/* * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "classfile/metadataOnStackMark.hpp" #include "classfile/systemDictionary.hpp" #include "code/debugInfoRec.hpp" #include "gc_interface/collectedHeap.inline.hpp" #include "interpreter/bytecodeStream.hpp" #include "interpreter/bytecodeTracer.hpp" #include "interpreter/bytecodes.hpp" #include "interpreter/interpreter.hpp" #include "interpreter/oopMapCache.hpp" #include "memory/gcLocker.hpp" #include "memory/generation.hpp" #include "memory/heapInspection.hpp" #include "memory/metadataFactory.hpp" #include "memory/metaspaceShared.hpp" #include "memory/oopFactory.hpp" #include "oops/constMethod.hpp" #include "oops/methodData.hpp" #include "oops/method.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/compilationPolicy.hpp" #include "runtime/frame.inline.hpp" #include "runtime/handles.inline.hpp" #include "runtime/orderAccess.inline.hpp" #include "runtime/relocator.hpp" #include "runtime/sharedRuntime.hpp" #include "runtime/signature.hpp" #include "utilities/quickSort.hpp" #include "utilities/xmlstream.hpp" PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC // 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, false, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags, size); } Method::Method(ConstMethod* xconst, AccessFlags access_flags, int size) { No_Safepoint_Verifier no_safepoint; set_constMethod(xconst); set_access_flags(access_flags); set_method_size(size); set_intrinsic_id(vmIntrinsics::_none); set_jfr_towrite(false); set_force_inline(false); set_hidden(false); set_dont_inline(false); set_has_injected_profile(false); set_running_emcp(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); clear_code(false /* don't need a lock */); // 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) { clear_jmethod_id(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; } 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(); } 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; } int Method::fast_exception_handler_bci_for(methodHandle mh, KlassHandle 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.is_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)); KlassHandle klass = KlassHandle(THREAD, k); assert(klass.not_null(), "klass not loaded"); if (ex_klass->is_subtype_of(klass())) { return handler_bci; } } } } return -1; } void Method::mask_for(int bci, InterpreterOopMap* mask) { Thread* myThread = Thread::current(); methodHandle h_this(myThread, this); #ifdef ASSERT bool has_capability = myThread->is_VM_thread() || myThread->is_ConcurrentGC_thread() || myThread->is_GC_task_thread(); if (!has_capability) { if (!VerifyStack && !VerifyLastFrame) { // verify stack calls this outside VM thread warning("oopmap should only be accessed by the " "VM, GC task or CMS threads (or during debugging)"); InterpreterOopMap local_mask; method_holder()->mask_for(h_this, bci, &local_mask); local_mask.print(); } } #endif method_holder()->mask_for(h_this, bci, mask); return; } int Method::bci_from(address bcp) const { #ifdef ASSERT { ResourceMark rm; assert(is_native() && bcp == code_base() || contains(bcp) || is_error_reported(), err_msg("bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s", bcp, name_and_sig_as_C_string())); } #endif return bcp - code_base(); } // Return (int)bcx if it appears to be a valid BCI. // Return bci_from((address)bcx) 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_bcx(intptr_t bcx) const { // keep bci as -1 if not a valid bci int bci = -1; if (bcx == 0 || (address)bcx == code_base()) { // code_size() may return 0 and we allow 0 here // the method may be native bci = 0; } else if (frame::is_bci(bcx)) { if (bcx < code_size()) { bci = (int)bcx; } } else if (contains((address)bcx)) { bci = (address)bcx - 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()), err_msg("illegal bci: %d", bci)); address bcp = code_base() + bci; assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method"); 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_size_up(extra_bytes, BytesPerWord) / BytesPerWord; return align_object_size(header_size() + extra_words); } Symbol* Method::klass_name() const { Klass* k = method_holder(); assert(k->is_klass(), "must be klass"); InstanceKlass* ik = (InstanceKlass*) k; return ik->name(); } // 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(), ""); } 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; } } #ifndef PRODUCT 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 "); method_holder()->name()->print_symbol_on(tty); tty->print("."); 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()); 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(methodHandle method, TRAPS) { // Do not profile method if current thread holds the pending list lock, // which avoids deadlock for acquiring the MethodData_lock. if (InstanceRefKlass::owns_pending_list_lock((JavaThread*)THREAD)) { 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, CHECK); 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) { methodHandle mh(m); ClassLoaderData* loader_data = mh->method_holder()->class_loader_data(); MethodCounters* counters = MethodCounters::allocate(loader_data, CHECK_NULL); if (!mh->init_method_counters(counters)) { MetadataFactory::free_metadata(loader_data, counters); } return mh->method_counters(); } void Method::cleanup_inline_caches() { // The current system doesn't use inline caches in the interpreter // => nothing to do (keep this method around for future use) } 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)); } BasicType Method::result_type() const { ResultTypeFinder rtf(signature()); return rtf.type(); } 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 "" "()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(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; } } _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 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()) { 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(), err_msg("is_nonv=%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::is_accessor() 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; if (java_code_at(4) != Bytecodes::_areturn && java_code_at(4) != Bytecodes::_ireturn ) 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 "" 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(); } objArrayHandle Method::resolved_checked_exceptions_impl(Method* this_oop, TRAPS) { int length = this_oop->checked_exceptions_length(); if (length == 0) { // common case return objArrayHandle(THREAD, Universe::the_empty_class_klass_array()); } else { methodHandle h_this(THREAD, this_oop); 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 { if (bci == SynchronizationEntryBCI) bci = 0; assert(bci == 0 || 0 <= bci && bci < code_size(), "illegal bci"); int best_bci = 0; int best_line = -1; if (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. nmethod* 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); clear_code(); } address Method::critical_native_function() { methodHandle mh(this); return NativeLookup::lookup_critical_entry(mh); } 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) { 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("levels "); for (int i = (int)CompLevel_none; i <= comp_level; i++) { tty->print("%d ", i); } } 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(int comp_level, bool report, const char* reason) { 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(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(int comp_level, bool report, const char* reason) { 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(this, comp_level), "sanity check"); } // Revert to using the interpreter and clear out the nmethod void Method::clear_code(bool acquire_lock /* = true */) { MutexLockerEx pl(acquire_lock ? Patching_lock : NULL, Mutex::_no_safepoint_check_flag); // 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; } // Called by class data sharing to remove any entry points (which are not shared) void Method::unlink_method() { _code = NULL; _i2i_entry = NULL; _from_interpreted_entry = NULL; if (is_native()) { *native_function_addr() = NULL; set_signature_handler(NULL); } NOT_PRODUCT(set_compiled_invocation_count(0);) _adapter = NULL; _from_compiled_entry = NULL; // In case of DumpSharedSpaces, _method_data should always be NULL. // // During runtime (!DumpSharedSpaces), when we are cleaning a // shared class that failed to load, this->link_method() may // have already been called (before an exception happened), so // this->_method_data may not be NULL. assert(!DumpSharedSpaces || _method_data == NULL, "unexpected method data?"); set_method_data(NULL); clear_method_counters(); } // 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(methodHandle h_method, TRAPS) { // If the code cache is full, we may reenter this function for the // leftover methods that weren't linked. if (_i2i_entry != NULL) return; assert(_adapter == NULL, "init'd to NULL" ); assert( _code == NULL, "nothing compiled yet" ); // Setup interpreter entrypoint assert(this == h_method(), "wrong h_method()" ); 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(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 ) { THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "out of space in CodeCache for adapters"); } mh->set_adapter_entry(adapter); mh->_from_compiled_entry = adapter->get_c2i_entry(); return adapter->get_c2i_entry(); } void Method::restore_unshareable_info(TRAPS) { // Since restore_unshareable_info can be called more than once for a method, don't // redo any work. If this field is restored, there is nothing to do. if (_from_compiled_entry == NULL) { // restore method's vtable by calling a virtual function restore_vtable(); methodHandle mh(THREAD, this); link_method(mh, CHECK); } } // 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(No_Safepoint_Verifier 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. nmethod *code = (nmethod *)OrderAccess::load_ptr_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(methodHandle mh, nmethod *code) { MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag); 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(); #ifdef SHARK mh->_from_interpreted_entry = code->insts_begin(); #else //!SHARK 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(); #endif //!SHARK } 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"); assert(ik->vtable() != NULL, "vtable should exist"); 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 { const bool use_new_reflection = JDK_Version::is_gte_jdk14x_version() && UseNewReflection; if (intrinsic_id() == vmIntrinsics::_invoke) { // This is Method.invoke() -- ignore it return true; } if (use_new_reflection && 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; methodHandle empty; KlassHandle 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(InstanceKlass::cast(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)) m->print_on(tty); return m; } Klass* Method::check_non_bcp_klass(Klass* klass) { if (klass != NULL && klass->class_loader() != NULL) { if (klass->oop_is_objArray()) klass = ObjArrayKlass::cast(klass)->bottom_klass(); return klass; } return NULL; } methodHandle Method::clone_with_new_data(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); int new_method_size = newm->method_size(); // 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(); memcpy(newm(), 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); newm->set_method_size(new_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* stackmap_data = MetadataFactory::new_array(loader_data, code_attribute_length, 0, CHECK_NULL); 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(cm); return newm; } vmSymbols::SID Method::klass_id_for_intrinsics(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 InstanceKlass* ik = InstanceKlass::cast(holder); if ((ik->class_loader() != NULL) && !SystemDictionary::is_ext_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) && 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) && 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); 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; } break; // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*. case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle): 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; } 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(methodHandle m, TRAPS) { if (THREAD->is_Compiler_thread()) { // 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(CHECK_(false)); 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(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* methods, bool idempotent, bool set_idnums) { int length = methods->length(); if (length > 1) { { No_Safepoint_Verifier nsv; QuickSort::sort(methods->data(), length, method_comparator, idempotent); } // 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); SignatureTypePrinter sig(signature(), st); st->print("%s ", is_static() ? "static" : "virtual"); 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 //----------------------------------------------------------------------------------- // Non-product code #ifndef PRODUCT 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); } #endif // not PRODUCT // Simple compression of line number tables. We use a regular compressed stream, except that we compress deltas // between (bci,line) pairs since they are smaller. If (bci delta, line delta) fits in (5-bit unsigned, 3-bit unsigned) // we save it as one byte, otherwise we write a 0xFF escape character and use regular compression. 0x0 is used // as end-of-stream terminator. void CompressedLineNumberWriteStream::write_pair_regular(int bci_delta, int line_delta) { // bci and line number does not compress into single byte. // Write out escape character and use regular compression for bci and line number. write_byte((jubyte)0xFF); write_signed_int(bci_delta); write_signed_int(line_delta); } // See comment in method.hpp which explains why this exists. #if defined(_M_AMD64) && _MSC_VER >= 1400 #pragma optimize("", off) void CompressedLineNumberWriteStream::write_pair(int bci, int line) { write_pair_inline(bci, line); } #pragma optimize("", on) #endif 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; } 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(err_msg("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); } 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); } } 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); SystemDictionary::notice_modification(); { // Deoptimize all dependents on this method HandleMark hm(thread); methodHandle mh(thread, method); Universe::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()); } // jmethodID handling // This is a block allocating object, sort of like JNIHandleBlock, only a // lot simpler. There aren't many of these, they aren't long, they are rarely // deleted and so we can do some suboptimal things. // It's allocated on the CHeap because once we allocate a jmethodID, we can // never get rid of it. // It would be nice to be able to parameterize the number of methods for // the null_class_loader but then we'd have to turn this and ClassLoaderData // into templates. // I feel like this brain dead class should exist somewhere in the STL class JNIMethodBlock : public CHeapObj { enum { number_of_methods = 8 }; Method* _methods[number_of_methods]; int _top; JNIMethodBlock* _next; public: static Method* const _free_method; JNIMethodBlock() : _next(NULL), _top(0) { for (int i = 0; i< number_of_methods; i++) _methods[i] = _free_method; } Method** add_method(Method* m) { if (_top < number_of_methods) { // top points to the next free entry. int i = _top; _methods[i] = m; _top++; return &_methods[i]; } else if (_top == number_of_methods) { // if the next free entry ran off the block see if there's a free entry for (int i = 0; i< number_of_methods; i++) { if (_methods[i] == _free_method) { _methods[i] = m; return &_methods[i]; } } // Only check each block once for frees. They're very unlikely. // Increment top past the end of the block. _top++; } // need to allocate a next block. if (_next == NULL) { _next = new JNIMethodBlock(); } return _next->add_method(m); } bool contains(Method** m) { for (JNIMethodBlock* b = this; b != NULL; b = b->_next) { for (int i = 0; i< number_of_methods; i++) { if (&(b->_methods[i]) == 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; } void clear_method(Method* m) { for (JNIMethodBlock* b = this; b != NULL; b = b->_next) { for (int i = 0; i < number_of_methods; i++) { if (b->_methods[i] == m) { b->_methods[i] = NULL; return; } } } // not found } // During class unloading the methods are cleared, which is different // than freed. void clear_all_methods() { for (JNIMethodBlock* b = this; b != NULL; b = b->_next) { for (int i = 0; i< number_of_methods; i++) { b->_methods[i] = NULL; } } } #ifndef PRODUCT int count_methods() { // count all allocated methods int count = 0; for (JNIMethodBlock* b = this; b != NULL; b = b->_next) { for (int i = 0; i< 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 markOop Method* const JNIMethodBlock::_free_method = (Method*)55; // 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. MutexLockerEx 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); } } // 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(), "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); if (m == NULL) { return false; } InstanceKlass* ik = m->method_holder(); if (ik == NULL) { return false; } 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; if (!Method::is_method_id(mid)) { 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 succeeded = _access_flags.set_on_stack(value); if (value && succeeded) { MetadataOnStackMark::record(this, Thread::current()); } } void Method::clear_jmethod_id(ClassLoaderData* loader_data) { loader_data->jmethod_ids()->clear_method(this); } // Called when the class loader is unloaded to make all methods weak. void Method::clear_jmethod_ids(ClassLoaderData* loader_data) { loader_data->jmethod_ids()->clear_all_methods(); } bool Method::has_method_vptr(const void* ptr) { Method m; // This assumes that the vtbl pointer is the first word of a C++ object. // This assumption is also in universe.cpp patch_klass_vtble void* vtbl2 = dereference_vptr((const void*)&m); void* this_vtbl = dereference_vptr(ptr); return vtbl2 == this_vtbl; } // Check that this pointer is valid by checking that the vtbl pointer matches bool Method::is_valid_method() const { if (this == NULL) { return false; } else if (!is_metaspace_object()) { return false; } else { return has_method_vptr((const void*)this); } } #ifndef PRODUCT void Method::print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) { out->print_cr("jni_method_id count = %d", loader_data->jmethod_ids()->count_methods()); } #endif // PRODUCT // Printing #ifndef PRODUCT void Method::print_on(outputStream* st) const { ResourceMark rm; assert(is_method(), "must be method"); st->print_cr("%s", internal_name()); // get the effect of PrintOopAddress, always, for methods: st->print_cr(" - this oop: "INTPTR_FORMAT, (intptr_t)this); st->print (" - method holder: "); method_holder()->print_value_on(st); st->cr(); st->print (" - constants: "INTPTR_FORMAT" ", (address)constants()); constants()->print_value_on(st); st->cr(); st->print (" - access: 0x%x ", access_flags().as_int()); access_flags().print_on(st); st->cr(); st->print (" - name: "); name()->print_value_on(st); st->cr(); st->print (" - signature: "); signature()->print_value_on(st); st->cr(); st->print_cr(" - max stack: %d", max_stack()); st->print_cr(" - max locals: %d", max_locals()); st->print_cr(" - size of params: %d", size_of_parameters()); st->print_cr(" - method size: %d", method_size()); if (intrinsic_id() != vmIntrinsics::_none) st->print_cr(" - intrinsic id: %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id())); if (highest_comp_level() != CompLevel_none) st->print_cr(" - highest level: %d", highest_comp_level()); st->print_cr(" - vtable index: %d", _vtable_index); st->print_cr(" - i2i entry: " INTPTR_FORMAT, interpreter_entry()); st->print( " - adapters: "); AdapterHandlerEntry* a = ((Method*)this)->adapter(); if (a == NULL) st->print_cr(INTPTR_FORMAT, a); else a->print_adapter_on(st); st->print_cr(" - compiled entry " INTPTR_FORMAT, from_compiled_entry()); st->print_cr(" - code size: %d", code_size()); if (code_size() != 0) { st->print_cr(" - code start: " INTPTR_FORMAT, code_base()); st->print_cr(" - code end (excl): " INTPTR_FORMAT, code_base() + code_size()); } if (method_data() != NULL) { st->print_cr(" - method data: " INTPTR_FORMAT, (address)method_data()); } st->print_cr(" - checked ex length: %d", checked_exceptions_length()); if (checked_exceptions_length() > 0) { CheckedExceptionElement* table = checked_exceptions_start(); st->print_cr(" - checked ex start: " INTPTR_FORMAT, table); if (Verbose) { for (int i = 0; i < checked_exceptions_length(); i++) { st->print_cr(" - throws %s", constants()->printable_name_at(table[i].class_cp_index)); } } } if (has_linenumber_table()) { u_char* table = compressed_linenumber_table(); st->print_cr(" - linenumber start: " INTPTR_FORMAT, table); if (Verbose) { CompressedLineNumberReadStream stream(table); while (stream.read_pair()) { st->print_cr(" - line %d: %d", stream.line(), stream.bci()); } } } st->print_cr(" - localvar length: %d", localvariable_table_length()); if (localvariable_table_length() > 0) { LocalVariableTableElement* table = localvariable_table_start(); st->print_cr(" - localvar start: " INTPTR_FORMAT, table); if (Verbose) { for (int i = 0; i < localvariable_table_length(); i++) { int bci = table[i].start_bci; int len = table[i].length; const char* name = constants()->printable_name_at(table[i].name_cp_index); const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index); int slot = table[i].slot; st->print_cr(" - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot); } } } if (code() != NULL) { st->print (" - compiled code: "); code()->print_value_on(st); } if (is_native()) { st->print_cr(" - native function: " INTPTR_FORMAT, native_function()); st->print_cr(" - signature handler: " INTPTR_FORMAT, signature_handler()); } } #endif //PRODUCT void Method::print_value_on(outputStream* st) const { assert(is_method(), "must be method"); st->print("%s", internal_name()); print_address_on(st); st->print(" "); name()->print_value_on(st); st->print(" "); signature()->print_value_on(st); st->print(" in "); method_holder()->print_value_on(st); if (WizardMode) st->print("#%d", _vtable_index); if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals()); if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code()); } #if INCLUDE_SERVICES // Size Statistics void Method::collect_statistics(KlassSizeStats *sz) const { int mysize = sz->count(this); sz->_method_bytes += mysize; sz->_method_all_bytes += mysize; sz->_rw_bytes += mysize; if (constMethod()) { constMethod()->collect_statistics(sz); } if (method_data()) { method_data()->collect_statistics(sz); } } #endif // INCLUDE_SERVICES // Verification void Method::verify_on(outputStream* st) { guarantee(is_method(), "object must be method"); guarantee(constants()->is_constantPool(), "should be constant pool"); guarantee(constMethod()->is_constMethod(), "should be ConstMethod*"); MethodData* md = method_data(); guarantee(md == NULL || md->is_methodData(), "should be method data"); }