jdk-sandbox: comparison hotspot/src/share/vm/oops/cpCacheOop.cpp

equal deleted inserted replaced

-:50c604cb0d5f
+:30245956af37
 #include "memory/universe.inline.hpp"
 #include "oops/cpCacheOop.hpp"
 #include "oops/objArrayOop.hpp"
 #include "oops/oop.inline.hpp"
 #include "prims/jvmtiRedefineClassesTrace.hpp"
+#include "prims/methodHandles.hpp"
 #include "runtime/handles.inline.hpp"
 // Implememtation of ConstantPoolCacheEntry
 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);
+_indices = (main_index << main_cp_index_bits);
 assert(main_entry_index() == main_index, "");
 }
-int ConstantPoolCacheEntry::as_flags(TosState state, bool is_final,
+int ConstantPoolCacheEntry::make_flags(TosState state,
-bool is_vfinal, bool is_volatile,
+int option_bits,
-bool is_method_interface, bool is_method) {
+int field_index_or_method_params) {
-int f = state;
+assert(state < number_of_states, "Invalid state in make_flags");
+int f = ((int)state << tos_state_shift) | option_bits | field_index_or_method_params;
-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
+// The low bits are a field offset, or else the method parameter size.
 #ifdef ASSERT
-int old_state = ((_flags >> tosBits) & 0x0F);
+TosState old_state = flag_state();
-assert(old_state == 0 || old_state == 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) {
+assert(!is_secondary_entry(), "must not overwrite main_entry_index");
 #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));
+OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_1_shift));
 }
 void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) {
+assert(!is_secondary_entry(), "must not overwrite main_entry_index");
 #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));
+OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_2_shift));
 }
-// Atomically sets f1 if it is still NULL, otherwise it keeps the
+// Sets f1, ordering with previous writes.
-// current value.
+void ConstantPoolCacheEntry::release_set_f1(oop f1) {
-void ConstantPoolCacheEntry::set_f1_if_null_atomic(oop f1) {
 // Use barriers as in oop_store
+assert(f1 != NULL, "");
 oop* f1_addr = (oop*) &_f1;
 update_barrier_set_pre(f1_addr, f1);
-void* result = Atomic::cmpxchg_ptr(f1, f1_addr, NULL);
+OrderAccess::release_store_ptr((intptr_t*)f1_addr, f1);
-bool success = (result == NULL);
+update_barrier_set((void*) f1_addr, f1);
-if (success) {
+}
-update_barrier_set((void*) f1_addr, 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);
 }
 #ifdef ASSERT
 // It is possible to have two different dummy methodOops created
 // when the resolve code for invoke interface executes concurrently
 TosState field_type,
 bool is_final,
 bool is_volatile) {
 set_f1(field_holder()->java_mirror());
 set_f2(field_offset);
-assert(field_index <= field_index_mask,
+assert((field_index & field_index_mask) == field_index,
 "field index does not fit in low flag bits");
-set_flags(as_flags(field_type, is_final, false, is_volatile, false, false) |
+set_field_flags(field_type,
-(field_index & field_index_mask));
+((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));
 }
-int  ConstantPoolCacheEntry::field_index() const {
+void ConstantPoolCacheEntry::set_parameter_size(int value) {
-return (_flags & field_index_mask);
+// 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(!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;
+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:
-case Bytecodes::_invokeinterface: {
+{
 if (method->can_be_statically_bound()) {
-set_f2((intptr_t)method());
+// set_f2_as_vfinal_method checks if is_vfinal flag is true.
-needs_vfinal_flag = 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::_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:
+// 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;
 }
-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) {
+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
 // 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);
+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) {
 assert(!is_secondary_entry(), "");
 klassOop 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_flags(as_flags(as_TosState(method->result_type()), method->is_final_method(), false, false, false, true) | method()->size_of_parameters());
+set_method_flags(as_TosState(method->result_type()),
+0,  // no option bits
+method()->size_of_parameters());
 set_bytecode_1(Bytecodes::_invokeinterface);
 }
-void ConstantPoolCacheEntry::initialize_bootstrap_method_index_in_cache(int bsm_cache_index) {
+void ConstantPoolCacheEntry::set_method_handle(methodHandle adapter, Handle appendix) {
-assert(!is_secondary_entry(), "only for JVM_CONSTANT_InvokeDynamic main entry");
+assert(!is_secondary_entry(), "");
-assert(_f2 == 0, "initialize once");
+set_method_handle_common(Bytecodes::_invokehandle, adapter, appendix);
-assert(bsm_cache_index == (int)(u2)bsm_cache_index, "oob");
+}
-set_f2(bsm_cache_index + constantPoolOopDesc::CPCACHE_INDEX_TAG);
-}
+void ConstantPoolCacheEntry::set_dynamic_call(methodHandle adapter, Handle appendix) {
-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_method_handle_common(Bytecodes::_invokedynamic, adapter, appendix);
-// 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).
+void ConstantPoolCacheEntry::set_method_handle_common(Bytecodes::Code invoke_code, methodHandle adapter, Handle appendix) {
-int param_size = signature_invoker->size_of_parameters();
+// NOTE: This CPCE can be the subject of data races.
-assert(param_size >= 1, "method argument size must include MH.this");
+// There are three words to update: flags, f2, f1 (in that order).
-param_size -= 1;  // do not count MH.this; it is not stacked for invokedynamic
+// Writers must store all other values before f1.
-bool is_final = true;
+// Readers must test f1 first for non-null before reading other fields.
-assert(signature_invoker->is_final_method(), "is_final");
+// Competing writers must acquire exclusive access on the first
-int flags = as_flags(as_TosState(signature_invoker->result_type()), is_final, false, false, false, true) | param_size;
+// write, to flags, using a compare/exchange.
-assert(_flags == 0 || _flags == flags, "flags should be the same");
+// A losing writer must spin until the winner writes f1,
-set_flags(flags);
+// so that when he returns, he can use the linked cache entry.
-// do not do set_bytecode on a secondary CP cache entry
-//set_bytecode_1(Bytecodes::_invokedynamic);
+bool has_appendix = appendix.not_null();
-set_f1_if_null_atomic(call_site());  // This must be the last one to set (see NOTE above)!
+if (!has_appendix) {
-}
+// The extra argument is not used, but we need a non-null value to signify linkage state.
+// Set it to something benign that will never leak memory.
+appendix = Universe::void_mirror();
-methodOop ConstantPoolCacheEntry::get_method_if_resolved(Bytecodes::Code invoke_code, constantPoolHandle cpool) {
+}
-assert(invoke_code > (Bytecodes::Code)0, "bad query");
+bool owner =
+init_method_flags_atomic(as_TosState(adapter->result_type()),
+((has_appendix ?  1 : 0) << has_appendix_shift) |
+(                 1      << is_vfinal_shift)    |
+(                 1      << is_final_shift),
+adapter->size_of_parameters());
+if (!owner) {
+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.
+// f1, 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.
+// f2 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 f2, as if for invokevfinal, and signatures are erased.
+// The appendix argument (if any) is added to the signature, and is counted in the parameter_size bits.
+// In principle this means that the method (with appendix) could take up to 256 parameter slots.
+//
+// This means that given a call site like (List)mh.invoke("foo"),
+// the f2 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 f1.
+// This allows us to create fewer method oops, while keeping type safety.
+//
+set_f2_as_vfinal_method(adapter());
+assert(appendix.not_null(), "needed for linkage state");
+release_set_f1(appendix());  // This must be the last one to set (see NOTE above)!
+if (!is_secondary_entry()) {
+// The interpreter assembly code does not check byte_2,
+// but it is used by is_resolved, method_if_resolved, etc.
+set_bytecode_2(invoke_code);
+}
+NOT_PRODUCT(verify(tty));
+if (TraceInvokeDynamic) {
+this->print(tty, 0);
+}
+}
+methodOop ConstantPoolCacheEntry::method_if_resolved(constantPoolHandle cpool) {
 if (is_secondary_entry()) {
-return cpool->cache()->entry_at(main_entry_index())->get_method_if_resolved(invoke_code, cpool);
+if (!is_f1_null())
+return f2_as_vfinal_method();
+return NULL;
 }
 // Decode the action of set_method and set_interface_call
-if (bytecode_1() == invoke_code) {
+Bytecodes::Code invoke_code = bytecode_1();
+if (invoke_code != (Bytecodes::Code)0) {
 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());
+return klassItable::method_for_itable_index(klassOop(f1), f2_as_index());
 case Bytecodes::_invokestatic:
 case Bytecodes::_invokespecial:
+assert(!has_appendix(), "");
 assert(f1->is_method(), "");
 return methodOop(f1);
 }
 }
 }
-if (bytecode_2() == invoke_code) {
+invoke_code = bytecode_2();
+if (invoke_code != (Bytecodes::Code)0) {
 switch (invoke_code) {
 case Bytecodes::_invokevirtual:
 if (is_vfinal()) {
 // invokevirtual
-methodOop m = methodOop((intptr_t) f2());
+methodOop 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()) {
 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 instanceKlass::cast(klass)->method_at_vtable(f2_as_index());
 }
 }
+break;
+case Bytecodes::_invokehandle:
+case Bytecodes::_invokedynamic:
+return f2_as_vfinal_method();
 }
 }
 return NULL;
 }
 class LocalOopClosure: public OopClosure {
 private:
 void (*_f)(oop*);
 // 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
+// virtual and final so _f2 contains method ptr instead of vtable index
-if (f2() == (intptr_t)old_method) {
+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",
 }
 methodOop m = NULL;
 if (is_vfinal()) {
 // virtual and final so _f2 contains method ptr instead of vtable index
-m = (methodOop)_f2;
+m = f2_as_vfinal_method();
-} else if ((oop)_f1 == NULL) {
+} else if (is_f1_null()) {
 // NULL _f1 means this is a virtual entry so also not interesting
 return false;
 } else {
-if (!((oop)_f1)->is_method()) {
+oop f1 = _f1;  // _f1 is volatile
+if (!f1->is_method()) {
 // _f1 can also contain a klassOop for an interface
 return false;
 }
-m = (methodOop)_f1;
+m = f1_as_method();
 }
 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

changeset 13391	30245956af37
parent 11956	c363dc1ac4b7