JDK14/Java14源码在线阅读
/*
* Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* questions.
*
*/
#include "precompiled.hpp"
#include "classfile/classLoaderDataGraph.hpp"
#include "classfile/metadataOnStackMark.hpp"
#include "classfile/symbolTable.hpp"
#include "classfile/systemDictionary.hpp"
#include "code/codeCache.hpp"
#include "code/debugInfoRec.hpp"
#include "compiler/compilationPolicy.hpp"
#include "gc/shared/collectedHeap.inline.hpp"
#include "interpreter/bytecodeStream.hpp"
#include "interpreter/bytecodeTracer.hpp"
#include "interpreter/bytecodes.hpp"
#include "interpreter/interpreter.hpp"
#include "interpreter/oopMapCache.hpp"
#include "logging/log.hpp"
#include "logging/logTag.hpp"
#include "memory/allocation.inline.hpp"
#include "memory/heapInspection.hpp"
#include "memory/metadataFactory.hpp"
#include "memory/metaspaceClosure.hpp"
#include "memory/metaspaceShared.hpp"
#include "memory/oopFactory.hpp"
#include "memory/resourceArea.hpp"
#include "memory/universe.hpp"
#include "oops/constMethod.hpp"
#include "oops/constantPool.hpp"
#include "oops/method.inline.hpp"
#include "oops/methodData.hpp"
#include "oops/objArrayKlass.hpp"
#include "oops/objArrayOop.inline.hpp"
#include "oops/oop.inline.hpp"
#include "oops/symbol.hpp"
#include "prims/jvmtiExport.hpp"
#include "prims/methodHandles.hpp"
#include "prims/nativeLookup.hpp"
#include "runtime/arguments.hpp"
#include "runtime/atomic.hpp"
#include "runtime/frame.inline.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/init.hpp"
#include "runtime/orderAccess.hpp"
#include "runtime/relocator.hpp"
#include "runtime/safepointVerifiers.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/signature.hpp"
#include "utilities/align.hpp"
#include "utilities/quickSort.hpp"
#include "utilities/vmError.hpp"
#include "utilities/xmlstream.hpp"
// Implementation of Method
Method* Method::allocate(ClassLoaderData* loader_data,
int byte_code_size,
AccessFlags access_flags,
InlineTableSizes* sizes,
ConstMethod::MethodType method_type,
TRAPS) {
assert(!access_flags.is_native() || byte_code_size == 0,
"native methods should not contain byte codes");
ConstMethod* cm = ConstMethod::allocate(loader_data,
byte_code_size,
sizes,
method_type,
CHECK_NULL);
int size = Method::size(access_flags.is_native());
return new (loader_data, size, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags);
}
Method::Method(ConstMethod* xconst, AccessFlags access_flags) {
NoSafepointVerifier no_safepoint;
set_constMethod(xconst);
set_access_flags(access_flags);
set_intrinsic_id(vmIntrinsics::_none);
set_force_inline(false);
set_hidden(false);
set_dont_inline(false);
set_has_injected_profile(false);
set_method_data(NULL);
clear_method_counters();
set_vtable_index(Method::garbage_vtable_index);
// Fix and bury in Method*
set_interpreter_entry(NULL); // sets i2i entry and from_int
set_adapter_entry(NULL);
Method::clear_code(); // from_c/from_i get set to c2i/i2i
if (access_flags.is_native()) {
clear_native_function();
set_signature_handler(NULL);
}
NOT_PRODUCT(set_compiled_invocation_count(0);)
}
// Release Method*. The nmethod will be gone when we get here because
// we've walked the code cache.
void Method::deallocate_contents(ClassLoaderData* loader_data) {
MetadataFactory::free_metadata(loader_data, constMethod());
set_constMethod(NULL);
MetadataFactory::free_metadata(loader_data, method_data());
set_method_data(NULL);
MetadataFactory::free_metadata(loader_data, method_counters());
clear_method_counters();
// The nmethod will be gone when we get here.
if (code() != NULL) _code = NULL;
}
void Method::release_C_heap_structures() {
if (method_data()) {
#if INCLUDE_JVMCI
FailedSpeculation::free_failed_speculations(method_data()->get_failed_speculations_address());
#endif
// Destroy MethodData
method_data()->~MethodData();
}
}
address Method::get_i2c_entry() {
assert(adapter() != NULL, "must have");
return adapter()->get_i2c_entry();
}
address Method::get_c2i_entry() {
assert(adapter() != NULL, "must have");
return adapter()->get_c2i_entry();
}
address Method::get_c2i_unverified_entry() {
assert(adapter() != NULL, "must have");
return adapter()->get_c2i_unverified_entry();
}
address Method::get_c2i_no_clinit_check_entry() {
assert(VM_Version::supports_fast_class_init_checks(), "");
assert(adapter() != NULL, "must have");
return adapter()->get_c2i_no_clinit_check_entry();
}
char* Method::name_and_sig_as_C_string() const {
return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
}
char* Method::name_and_sig_as_C_string(char* buf, int size) const {
return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
}
char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
const char* klass_name = klass->external_name();
int klass_name_len = (int)strlen(klass_name);
int method_name_len = method_name->utf8_length();
int len = klass_name_len + 1 + method_name_len + signature->utf8_length();
char* dest = NEW_RESOURCE_ARRAY(char, len + 1);
strcpy(dest, klass_name);
dest[klass_name_len] = '.';
strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
dest[len] = 0;
return dest;
}
char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
Symbol* klass_name = klass->name();
klass_name->as_klass_external_name(buf, size);
int len = (int)strlen(buf);
if (len < size - 1) {
buf[len++] = '.';
method_name->as_C_string(&(buf[len]), size - len);
len = (int)strlen(buf);
signature->as_C_string(&(buf[len]), size - len);
}
return buf;
}
const char* Method::external_name() const {
return external_name(constants()->pool_holder(), name(), signature());
}
void Method::print_external_name(outputStream *os) const {
print_external_name(os, constants()->pool_holder(), name(), signature());
}
const char* Method::external_name(Klass* klass, Symbol* method_name, Symbol* signature) {
stringStream ss;
print_external_name(&ss, klass, method_name, signature);
return ss.as_string();
}
void Method::print_external_name(outputStream *os, Klass* klass, Symbol* method_name, Symbol* signature) {
signature->print_as_signature_external_return_type(os);
os->print(" %s.%s(", klass->external_name(), method_name->as_C_string());
signature->print_as_signature_external_parameters(os);
os->print(")");
}
int Method::fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS) {
// exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
// access exception table
ExceptionTable table(mh());
int length = table.length();
// iterate through all entries sequentially
constantPoolHandle pool(THREAD, mh->constants());
for (int i = 0; i < length; i ++) {
//reacquire the table in case a GC happened
ExceptionTable table(mh());
int beg_bci = table.start_pc(i);
int end_bci = table.end_pc(i);
assert(beg_bci <= end_bci, "inconsistent exception table");
if (beg_bci <= throw_bci && throw_bci < end_bci) {
// exception handler bci range covers throw_bci => investigate further
int handler_bci = table.handler_pc(i);
int klass_index = table.catch_type_index(i);
if (klass_index == 0) {
return handler_bci;
} else if (ex_klass == NULL) {
return handler_bci;
} else {
// we know the exception class => get the constraint class
// this may require loading of the constraint class; if verification
// fails or some other exception occurs, return handler_bci
Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci));
assert(k != NULL, "klass not loaded");
if (ex_klass->is_subtype_of(k)) {
return handler_bci;
}
}
}
}
return -1;
}
void Method::mask_for(int bci, InterpreterOopMap* mask) {
methodHandle h_this(Thread::current(), this);
// Only GC uses the OopMapCache during thread stack root scanning
// any other uses generate an oopmap but do not save it in the cache.
if (Universe::heap()->is_gc_active()) {
method_holder()->mask_for(h_this, bci, mask);
} else {
OopMapCache::compute_one_oop_map(h_this, bci, mask);
}
return;
}
int Method::bci_from(address bcp) const {
if (is_native() && bcp == 0) {
return 0;
}
#ifdef ASSERT
{
ResourceMark rm;
assert(is_native() && bcp == code_base() || contains(bcp) || VMError::is_error_reported(),
"bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s",
p2i(bcp), name_and_sig_as_C_string());
}
#endif
return bcp - code_base();
}
int Method::validate_bci(int bci) const {
return (bci == 0 || bci < code_size()) ? bci : -1;
}
// Return bci if it appears to be a valid bcp
// Return -1 otherwise.
// Used by profiling code, when invalid data is a possibility.
// The caller is responsible for validating the Method* itself.
int Method::validate_bci_from_bcp(address bcp) const {
// keep bci as -1 if not a valid bci
int bci = -1;
if (bcp == 0 || bcp == code_base()) {
// code_size() may return 0 and we allow 0 here
// the method may be native
bci = 0;
} else if (contains(bcp)) {
bci = bcp - code_base();
}
// Assert that if we have dodged any asserts, bci is negative.
assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
return bci;
}
address Method::bcp_from(int bci) const {
assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()),
"illegal bci: %d for %s method", bci, is_native() ? "native" : "non-native");
address bcp = code_base() + bci;
assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
return bcp;
}
address Method::bcp_from(address bcp) const {
if (is_native() && bcp == NULL) {
return code_base();
} else {
return bcp;
}
}
int Method::size(bool is_native) {
// If native, then include pointers for native_function and signature_handler
int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
int extra_words = align_up(extra_bytes, BytesPerWord) / BytesPerWord;
return align_metadata_size(header_size() + extra_words);
}
Symbol* Method::klass_name() const {
return method_holder()->name();
}
void Method::metaspace_pointers_do(MetaspaceClosure* it) {
log_trace(cds)("Iter(Method): %p", this);
it->push(&_constMethod);
it->push(&_method_data);
it->push(&_method_counters);
Method* this_ptr = this;
it->push_method_entry(&this_ptr, (intptr_t*)&_i2i_entry);
it->push_method_entry(&this_ptr, (intptr_t*)&_from_compiled_entry);
it->push_method_entry(&this_ptr, (intptr_t*)&_from_interpreted_entry);
}
// Attempt to return method oop to original state. Clear any pointers
// (to objects outside the shared spaces). We won't be able to predict
// where they should point in a new JVM. Further initialize some
// entries now in order allow them to be write protected later.
void Method::remove_unshareable_info() {
unlink_method();
}
void Method::set_vtable_index(int index) {
if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
// At runtime initialize_vtable is rerun as part of link_class_impl()
// for a shared class loaded by the non-boot loader to obtain the loader
// constraints based on the runtime classloaders' context.
return; // don't write into the shared class
} else {
_vtable_index = index;
}
}
void Method::set_itable_index(int index) {
if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
// At runtime initialize_itable is rerun as part of link_class_impl()
// for a shared class loaded by the non-boot loader to obtain the loader
// constraints based on the runtime classloaders' context. The dumptime
// itable index should be the same as the runtime index.
assert(_vtable_index == itable_index_max - index,
"archived itable index is different from runtime index");
return; // don’t write into the shared class
} else {
_vtable_index = itable_index_max - index;
}
assert(valid_itable_index(), "");
}
// The RegisterNatives call being attempted tried to register with a method that
// is not native. Ask JVM TI what prefixes have been specified. Then check
// to see if the native method is now wrapped with the prefixes. See the
// SetNativeMethodPrefix(es) functions in the JVM TI Spec for details.
static Method* find_prefixed_native(Klass* k, Symbol* name, Symbol* signature, TRAPS) {
#if INCLUDE_JVMTI
ResourceMark rm(THREAD);
Method* method;
int name_len = name->utf8_length();
char* name_str = name->as_utf8();
int prefix_count;
char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
for (int i = 0; i < prefix_count; i++) {
char* prefix = prefixes[i];
int prefix_len = (int)strlen(prefix);
// try adding this prefix to the method name and see if it matches another method name
int trial_len = name_len + prefix_len;
char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1);
strcpy(trial_name_str, prefix);
strcat(trial_name_str, name_str);
TempNewSymbol trial_name = SymbolTable::probe(trial_name_str, trial_len);
if (trial_name == NULL) {
continue; // no such symbol, so this prefix wasn't used, try the next prefix
}
method = k->lookup_method(trial_name, signature);
if (method == NULL) {
continue; // signature doesn't match, try the next prefix
}
if (method->is_native()) {
method->set_is_prefixed_native();
return method; // wahoo, we found a prefixed version of the method, return it
}
// found as non-native, so prefix is good, add it, probably just need more prefixes
name_len = trial_len;
name_str = trial_name_str;
}
#endif // INCLUDE_JVMTI
return NULL; // not found
}
bool Method::register_native(Klass* k, Symbol* name, Symbol* signature, address entry, TRAPS) {
Method* method = k->lookup_method(name, signature);
if (method == NULL) {
ResourceMark rm(THREAD);
stringStream st;
st.print("Method '");
print_external_name(&st, k, name, signature);
st.print("' name or signature does not match");
THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false);
}
if (!method->is_native()) {
// trying to register to a non-native method, see if a JVM TI agent has added prefix(es)
method = find_prefixed_native(k, name, signature, THREAD);
if (method == NULL) {
ResourceMark rm(THREAD);
stringStream st;
st.print("Method '");
print_external_name(&st, k, name, signature);
st.print("' is not declared as native");
THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false);
}
}
if (entry != NULL) {
method->set_native_function(entry, native_bind_event_is_interesting);
} else {
method->clear_native_function();
}
if (log_is_enabled(Debug, jni, resolve)) {
ResourceMark rm(THREAD);
log_debug(jni, resolve)("[Registering JNI native method %s.%s]",
method->method_holder()->external_name(),
method->name()->as_C_string());
}
return true;
}
bool Method::was_executed_more_than(int n) {
// Invocation counter is reset when the Method* is compiled.
// If the method has compiled code we therefore assume it has
// be excuted more than n times.
if (is_accessor() || is_empty_method() || (code() != NULL)) {
// interpreter doesn't bump invocation counter of trivial methods
// compiler does not bump invocation counter of compiled methods
return true;
}
else if ((method_counters() != NULL &&
method_counters()->invocation_counter()->carry()) ||
(method_data() != NULL &&
method_data()->invocation_counter()->carry())) {
// The carry bit is set when the counter overflows and causes
// a compilation to occur. We don't know how many times
// the counter has been reset, so we simply assume it has
// been executed more than n times.
return true;
} else {
return invocation_count() > n;
}
}
void Method::print_invocation_count() {
if (is_static()) tty->print("static ");
if (is_final()) tty->print("final ");
if (is_synchronized()) tty->print("synchronized ");
if (is_native()) tty->print("native ");
tty->print("%s::", method_holder()->external_name());
name()->print_symbol_on(tty);
signature()->print_symbol_on(tty);
if (WizardMode) {
// dump the size of the byte codes
tty->print(" {%d}", code_size());
}
tty->cr();
tty->print_cr (" interpreter_invocation_count: %8d ", interpreter_invocation_count());
tty->print_cr (" invocation_counter: %8d ", invocation_count());
tty->print_cr (" backedge_counter: %8d ", backedge_count());
#ifndef PRODUCT
if (CountCompiledCalls) {
tty->print_cr (" compiled_invocation_count: %8d ", compiled_invocation_count());
}
#endif
}
// Build a MethodData* object to hold information about this method
// collected in the interpreter.
void Method::build_interpreter_method_data(const methodHandle& method, TRAPS) {
// Do not profile the method if metaspace has hit an OOM previously
// allocating profiling data. Callers clear pending exception so don't
// add one here.
if (ClassLoaderDataGraph::has_metaspace_oom()) {
return;
}
// Grab a lock here to prevent multiple
// MethodData*s from being created.
MutexLocker ml(MethodData_lock, THREAD);
if (method->method_data() == NULL) {
ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
if (HAS_PENDING_EXCEPTION) {
CompileBroker::log_metaspace_failure();
ClassLoaderDataGraph::set_metaspace_oom(true);
return; // return the exception (which is cleared)
}
method->set_method_data(method_data);
if (PrintMethodData && (Verbose || WizardMode)) {
ResourceMark rm(THREAD);
tty->print("build_interpreter_method_data for ");
method->print_name(tty);
tty->cr();
// At the end of the run, the MDO, full of data, will be dumped.
}
}
}
MethodCounters* Method::build_method_counters(Method* m, TRAPS) {
// Do not profile the method if metaspace has hit an OOM previously
if (ClassLoaderDataGraph::has_metaspace_oom()) {
return NULL;
}
methodHandle mh(THREAD, m);
MethodCounters* counters = MethodCounters::allocate(mh, THREAD);
if (HAS_PENDING_EXCEPTION) {
CompileBroker::log_metaspace_failure();
ClassLoaderDataGraph::set_metaspace_oom(true);
return NULL; // return the exception (which is cleared)
}
if (!mh->init_method_counters(counters)) {
MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
}
if (LogTouchedMethods) {
mh->log_touched(CHECK_NULL);
}
return mh->method_counters();
}
bool Method::init_method_counters(MethodCounters* counters) {
// Try to install a pointer to MethodCounters, return true on success.
return Atomic::replace_if_null(&_method_counters, counters);
}
int Method::extra_stack_words() {
// not an inline function, to avoid a header dependency on Interpreter
return extra_stack_entries() * Interpreter::stackElementSize;
}
void Method::compute_size_of_parameters(Thread *thread) {
ArgumentSizeComputer asc(signature());
set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));
}
bool Method::is_empty_method() const {
return code_size() == 1
&& *code_base() == Bytecodes::_return;
}
bool Method::is_vanilla_constructor() const {
// Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
// which only calls the superclass vanilla constructor and possibly does stores of
// zero constants to local fields:
//
// aload_0
// invokespecial
// indexbyte1
// indexbyte2
//
// followed by an (optional) sequence of:
//
// aload_0
// aconst_null / iconst_0 / fconst_0 / dconst_0
// putfield
// indexbyte1
// indexbyte2
//
// followed by:
//
// return
assert(name() == vmSymbols::object_initializer_name(), "Should only be called for default constructors");
assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
int size = code_size();
// Check if size match
if (size == 0 || size % 5 != 0) return false;
address cb = code_base();
int last = size - 1;
if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
// Does not call superclass default constructor
return false;
}
// Check optional sequence
for (int i = 4; i < last; i += 5) {
if (cb[i] != Bytecodes::_aload_0) return false;
if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
if (cb[i+2] != Bytecodes::_putfield) return false;
}
return true;
}
bool Method::compute_has_loops_flag() {
BytecodeStream bcs(methodHandle(Thread::current(), this));
Bytecodes::Code bc;
while ((bc = bcs.next()) >= 0) {
switch( bc ) {
case Bytecodes::_ifeq:
case Bytecodes::_ifnull:
case Bytecodes::_iflt:
case Bytecodes::_ifle:
case Bytecodes::_ifne:
case Bytecodes::_ifnonnull:
case Bytecodes::_ifgt:
case Bytecodes::_ifge:
case Bytecodes::_if_icmpeq:
case Bytecodes::_if_icmpne:
case Bytecodes::_if_icmplt:
case Bytecodes::_if_icmpgt:
case Bytecodes::_if_icmple:
case Bytecodes::_if_icmpge:
case Bytecodes::_if_acmpeq:
case Bytecodes::_if_acmpne:
case Bytecodes::_goto:
case Bytecodes::_jsr:
if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();
break;
case Bytecodes::_goto_w:
case Bytecodes::_jsr_w:
if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();
break;
default:
break;
}
}
_access_flags.set_loops_flag_init();
return _access_flags.has_loops();
}
bool Method::is_final_method(AccessFlags class_access_flags) const {
// or "does_not_require_vtable_entry"
// default method or overpass can occur, is not final (reuses vtable entry)
// private methods in classes get vtable entries for backward class compatibility.
if (is_overpass() || is_default_method()) return false;
return is_final() || class_access_flags.is_final();
}
bool Method::is_final_method() const {
return is_final_method(method_holder()->access_flags());
}
bool Method::is_default_method() const {
if (method_holder() != NULL &&
method_holder()->is_interface() &&
!is_abstract() && !is_private()) {
return true;
} else {
return false;
}
}
bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
if (is_final_method(class_access_flags)) return true;
#ifdef ASSERT
ResourceMark rm;
bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
if (class_access_flags.is_interface()) {
assert(is_nonv == is_static() || is_nonv == is_private(),
"nonvirtual unexpected for non-static, non-private: %s",
name_and_sig_as_C_string());
}
#endif
assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
return vtable_index() == nonvirtual_vtable_index;
}
bool Method::can_be_statically_bound() const {
return can_be_statically_bound(method_holder()->access_flags());
}
bool Method::can_be_statically_bound(InstanceKlass* context) const {
return (method_holder() == context) && can_be_statically_bound();
}
bool Method::is_accessor() const {
return is_getter() || is_setter();
}
bool Method::is_getter() const {
if (code_size() != 5) return false;
if (size_of_parameters() != 1) return false;
if (java_code_at(0) != Bytecodes::_aload_0) return false;
if (java_code_at(1) != Bytecodes::_getfield) return false;
switch (java_code_at(4)) {
case Bytecodes::_ireturn:
case Bytecodes::_lreturn:
case Bytecodes::_freturn:
case Bytecodes::_dreturn:
case Bytecodes::_areturn:
break;
default:
return false;
}
return true;
}
bool Method::is_setter() const {
if (code_size() != 6) return false;
if (java_code_at(0) != Bytecodes::_aload_0) return false;
switch (java_code_at(1)) {
case Bytecodes::_iload_1:
case Bytecodes::_aload_1:
case Bytecodes::_fload_1:
if (size_of_parameters() != 2) return false;
break;
case Bytecodes::_dload_1:
case Bytecodes::_lload_1:
if (size_of_parameters() != 3) return false;
break;
default:
return false;
}
if (java_code_at(2) != Bytecodes::_putfield) return false;
if (java_code_at(5) != Bytecodes::_return) return false;
return true;
}
bool Method::is_constant_getter() const {
int last_index = code_size() - 1;
// Check if the first 1-3 bytecodes are a constant push
// and the last bytecode is a return.
return (2 <= code_size() && code_size() <= 4 &&
Bytecodes::is_const(java_code_at(0)) &&
Bytecodes::length_for(java_code_at(0)) == last_index &&
Bytecodes::is_return(java_code_at(last_index)));
}
bool Method::is_initializer() const {
return is_object_initializer() || is_static_initializer();
}
bool Method::has_valid_initializer_flags() const {
return (is_static() ||
method_holder()->major_version() < 51);
}
bool Method::is_static_initializer() const {
// For classfiles version 51 or greater, ensure that the clinit method is
// static. Non-static methods with the name "<clinit>" are not static
// initializers. (older classfiles exempted for backward compatibility)
return name() == vmSymbols::class_initializer_name() &&
has_valid_initializer_flags();
}
bool Method::is_object_initializer() const {
return name() == vmSymbols::object_initializer_name();
}
bool Method::needs_clinit_barrier() const {
return is_static() && !method_holder()->is_initialized();
}
objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
int length = method->checked_exceptions_length();
if (length == 0) { // common case
return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
} else {
methodHandle h_this(THREAD, method);
objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
objArrayHandle mirrors (THREAD, m_oop);
for (int i = 0; i < length; i++) {
CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
assert(k->is_subclass_of(SystemDictionary::Throwable_klass()), "invalid exception class");
mirrors->obj_at_put(i, k->java_mirror());
}
return mirrors;
}
};
int Method::line_number_from_bci(int bci) const {
int best_bci = 0;
int best_line = -1;
if (bci == SynchronizationEntryBCI) bci = 0;
if (0 <= bci && bci < code_size() && has_linenumber_table()) {
// The line numbers are a short array of 2-tuples [start_pc, line_number].
// Not necessarily sorted and not necessarily one-to-one.
CompressedLineNumberReadStream stream(compressed_linenumber_table());
while (stream.read_pair()) {
if (stream.bci() == bci) {
// perfect match
return stream.line();
} else {
// update best_bci/line
if (stream.bci() < bci && stream.bci() >= best_bci) {
best_bci = stream.bci();
best_line = stream.line();
}
}
}
}
return best_line;
}
bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
Thread *thread = Thread::current();
Symbol* klass_name = constants()->klass_name_at(klass_index);
Handle loader(thread, method_holder()->class_loader());
Handle prot (thread, method_holder()->protection_domain());
return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
} else {
return true;
}
}
bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
int klass_index = constants()->klass_ref_index_at(refinfo_index);
if (must_be_resolved) {
// Make sure klass is resolved in constantpool.
if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
}
return is_klass_loaded_by_klass_index(klass_index);
}
void Method::set_native_function(address function, bool post_event_flag) {
assert(function != NULL, "use clear_native_function to unregister natives");
assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
address* native_function = native_function_addr();
// We can see racers trying to place the same native function into place. Once
// is plenty.
address current = *native_function;
if (current == function) return;
if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
function != NULL) {
// native_method_throw_unsatisfied_link_error_entry() should only
// be passed when post_event_flag is false.
assert(function !=
SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
"post_event_flag mis-match");
// post the bind event, and possible change the bind function
JvmtiExport::post_native_method_bind(this, &function);
}
*native_function = function;
// This function can be called more than once. We must make sure that we always
// use the latest registered method -> check if a stub already has been generated.
// If so, we have to make it not_entrant.
CompiledMethod* nm = code(); // Put it into local variable to guard against concurrent updates
if (nm != NULL) {
nm->make_not_entrant();
}
}
bool Method::has_native_function() const {
if (is_method_handle_intrinsic())
return false; // special-cased in SharedRuntime::generate_native_wrapper
address func = native_function();
return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
}
void Method::clear_native_function() {
// Note: is_method_handle_intrinsic() is allowed here.
set_native_function(
SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
!native_bind_event_is_interesting);
this->unlink_code();
}
void Method::set_signature_handler(address handler) {
address* signature_handler = signature_handler_addr();
*signature_handler = handler;
}
void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
assert(reason != NULL, "must provide a reason");
if (PrintCompilation && report) {
ttyLocker ttyl;
tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
if (comp_level == CompLevel_all) {
tty->print("all levels ");
} else {
tty->print("level %d ", comp_level);
}
this->print_short_name(tty);
int size = this->code_size();
if (size > 0) {
tty->print(" (%d bytes)", size);
}
if (reason != NULL) {
tty->print(" %s", reason);
}
tty->cr();
}
if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
ttyLocker ttyl;
xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
os::current_thread_id(), is_osr, comp_level);
if (reason != NULL) {
xtty->print(" reason=\'%s\'", reason);
}
xtty->method(this);
xtty->stamp();
xtty->end_elem();
}
}
bool Method::is_always_compilable() const {
// Generated adapters must be compiled
if (is_method_handle_intrinsic() && is_synthetic()) {
assert(!is_not_c1_compilable(), "sanity check");
assert(!is_not_c2_compilable(), "sanity check");
return true;
}
return false;
}
bool Method::is_not_compilable(int comp_level) const {
if (number_of_breakpoints() > 0)
return true;
if (is_always_compilable())
return false;
if (comp_level == CompLevel_any)
return is_not_c1_compilable() || is_not_c2_compilable();
if (is_c1_compile(comp_level))
return is_not_c1_compilable();
if (is_c2_compile(comp_level))
return is_not_c2_compilable();
return false;
}
// call this when compiler finds that this method is not compilable
void Method::set_not_compilable(const char* reason, int comp_level, bool report) {
if (is_always_compilable()) {
// Don't mark a method which should be always compilable
return;
}
print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
if (comp_level == CompLevel_all) {
set_not_c1_compilable();
set_not_c2_compilable();
} else {
if (is_c1_compile(comp_level))
set_not_c1_compilable();
if (is_c2_compile(comp_level))
set_not_c2_compilable();
}
CompilationPolicy::policy()->disable_compilation(this);
assert(!CompilationPolicy::can_be_compiled(methodHandle(Thread::current(), this), comp_level), "sanity check");
}
bool Method::is_not_osr_compilable(int comp_level) const {
if (is_not_compilable(comp_level))
return true;
if (comp_level == CompLevel_any)
return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
if (is_c1_compile(comp_level))
return is_not_c1_osr_compilable();
if (is_c2_compile(comp_level))
return is_not_c2_osr_compilable();
return false;
}
void Method::set_not_osr_compilable(const char* reason, int comp_level, bool report) {
print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
if (comp_level == CompLevel_all) {
set_not_c1_osr_compilable();
set_not_c2_osr_compilable();
} else {
if (is_c1_compile(comp_level))
set_not_c1_osr_compilable();
if (is_c2_compile(comp_level))
set_not_c2_osr_compilable();
}
CompilationPolicy::policy()->disable_compilation(this);
assert(!CompilationPolicy::can_be_osr_compiled(methodHandle(Thread::current(), this), comp_level), "sanity check");
}
// Revert to using the interpreter and clear out the nmethod
void Method::clear_code() {
// this may be NULL if c2i adapters have not been made yet
// Only should happen at allocate time.
if (adapter() == NULL) {
_from_compiled_entry = NULL;
} else {
_from_compiled_entry = adapter()->get_c2i_entry();
}
OrderAccess::storestore();
_from_interpreted_entry = _i2i_entry;
OrderAccess::storestore();
_code = NULL;
}
void Method::unlink_code(CompiledMethod *compare) {
MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
// We need to check if either the _code or _from_compiled_code_entry_point
// refer to this nmethod because there is a race in setting these two fields
// in Method* as seen in bugid 4947125.
// If the vep() points to the zombie nmethod, the memory for the nmethod
// could be flushed and the compiler and vtable stubs could still call
// through it.
if (code() == compare ||
from_compiled_entry() == compare->verified_entry_point()) {
clear_code();
}
}
void Method::unlink_code() {
MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
clear_code();
}
#if INCLUDE_CDS
// Called by class data sharing to remove any entry points (which are not shared)
void Method::unlink_method() {
_code = NULL;
Arguments::assert_is_dumping_archive();
// Set the values to what they should be at run time. Note that
// this Method can no longer be executed during dump time.
_i2i_entry = Interpreter::entry_for_cds_method(methodHandle(Thread::current(), this));
_from_interpreted_entry = _i2i_entry;
if (DynamicDumpSharedSpaces) {
assert(_from_compiled_entry != NULL, "sanity");
} else {
// TODO: Simplify the adapter trampoline allocation for static archiving.
// Remove the use of CDSAdapterHandlerEntry.
CDSAdapterHandlerEntry* cds_adapter = (CDSAdapterHandlerEntry*)adapter();
constMethod()->set_adapter_trampoline(cds_adapter->get_adapter_trampoline());
_from_compiled_entry = cds_adapter->get_c2i_entry_trampoline();
assert(*((int*)_from_compiled_entry) == 0,
"must be NULL during dump time, to be initialized at run time");
}
if (is_native()) {
*native_function_addr() = NULL;
set_signature_handler(NULL);
}
NOT_PRODUCT(set_compiled_invocation_count(0);)
set_method_data(NULL);
clear_method_counters();
}
#endif
/****************************************************************************
// The following illustrates how the entries work for CDS shared Methods:
//
// Our goal is to delay writing into a shared Method until it's compiled.
// Hence, we want to determine the initial values for _i2i_entry,
// _from_interpreted_entry and _from_compiled_entry during CDS dump time.
//
// In this example, both Methods A and B have the _i2i_entry of "zero_locals".
// They also have similar signatures so that they will share the same
// AdapterHandlerEntry.
//
// _adapter_trampoline points to a fixed location in the RW section of
// the CDS archive. This location initially contains a NULL pointer. When the
// first of method A or B is linked, an AdapterHandlerEntry is allocated
// dynamically, and its c2i/i2c entries are generated.
//
// _i2i_entry and _from_interpreted_entry initially points to the same
// (fixed) location in the CODE section of the CDS archive. This contains
// an unconditional branch to the actual entry for "zero_locals", which is
// generated at run time and may be on an arbitrary address. Thus, the
// unconditional branch is also generated at run time to jump to the correct
// address.
//
// Similarly, _from_compiled_entry points to a fixed address in the CODE
// section. This address has enough space for an unconditional branch
// instruction, and is initially zero-filled. After the AdapterHandlerEntry is
// initialized, and the address for the actual c2i_entry is known, we emit a
// branch instruction here to branch to the actual c2i_entry.
//
// The effect of the extra branch on the i2i and c2i entries is negligible.
//
// The reason for putting _adapter_trampoline in RO is many shared Methods
// share the same AdapterHandlerEntry, so we can save space in the RW section
// by having the extra indirection.
[Method A: RW]
_constMethod ----> [ConstMethod: RO]
_adapter_trampoline -----------+
|
_i2i_entry (same value as method B) |
_from_interpreted_entry (same value as method B) |
_from_compiled_entry (same value as method B) |
|
|
[Method B: RW] +--------+
_constMethod ----> [ConstMethod: RO] |
_adapter_trampoline --+--->(AdapterHandlerEntry* ptr: RW)-+
|
+-------------------------------+
|
+----> [AdapterHandlerEntry] (allocated at run time)
_fingerprint
_c2i_entry ---------------------------------+->[c2i entry..]
_i2i_entry -------------+ _i2c_entry ---------------+-> [i2c entry..] |
_from_interpreted_entry | _c2i_unverified_entry | |
| | _c2i_no_clinit_check_entry| |
| | (_cds_entry_table: CODE) | |
| +->[0]: jmp _entry_table[0] --> (i2i_entry_for "zero_locals") | |
| | (allocated at run time) | |
| | ... [asm code ...] | |
+-[not compiled]-+ [n]: jmp _entry_table[n] | |
| | |
| | |
+-[compiled]-------------------------------------------------------------------+ |
|
_from_compiled_entry------------> (_c2i_entry_trampoline: CODE) |
[jmp c2i_entry] ------------------------------------------------------+
***/
// Called when the method_holder is getting linked. Setup entrypoints so the method
// is ready to be called from interpreter, compiler, and vtables.
void Method::link_method(const methodHandle& h_method, TRAPS) {
// If the code cache is full, we may reenter this function for the
// leftover methods that weren't linked.
if (is_shared()) {
address entry = Interpreter::entry_for_cds_method(h_method);
assert(entry != NULL && entry == _i2i_entry,
"should be correctly set during dump time");
if (adapter() != NULL) {
return;
}
assert(entry == _from_interpreted_entry,
"should be correctly set during dump time");
} else if (_i2i_entry != NULL) {
return;
}
assert( _code == NULL, "nothing compiled yet" );
// Setup interpreter entrypoint
assert(this == h_method(), "wrong h_method()" );
if (!is_shared()) {
assert(adapter() == NULL, "init'd to NULL");
address entry = Interpreter::entry_for_method(h_method);
assert(entry != NULL, "interpreter entry must be non-null");
// Sets both _i2i_entry and _from_interpreted_entry
set_interpreter_entry(entry);
}
// Don't overwrite already registered native entries.
if (is_native() && !has_native_function()) {
set_native_function(
SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
!native_bind_event_is_interesting);
}
// Setup compiler entrypoint. This is made eagerly, so we do not need
// special handling of vtables. An alternative is to make adapters more
// lazily by calling make_adapter() from from_compiled_entry() for the
// normal calls. For vtable calls life gets more complicated. When a
// call-site goes mega-morphic we need adapters in all methods which can be
// called from the vtable. We need adapters on such methods that get loaded
// later. Ditto for mega-morphic itable calls. If this proves to be a
// problem we'll make these lazily later.
(void) make_adapters(h_method, CHECK);
// ONLY USE the h_method now as make_adapter may have blocked
}
address Method::make_adapters(const methodHandle& mh, TRAPS) {
// Adapters for compiled code are made eagerly here. They are fairly
// small (generally < 100 bytes) and quick to make (and cached and shared)
// so making them eagerly shouldn't be too expensive.
AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
if (adapter == NULL ) {
if (!is_init_completed()) {
// Don't throw exceptions during VM initialization because java.lang.* classes
// might not have been initialized, causing problems when constructing the
// Java exception object.
vm_exit_during_initialization("Out of space in CodeCache for adapters");
} else {
THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for adapters");
}
}
if (mh->is_shared()) {
assert(mh->adapter() == adapter, "must be");
assert(mh->_from_compiled_entry != NULL, "must be");
} else {
mh->set_adapter_entry(adapter);
mh->_from_compiled_entry = adapter->get_c2i_entry();
}
return adapter->get_c2i_entry();
}
void Method::restore_unshareable_info(TRAPS) {
assert(is_method() && is_valid_method(this), "ensure C++ vtable is restored");
// Since restore_unshareable_info can be called more than once for a method, don't
// redo any work.
if (adapter() == NULL) {
methodHandle mh(THREAD, this);
link_method(mh, CHECK);
}
}
address Method::from_compiled_entry_no_trampoline() const {
CompiledMethod *code = Atomic::load_acquire(&_code);
if (code) {
return code->verified_entry_point();
} else {
return adapter()->get_c2i_entry();
}
}
// The verified_code_entry() must be called when a invoke is resolved
// on this method.
// It returns the compiled code entry point, after asserting not null.
// This function is called after potential safepoints so that nmethod
// or adapter that it points to is still live and valid.
// This function must not hit a safepoint!
address Method::verified_code_entry() {
debug_only(NoSafepointVerifier nsv;)
assert(_from_compiled_entry != NULL, "must be set");
return _from_compiled_entry;
}
// Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
// (could be racing a deopt).
// Not inline to avoid circular ref.
bool Method::check_code() const {
// cached in a register or local. There's a race on the value of the field.
CompiledMethod *code = Atomic::load_acquire(&_code);
return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
}
// Install compiled code. Instantly it can execute.
void Method::set_code(const methodHandle& mh, CompiledMethod *code) {
assert_lock_strong(CompiledMethod_lock);
assert( code, "use clear_code to remove code" );
assert( mh->check_code(), "" );
guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
// These writes must happen in this order, because the interpreter will
// directly jump to from_interpreted_entry which jumps to an i2c adapter
// which jumps to _from_compiled_entry.
mh->_code = code; // Assign before allowing compiled code to exec
int comp_level = code->comp_level();
// In theory there could be a race here. In practice it is unlikely
// and not worth worrying about.
if (comp_level > mh->highest_comp_level()) {
mh->set_highest_comp_level(comp_level);
}
OrderAccess::storestore();
mh->_from_compiled_entry = code->verified_entry_point();
OrderAccess::storestore();
// Instantly compiled code can execute.
if (!mh->is_method_handle_intrinsic())
mh->_from_interpreted_entry = mh->get_i2c_entry();
}
bool Method::is_overridden_in(Klass* k) const {
InstanceKlass* ik = InstanceKlass::cast(k);
if (ik->is_interface()) return false;
// If method is an interface, we skip it - except if it
// is a miranda method
if (method_holder()->is_interface()) {
// Check that method is not a miranda method
if (ik->lookup_method(name(), signature()) == NULL) {
// No implementation exist - so miranda method
return false;
}
return true;
}
assert(ik->is_subclass_of(method_holder()), "should be subklass");
if (!has_vtable_index()) {
return false;
} else {
Method* vt_m = ik->method_at_vtable(vtable_index());
return vt_m != this;
}
}
// give advice about whether this Method* should be cached or not
bool Method::should_not_be_cached() const {
if (is_old()) {
// This method has been redefined. It is either EMCP or obsolete
// and we don't want to cache it because that would pin the method
// down and prevent it from being collectible if and when it
// finishes executing.
return true;
}
// caching this method should be just fine
return false;
}
/**
* Returns true if this is one of the specially treated methods for
* security related stack walks (like Reflection.getCallerClass).
*/
bool Method::is_ignored_by_security_stack_walk() const {
if (intrinsic_id() == vmIntrinsics::_invoke) {
// This is Method.invoke() -- ignore it
return true;
}
if (method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
// This is an auxilary frame -- ignore it
return true;
}
if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
// This is an internal adapter frame for method handles -- ignore it
return true;
}
return false;
}
// Constant pool structure for invoke methods:
enum {
_imcp_invoke_name = 1, // utf8: 'invokeExact', etc.
_imcp_invoke_signature, // utf8: (variable Symbol*)
_imcp_limit
};
// Test if this method is an MH adapter frame generated by Java code.
// Cf. java/lang/invoke/InvokerBytecodeGenerator
bool Method::is_compiled_lambda_form() const {
return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
}
// Test if this method is an internal MH primitive method.
bool Method::is_method_handle_intrinsic() const {
vmIntrinsics::ID iid = intrinsic_id();
return (MethodHandles::is_signature_polymorphic(iid) &&
MethodHandles::is_signature_polymorphic_intrinsic(iid));
}
bool Method::has_member_arg() const {
vmIntrinsics::ID iid = intrinsic_id();
return (MethodHandles::is_signature_polymorphic(iid) &&
MethodHandles::has_member_arg(iid));
}
// Make an instance of a signature-polymorphic internal MH primitive.
methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
Symbol* signature,
TRAPS) {
ResourceMark rm(THREAD);
methodHandle empty;
InstanceKlass* holder = SystemDictionary::MethodHandle_klass();
Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
if (TraceMethodHandles) {
tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
}
// invariant: cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
name->increment_refcount();
signature->increment_refcount();
int cp_length = _imcp_limit;
ClassLoaderData* loader_data = holder->class_loader_data();
constantPoolHandle cp;
{
ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
cp = constantPoolHandle(THREAD, cp_oop);
}
cp->set_pool_holder(holder);
cp->symbol_at_put(_imcp_invoke_name, name);
cp->symbol_at_put(_imcp_invoke_signature, signature);
cp->set_has_preresolution();
// decide on access bits: public or not?
int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
if (must_be_static) flags_bits |= JVM_ACC_STATIC;
assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
methodHandle m;
{
InlineTableSizes sizes;
Method* m_oop = Method::allocate(loader_data, 0,
accessFlags_from(flags_bits), &sizes,
ConstMethod::NORMAL, CHECK_(empty));
m = methodHandle(THREAD, m_oop);
}
m->set_constants(cp());
m->set_name_index(_imcp_invoke_name);
m->set_signature_index(_imcp_invoke_signature);
assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
assert(m->signature() == signature, "");
ResultTypeFinder rtf(signature);
m->constMethod()->set_result_type(rtf.type());
m->compute_size_of_parameters(THREAD);
m->init_intrinsic_id();
assert(m->is_method_handle_intrinsic(), "");
#ifdef ASSERT
if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id())) m->print();
assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
assert(m->intrinsic_id() == iid, "correctly predicted iid");
#endif //ASSERT
// Finally, set up its entry points.
assert(m->can_be_statically_bound(), "");
m->set_vtable_index(Method::nonvirtual_vtable_index);
m->link_method(m, CHECK_(empty));
if (TraceMethodHandles && (Verbose || WizardMode)) {
ttyLocker ttyl;
m->print_on(tty);
}
return m;
}
Klass* Method::check_non_bcp_klass(Klass* klass) {
if (klass != NULL && klass->class_loader() != NULL) {
if (klass->is_objArray_klass())
klass = ObjArrayKlass::cast(klass)->bottom_klass();
return klass;
}
return NULL;
}
methodHandle Method::clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
// Code below does not work for native methods - they should never get rewritten anyway
assert(!m->is_native(), "cannot rewrite native methods");
// Allocate new Method*
AccessFlags flags = m->access_flags();
ConstMethod* cm = m->constMethod();
int checked_exceptions_len = cm->checked_exceptions_length();
int localvariable_len = cm->localvariable_table_length();
int exception_table_len = cm->exception_table_length();
int method_parameters_len = cm->method_parameters_length();
int method_annotations_len = cm->method_annotations_length();
int parameter_annotations_len = cm->parameter_annotations_length();
int type_annotations_len = cm->type_annotations_length();
int default_annotations_len = cm->default_annotations_length();
InlineTableSizes sizes(
localvariable_len,
new_compressed_linenumber_size,
exception_table_len,
checked_exceptions_len,
method_parameters_len,
cm->generic_signature_index(),
method_annotations_len,
parameter_annotations_len,
type_annotations_len,
default_annotations_len,
0);
ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
Method* newm_oop = Method::allocate(loader_data,
new_code_length,
flags,
&sizes,
m->method_type(),
CHECK_(methodHandle()));
methodHandle newm (THREAD, newm_oop);
// Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
ConstMethod* newcm = newm->constMethod();
int new_const_method_size = newm->constMethod()->size();
// This works because the source and target are both Methods. Some compilers
// (e.g., clang) complain that the target vtable pointer will be stomped,
// so cast away newm()'s and m()'s Methodness.
memcpy((void*)newm(), (void*)m(), sizeof(Method));
// Create shallow copy of ConstMethod.
memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
// Reset correct method/const method, method size, and parameter info
newm->set_constMethod(newcm);
newm->constMethod()->set_code_size(new_code_length);
newm->constMethod()->set_constMethod_size(new_const_method_size);
assert(newm->code_size() == new_code_length, "check");
assert(newm->method_parameters_length() == method_parameters_len, "check");
assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
assert(newm->exception_table_length() == exception_table_len, "check");
assert(newm->localvariable_table_length() == localvariable_len, "check");
// Copy new byte codes
memcpy(newm->code_base(), new_code, new_code_length);
// Copy line number table
if (new_compressed_linenumber_size > 0) {
memcpy(newm->compressed_linenumber_table(),
new_compressed_linenumber_table,
new_compressed_linenumber_size);
}
// Copy method_parameters
if (method_parameters_len > 0) {
memcpy(newm->method_parameters_start(),
m->method_parameters_start(),
method_parameters_len * sizeof(MethodParametersElement));
}
// Copy checked_exceptions
if (checked_exceptions_len > 0) {
memcpy(newm->checked_exceptions_start(),
m->checked_exceptions_start(),
checked_exceptions_len * sizeof(CheckedExceptionElement));
}
// Copy exception table
if (exception_table_len > 0) {
memcpy(newm->exception_table_start(),
m->exception_table_start(),
exception_table_len * sizeof(ExceptionTableElement));
}
// Copy local variable number table
if (localvariable_len > 0) {
memcpy(newm->localvariable_table_start(),
m->localvariable_table_start(),
localvariable_len * sizeof(LocalVariableTableElement));
}
// Copy stackmap table
if (m->has_stackmap_table()) {
int code_attribute_length = m->stackmap_data()->length();
Array<u1>* stackmap_data =
MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_(methodHandle()));
memcpy((void*)stackmap_data->adr_at(0),
(void*)m->stackmap_data()->adr_at(0), code_attribute_length);
newm->set_stackmap_data(stackmap_data);
}
// copy annotations over to new method
newcm->copy_annotations_from(loader_data, cm, CHECK_(methodHandle()));
return newm;
}
vmSymbols::SID Method::klass_id_for_intrinsics(const Klass* holder) {
// if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
// because we are not loading from core libraries
// exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
// which does not use the class default class loader so we check for its loader here
const InstanceKlass* ik = InstanceKlass::cast(holder);
if ((ik->class_loader() != NULL) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) {
return vmSymbols::NO_SID; // regardless of name, no intrinsics here
}
// see if the klass name is well-known:
Symbol* klass_name = ik->name();
return vmSymbols::find_sid(klass_name);
}
void Method::init_intrinsic_id() {
assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");
const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
// the klass name is well-known:
vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());
assert(klass_id != vmSymbols::NO_SID, "caller responsibility");
// ditto for method and signature:
vmSymbols::SID name_id = vmSymbols::find_sid(name());
if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
&& klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
&& name_id == vmSymbols::NO_SID) {
return;
}
vmSymbols::SID sig_id = vmSymbols::find_sid(signature());
if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
&& klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
&& sig_id == vmSymbols::NO_SID) {
return;
}
jshort flags = access_flags().as_short();
vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
if (id != vmIntrinsics::_none) {
set_intrinsic_id(id);
if (id == vmIntrinsics::_Class_cast) {
// Even if the intrinsic is rejected, we want to inline this simple method.
set_force_inline(true);
}
return;
}
// A few slightly irregular cases:
switch (klass_id) {
case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
// Second chance: check in regular Math.
switch (name_id) {
case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
// pretend it is the corresponding method in the non-strict class:
klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
break;
default:
break;
}
break;
// Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle
case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle):
if (!is_native()) break;
id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
id = vmIntrinsics::_none;
break;
default:
break;
}
if (id != vmIntrinsics::_none) {
// Set up its iid. It is an alias method.
set_intrinsic_id(id);
return;
}
}
// These two methods are static since a GC may move the Method
bool Method::load_signature_classes(const methodHandle& m, TRAPS) {
if (!THREAD->can_call_java()) {
// There is nothing useful this routine can do from within the Compile thread.
// Hopefully, the signature contains only well-known classes.
// We could scan for this and return true/false, but the caller won't care.
return false;
}
bool sig_is_loaded = true;
Handle class_loader(THREAD, m->method_holder()->class_loader());
Handle protection_domain(THREAD, m->method_holder()->protection_domain());
ResourceMark rm(THREAD);
Symbol* signature = m->signature();
for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
if (ss.is_object()) {
Symbol* sym = ss.as_symbol();
Symbol* name = sym;
Klass* klass = SystemDictionary::resolve_or_null(name, class_loader,
protection_domain, THREAD);
// We are loading classes eagerly. If a ClassNotFoundException or
// a LinkageError was generated, be sure to ignore it.
if (HAS_PENDING_EXCEPTION) {
if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
CLEAR_PENDING_EXCEPTION;
} else {
return false;
}
}
if( klass == NULL) { sig_is_loaded = false; }
}
}
return sig_is_loaded;
}
bool Method::has_unloaded_classes_in_signature(const methodHandle& m, TRAPS) {
Handle class_loader(THREAD, m->method_holder()->class_loader());
Handle protection_domain(THREAD, m->method_holder()->protection_domain());
ResourceMark rm(THREAD);
Symbol* signature = m->signature();
for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
if (ss.type() == T_OBJECT) {
Symbol* name = ss.as_symbol_or_null();
if (name == NULL) return true;
Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);
if (klass == NULL) return true;
}
}
return false;
}
// Exposed so field engineers can debug VM
void Method::print_short_name(outputStream* st) {
ResourceMark rm;
#ifdef PRODUCT
st->print(" %s::", method_holder()->external_name());
#else
st->print(" %s::", method_holder()->internal_name());
#endif
name()->print_symbol_on(st);
if (WizardMode) signature()->print_symbol_on(st);
else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
MethodHandles::print_as_basic_type_signature_on(st, signature(), true);
}
// Comparer for sorting an object array containing
// Method*s.
static int method_comparator(Method* a, Method* b) {
return a->name()->fast_compare(b->name());
}
// This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
// default_methods also uses this without the ordering for fast find_method
void Method::sort_methods(Array<Method*>* methods, bool set_idnums, method_comparator_func func) {
int length = methods->length();
if (length > 1) {
if (func == NULL) {
func = method_comparator;
}
{
NoSafepointVerifier nsv;
QuickSort::sort(methods->data(), length, func, /*idempotent=*/false);
}
// Reset method ordering
if (set_idnums) {
for (int i = 0; i < length; i++) {
Method* m = methods->at(i);
m->set_method_idnum(i);
m->set_orig_method_idnum(i);
}
}
}
}
//-----------------------------------------------------------------------------------
// Non-product code unless JVM/TI needs it
#if !defined(PRODUCT) || INCLUDE_JVMTI
class SignatureTypePrinter : public SignatureTypeNames {
private:
outputStream* _st;
bool _use_separator;
void type_name(const char* name) {
if (_use_separator) _st->print(", ");
_st->print("%s", name);
_use_separator = true;
}
public:
SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
_st = st;
_use_separator = false;
}
void print_parameters() { _use_separator = false; iterate_parameters(); }
void print_returntype() { _use_separator = false; iterate_returntype(); }
};
void Method::print_name(outputStream* st) {
Thread *thread = Thread::current();
ResourceMark rm(thread);
st->print("%s ", is_static() ? "static" : "virtual");
if (WizardMode) {
st->print("%s.", method_holder()->internal_name());
name()->print_symbol_on(st);
signature()->print_symbol_on(st);
} else {
SignatureTypePrinter sig(signature(), st);
sig.print_returntype();
st->print(" %s.", method_holder()->internal_name());
name()->print_symbol_on(st);
st->print("(");
sig.print_parameters();
st->print(")");
}
}
#endif // !PRODUCT || INCLUDE_JVMTI
void Method::print_codes_on(outputStream* st) const {
print_codes_on(0, code_size(), st);
}
void Method::print_codes_on(int from, int to, outputStream* st) const {
Thread *thread = Thread::current();
ResourceMark rm(thread);
methodHandle mh (thread, (Method*)this);
BytecodeStream s(mh);
s.set_interval(from, to);
BytecodeTracer::set_closure(BytecodeTracer::std_closure());
while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
}
CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
_bci = 0;
_line = 0;
};
bool CompressedLineNumberReadStream::read_pair() {
jubyte next = read_byte();
// Check for terminator
if (next == 0) return false;
if (next == 0xFF) {
// Escape character, regular compression used
_bci += read_signed_int();
_line += read_signed_int();
} else {
// Single byte compression used
_bci += next >> 3;
_line += next & 0x7;
}
return true;
}
#if INCLUDE_JVMTI
Bytecodes::Code Method::orig_bytecode_at(int bci) const {
BreakpointInfo* bp = method_holder()->breakpoints();
for (; bp != NULL; bp = bp->next()) {
if (bp->match(this, bci)) {
return bp->orig_bytecode();
}
}
{
ResourceMark rm;
fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
}
return Bytecodes::_shouldnotreachhere;
}
void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
BreakpointInfo* bp = method_holder()->breakpoints();
for (; bp != NULL; bp = bp->next()) {
if (bp->match(this, bci)) {
bp->set_orig_bytecode(code);
// and continue, in case there is more than one
}
}
}
void Method::set_breakpoint(int bci) {
InstanceKlass* ik = method_holder();
BreakpointInfo *bp = new BreakpointInfo(this, bci);
bp->set_next(ik->breakpoints());
ik->set_breakpoints(bp);
// do this last:
bp->set(this);
}
static void clear_matches(Method* m, int bci) {
InstanceKlass* ik = m->method_holder();
BreakpointInfo* prev_bp = NULL;
BreakpointInfo* next_bp;
for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
next_bp = bp->next();
// bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
// do this first:
bp->clear(m);
// unhook it
if (prev_bp != NULL)
prev_bp->set_next(next_bp);
else
ik->set_breakpoints(next_bp);
delete bp;
// When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
// at same location. So we have multiple matching (method_index and bci)
// BreakpointInfo nodes in BreakpointInfo list. We should just delete one
// breakpoint for clear_breakpoint request and keep all other method versions
// BreakpointInfo for future clear_breakpoint request.
// bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
// which is being called when class is unloaded. We delete all the Breakpoint
// information for all versions of method. We may not correctly restore the original
// bytecode in all method versions, but that is ok. Because the class is being unloaded
// so these methods won't be used anymore.
if (bci >= 0) {
break;
}
} else {
// This one is a keeper.
prev_bp = bp;
}
}
}
void Method::clear_breakpoint(int bci) {
assert(bci >= 0, "");
clear_matches(this, bci);
}
void Method::clear_all_breakpoints() {
clear_matches(this, -1);
}
#endif // INCLUDE_JVMTI
int Method::invocation_count() {
MethodCounters *mcs = method_counters();
if (TieredCompilation) {
MethodData* const mdo = method_data();
if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
return InvocationCounter::count_limit;
} else {
return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
}
} else {
return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
}
}
int Method::backedge_count() {
MethodCounters *mcs = method_counters();
if (TieredCompilation) {
MethodData* const mdo = method_data();
if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
return InvocationCounter::count_limit;
} else {
return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
}
} else {
return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
}
}
int Method::highest_comp_level() const {
const MethodCounters* mcs = method_counters();
if (mcs != NULL) {
return mcs->highest_comp_level();
} else {
return CompLevel_none;
}
}
int Method::highest_osr_comp_level() const {
const MethodCounters* mcs = method_counters();
if (mcs != NULL) {
return mcs->highest_osr_comp_level();
} else {
return CompLevel_none;
}
}
void Method::set_highest_comp_level(int level) {
MethodCounters* mcs = method_counters();
if (mcs != NULL) {
mcs->set_highest_comp_level(level);
}
}
void Method::set_highest_osr_comp_level(int level) {
MethodCounters* mcs = method_counters();
if (mcs != NULL) {
mcs->set_highest_osr_comp_level(level);
}
}
#if INCLUDE_JVMTI
BreakpointInfo::BreakpointInfo(Method* m, int bci) {
_bci = bci;
_name_index = m->name_index();
_signature_index = m->signature_index();
_orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
if (_orig_bytecode == Bytecodes::_breakpoint)
_orig_bytecode = m->orig_bytecode_at(_bci);
_next = NULL;
}
void BreakpointInfo::set(Method* method) {
#ifdef ASSERT
{
Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
if (code == Bytecodes::_breakpoint)
code = method->orig_bytecode_at(_bci);
assert(orig_bytecode() == code, "original bytecode must be the same");
}
#endif
Thread *thread = Thread::current();
*method->bcp_from(_bci) = Bytecodes::_breakpoint;
method->incr_number_of_breakpoints(thread);
{
// Deoptimize all dependents on this method
HandleMark hm(thread);
methodHandle mh(thread, method);
CodeCache::flush_dependents_on_method(mh);
}
}
void BreakpointInfo::clear(Method* method) {
*method->bcp_from(_bci) = orig_bytecode();
assert(method->number_of_breakpoints() > 0, "must not go negative");
method->decr_number_of_breakpoints(Thread::current());
}
#endif // INCLUDE_JVMTI
// jmethodID handling
// This is a block allocating object, sort of like JNIHandleBlock, only a
// lot simpler.
// It's allocated on the CHeap because once we allocate a jmethodID, we can
// never get rid of it.
static const int min_block_size = 8;
class JNIMethodBlockNode : public CHeapObj<mtClass> {
friend class JNIMethodBlock;
Method** _methods;
int _number_of_methods;
int _top;
JNIMethodBlockNode* _next;
public:
JNIMethodBlockNode(int num_methods = min_block_size);
~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
void ensure_methods(int num_addl_methods) {
if (_top < _number_of_methods) {
num_addl_methods -= _number_of_methods - _top;
if (num_addl_methods <= 0) {
return;
}
}
if (_next == NULL) {
_next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
} else {
_next->ensure_methods(num_addl_methods);
}
}
};
class JNIMethodBlock : public CHeapObj<mtClass> {
JNIMethodBlockNode _head;
JNIMethodBlockNode *_last_free;
public:
static Method* const _free_method;
JNIMethodBlock(int initial_capacity = min_block_size)
: _head(initial_capacity), _last_free(&_head) {}
void ensure_methods(int num_addl_methods) {
_last_free->ensure_methods(num_addl_methods);
}
Method** add_method(Method* m) {
for (JNIMethodBlockNode* b = _last_free; b != NULL; b = b->_next) {
if (b->_top < b->_number_of_methods) {
// top points to the next free entry.
int i = b->_top;
b->_methods[i] = m;
b->_top++;
_last_free = b;
return &(b->_methods[i]);
} else if (b->_top == b->_number_of_methods) {
// if the next free entry ran off the block see if there's a free entry
for (int i = 0; i < b->_number_of_methods; i++) {
if (b->_methods[i] == _free_method) {
b->_methods[i] = m;
_last_free = b;
return &(b->_methods[i]);
}
}
// Only check each block once for frees. They're very unlikely.
// Increment top past the end of the block.
b->_top++;
}
// need to allocate a next block.
if (b->_next == NULL) {
b->_next = _last_free = new JNIMethodBlockNode();
}
}
guarantee(false, "Should always allocate a free block");
return NULL;
}
bool contains(Method** m) {
if (m == NULL) return false;
for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
// This is a bit of extra checking, for two reasons. One is
// that contains() deals with pointers that are passed in by
// JNI code, so making sure that the pointer is aligned
// correctly is valuable. The other is that <= and > are
// technically not defined on pointers, so the if guard can
// pass spuriously; no modern compiler is likely to make that
// a problem, though (and if one did, the guard could also
// fail spuriously, which would be bad).
ptrdiff_t idx = m - b->_methods;
if (b->_methods + idx == m) {
return true;
}
}
}
return false; // not found
}
// Doesn't really destroy it, just marks it as free so it can be reused.
void destroy_method(Method** m) {
#ifdef ASSERT
assert(contains(m), "should be a methodID");
#endif // ASSERT
*m = _free_method;
}
// During class unloading the methods are cleared, which is different
// than freed.
void clear_all_methods() {
for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
for (int i = 0; i< b->_number_of_methods; i++) {
b->_methods[i] = NULL;
}
}
}
#ifndef PRODUCT
int count_methods() {
// count all allocated methods
int count = 0;
for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
for (int i = 0; i< b->_number_of_methods; i++) {
if (b->_methods[i] != _free_method) count++;
}
}
return count;
}
#endif // PRODUCT
};
// Something that can't be mistaken for an address or a markWord
Method* const JNIMethodBlock::_free_method = (Method*)55;
JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _top(0), _next(NULL) {
_number_of_methods = MAX2(num_methods, min_block_size);
_methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
for (int i = 0; i < _number_of_methods; i++) {
_methods[i] = JNIMethodBlock::_free_method;
}
}
void Method::ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity) {
ClassLoaderData* cld = loader_data;
if (!SafepointSynchronize::is_at_safepoint()) {
// Have to add jmethod_ids() to class loader data thread-safely.
// Also have to add the method to the list safely, which the cld lock
// protects as well.
MutexLocker ml(cld->metaspace_lock(), Mutex::_no_safepoint_check_flag);
if (cld->jmethod_ids() == NULL) {
cld->set_jmethod_ids(new JNIMethodBlock(capacity));
} else {
cld->jmethod_ids()->ensure_methods(capacity);
}
} else {
// At safepoint, we are single threaded and can set this.
if (cld->jmethod_ids() == NULL) {
cld->set_jmethod_ids(new JNIMethodBlock(capacity));
} else {
cld->jmethod_ids()->ensure_methods(capacity);
}
}
}
// Add a method id to the jmethod_ids
jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
ClassLoaderData* cld = loader_data;
if (!SafepointSynchronize::is_at_safepoint()) {
// Have to add jmethod_ids() to class loader data thread-safely.
// Also have to add the method to the list safely, which the cld lock
// protects as well.
MutexLocker ml(cld->metaspace_lock(), Mutex::_no_safepoint_check_flag);
if (cld->jmethod_ids() == NULL) {
cld->set_jmethod_ids(new JNIMethodBlock());
}
// jmethodID is a pointer to Method*
return (jmethodID)cld->jmethod_ids()->add_method(m);
} else {
// At safepoint, we are single threaded and can set this.
if (cld->jmethod_ids() == NULL) {
cld->set_jmethod_ids(new JNIMethodBlock());
}
// jmethodID is a pointer to Method*
return (jmethodID)cld->jmethod_ids()->add_method(m);
}
}
jmethodID Method::jmethod_id() {
methodHandle mh(Thread::current(), this);
return method_holder()->get_jmethod_id(mh);
}
// Mark a jmethodID as free. This is called when there is a data race in
// InstanceKlass while creating the jmethodID cache.
void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
ClassLoaderData* cld = loader_data;
Method** ptr = (Method**)m;
assert(cld->jmethod_ids() != NULL, "should have method handles");
cld->jmethod_ids()->destroy_method(ptr);
}
void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
// Can't assert the method_holder is the same because the new method has the
// scratch method holder.
assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
== new_method->method_holder()->class_loader() ||
new_method->method_holder()->class_loader() == NULL, // allow Unsafe substitution
"changing to a different class loader");
// Just change the method in place, jmethodID pointer doesn't change.
*((Method**)jmid) = new_method;
}
bool Method::is_method_id(jmethodID mid) {
Method* m = resolve_jmethod_id(mid);
assert(m != NULL, "should be called with non-null method");
InstanceKlass* ik = m->method_holder();
ClassLoaderData* cld = ik->class_loader_data();
if (cld->jmethod_ids() == NULL) return false;
return (cld->jmethod_ids()->contains((Method**)mid));
}
Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
if (mid == NULL) return NULL;
Method* o = resolve_jmethod_id(mid);
if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
return NULL;
}
return o;
};
void Method::set_on_stack(const bool value) {
// Set both the method itself and its constant pool. The constant pool
// on stack means some method referring to it is also on the stack.
constants()->set_on_stack(value);
bool already_set = on_stack();
_access_flags.set_on_stack(value);
if (value && !already_set) {
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