } + if (str.bci() < max_bci) { + Bytecodes::Code bc = str.next(); + if (bc >= 0) { + // The interpreter oop map generator reports results before + // the current bytecode has executed except in the case of + // calls. It seems to be hard to tell whether the compiler + // has emitted debug information matching the "state before" + // a given bytecode or the state after, so we try both + switch (cur_code) { + case Bytecodes::_invokevirtual: + case Bytecodes::_invokespecial: + case Bytecodes::_invokestatic: + case Bytecodes::_invokeinterface: + case Bytecodes::_athrow: + break; + default: { + InterpreterOopMap next_mask; + OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask); + next_mask_expression_stack_size = next_mask.expression_stack_size(); + // Need to subtract off the size of the result type of + // the bytecode because this is not described in the + // debug info but returned to the interpreter in the TOS + // caching register + BasicType bytecode_result_type = Bytecodes::result_type(cur_code); + if (bytecode_result_type != T_ILLEGAL) { + top_frame_expression_stack_adjustment = type2size[bytecode_result_type]; + } + assert(top_frame_expression_stack_adjustment >= 0, ""); + try_next_mask = true; + break; + } + } + } + } + + // Verify stack depth and oops in frame + // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc) + if (!( + /* SPARC */ + (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) || + /* x86 */ + (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) || + (try_next_mask && + (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size - + top_frame_expression_stack_adjustment))) || + (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) || + (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute) && + (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size)) + )) { + ttyLocker ttyl; + + // Print out some information that will help us debug the problem + tty->print_cr("Wrong number of expression stack elements during deoptimization"); + tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1); + tty->print_cr(" Fabricated interpreter frame had %d expression stack elements", + iframe->interpreter_frame_expression_stack_size()); + tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size()); + tty->print_cr(" try_next_mask = %d", try_next_mask); + tty->print_cr(" next_mask_expression_stack_size = %d", next_mask_expression_stack_size); + tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters); + tty->print_cr(" callee_max_locals = %d", callee_max_locals); + tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment); + tty->print_cr(" exec_mode = %d", exec_mode); + tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size); + tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id()); + tty->print_cr(" Interpreted frames:"); + for (int k = 0; k < cur_array->frames(); k++) { + vframeArrayElement* el = cur_array->element(k); + tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci()); + } + cur_array->print_on_2(tty); + guarantee(false, "wrong number of expression stack elements during deopt"); + } + VerifyOopClosure verify; + iframe->oops_interpreted_do(&verify, &rm, false); + callee_size_of_parameters = mh->size_of_parameters(); + callee_max_locals = mh->max_locals(); + is_top_frame = false; + } + } +#endif /* !PRODUCT */ + + + return bt; +JRT_END + + +int Deoptimization::deoptimize_dependents() { + Threads::deoptimized_wrt_marked_nmethods(); + return 0; +} + + +#ifdef COMPILER2 +bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray* objects, TRAPS) { + Handle pending_exception(thread->pending_exception()); + const char* exception_file = thread->exception_file(); + int exception_line = thread->exception_line(); + thread->clear_pending_exception(); + + for (int i = 0; i < objects->length(); i++) { + assert(objects->at(i)->is_object(), "invalid debug information"); + ObjectValue* sv = (ObjectValue*) objects->at(i); + + KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()()); + oop obj = NULL; + + if (k->oop_is_instance()) { + instanceKlass* ik = instanceKlass::cast(k()); + obj = ik->allocate_instance(CHECK_(false)); + } else if (k->oop_is_typeArray()) { + typeArrayKlass* ak = typeArrayKlass::cast(k()); + assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length"); + int len = sv->field_size() / type2size[ak->element_type()]; + obj = ak->allocate(len, CHECK_(false)); + } else if (k->oop_is_objArray()) { + objArrayKlass* ak = objArrayKlass::cast(k()); + obj = ak->allocate(sv->field_size(), CHECK_(false)); + } + + assert(obj != NULL, "allocation failed"); + assert(sv->value().is_null(), "redundant reallocation"); + sv->set_value(obj); + } + + if (pending_exception.not_null()) { + thread->set_pending_exception(pending_exception(), exception_file, exception_line); + } + + return true; +} + +// This assumes that the fields are stored in ObjectValue in the same order +// they are yielded by do_nonstatic_fields. +class FieldReassigner: public FieldClosure { + frame* _fr; + RegisterMap* _reg_map; + ObjectValue* _sv; + instanceKlass* _ik; + oop _obj; + + int _i; +public: + FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) : + _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {} + + int i() const { return _i; } + + + void do_field(fieldDescriptor* fd) { + StackValue* value = + StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i())); + int offset = fd->offset(); + switch (fd->field_type()) { + case T_OBJECT: case T_ARRAY: + assert(value->type() == T_OBJECT, "Agreement."); + _obj->obj_field_put(offset, value->get_obj()()); + break; + + case T_LONG: case T_DOUBLE: { + assert(value->type() == T_INT, "Agreement."); + StackValue* low = + StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i)); + jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int()); + _obj->long_field_put(offset, res); + break; + } + + case T_INT: case T_FLOAT: // 4 bytes. + assert(value->type() == T_INT, "Agreement."); + _obj->int_field_put(offset, (jint)value->get_int()); + break; + + case T_SHORT: case T_CHAR: // 2 bytes + assert(value->type() == T_INT, "Agreement."); + _obj->short_field_put(offset, (jshort)value->get_int()); + break; + + case T_BOOLEAN: // 1 byte + assert(value->type() == T_INT, "Agreement."); + _obj->bool_field_put(offset, (jboolean)value->get_int()); + break; + + default: + ShouldNotReachHere(); + } + _i++; + } +}; + +// restore elements of an eliminated type array +void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) { + StackValue* low; + jlong lval; + int index = 0; + + for (int i = 0; i < sv->field_size(); i++) { + StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i)); + switch(type) { + case T_BOOLEAN: obj->bool_at_put (index, (jboolean) value->get_int()); break; + case T_BYTE: obj->byte_at_put (index, (jbyte) value->get_int()); break; + case T_CHAR: obj->char_at_put (index, (jchar) value->get_int()); break; + case T_SHORT: obj->short_at_put(index, (jshort) value->get_int()); break; + case T_INT: obj->int_at_put (index, (jint) value->get_int()); break; + case T_FLOAT: obj->float_at_put(index, (jfloat) value->get_int()); break; + case T_LONG: + case T_DOUBLE: + low = StackValue::create_stack_value(fr, reg_map, sv->field_at(++i)); + lval = jlong_from((jint)value->get_int(), (jint)low->get_int()); + sv->value()->long_field_put(index, lval); + break; + default: + ShouldNotReachHere(); + } + index++; + } +} + + +// restore fields of an eliminated object array +void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) { + for (int i = 0; i < sv->field_size(); i++) { + StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i)); + assert(value->type() == T_OBJECT, "object element expected"); + obj->obj_at_put(i, value->get_obj()()); + } +} + + +// restore fields of all eliminated objects and arrays +void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray* objects) { + for (int i = 0; i < objects->length(); i++) { + ObjectValue* sv = (ObjectValue*) objects->at(i); + KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()()); + Handle obj = sv->value(); + assert(obj.not_null(), "reallocation was missed"); + + if (k->oop_is_instance()) { + instanceKlass* ik = instanceKlass::cast(k()); + FieldReassigner reassign(fr, reg_map, sv, obj()); + ik->do_nonstatic_fields(&reassign); + } else if (k->oop_is_typeArray()) { + typeArrayKlass* ak = typeArrayKlass::cast(k()); + reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type()); + } else if (k->oop_is_objArray()) { + reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj()); + } + } +} + + +// relock objects for which synchronization was eliminated +void Deoptimization::relock_objects(frame* fr, RegisterMap* reg_map, GrowableArray* monitors) { + for (int i = 0; i < monitors->length(); i++) { + MonitorValue* mv = monitors->at(i); + StackValue* owner = StackValue::create_stack_value(fr, reg_map, mv->owner()); + if (mv->eliminated()) { + Handle obj = owner->get_obj(); + assert(obj.not_null(), "reallocation was missed"); + BasicLock* lock = StackValue::resolve_monitor_lock(fr, mv->basic_lock()); + lock->set_displaced_header(obj->mark()); + obj->set_mark((markOop) lock); + } + assert(owner->get_obj()->is_locked(), "object must be locked now"); + } +} + + +#ifndef PRODUCT +// print information about reallocated objects +void Deoptimization::print_objects(GrowableArray* objects) { + fieldDescriptor fd; + + for (int i = 0; i < objects->length(); i++) { + ObjectValue* sv = (ObjectValue*) objects->at(i); + KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()()); + Handle obj = sv->value(); + + tty->print(" object <" INTPTR_FORMAT "> of type ", sv->value()()); + k->as_klassOop()->print_value(); + tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize); + tty->cr(); + + if (Verbose) { + k->oop_print_on(obj(), tty); + } + } +} +#endif +#endif // COMPILER2 + +vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray* chunk) { + +#ifndef PRODUCT + if (TraceDeoptimization) { + ttyLocker ttyl; + tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread); + fr.print_on(tty); + tty->print_cr(" Virtual frames (innermost first):"); + for (int index = 0; index < chunk->length(); index++) { + compiledVFrame* vf = chunk->at(index); + tty->print(" %2d - ", index); + vf->print_value(); + int bci = chunk->at(index)->raw_bci(); + const char* code_name; + if (bci == SynchronizationEntryBCI) { + code_name = "sync entry"; + } else { + Bytecodes::Code code = Bytecodes::code_at(vf->method(), bci); + code_name = Bytecodes::name(code); + } + tty->print(" - %s", code_name); + tty->print_cr(" @ bci %d ", bci); + if (Verbose) { + vf->print(); + tty->cr(); + } + } + } +#endif + + // Register map for next frame (used for stack crawl). We capture + // the state of the deopt'ing frame's caller. Thus if we need to + // stuff a C2I adapter we can properly fill in the callee-save + // register locations. + frame caller = fr.sender(reg_map); + int frame_size = caller.sp() - fr.sp(); + + frame sender = caller; + + // Since the Java thread being deoptimized will eventually adjust it's own stack, + // the vframeArray containing the unpacking information is allocated in the C heap. + // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames(). + vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr); + + // Compare the vframeArray to the collected vframes + assert(array->structural_compare(thread, chunk), "just checking"); + Events::log("# vframes = %d", (intptr_t)chunk->length()); + +#ifndef PRODUCT + if (TraceDeoptimization) { + ttyLocker ttyl; + tty->print_cr(" Created vframeArray " INTPTR_FORMAT, array); + if (Verbose) { + int count = 0; + // this used to leak deoptimizedVFrame like it was going out of style!!! + for (int index = 0; index < array->frames(); index++ ) { + vframeArrayElement* e = array->element(index); + e->print(tty); + + /* + No printing yet. + array->vframe_at(index)->print_activation(count++); + // better as... + array->print_activation_for(index, count++); + */ + } + } + } +#endif // PRODUCT + + return array; +} + + +static void collect_monitors(compiledVFrame* cvf, GrowableArray* objects_to_revoke) { + GrowableArray* monitors = cvf->monitors(); + for (int i = 0; i < monitors->length(); i++) { + MonitorInfo* mon_info = monitors->at(i); + if (mon_info->owner() != NULL) { + objects_to_revoke->append(Handle(mon_info->owner())); + } + } +} + + +void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) { + if (!UseBiasedLocking) { + return; + } + + GrowableArray* objects_to_revoke = new GrowableArray(); + + // Unfortunately we don't have a RegisterMap available in most of + // the places we want to call this routine so we need to walk the + // stack again to update the register map. + if (map == NULL || !map->update_map()) { + StackFrameStream sfs(thread, true); + bool found = false; + while (!found && !sfs.is_done()) { + frame* cur = sfs.current(); + sfs.next(); + found = cur->id() == fr.id(); + } + assert(found, "frame to be deoptimized not found on target thread's stack"); + map = sfs.register_map(); + } + + vframe* vf = vframe::new_vframe(&fr, map, thread); + compiledVFrame* cvf = compiledVFrame::cast(vf); + // Revoke monitors' biases in all scopes + while (!cvf->is_top()) { + collect_monitors(cvf, objects_to_revoke); + cvf = compiledVFrame::cast(cvf->sender()); + } + collect_monitors(cvf, objects_to_revoke); + + if (SafepointSynchronize::is_at_safepoint()) { + BiasedLocking::revoke_at_safepoint(objects_to_revoke); + } else { + BiasedLocking::revoke(objects_to_revoke); + } +} + + +void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) { + if (!UseBiasedLocking) { + return; + } + + assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint"); + GrowableArray* objects_to_revoke = new GrowableArray(); + for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) { + if (jt->has_last_Java_frame()) { + StackFrameStream sfs(jt, true); + while (!sfs.is_done()) { + frame* cur = sfs.current(); + if (cb->contains(cur->pc())) { + vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt); + compiledVFrame* cvf = compiledVFrame::cast(vf); + // Revoke monitors' biases in all scopes + while (!cvf->is_top()) { + collect_monitors(cvf, objects_to_revoke); + cvf = compiledVFrame::cast(cvf->sender()); + } + collect_monitors(cvf, objects_to_revoke); + } + sfs.next(); + } + } + } + BiasedLocking::revoke_at_safepoint(objects_to_revoke); +} + + +void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) { + assert(fr.can_be_deoptimized(), "checking frame type"); + + gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal); + + EventMark m("Deoptimization (pc=" INTPTR_FORMAT ", sp=" INTPTR_FORMAT ")", fr.pc(), fr.id()); + + // Patch the nmethod so that when execution returns to it we will + // deopt the execution state and return to the interpreter. + fr.deoptimize(thread); +} + +void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) { + // Deoptimize only if the frame comes from compile code. + // Do not deoptimize the frame which is already patched + // during the execution of the loops below. + if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) { + return; + } + ResourceMark rm; + DeoptimizationMarker dm; + if (UseBiasedLocking) { + revoke_biases_of_monitors(thread, fr, map); + } + deoptimize_single_frame(thread, fr); + +} + + +void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) { + // Compute frame and register map based on thread and sp. + RegisterMap reg_map(thread, UseBiasedLocking); + frame fr = thread->last_frame(); + while (fr.id() != id) { + fr = fr.sender(®_map); + } + deoptimize(thread, fr, ®_map); +} + + +// JVMTI PopFrame support +JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address)) +{ + thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address); +} +JRT_END + + +#ifdef COMPILER2 +void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) { + // in case of an unresolved klass entry, load the class. + if (constant_pool->tag_at(index).is_unresolved_klass()) { + klassOop tk = constant_pool->klass_at(index, CHECK); + return; + } + + if (!constant_pool->tag_at(index).is_symbol()) return; + + Handle class_loader (THREAD, instanceKlass::cast(constant_pool->pool_holder())->class_loader()); + symbolHandle symbol (THREAD, constant_pool->symbol_at(index)); + + // class name? + if (symbol->byte_at(0) != '(') { + Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain()); + SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK); + return; + } + + // then it must be a signature! + for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) { + if (ss.is_object()) { + symbolOop s = ss.as_symbol(CHECK); + symbolHandle class_name (THREAD, s); + Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain()); + SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK); + } + } +} + + +void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) { + EXCEPTION_MARK; + load_class_by_index(constant_pool, index, THREAD); + if (HAS_PENDING_EXCEPTION) { + // Exception happened during classloading. We ignore the exception here, since it + // is going to be rethrown since the current activation is going to be deoptimzied and + // the interpreter will re-execute the bytecode. + CLEAR_PENDING_EXCEPTION; + } +} + +JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) { + HandleMark hm; + + // uncommon_trap() is called at the beginning of the uncommon trap + // handler. Note this fact before we start generating temporary frames + // that can confuse an asynchronous stack walker. This counter is + // decremented at the end of unpack_frames(). + thread->inc_in_deopt_handler(); + + // We need to update the map if we have biased locking. + RegisterMap reg_map(thread, UseBiasedLocking); + frame stub_frame = thread->last_frame(); + frame fr = stub_frame.sender(®_map); + // Make sure the calling nmethod is not getting deoptimized and removed + // before we are done with it. + nmethodLocker nl(fr.pc()); + + { + ResourceMark rm; + + // Revoke biases of any monitors in the frame to ensure we can migrate them + revoke_biases_of_monitors(thread, fr, ®_map); + + DeoptReason reason = trap_request_reason(trap_request); + DeoptAction action = trap_request_action(trap_request); + jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1 + + Events::log("Uncommon trap occurred @" INTPTR_FORMAT " unloaded_class_index = %d", fr.pc(), (int) trap_request); + vframe* vf = vframe::new_vframe(&fr, ®_map, thread); + compiledVFrame* cvf = compiledVFrame::cast(vf); + + nmethod* nm = cvf->code(); + + ScopeDesc* trap_scope = cvf->scope(); + methodHandle trap_method = trap_scope->method(); + int trap_bci = trap_scope->bci(); + Bytecodes::Code trap_bc = Bytecode_at(trap_method->bcp_from(trap_bci))->java_code(); + + // Record this event in the histogram. + gather_statistics(reason, action, trap_bc); + + // Ensure that we can record deopt. history: + bool create_if_missing = ProfileTraps; + + methodDataHandle trap_mdo + (THREAD, get_method_data(thread, trap_method, create_if_missing)); + + // Print a bunch of diagnostics, if requested. + if (TraceDeoptimization || LogCompilation) { + ResourceMark rm; + ttyLocker ttyl; + char buf[100]; + if (xtty != NULL) { + xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s", + os::current_thread_id(), + format_trap_request(buf, sizeof(buf), trap_request)); + nm->log_identity(xtty); + } + symbolHandle class_name; + bool unresolved = false; + if (unloaded_class_index >= 0) { + constantPoolHandle constants (THREAD, trap_method->constants()); + if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) { + class_name = symbolHandle(THREAD, + constants->klass_name_at(unloaded_class_index)); + unresolved = true; + if (xtty != NULL) + xtty->print(" unresolved='1'"); + } else if (constants->tag_at(unloaded_class_index).is_symbol()) { + class_name = symbolHandle(THREAD, + constants->symbol_at(unloaded_class_index)); + } + if (xtty != NULL) + xtty->name(class_name); + } + if (xtty != NULL && trap_mdo.not_null()) { + // Dump the relevant MDO state. + // This is the deopt count for the current reason, any previous + // reasons or recompiles seen at this point. + int dcnt = trap_mdo->trap_count(reason); + if (dcnt != 0) + xtty->print(" count='%d'", dcnt); + ProfileData* pdata = trap_mdo->bci_to_data(trap_bci); + int dos = (pdata == NULL)? 0: pdata->trap_state(); + if (dos != 0) { + xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos)); + if (trap_state_is_recompiled(dos)) { + int recnt2 = trap_mdo->overflow_recompile_count(); + if (recnt2 != 0) + xtty->print(" recompiles2='%d'", recnt2); + } + } + } + if (xtty != NULL) { + xtty->stamp(); + xtty->end_head(); + } + if (TraceDeoptimization) { // make noise on the tty + tty->print("Uncommon trap occurred in"); + nm->method()->print_short_name(tty); + tty->print(" (@" INTPTR_FORMAT ") thread=%d reason=%s action=%s unloaded_class_index=%d", + fr.pc(), + (int) os::current_thread_id(), + trap_reason_name(reason), + trap_action_name(action), + unloaded_class_index); + if (class_name.not_null()) { + tty->print(unresolved ? " unresolved class: " : " symbol: "); + class_name->print_symbol_on(tty); + } + tty->cr(); + } + if (xtty != NULL) { + // Log the precise location of the trap. + for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) { + xtty->begin_elem("jvms bci='%d'", sd->bci()); + xtty->method(sd->method()); + xtty->end_elem(); + if (sd->is_top()) break; + } + xtty->tail("uncommon_trap"); + } + } + // (End diagnostic printout.) + + // Load class if necessary + if (unloaded_class_index >= 0) { + constantPoolHandle constants(THREAD, trap_method->constants()); + load_class_by_index(constants, unloaded_class_index); + } + + // Flush the nmethod if necessary and desirable. + // + // We need to avoid situations where we are re-flushing the nmethod + // because of a hot deoptimization site. Repeated flushes at the same + // point need to be detected by the compiler and avoided. If the compiler + // cannot avoid them (or has a bug and "refuses" to avoid them), this + // module must take measures to avoid an infinite cycle of recompilation + // and deoptimization. There are several such measures: + // + // 1. If a recompilation is ordered a second time at some site X + // and for the same reason R, the action is adjusted to 'reinterpret', + // to give the interpreter time to exercise the method more thoroughly. + // If this happens, the method's overflow_recompile_count is incremented. + // + // 2. If the compiler fails to reduce the deoptimization rate, then + // the method's overflow_recompile_count will begin to exceed the set + // limit PerBytecodeRecompilationCutoff. If this happens, the action + // is adjusted to 'make_not_compilable', and the method is abandoned + // to the interpreter. This is a performance hit for hot methods, + // but is better than a disastrous infinite cycle of recompilations. + // (Actually, only the method containing the site X is abandoned.) + // + // 3. In parallel with the previous measures, if the total number of + // recompilations of a method exceeds the much larger set limit + // PerMethodRecompilationCutoff, the method is abandoned. + // This should only happen if the method is very large and has + // many "lukewarm" deoptimizations. The code which enforces this + // limit is elsewhere (class nmethod, class methodOopDesc). + // + // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance + // to recompile at each bytecode independently of the per-BCI cutoff. + // + // The decision to update code is up to the compiler, and is encoded + // in the Action_xxx code. If the compiler requests Action_none + // no trap state is changed, no compiled code is changed, and the + // computation suffers along in the interpreter. + // + // The other action codes specify various tactics for decompilation + // and recompilation. Action_maybe_recompile is the loosest, and + // allows the compiled code to stay around until enough traps are seen, + // and until the compiler gets around to recompiling the trapping method. + // + // The other actions cause immediate removal of the present code. + + bool update_trap_state = true; + bool make_not_entrant = false; + bool make_not_compilable = false; + bool reset_counters = false; + switch (action) { + case Action_none: + // Keep the old code. + update_trap_state = false; + break; + case Action_maybe_recompile: + // Do not need to invalidate the present code, but we can + // initiate another + // Start compiler without (necessarily) invalidating the nmethod. + // The system will tolerate the old code, but new code should be + // generated when possible. + break; + case Action_reinterpret: + // Go back into the interpreter for a while, and then consider + // recompiling form scratch. + make_not_entrant = true; + // Reset invocation counter for outer most method. + // This will allow the interpreter to exercise the bytecodes + // for a while before recompiling. + // By contrast, Action_make_not_entrant is immediate. + // + // Note that the compiler will track null_check, null_assert, + // range_check, and class_check events and log them as if they + // had been traps taken from compiled code. This will update + // the MDO trap history so that the next compilation will + // properly detect hot trap sites. + reset_counters = true; + break; + case Action_make_not_entrant: + // Request immediate recompilation, and get rid of the old code. + // Make them not entrant, so next time they are called they get + // recompiled. Unloaded classes are loaded now so recompile before next + // time they are called. Same for uninitialized. The interpreter will + // link the missing class, if any. + make_not_entrant = true; + break; + case Action_make_not_compilable: + // Give up on compiling this method at all. + make_not_entrant = true; + make_not_compilable = true; + break; + default: + ShouldNotReachHere(); + } + + // Setting +ProfileTraps fixes the following, on all platforms: + // 4852688: ProfileInterpreter is off by default for ia64. The result is + // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the + // recompile relies on a methodDataOop to record heroic opt failures. + + // Whether the interpreter is producing MDO data or not, we also need + // to use the MDO to detect hot deoptimization points and control + // aggressive optimization. + if (ProfileTraps && update_trap_state && trap_mdo.not_null()) { + assert(trap_mdo() == get_method_data(thread, trap_method, false), "sanity"); + uint this_trap_count = 0; + bool maybe_prior_trap = false; + bool maybe_prior_recompile = false; + ProfileData* pdata + = query_update_method_data(trap_mdo, trap_bci, reason, + //outputs: + this_trap_count, + maybe_prior_trap, + maybe_prior_recompile); + // Because the interpreter also counts null, div0, range, and class + // checks, these traps from compiled code are double-counted. + // This is harmless; it just means that the PerXTrapLimit values + // are in effect a little smaller than they look. + + DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason); + if (per_bc_reason != Reason_none) { + // Now take action based on the partially known per-BCI history. + if (maybe_prior_trap + && this_trap_count >= (uint)PerBytecodeTrapLimit) { + // If there are too many traps at this BCI, force a recompile. + // This will allow the compiler to see the limit overflow, and + // take corrective action, if possible. The compiler generally + // does not use the exact PerBytecodeTrapLimit value, but instead + // changes its tactics if it sees any traps at all. This provides + // a little hysteresis, delaying a recompile until a trap happens + // several times. + // + // Actually, since there is only one bit of counter per BCI, + // the possible per-BCI counts are {0,1,(per-method count)}. + // This produces accurate results if in fact there is only + // one hot trap site, but begins to get fuzzy if there are + // many sites. For example, if there are ten sites each + // trapping two or more times, they each get the blame for + // all of their traps. + make_not_entrant = true; + } + + // Detect repeated recompilation at the same BCI, and enforce a limit. + if (make_not_entrant && maybe_prior_recompile) { + // More than one recompile at this point. + trap_mdo->inc_overflow_recompile_count(); + if (maybe_prior_trap + && ((uint)trap_mdo->overflow_recompile_count() + > (uint)PerBytecodeRecompilationCutoff)) { + // Give up on the method containing the bad BCI. + if (trap_method() == nm->method()) { + make_not_compilable = true; + } else { + trap_method->set_not_compilable(); + // But give grace to the enclosing nm->method(). + } + } + } + } else { + // For reasons which are not recorded per-bytecode, we simply + // force recompiles unconditionally. + // (Note that PerMethodRecompilationCutoff is enforced elsewhere.) + make_not_entrant = true; + } + + // Go back to the compiler if there are too many traps in this method. + if (this_trap_count >= (uint)PerMethodTrapLimit) { + // If there are too many traps in this method, force a recompile. + // This will allow the compiler to see the limit overflow, and + // take corrective action, if possible. + // (This condition is an unlikely backstop only, because the + // PerBytecodeTrapLimit is more likely to take effect first, + // if it is applicable.) + make_not_entrant = true; + } + + // Here's more hysteresis: If there has been a recompile at + // this trap point already, run the method in the interpreter + // for a while to exercise it more thoroughly. + if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) { + reset_counters = true; + } + + if (make_not_entrant && pdata != NULL) { + // Record the recompilation event, if any. + int tstate0 = pdata->trap_state(); + int tstate1 = trap_state_set_recompiled(tstate0, true); + if (tstate1 != tstate0) + pdata->set_trap_state(tstate1); + } + } + + // Take requested actions on the method: + + // Reset invocation counters + if (reset_counters) { + if (nm->is_osr_method()) + reset_invocation_counter(trap_scope, CompileThreshold); + else + reset_invocation_counter(trap_scope); + } + + // Recompile + if (make_not_entrant) { + nm->make_not_entrant(); + } + + // Give up compiling + if (make_not_compilable) { + assert(make_not_entrant, "consistent"); + nm->method()->set_not_compilable(); + } + + } // Free marked resources + +} +JRT_END + +methodDataOop +Deoptimization::get_method_data(JavaThread* thread, methodHandle m, + bool create_if_missing) { + Thread* THREAD = thread; + methodDataOop mdo = m()->method_data(); + if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) { + // Build an MDO. Ignore errors like OutOfMemory; + // that simply means we won't have an MDO to update. + methodOopDesc::build_interpreter_method_data(m, THREAD); + if (HAS_PENDING_EXCEPTION) { + assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here"); + CLEAR_PENDING_EXCEPTION; + } + mdo = m()->method_data(); + } + return mdo; +} + +ProfileData* +Deoptimization::query_update_method_data(methodDataHandle trap_mdo, + int trap_bci, + Deoptimization::DeoptReason reason, + //outputs: + uint& ret_this_trap_count, + bool& ret_maybe_prior_trap, + bool& ret_maybe_prior_recompile) { + uint prior_trap_count = trap_mdo->trap_count(reason); + uint this_trap_count = trap_mdo->inc_trap_count(reason); + + // If the runtime cannot find a place to store trap history, + // it is estimated based on the general condition of the method. + // If the method has ever been recompiled, or has ever incurred + // a trap with the present reason , then this BCI is assumed + // (pessimistically) to be the culprit. + bool maybe_prior_trap = (prior_trap_count != 0); + bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0); + ProfileData* pdata = NULL; + + + // For reasons which are recorded per bytecode, we check per-BCI data. + DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason); + if (per_bc_reason != Reason_none) { + // Find the profile data for this BCI. If there isn't one, + // try to allocate one from the MDO's set of spares. + // This will let us detect a repeated trap at this point. + pdata = trap_mdo->allocate_bci_to_data(trap_bci); + + if (pdata != NULL) { + // Query the trap state of this profile datum. + int tstate0 = pdata->trap_state(); + if (!trap_state_has_reason(tstate0, per_bc_reason)) + maybe_prior_trap = false; + if (!trap_state_is_recompiled(tstate0)) + maybe_prior_recompile = false; + + // Update the trap state of this profile datum. + int tstate1 = tstate0; + // Record the reason. + tstate1 = trap_state_add_reason(tstate1, per_bc_reason); + // Store the updated state on the MDO, for next time. + if (tstate1 != tstate0) + pdata->set_trap_state(tstate1); + } else { + if (LogCompilation && xtty != NULL) + // Missing MDP? Leave a small complaint in the log. + xtty->elem("missing_mdp bci='%d'", trap_bci); + } + } + + // Return results: + ret_this_trap_count = this_trap_count; + ret_maybe_prior_trap = maybe_prior_trap; + ret_maybe_prior_recompile = maybe_prior_recompile; + return pdata; +} + +void +Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) { + ResourceMark rm; + // Ignored outputs: + uint ignore_this_trap_count; + bool ignore_maybe_prior_trap; + bool ignore_maybe_prior_recompile; + query_update_method_data(trap_mdo, trap_bci, + (DeoptReason)reason, + ignore_this_trap_count, + ignore_maybe_prior_trap, + ignore_maybe_prior_recompile); +} + +void Deoptimization::reset_invocation_counter(ScopeDesc* trap_scope, jint top_count) { + ScopeDesc* sd = trap_scope; + for (; !sd->is_top(); sd = sd->sender()) { + // Reset ICs of inlined methods, since they can trigger compilations also. + sd->method()->invocation_counter()->reset(); + } + InvocationCounter* c = sd->method()->invocation_counter(); + if (top_count != _no_count) { + // It was an OSR method, so bump the count higher. + c->set(c->state(), top_count); + } else { + c->reset(); + } + sd->method()->backedge_counter()->reset(); +} + +Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) { + + // Still in Java no safepoints + { + // This enters VM and may safepoint + uncommon_trap_inner(thread, trap_request); + } + return fetch_unroll_info_helper(thread); +} + +// Local derived constants. +// Further breakdown of DataLayout::trap_state, as promised by DataLayout. +const int DS_REASON_MASK = DataLayout::trap_mask >> 1; +const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK; + +//---------------------------trap_state_reason--------------------------------- +Deoptimization::DeoptReason +Deoptimization::trap_state_reason(int trap_state) { + // This assert provides the link between the width of DataLayout::trap_bits + // and the encoding of "recorded" reasons. It ensures there are enough + // bits to store all needed reasons in the per-BCI MDO profile. + assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits"); + int recompile_bit = (trap_state & DS_RECOMPILE_BIT); + trap_state -= recompile_bit; + if (trap_state == DS_REASON_MASK) { + return Reason_many; + } else { + assert((int)Reason_none == 0, "state=0 => Reason_none"); + return (DeoptReason)trap_state; + } +} +//-------------------------trap_state_has_reason------------------------------- +int Deoptimization::trap_state_has_reason(int trap_state, int reason) { + assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason"); + assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits"); + int recompile_bit = (trap_state & DS_RECOMPILE_BIT); + trap_state -= recompile_bit; + if (trap_state == DS_REASON_MASK) { + return -1; // true, unspecifically (bottom of state lattice) + } else if (trap_state == reason) { + return 1; // true, definitely + } else if (trap_state == 0) { + return 0; // false, definitely (top of state lattice) + } else { + return 0; // false, definitely + } +} +//-------------------------trap_state_add_reason------------------------------- +int Deoptimization::trap_state_add_reason(int trap_state, int reason) { + assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason"); + int recompile_bit = (trap_state & DS_RECOMPILE_BIT); + trap_state -= recompile_bit; + if (trap_state == DS_REASON_MASK) { + return trap_state + recompile_bit; // already at state lattice bottom + } else if (trap_state == reason) { + return trap_state + recompile_bit; // the condition is already true + } else if (trap_state == 0) { + return reason + recompile_bit; // no condition has yet been true + } else { + return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom + } +} +//-----------------------trap_state_is_recompiled------------------------------ +bool Deoptimization::trap_state_is_recompiled(int trap_state) { + return (trap_state & DS_RECOMPILE_BIT) != 0; +} +//-----------------------trap_state_set_recompiled----------------------------- +int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) { + if (z) return trap_state | DS_RECOMPILE_BIT; + else return trap_state & ~DS_RECOMPILE_BIT; +} +//---------------------------format_trap_state--------------------------------- +// This is used for debugging and diagnostics, including hotspot.log output. +const char* Deoptimization::format_trap_state(char* buf, size_t buflen, + int trap_state) { + DeoptReason reason = trap_state_reason(trap_state); + bool recomp_flag = trap_state_is_recompiled(trap_state); + // Re-encode the state from its decoded components. + int decoded_state = 0; + if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many) + decoded_state = trap_state_add_reason(decoded_state, reason); + if (recomp_flag) + decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag); + // If the state re-encodes properly, format it symbolically. + // Because this routine is used for debugging and diagnostics, + // be robust even if the state is a strange value. + size_t len; + if (decoded_state != trap_state) { + // Random buggy state that doesn't decode?? + len = jio_snprintf(buf, buflen, "#%d", trap_state); + } else { + len = jio_snprintf(buf, buflen, "%s%s", + trap_reason_name(reason), + recomp_flag ? " recompiled" : ""); + } + if (len >= buflen) + buf[buflen-1] = '\0'; + return buf; +} + + +//--------------------------------statics-------------------------------------- +Deoptimization::DeoptAction Deoptimization::_unloaded_action + = Deoptimization::Action_reinterpret; +const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = { + // Note: Keep this in sync. with enum DeoptReason. + "none", + "null_check", + "null_assert", + "range_check", + "class_check", + "array_check", + "intrinsic", + "unloaded", + "uninitialized", + "unreached", + "unhandled", + "constraint", + "div0_check", + "age" +}; +const char* Deoptimization::_trap_action_name[Action_LIMIT] = { + // Note: Keep this in sync. with enum DeoptAction. + "none", + "maybe_recompile", + "reinterpret", + "make_not_entrant", + "make_not_compilable" +}; + +const char* Deoptimization::trap_reason_name(int reason) { + if (reason == Reason_many) return "many"; + if ((uint)reason < Reason_LIMIT) + return _trap_reason_name[reason]; + static char buf[20]; + sprintf(buf, "reason%d", reason); + return buf; +} +const char* Deoptimization::trap_action_name(int action) { + if ((uint)action < Action_LIMIT) + return _trap_action_name[action]; + static char buf[20]; + sprintf(buf, "action%d", action); + return buf; +} + +// This is used for debugging and diagnostics, including hotspot.log output. +const char* Deoptimization::format_trap_request(char* buf, size_t buflen, + int trap_request) { + jint unloaded_class_index = trap_request_index(trap_request); + const char* reason = trap_reason_name(trap_request_reason(trap_request)); + const char* action = trap_action_name(trap_request_action(trap_request)); + size_t len; + if (unloaded_class_index < 0) { + len = jio_snprintf(buf, buflen, "reason='%s' action='%s'", + reason, action); + } else { + len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'", + reason, action, unloaded_class_index); + } + if (len >= buflen) + buf[buflen-1] = '\0'; + return buf; +} + +juint Deoptimization::_deoptimization_hist + [Deoptimization::Reason_LIMIT] + [1 + Deoptimization::Action_LIMIT] + [Deoptimization::BC_CASE_LIMIT] + = {0}; + +enum { + LSB_BITS = 8, + LSB_MASK = right_n_bits(LSB_BITS) +}; + +void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action, + Bytecodes::Code bc) { + assert(reason >= 0 && reason < Reason_LIMIT, "oob"); + assert(action >= 0 && action < Action_LIMIT, "oob"); + _deoptimization_hist[Reason_none][0][0] += 1; // total + _deoptimization_hist[reason][0][0] += 1; // per-reason total + juint* cases = _deoptimization_hist[reason][1+action]; + juint* bc_counter_addr = NULL; + juint bc_counter = 0; + // Look for an unused counter, or an exact match to this BC. + if (bc != Bytecodes::_illegal) { + for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) { + juint* counter_addr = &cases[bc_case]; + juint counter = *counter_addr; + if ((counter == 0 && bc_counter_addr == NULL) + || (Bytecodes::Code)(counter & LSB_MASK) == bc) { + // this counter is either free or is already devoted to this BC + bc_counter_addr = counter_addr; + bc_counter = counter | bc; + } + } + } + if (bc_counter_addr == NULL) { + // Overflow, or no given bytecode. + bc_counter_addr = &cases[BC_CASE_LIMIT-1]; + bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB + } + *bc_counter_addr = bc_counter + (1 << LSB_BITS); +} + +jint Deoptimization::total_deoptimization_count() { + return _deoptimization_hist[Reason_none][0][0]; +} + +jint Deoptimization::deoptimization_count(DeoptReason reason) { + assert(reason >= 0 && reason < Reason_LIMIT, "oob"); + return _deoptimization_hist[reason][0][0]; +} + +void Deoptimization::print_statistics() { + juint total = total_deoptimization_count(); + juint account = total; + if (total != 0) { + ttyLocker ttyl; + if (xtty != NULL) xtty->head("statistics type='deoptimization'"); + tty->print_cr("Deoptimization traps recorded:"); + #define PRINT_STAT_LINE(name, r) \ + tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name); + PRINT_STAT_LINE("total", total); + // For each non-zero entry in the histogram, print the reason, + // the action, and (if specifically known) the type of bytecode. + for (int reason = 0; reason < Reason_LIMIT; reason++) { + for (int action = 0; action < Action_LIMIT; action++) { + juint* cases = _deoptimization_hist[reason][1+action]; + for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) { + juint counter = cases[bc_case]; + if (counter != 0) { + char name[1*K]; + Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK); + if (bc_case == BC_CASE_LIMIT && (int)bc == 0) + bc = Bytecodes::_illegal; + sprintf(name, "%s/%s/%s", + trap_reason_name(reason), + trap_action_name(action), + Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other"); + juint r = counter >> LSB_BITS; + tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total); + account -= r; + } + } + } + } + if (account != 0) { + PRINT_STAT_LINE("unaccounted", account); + } + #undef PRINT_STAT_LINE + if (xtty != NULL) xtty->tail("statistics"); + } +} +#else // COMPILER2 + + +// Stubs for C1 only system. +bool Deoptimization::trap_state_is_recompiled(int trap_state) { + return false; +} + +const char* Deoptimization::trap_reason_name(int reason) { + return "unknown"; +} + +void Deoptimization::print_statistics() { + // no output +} + +void +Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) { + // no udpate +} + +int Deoptimization::trap_state_has_reason(int trap_state, int reason) { + return 0; +} + +void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action, + Bytecodes::Code bc) { + // no update +} + +const char* Deoptimization::format_trap_state(char* buf, size_t buflen, + int trap_state) { + jio_snprintf(buf, buflen, "#%d", trap_state); + return buf; +} + +#endif // COMPILER2