--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/oops/cpCache.cpp Sat Sep 01 13:25:18 2012 -0400
@@ -0,0 +1,604 @@
+/*
+ * Copyright (c) 1998, 2012, 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/cpCache.hpp"
+#include "oops/objArrayOop.hpp"
+#include "oops/oop.inline.hpp"
+#include "prims/jvmtiRedefineClassesTrace.hpp"
+#include "prims/methodHandles.hpp"
+#include "runtime/handles.inline.hpp"
+#ifndef SERIALGC
+# include "gc_implementation/parallelScavenge/psPromotionManager.hpp"
+#endif
+
+
+// Implememtation of ConstantPoolCacheEntry
+
+void ConstantPoolCacheEntry::initialize_entry(int index) {
+ assert(0 < index && index < 0x10000, "sanity check");
+ _indices = index;
+ assert(constant_pool_index() == index, "");
+}
+
+int ConstantPoolCacheEntry::make_flags(TosState state,
+ int option_bits,
+ int field_index_or_method_params) {
+ assert(state < number_of_states, "Invalid state in make_flags");
+ int f = ((int)state << tos_state_shift) | option_bits | field_index_or_method_params;
+ // Preserve existing flag bit values
+ // The low bits are a field offset, or else the method parameter size.
+#ifdef ASSERT
+ TosState old_state = flag_state();
+ assert(old_state == (TosState)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 << bytecode_1_shift));
+}
+
+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 << bytecode_2_shift));
+}
+
+// Sets f1, ordering with previous writes.
+void ConstantPoolCacheEntry::release_set_f1(Metadata* f1) {
+ assert(f1 != NULL, "");
+ OrderAccess::release_store_ptr((HeapWord*) &_f1, f1);
+}
+
+// Sets flags, but only if the value was previously zero.
+bool ConstantPoolCacheEntry::init_flags_atomic(intptr_t flags) {
+ intptr_t result = Atomic::cmpxchg_ptr(flags, &_flags, 0);
+ return (result == 0);
+}
+
+// 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 field_index,
+ int field_offset,
+ TosState field_type,
+ bool is_final,
+ bool is_volatile,
+ Klass* root_klass) {
+ set_f1(field_holder());
+ set_f2(field_offset);
+ assert((field_index & field_index_mask) == field_index,
+ "field index does not fit in low flag bits");
+ set_field_flags(field_type,
+ ((is_volatile ? 1 : 0) << is_volatile_shift) |
+ ((is_final ? 1 : 0) << is_final_shift),
+ field_index);
+ set_bytecode_1(get_code);
+ set_bytecode_2(put_code);
+ NOT_PRODUCT(verify(tty));
+}
+
+void ConstantPoolCacheEntry::set_parameter_size(int value) {
+ // This routine is called only in corner cases where the CPCE is not yet initialized.
+ // See AbstractInterpreter::deopt_continue_after_entry.
+ assert(_flags == 0 || parameter_size() == 0 || parameter_size() == value,
+ err_msg("size must not change: parameter_size=%d, value=%d", parameter_size(), value));
+ // Setting the parameter size by itself is only safe if the
+ // current value of _flags is 0, otherwise another thread may have
+ // updated it and we don't want to overwrite that value. Don't
+ // bother trying to update it once it's nonzero but always make
+ // sure that the final parameter size agrees with what was passed.
+ if (_flags == 0) {
+ Atomic::cmpxchg_ptr((value & parameter_size_mask), &_flags, 0);
+ }
+ guarantee(parameter_size() == value,
+ err_msg("size must not change: parameter_size=%d, value=%d", parameter_size(), value));
+}
+
+void ConstantPoolCacheEntry::set_method(Bytecodes::Code invoke_code,
+ methodHandle method,
+ int vtable_index) {
+ assert(method->interpreter_entry() != NULL, "should have been set at this point");
+ assert(!method->is_obsolete(), "attempt to write obsolete method to cpCache");
+
+ int byte_no = -1;
+ bool change_to_virtual = false;
+
+ switch (invoke_code) {
+ case Bytecodes::_invokeinterface:
+ // We get here from InterpreterRuntime::resolve_invoke when an invokeinterface
+ // instruction somehow links to a non-interface method (in Object).
+ // In that case, the method has no itable index and must be invoked as a virtual.
+ // Set a flag to keep track of this corner case.
+ change_to_virtual = true;
+
+ // ...and fall through as if we were handling invokevirtual:
+ case Bytecodes::_invokevirtual:
+ {
+ if (method->can_be_statically_bound()) {
+ // set_f2_as_vfinal_method checks if is_vfinal flag is true.
+ set_method_flags(as_TosState(method->result_type()),
+ ( 1 << is_vfinal_shift) |
+ ((method->is_final_method() ? 1 : 0) << is_final_shift) |
+ ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),
+ method()->size_of_parameters());
+ set_f2_as_vfinal_method(method());
+ } else {
+ assert(vtable_index >= 0, "valid index");
+ assert(!method->is_final_method(), "sanity");
+ set_method_flags(as_TosState(method->result_type()),
+ ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),
+ method()->size_of_parameters());
+ set_f2(vtable_index);
+ }
+ byte_no = 2;
+ break;
+ }
+
+ case Bytecodes::_invokespecial:
+ case Bytecodes::_invokestatic:
+ // Note: Read and preserve the value of the is_vfinal flag on any
+ // invokevirtual bytecode shared with this constant pool cache entry.
+ // It is cheap and safe to consult is_vfinal() at all times.
+ // Once is_vfinal is set, it must stay that way, lest we get a dangling oop.
+ set_method_flags(as_TosState(method->result_type()),
+ ((is_vfinal() ? 1 : 0) << is_vfinal_shift) |
+ ((method->is_final_method() ? 1 : 0) << is_final_shift),
+ method()->size_of_parameters());
+ set_f1(method());
+ byte_no = 1;
+ break;
+ default:
+ ShouldNotReachHere();
+ break;
+ }
+
+ // Note: byte_no also appears in TemplateTable::resolve.
+ if (byte_no == 1) {
+ assert(invoke_code != Bytecodes::_invokevirtual &&
+ invoke_code != Bytecodes::_invokeinterface, "");
+ set_bytecode_1(invoke_code);
+ } else if (byte_no == 2) {
+ if (change_to_virtual) {
+ assert(invoke_code == Bytecodes::_invokeinterface, "");
+ // 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);
+ } else {
+ assert(invoke_code == Bytecodes::_invokevirtual, "");
+ }
+ // set up for invokevirtual, even if linking for invokeinterface also:
+ set_bytecode_2(Bytecodes::_invokevirtual);
+ } else {
+ ShouldNotReachHere();
+ }
+ NOT_PRODUCT(verify(tty));
+}
+
+
+void ConstantPoolCacheEntry::set_interface_call(methodHandle method, int index) {
+ Klass* interf = method->method_holder();
+ assert(InstanceKlass::cast(interf)->is_interface(), "must be an interface");
+ assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here");
+ set_f1(interf);
+ set_f2(index);
+ set_method_flags(as_TosState(method->result_type()),
+ 0, // no option bits
+ method()->size_of_parameters());
+ set_bytecode_1(Bytecodes::_invokeinterface);
+}
+
+
+void ConstantPoolCacheEntry::set_method_handle(methodHandle adapter, Handle appendix,
+ objArrayHandle resolved_references) {
+ set_method_handle_common(Bytecodes::_invokehandle, adapter, appendix, resolved_references);
+}
+
+void ConstantPoolCacheEntry::set_dynamic_call(methodHandle adapter, Handle appendix,
+ objArrayHandle resolved_references) {
+ set_method_handle_common(Bytecodes::_invokedynamic, adapter, appendix, resolved_references);
+}
+
+void ConstantPoolCacheEntry::set_method_handle_common(Bytecodes::Code invoke_code,
+ methodHandle adapter,
+ Handle appendix,
+ objArrayHandle resolved_references) {
+ // NOTE: This CPCE can be the subject of data races.
+ // There are three words to update: flags, refs[f2], f1 (in that order).
+ // Writers must store all other values before f1.
+ // Readers must test f1 first for non-null before reading other fields.
+ // Competing writers must acquire exclusive access on the first
+ // write, to flags, using a compare/exchange.
+ // A losing writer to flags must spin until the winner writes f1,
+ // so that when he returns, he can use the linked cache entry.
+
+ bool has_appendix = appendix.not_null();
+
+ // Write the flags.
+ bool owner =
+ init_method_flags_atomic(as_TosState(adapter->result_type()),
+ ((has_appendix ? 1 : 0) << has_appendix_shift) |
+ ( 1 << is_final_shift),
+ adapter->size_of_parameters());
+ if (!owner) {
+ // Somebody else is working on the same CPCE. Let them proceed.
+ while (is_f1_null()) {
+ // Pause momentarily on a low-level lock, to allow racing thread to win.
+ MutexLockerEx mu(Patching_lock, Mutex::_no_safepoint_check_flag);
+ os::yield();
+ }
+ return;
+ }
+
+ if (TraceInvokeDynamic) {
+ tty->print_cr("set_method_handle bc=%d appendix="PTR_FORMAT"%s method="PTR_FORMAT" ",
+ invoke_code,
+ (intptr_t)appendix(), (has_appendix ? "" : " (unused)"),
+ (intptr_t)adapter());
+ adapter->print();
+ if (has_appendix) appendix()->print();
+ }
+
+ // Method handle invokes and invokedynamic sites use both cp cache words.
+ // refs[f2], if not null, contains a value passed as a trailing argument to the adapter.
+ // In the general case, this could be the call site's MethodType,
+ // for use with java.lang.Invokers.checkExactType, or else a CallSite object.
+ // f1 contains the adapter method which manages the actual call.
+ // In the general case, this is a compiled LambdaForm.
+ // (The Java code is free to optimize these calls by binding other
+ // sorts of methods and appendices to call sites.)
+ // JVM-level linking is via f1, as if for invokespecial, and signatures are erased.
+ // The appendix argument (if any) is added to the signature, and is counted in the parameter_size bits.
+ // Even with the appendix, the method will never take more than 255 parameter slots.
+ //
+ // This means that given a call site like (List)mh.invoke("foo"),
+ // the f1 method has signature '(Ljl/Object;Ljl/invoke/MethodType;)Ljl/Object;',
+ // not '(Ljava/lang/String;)Ljava/util/List;'.
+ // The fact that String and List are involved is encoded in the MethodType in refs[f2].
+ // This allows us to create fewer method oops, while keeping type safety.
+ //
+
+ if (has_appendix) {
+ int ref_index = f2_as_index();
+ assert(ref_index >= 0 && ref_index < resolved_references->length(), "oob");
+ assert(resolved_references->obj_at(ref_index) == NULL, "init just once");
+ resolved_references->obj_at_put(ref_index, appendix());
+ }
+
+ release_set_f1(adapter()); // This must be the last one to set (see NOTE above)!
+
+ // The interpreter assembly code does not check byte_2,
+ // but it is used by is_resolved, method_if_resolved, etc.
+ set_bytecode_1(invoke_code);
+ NOT_PRODUCT(verify(tty));
+ if (TraceInvokeDynamic) {
+ this->print(tty, 0);
+ }
+}
+
+Method* ConstantPoolCacheEntry::method_if_resolved(constantPoolHandle cpool) {
+ // Decode the action of set_method and set_interface_call
+ Bytecodes::Code invoke_code = bytecode_1();
+ if (invoke_code != (Bytecodes::Code)0) {
+ Metadata* f1 = (Metadata*)_f1;
+ if (f1 != NULL) {
+ switch (invoke_code) {
+ case Bytecodes::_invokeinterface:
+ assert(f1->is_klass(), "");
+ return klassItable::method_for_itable_index((Klass*)f1, f2_as_index());
+ case Bytecodes::_invokestatic:
+ case Bytecodes::_invokespecial:
+ assert(!has_appendix(), "");
+ case Bytecodes::_invokehandle:
+ case Bytecodes::_invokedynamic:
+ assert(f1->is_method(), "");
+ return (Method*)f1;
+ }
+ }
+ }
+ invoke_code = bytecode_2();
+ if (invoke_code != (Bytecodes::Code)0) {
+ switch (invoke_code) {
+ case Bytecodes::_invokevirtual:
+ if (is_vfinal()) {
+ // invokevirtual
+ Method* m = f2_as_vfinal_method();
+ 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()) {
+ Klass* 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(f2_as_index());
+ }
+ }
+ break;
+ }
+ }
+ return NULL;
+}
+
+
+oop ConstantPoolCacheEntry::appendix_if_resolved(constantPoolHandle cpool) {
+ if (is_f1_null() || !has_appendix())
+ return NULL;
+ int ref_index = f2_as_index();
+ objArrayOop resolved_references = cpool->resolved_references();
+ return resolved_references->obj_at(ref_index);
+}
+
+
+// RedefineClasses() API support:
+// If this constantPoolCacheEntry refers to old_method then update it
+// to refer to new_method.
+bool ConstantPoolCacheEntry::adjust_method_entry(Method* old_method,
+ Method* new_method, bool * trace_name_printed) {
+
+ if (is_vfinal()) {
+ // virtual and final so _f2 contains method ptr instead of vtable index
+ if (f2_as_vfinal_method() == old_method) {
+ // match old_method so need an update
+ // NOTE: can't use set_f2_as_vfinal_method as it asserts on different values
+ _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 (_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 (_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;
+}
+
+#ifndef PRODUCT
+bool ConstantPoolCacheEntry::check_no_old_entries() {
+ if (is_vfinal()) {
+ Metadata* f2 = (Metadata*)_f2;
+ return (f2->is_valid() && f2->is_method() && !((Method*)f2)->is_old());
+ } else {
+ return (_f1 == NULL || (_f1->is_valid() && _f1->is_method() && !((Method*)_f1)->is_old()));
+ }
+}
+#endif
+
+bool ConstantPoolCacheEntry::is_interesting_method_entry(Klass* k) {
+ if (!is_method_entry()) {
+ // not a method entry so not interesting by default
+ return false;
+ }
+
+ Method* m = NULL;
+ if (is_vfinal()) {
+ // virtual and final so _f2 contains method ptr instead of vtable index
+ m = f2_as_vfinal_method();
+ } else if (is_f1_null()) {
+ // NULL _f1 means this is a virtual entry so also not interesting
+ return false;
+ } else {
+ if (!(_f1->is_method())) {
+ // _f1 can also contain a Klass* for an interface
+ return false;
+ }
+ m = f1_as_method();
+ }
+
+ assert(m != NULL && m->is_method(), "sanity check");
+ if (m == NULL || !m->is_method() || (k != NULL && 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) st->print_cr(" -------------");
+ // print entry
+ st->print("%3d ("PTR_FORMAT") ", index, (intptr_t)this);
+ st->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(), constant_pool_index());
+ st->print_cr(" [ "PTR_FORMAT"]", (intptr_t)_f1);
+ st->print_cr(" [ "PTR_FORMAT"]", (intptr_t)_f2);
+ st->print_cr(" [ "PTR_FORMAT"]", (intptr_t)_flags);
+ st->print_cr(" -------------");
+}
+
+void ConstantPoolCacheEntry::verify(outputStream* st) const {
+ // not implemented yet
+}
+
+// Implementation of ConstantPoolCache
+
+ConstantPoolCache* ConstantPoolCache::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
+ int size = ConstantPoolCache::size(length);
+
+ return new (loader_data, size, false, THREAD) ConstantPoolCache(length);
+}
+
+void ConstantPoolCache::initialize(intArray& inverse_index_map, intArray& invokedynamic_references_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];
+ e->initialize_entry(original_index);
+ assert(entry_at(i) == e, "sanity");
+ }
+ for (int ref = 0; ref < invokedynamic_references_map.length(); ref++) {
+ int cpci = invokedynamic_references_map[ref];
+ if (cpci >= 0)
+ entry_at(cpci)->initialize_resolved_reference_index(ref);
+ }
+}
+
+// RedefineClasses() API support:
+// If any entry of this constantPoolCache points to any of
+// old_methods, replace it with the corresponding new_method.
+void ConstantPoolCache::adjust_method_entries(Method** old_methods, Method** 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
+ Klass* 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++) {
+ Method* old_method = old_methods[j];
+ Method* 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;
+ }
+ }
+ }
+}
+
+#ifndef PRODUCT
+bool ConstantPoolCache::check_no_old_entries() {
+ for (int i = 1; i < length(); i++) {
+ if (entry_at(i)->is_interesting_method_entry(NULL) &&
+ !entry_at(i)->check_no_old_entries()) {
+ return false;
+ }
+ }
+ return true;
+}
+#endif // PRODUCT
+
+
+// Printing
+
+void ConstantPoolCache::print_on(outputStream* st) const {
+ assert(is_constantPoolCache(), "obj must be constant pool cache");
+ st->print_cr(internal_name());
+ // print constant pool cache entries
+ for (int i = 0; i < length(); i++) entry_at(i)->print(st, i);
+}
+
+void ConstantPoolCache::print_value_on(outputStream* st) const {
+ assert(is_constantPoolCache(), "obj must be constant pool cache");
+ st->print("cache [%d]", length());
+ print_address_on(st);
+ st->print(" for ");
+ constant_pool()->print_value_on(st);
+}
+
+
+// Verification
+
+void ConstantPoolCache::verify_on(outputStream* st) {
+ guarantee(is_constantPoolCache(), "obj must be constant pool cache");
+ // print constant pool cache entries
+ for (int i = 0; i < length(); i++) entry_at(i)->verify(st);
+}