/* * Copyright (c) 1998, 2011, 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 "gc_implementation/shared/markSweep.inline.hpp" #include "interpreter/interpreter.hpp" #include "interpreter/rewriter.hpp" #include "memory/universe.inline.hpp" #include "oops/cpCacheOop.hpp" #include "oops/objArrayOop.hpp" #include "oops/oop.inline.hpp" #include "prims/jvmtiRedefineClassesTrace.hpp" #include "runtime/handles.inline.hpp" // Implememtation of ConstantPoolCacheEntry void ConstantPoolCacheEntry::initialize_entry(int index) { assert(0 < index && index < 0x10000, "sanity check"); _indices = index; assert(constant_pool_index() == index, ""); } void ConstantPoolCacheEntry::initialize_secondary_entry(int main_index) { assert(0 <= main_index && main_index < 0x10000, "sanity check"); _indices = (main_index << 16); assert(main_entry_index() == main_index, ""); } int ConstantPoolCacheEntry::as_flags(TosState state, bool is_final, bool is_vfinal, bool is_volatile, bool is_method_interface, bool is_method) { int f = state; assert( state < number_of_states, "Invalid state in as_flags"); f <<= 1; if (is_final) f |= 1; f <<= 1; if (is_vfinal) f |= 1; f <<= 1; if (is_volatile) f |= 1; f <<= 1; if (is_method_interface) f |= 1; f <<= 1; if (is_method) f |= 1; f <<= ConstantPoolCacheEntry::hotSwapBit; // Preserve existing flag bit values #ifdef ASSERT int old_state = ((_flags >> tosBits) & 0x0F); assert(old_state == 0 || old_state == state, "inconsistent cpCache flags state"); #endif return (_flags | f) ; } void ConstantPoolCacheEntry::set_bytecode_1(Bytecodes::Code code) { #ifdef ASSERT // Read once. volatile Bytecodes::Code c = bytecode_1(); assert(c == 0 || c == code || code == 0, "update must be consistent"); #endif // Need to flush pending stores here before bytecode is written. OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << 16)); } void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) { #ifdef ASSERT // Read once. volatile Bytecodes::Code c = bytecode_2(); assert(c == 0 || c == code || code == 0, "update must be consistent"); #endif // Need to flush pending stores here before bytecode is written. OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << 24)); } // Atomically sets f1 if it is still NULL, otherwise it keeps the // current value. void ConstantPoolCacheEntry::set_f1_if_null_atomic(oop f1) { // Use barriers as in oop_store oop* f1_addr = (oop*) &_f1; update_barrier_set_pre(f1_addr, f1); void* result = Atomic::cmpxchg_ptr(f1, f1_addr, NULL); bool success = (result == NULL); if (success) { update_barrier_set((void*) f1_addr, f1); } } #ifdef ASSERT // It is possible to have two different dummy methodOops created // when the resolve code for invoke interface executes concurrently // Hence the assertion below is weakened a bit for the invokeinterface // case. bool ConstantPoolCacheEntry::same_methodOop(oop cur_f1, oop f1) { return (cur_f1 == f1 || ((methodOop)cur_f1)->name() == ((methodOop)f1)->name() || ((methodOop)cur_f1)->signature() == ((methodOop)f1)->signature()); } #endif // Note that concurrent update of both bytecodes can leave one of them // reset to zero. This is harmless; the interpreter will simply re-resolve // the damaged entry. More seriously, the memory synchronization is needed // to flush other fields (f1, f2) completely to memory before the bytecodes // are updated, lest other processors see a non-zero bytecode but zero f1/f2. void ConstantPoolCacheEntry::set_field(Bytecodes::Code get_code, Bytecodes::Code put_code, KlassHandle field_holder, int orig_field_index, int field_offset, TosState field_type, bool is_final, bool is_volatile) { set_f1(field_holder()->java_mirror()); set_f2(field_offset); // The field index is used by jvm/ti and is the index into fields() array // in holder instanceKlass. This is scaled by instanceKlass::next_offset. assert((orig_field_index % instanceKlass::next_offset) == 0, "wierd index"); const int field_index = orig_field_index / instanceKlass::next_offset; assert(field_index <= field_index_mask, "field index does not fit in low flag bits"); set_flags(as_flags(field_type, is_final, false, is_volatile, false, false) | (field_index & field_index_mask)); set_bytecode_1(get_code); set_bytecode_2(put_code); NOT_PRODUCT(verify(tty)); } int ConstantPoolCacheEntry::field_index() const { return (_flags & field_index_mask) * instanceKlass::next_offset; } void ConstantPoolCacheEntry::set_method(Bytecodes::Code invoke_code, methodHandle method, int vtable_index) { assert(!is_secondary_entry(), ""); assert(method->interpreter_entry() != NULL, "should have been set at this point"); assert(!method->is_obsolete(), "attempt to write obsolete method to cpCache"); bool change_to_virtual = (invoke_code == Bytecodes::_invokeinterface); int byte_no = -1; bool needs_vfinal_flag = false; switch (invoke_code) { case Bytecodes::_invokevirtual: case Bytecodes::_invokeinterface: { if (method->can_be_statically_bound()) { set_f2((intptr_t)method()); needs_vfinal_flag = true; } else { assert(vtable_index >= 0, "valid index"); set_f2(vtable_index); } byte_no = 2; break; } case Bytecodes::_invokedynamic: // similar to _invokevirtual if (TraceInvokeDynamic) { tty->print_cr("InvokeDynamic set_method%s method="PTR_FORMAT" index=%d", (is_secondary_entry() ? " secondary" : ""), (intptr_t)method(), vtable_index); method->print(); this->print(tty, 0); } assert(method->can_be_statically_bound(), "must be a MH invoker method"); assert(_f2 >= constantPoolOopDesc::CPCACHE_INDEX_TAG, "BSM index initialized"); // SystemDictionary::find_method_handle_invoke only caches // methods which signature classes are on the boot classpath, // otherwise the newly created method is returned. To avoid // races in that case we store the first one coming in into the // cp-cache atomically if it's still unset. set_f1_if_null_atomic(method()); needs_vfinal_flag = false; // _f2 is not an oop assert(!is_vfinal(), "f2 not an oop"); byte_no = 1; // coordinate this with bytecode_number & is_resolved break; case Bytecodes::_invokespecial: // Preserve the value of the vfinal flag on invokevirtual bytecode // which may be shared with this constant pool cache entry. needs_vfinal_flag = is_resolved(Bytecodes::_invokevirtual) && is_vfinal(); // fall through case Bytecodes::_invokestatic: set_f1(method()); byte_no = 1; break; default: ShouldNotReachHere(); break; } set_flags(as_flags(as_TosState(method->result_type()), method->is_final_method(), needs_vfinal_flag, false, change_to_virtual, true)| method()->size_of_parameters()); // Note: byte_no also appears in TemplateTable::resolve. if (byte_no == 1) { set_bytecode_1(invoke_code); } else if (byte_no == 2) { if (change_to_virtual) { // NOTE: THIS IS A HACK - BE VERY CAREFUL!!! // // Workaround for the case where we encounter an invokeinterface, but we // should really have an _invokevirtual since the resolved method is a // virtual method in java.lang.Object. This is a corner case in the spec // but is presumably legal. javac does not generate this code. // // We set bytecode_1() to _invokeinterface, because that is the // bytecode # used by the interpreter to see if it is resolved. // We set bytecode_2() to _invokevirtual. // See also interpreterRuntime.cpp. (8/25/2000) // Only set resolved for the invokeinterface case if method is public. // Otherwise, the method needs to be reresolved with caller for each // interface call. if (method->is_public()) set_bytecode_1(invoke_code); set_bytecode_2(Bytecodes::_invokevirtual); } else { set_bytecode_2(invoke_code); } } else { ShouldNotReachHere(); } NOT_PRODUCT(verify(tty)); } void ConstantPoolCacheEntry::set_interface_call(methodHandle method, int index) { assert(!is_secondary_entry(), ""); klassOop interf = method->method_holder(); assert(instanceKlass::cast(interf)->is_interface(), "must be an interface"); set_f1(interf); set_f2(index); set_flags(as_flags(as_TosState(method->result_type()), method->is_final_method(), false, false, false, true) | method()->size_of_parameters()); set_bytecode_1(Bytecodes::_invokeinterface); } void ConstantPoolCacheEntry::initialize_bootstrap_method_index_in_cache(int bsm_cache_index) { assert(!is_secondary_entry(), "only for JVM_CONSTANT_InvokeDynamic main entry"); assert(_f2 == 0, "initialize once"); assert(bsm_cache_index == (int)(u2)bsm_cache_index, "oob"); set_f2(bsm_cache_index + constantPoolOopDesc::CPCACHE_INDEX_TAG); } int ConstantPoolCacheEntry::bootstrap_method_index_in_cache() { assert(!is_secondary_entry(), "only for JVM_CONSTANT_InvokeDynamic main entry"); intptr_t bsm_cache_index = (intptr_t) _f2 - constantPoolOopDesc::CPCACHE_INDEX_TAG; assert(bsm_cache_index == (intptr_t)(u2)bsm_cache_index, "oob"); return (int) bsm_cache_index; } void ConstantPoolCacheEntry::set_dynamic_call(Handle call_site, methodHandle signature_invoker) { assert(is_secondary_entry(), ""); // NOTE: it's important that all other values are set before f1 is // set since some users short circuit on f1 being set // (i.e. non-null) and that may result in uninitialized values for // other racing threads (e.g. flags). int param_size = signature_invoker->size_of_parameters(); assert(param_size >= 1, "method argument size must include MH.this"); param_size -= 1; // do not count MH.this; it is not stacked for invokedynamic bool is_final = true; assert(signature_invoker->is_final_method(), "is_final"); int flags = as_flags(as_TosState(signature_invoker->result_type()), is_final, false, false, false, true) | param_size; assert(_flags == 0 || _flags == flags, "flags should be the same"); set_flags(flags); // do not do set_bytecode on a secondary CP cache entry //set_bytecode_1(Bytecodes::_invokedynamic); set_f1_if_null_atomic(call_site()); // This must be the last one to set (see NOTE above)! } methodOop ConstantPoolCacheEntry::get_method_if_resolved(Bytecodes::Code invoke_code, constantPoolHandle cpool) { assert(invoke_code > (Bytecodes::Code)0, "bad query"); if (is_secondary_entry()) { return cpool->cache()->entry_at(main_entry_index())->get_method_if_resolved(invoke_code, cpool); } // Decode the action of set_method and set_interface_call if (bytecode_1() == invoke_code) { oop f1 = _f1; if (f1 != NULL) { switch (invoke_code) { case Bytecodes::_invokeinterface: assert(f1->is_klass(), ""); return klassItable::method_for_itable_index(klassOop(f1), (int) f2()); case Bytecodes::_invokestatic: case Bytecodes::_invokespecial: assert(f1->is_method(), ""); return methodOop(f1); } } } if (bytecode_2() == invoke_code) { switch (invoke_code) { case Bytecodes::_invokevirtual: if (is_vfinal()) { // invokevirtual methodOop m = methodOop((intptr_t) f2()); assert(m->is_method(), ""); return m; } else { int holder_index = cpool->uncached_klass_ref_index_at(constant_pool_index()); if (cpool->tag_at(holder_index).is_klass()) { klassOop klass = cpool->resolved_klass_at(holder_index); if (!Klass::cast(klass)->oop_is_instance()) klass = SystemDictionary::Object_klass(); return instanceKlass::cast(klass)->method_at_vtable((int) f2()); } } } } return NULL; } class LocalOopClosure: public OopClosure { private: void (*_f)(oop*); public: LocalOopClosure(void f(oop*)) { _f = f; } virtual void do_oop(oop* o) { _f(o); } virtual void do_oop(narrowOop *o) { ShouldNotReachHere(); } }; void ConstantPoolCacheEntry::oops_do(void f(oop*)) { LocalOopClosure blk(f); oop_iterate(&blk); } void ConstantPoolCacheEntry::oop_iterate(OopClosure* blk) { assert(in_words(size()) == 4, "check code below - may need adjustment"); // field[1] is always oop or NULL blk->do_oop((oop*)&_f1); if (is_vfinal()) { blk->do_oop((oop*)&_f2); } } void ConstantPoolCacheEntry::oop_iterate_m(OopClosure* blk, MemRegion mr) { assert(in_words(size()) == 4, "check code below - may need adjustment"); // field[1] is always oop or NULL if (mr.contains((oop *)&_f1)) blk->do_oop((oop*)&_f1); if (is_vfinal()) { if (mr.contains((oop *)&_f2)) blk->do_oop((oop*)&_f2); } } void ConstantPoolCacheEntry::follow_contents() { assert(in_words(size()) == 4, "check code below - may need adjustment"); // field[1] is always oop or NULL MarkSweep::mark_and_push((oop*)&_f1); if (is_vfinal()) { MarkSweep::mark_and_push((oop*)&_f2); } } #ifndef SERIALGC void ConstantPoolCacheEntry::follow_contents(ParCompactionManager* cm) { assert(in_words(size()) == 4, "check code below - may need adjustment"); // field[1] is always oop or NULL PSParallelCompact::mark_and_push(cm, (oop*)&_f1); if (is_vfinal()) { PSParallelCompact::mark_and_push(cm, (oop*)&_f2); } } #endif // SERIALGC void ConstantPoolCacheEntry::adjust_pointers() { assert(in_words(size()) == 4, "check code below - may need adjustment"); // field[1] is always oop or NULL MarkSweep::adjust_pointer((oop*)&_f1); if (is_vfinal()) { MarkSweep::adjust_pointer((oop*)&_f2); } } #ifndef SERIALGC void ConstantPoolCacheEntry::update_pointers() { assert(in_words(size()) == 4, "check code below - may need adjustment"); // field[1] is always oop or NULL PSParallelCompact::adjust_pointer((oop*)&_f1); if (is_vfinal()) { PSParallelCompact::adjust_pointer((oop*)&_f2); } } #endif // SERIALGC // RedefineClasses() API support: // If this constantPoolCacheEntry refers to old_method then update it // to refer to new_method. bool ConstantPoolCacheEntry::adjust_method_entry(methodOop old_method, methodOop new_method, bool * trace_name_printed) { if (is_vfinal()) { // virtual and final so f2() contains method ptr instead of vtable index if (f2() == (intptr_t)old_method) { // match old_method so need an update _f2 = (intptr_t)new_method; if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) { if (!(*trace_name_printed)) { // RC_TRACE_MESG macro has an embedded ResourceMark RC_TRACE_MESG(("adjust: name=%s", Klass::cast(old_method->method_holder())->external_name())); *trace_name_printed = true; } // RC_TRACE macro has an embedded ResourceMark RC_TRACE(0x00400000, ("cpc vf-entry update: %s(%s)", new_method->name()->as_C_string(), new_method->signature()->as_C_string())); } return true; } // f1() is not used with virtual entries so bail out return false; } if ((oop)_f1 == NULL) { // NULL f1() means this is a virtual entry so bail out // We are assuming that the vtable index does not need change. return false; } if ((oop)_f1 == old_method) { _f1 = new_method; if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) { if (!(*trace_name_printed)) { // RC_TRACE_MESG macro has an embedded ResourceMark RC_TRACE_MESG(("adjust: name=%s", Klass::cast(old_method->method_holder())->external_name())); *trace_name_printed = true; } // RC_TRACE macro has an embedded ResourceMark RC_TRACE(0x00400000, ("cpc entry update: %s(%s)", new_method->name()->as_C_string(), new_method->signature()->as_C_string())); } return true; } return false; } bool ConstantPoolCacheEntry::is_interesting_method_entry(klassOop k) { if (!is_method_entry()) { // not a method entry so not interesting by default return false; } methodOop m = NULL; if (is_vfinal()) { // virtual and final so _f2 contains method ptr instead of vtable index m = (methodOop)_f2; } else if ((oop)_f1 == NULL) { // NULL _f1 means this is a virtual entry so also not interesting return false; } else { if (!((oop)_f1)->is_method()) { // _f1 can also contain a klassOop for an interface return false; } m = (methodOop)_f1; } assert(m != NULL && m->is_method(), "sanity check"); if (m == NULL || !m->is_method() || m->method_holder() != k) { // robustness for above sanity checks or method is not in // the interesting class return false; } // the method is in the interesting class so the entry is interesting return true; } void ConstantPoolCacheEntry::print(outputStream* st, int index) const { // print separator if (index == 0) tty->print_cr(" -------------"); // print entry tty->print("%3d ("PTR_FORMAT") ", index, (intptr_t)this); if (is_secondary_entry()) tty->print_cr("[%5d|secondary]", main_entry_index()); else tty->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(), constant_pool_index()); tty->print_cr(" [ "PTR_FORMAT"]", (intptr_t)(oop)_f1); tty->print_cr(" [ "PTR_FORMAT"]", (intptr_t)_f2); tty->print_cr(" [ "PTR_FORMAT"]", (intptr_t)_flags); tty->print_cr(" -------------"); } void ConstantPoolCacheEntry::verify(outputStream* st) const { // not implemented yet } // Implementation of ConstantPoolCache void constantPoolCacheOopDesc::initialize(intArray& inverse_index_map) { assert(inverse_index_map.length() == length(), "inverse index map must have same length as cache"); for (int i = 0; i < length(); i++) { ConstantPoolCacheEntry* e = entry_at(i); int original_index = inverse_index_map[i]; if ((original_index & Rewriter::_secondary_entry_tag) != 0) { int main_index = (original_index - Rewriter::_secondary_entry_tag); assert(!entry_at(main_index)->is_secondary_entry(), "valid main index"); e->initialize_secondary_entry(main_index); } else { e->initialize_entry(original_index); } assert(entry_at(i) == e, "sanity"); } } // RedefineClasses() API support: // If any entry of this constantPoolCache points to any of // old_methods, replace it with the corresponding new_method. void constantPoolCacheOopDesc::adjust_method_entries(methodOop* old_methods, methodOop* new_methods, int methods_length, bool * trace_name_printed) { if (methods_length == 0) { // nothing to do if there are no methods return; } // get shorthand for the interesting class klassOop old_holder = old_methods[0]->method_holder(); for (int i = 0; i < length(); i++) { if (!entry_at(i)->is_interesting_method_entry(old_holder)) { // skip uninteresting methods continue; } // The constantPoolCache contains entries for several different // things, but we only care about methods. In fact, we only care // about methods in the same class as the one that contains the // old_methods. At this point, we have an interesting entry. for (int j = 0; j < methods_length; j++) { methodOop old_method = old_methods[j]; methodOop new_method = new_methods[j]; if (entry_at(i)->adjust_method_entry(old_method, new_method, trace_name_printed)) { // current old_method matched this entry and we updated it so // break out and get to the next interesting entry if there one break; } } } }