/* * Copyright (c) 1997, 2014, 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/systemDictionary.hpp" #include "code/codeCache.hpp" #include "code/compiledIC.hpp" #include "code/icBuffer.hpp" #include "code/nmethod.hpp" #include "code/vtableStubs.hpp" #include "interpreter/interpreter.hpp" #include "interpreter/linkResolver.hpp" #include "memory/metadataFactory.hpp" #include "memory/oopFactory.hpp" #include "oops/method.hpp" #include "oops/oop.inline.hpp" #include "oops/symbol.hpp" #include "runtime/icache.hpp" #include "runtime/sharedRuntime.hpp" #include "runtime/stubRoutines.hpp" #include "utilities/events.hpp" // Every time a compiled IC is changed or its type is being accessed, // either the CompiledIC_lock must be set or we must be at a safe point. //----------------------------------------------------------------------------- // Low-level access to an inline cache. Private, since they might not be // MT-safe to use. void* CompiledIC::cached_value() const { assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), ""); assert (!is_optimized(), "an optimized virtual call does not have a cached metadata"); if (!is_in_transition_state()) { void* data = (void*)_value->data(); // If we let the metadata value here be initialized to zero... assert(data != NULL || Universe::non_oop_word() == NULL, "no raw nulls in CompiledIC metadatas, because of patching races"); return (data == (void*)Universe::non_oop_word()) ? NULL : data; } else { return InlineCacheBuffer::cached_value_for((CompiledIC *)this); } } void CompiledIC::internal_set_ic_destination(address entry_point, bool is_icstub, void* cache, bool is_icholder) { assert(entry_point != NULL, "must set legal entry point"); assert(CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), ""); assert (!is_optimized() || cache == NULL, "an optimized virtual call does not have a cached metadata"); assert (cache == NULL || cache != (Metadata*)badOopVal, "invalid metadata"); assert(!is_icholder || is_icholder_entry(entry_point), "must be"); // Don't use ic_destination for this test since that forwards // through ICBuffer instead of returning the actual current state of // the CompiledIC. if (is_icholder_entry(_ic_call->destination())) { // When patching for the ICStub case the cached value isn't // overwritten until the ICStub copied into the CompiledIC during // the next safepoint. Make sure that the CompiledICHolder* is // marked for release at this point since it won't be identifiable // once the entry point is overwritten. InlineCacheBuffer::queue_for_release((CompiledICHolder*)_value->data()); } if (TraceCompiledIC) { tty->print(" "); print_compiled_ic(); tty->print(" changing destination to " INTPTR_FORMAT, p2i(entry_point)); if (!is_optimized()) { tty->print(" changing cached %s to " INTPTR_FORMAT, is_icholder ? "icholder" : "metadata", p2i((address)cache)); } if (is_icstub) { tty->print(" (icstub)"); } tty->cr(); } { MutexLockerEx pl(SafepointSynchronize::is_at_safepoint() ? NULL : Patching_lock, Mutex::_no_safepoint_check_flag); #ifdef ASSERT CodeBlob* cb = CodeCache::find_blob_unsafe(_ic_call); assert(cb != NULL && cb->is_nmethod(), "must be nmethod"); #endif _ic_call->set_destination_mt_safe(entry_point); } if (is_optimized() || is_icstub) { // Optimized call sites don't have a cache value and ICStub call // sites only change the entry point. Changing the value in that // case could lead to MT safety issues. assert(cache == NULL, "must be null"); return; } if (cache == NULL) cache = (void*)Universe::non_oop_word(); _value->set_data((intptr_t)cache); } void CompiledIC::set_ic_destination(ICStub* stub) { internal_set_ic_destination(stub->code_begin(), true, NULL, false); } address CompiledIC::ic_destination() const { assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), ""); if (!is_in_transition_state()) { return _ic_call->destination(); } else { return InlineCacheBuffer::ic_destination_for((CompiledIC *)this); } } bool CompiledIC::is_in_transition_state() const { assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), ""); return InlineCacheBuffer::contains(_ic_call->destination()); } bool CompiledIC::is_icholder_call() const { assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), ""); return !_is_optimized && is_icholder_entry(ic_destination()); } // Returns native address of 'call' instruction in inline-cache. Used by // the InlineCacheBuffer when it needs to find the stub. address CompiledIC::stub_address() const { assert(is_in_transition_state(), "should only be called when we are in a transition state"); return _ic_call->destination(); } // Clears the IC stub if the compiled IC is in transition state void CompiledIC::clear_ic_stub() { if (is_in_transition_state()) { ICStub* stub = ICStub_from_destination_address(stub_address()); stub->clear(); } } //----------------------------------------------------------------------------- // High-level access to an inline cache. Guaranteed to be MT-safe. void CompiledIC::initialize_from_iter(RelocIterator* iter) { assert(iter->addr() == _ic_call->instruction_address(), "must find ic_call"); if (iter->type() == relocInfo::virtual_call_type) { virtual_call_Relocation* r = iter->virtual_call_reloc(); _is_optimized = false; _value = nativeMovConstReg_at(r->cached_value()); } else { assert(iter->type() == relocInfo::opt_virtual_call_type, "must be a virtual call"); _is_optimized = true; _value = NULL; } } CompiledIC::CompiledIC(nmethod* nm, NativeCall* call) : _ic_call(call) { address ic_call = _ic_call->instruction_address(); assert(ic_call != NULL, "ic_call address must be set"); assert(nm != NULL, "must pass nmethod"); assert(nm->contains(ic_call), "must be in nmethod"); // Search for the ic_call at the given address. RelocIterator iter(nm, ic_call, ic_call+1); bool ret = iter.next(); assert(ret == true, "relocInfo must exist at this address"); assert(iter.addr() == ic_call, "must find ic_call"); initialize_from_iter(&iter); } CompiledIC::CompiledIC(RelocIterator* iter) : _ic_call(nativeCall_at(iter->addr())) { address ic_call = _ic_call->instruction_address(); nmethod* nm = iter->code(); assert(ic_call != NULL, "ic_call address must be set"); assert(nm != NULL, "must pass nmethod"); assert(nm->contains(ic_call), "must be in nmethod"); initialize_from_iter(iter); } bool CompiledIC::set_to_megamorphic(CallInfo* call_info, Bytecodes::Code bytecode, TRAPS) { assert(CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), ""); assert(!is_optimized(), "cannot set an optimized virtual call to megamorphic"); assert(is_call_to_compiled() || is_call_to_interpreted(), "going directly to megamorphic?"); address entry; if (call_info->call_kind() == CallInfo::itable_call) { assert(bytecode == Bytecodes::_invokeinterface, ""); int itable_index = call_info->itable_index(); entry = VtableStubs::find_itable_stub(itable_index); if (entry == false) { return false; } #ifdef ASSERT int index = call_info->resolved_method()->itable_index(); assert(index == itable_index, "CallInfo pre-computes this"); #endif //ASSERT InstanceKlass* k = call_info->resolved_method()->method_holder(); assert(k->verify_itable_index(itable_index), "sanity check"); InlineCacheBuffer::create_transition_stub(this, k, entry); } else { assert(call_info->call_kind() == CallInfo::vtable_call, "either itable or vtable"); // Can be different than selected_method->vtable_index(), due to package-private etc. int vtable_index = call_info->vtable_index(); assert(call_info->resolved_klass()->verify_vtable_index(vtable_index), "sanity check"); entry = VtableStubs::find_vtable_stub(vtable_index); if (entry == NULL) { return false; } InlineCacheBuffer::create_transition_stub(this, NULL, entry); } if (TraceICs) { ResourceMark rm; tty->print_cr ("IC@" INTPTR_FORMAT ": to megamorphic %s entry: " INTPTR_FORMAT, p2i(instruction_address()), call_info->selected_method()->print_value_string(), p2i(entry)); } // We can't check this anymore. With lazy deopt we could have already // cleaned this IC entry before we even return. This is possible if // we ran out of space in the inline cache buffer trying to do the // set_next and we safepointed to free up space. This is a benign // race because the IC entry was complete when we safepointed so // cleaning it immediately is harmless. // assert(is_megamorphic(), "sanity check"); return true; } // true if destination is megamorphic stub bool CompiledIC::is_megamorphic() const { assert(CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), ""); assert(!is_optimized(), "an optimized call cannot be megamorphic"); // Cannot rely on cached_value. It is either an interface or a method. return VtableStubs::is_entry_point(ic_destination()); } bool CompiledIC::is_call_to_compiled() const { assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), ""); // Use unsafe, since an inline cache might point to a zombie method. However, the zombie // method is guaranteed to still exist, since we only remove methods after all inline caches // has been cleaned up CodeBlob* cb = CodeCache::find_blob_unsafe(ic_destination()); bool is_monomorphic = (cb != NULL && cb->is_nmethod()); // Check that the cached_value is a klass for non-optimized monomorphic calls // This assertion is invalid for compiler1: a call that does not look optimized (no static stub) can be used // for calling directly to vep without using the inline cache (i.e., cached_value == NULL) #ifdef ASSERT CodeBlob* caller = CodeCache::find_blob_unsafe(instruction_address()); bool is_c1_method = caller->is_compiled_by_c1(); assert( is_c1_method || !is_monomorphic || is_optimized() || !caller->is_alive() || (cached_metadata() != NULL && cached_metadata()->is_klass()), "sanity check"); #endif // ASSERT return is_monomorphic; } bool CompiledIC::is_call_to_interpreted() const { assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), ""); // Call to interpreter if destination is either calling to a stub (if it // is optimized), or calling to an I2C blob bool is_call_to_interpreted = false; if (!is_optimized()) { // must use unsafe because the destination can be a zombie (and we're cleaning) // and the print_compiled_ic code wants to know if site (in the non-zombie) // is to the interpreter. CodeBlob* cb = CodeCache::find_blob_unsafe(ic_destination()); is_call_to_interpreted = (cb != NULL && cb->is_adapter_blob()); assert(!is_call_to_interpreted || (is_icholder_call() && cached_icholder() != NULL), "sanity check"); } else { // Check if we are calling into our own codeblob (i.e., to a stub) CodeBlob* cb = CodeCache::find_blob(_ic_call->instruction_address()); address dest = ic_destination(); #ifdef ASSERT { CodeBlob* db = CodeCache::find_blob_unsafe(dest); assert(!db->is_adapter_blob(), "must use stub!"); } #endif /* ASSERT */ is_call_to_interpreted = cb->contains(dest); } return is_call_to_interpreted; } void CompiledIC::set_to_clean(bool in_use) { assert(SafepointSynchronize::is_at_safepoint() || CompiledIC_lock->is_locked() , "MT-unsafe call"); if (TraceInlineCacheClearing || TraceICs) { tty->print_cr("IC@" INTPTR_FORMAT ": set to clean", p2i(instruction_address())); print(); } address entry; if (is_optimized()) { entry = SharedRuntime::get_resolve_opt_virtual_call_stub(); } else { entry = SharedRuntime::get_resolve_virtual_call_stub(); } // A zombie transition will always be safe, since the metadata has already been set to NULL, so // we only need to patch the destination bool safe_transition = !in_use || is_optimized() || SafepointSynchronize::is_at_safepoint(); if (safe_transition) { // Kill any leftover stub we might have too clear_ic_stub(); if (is_optimized()) { set_ic_destination(entry); } else { set_ic_destination_and_value(entry, (void*)NULL); } } else { // Unsafe transition - create stub. InlineCacheBuffer::create_transition_stub(this, NULL, entry); } // We can't check this anymore. With lazy deopt we could have already // cleaned this IC entry before we even return. This is possible if // we ran out of space in the inline cache buffer trying to do the // set_next and we safepointed to free up space. This is a benign // race because the IC entry was complete when we safepointed so // cleaning it immediately is harmless. // assert(is_clean(), "sanity check"); } bool CompiledIC::is_clean() const { assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), ""); bool is_clean = false; address dest = ic_destination(); is_clean = dest == SharedRuntime::get_resolve_opt_virtual_call_stub() || dest == SharedRuntime::get_resolve_virtual_call_stub(); assert(!is_clean || is_optimized() || cached_value() == NULL, "sanity check"); return is_clean; } void CompiledIC::set_to_monomorphic(CompiledICInfo& info) { assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), ""); // Updating a cache to the wrong entry can cause bugs that are very hard // to track down - if cache entry gets invalid - we just clean it. In // this way it is always the same code path that is responsible for // updating and resolving an inline cache // // The above is no longer true. SharedRuntime::fixup_callers_callsite will change optimized // callsites. In addition ic_miss code will update a site to monomorphic if it determines // that an monomorphic call to the interpreter can now be monomorphic to compiled code. // // In both of these cases the only thing being modifed is the jump/call target and these // transitions are mt_safe Thread *thread = Thread::current(); if (info.to_interpreter()) { // Call to interpreter if (info.is_optimized() && is_optimized()) { assert(is_clean(), "unsafe IC path"); MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag); // the call analysis (callee structure) specifies that the call is optimized // (either because of CHA or the static target is final) // At code generation time, this call has been emitted as static call // Call via stub assert(info.cached_metadata() != NULL && info.cached_metadata()->is_method(), "sanity check"); CompiledStaticCall* csc = compiledStaticCall_at(instruction_address()); methodHandle method (thread, (Method*)info.cached_metadata()); csc->set_to_interpreted(method, info.entry()); if (TraceICs) { ResourceMark rm(thread); tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to interpreter: %s", p2i(instruction_address()), method->print_value_string()); } } else { // Call via method-klass-holder InlineCacheBuffer::create_transition_stub(this, info.claim_cached_icholder(), info.entry()); if (TraceICs) { ResourceMark rm(thread); tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to interpreter via icholder ", p2i(instruction_address())); } } } else { // Call to compiled code bool static_bound = info.is_optimized() || (info.cached_metadata() == NULL); #ifdef ASSERT CodeBlob* cb = CodeCache::find_blob_unsafe(info.entry()); assert (cb->is_nmethod(), "must be compiled!"); #endif /* ASSERT */ // This is MT safe if we come from a clean-cache and go through a // non-verified entry point bool safe = SafepointSynchronize::is_at_safepoint() || (!is_in_transition_state() && (info.is_optimized() || static_bound || is_clean())); if (!safe) { InlineCacheBuffer::create_transition_stub(this, info.cached_metadata(), info.entry()); } else { if (is_optimized()) { set_ic_destination(info.entry()); } else { set_ic_destination_and_value(info.entry(), info.cached_metadata()); } } if (TraceICs) { ResourceMark rm(thread); assert(info.cached_metadata() == NULL || info.cached_metadata()->is_klass(), "must be"); tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to compiled (rcvr klass) %s: %s", p2i(instruction_address()), ((Klass*)info.cached_metadata())->print_value_string(), (safe) ? "" : "via stub"); } } // We can't check this anymore. With lazy deopt we could have already // cleaned this IC entry before we even return. This is possible if // we ran out of space in the inline cache buffer trying to do the // set_next and we safepointed to free up space. This is a benign // race because the IC entry was complete when we safepointed so // cleaning it immediately is harmless. // assert(is_call_to_compiled() || is_call_to_interpreted(), "sanity check"); } // is_optimized: Compiler has generated an optimized call (i.e., no inline // cache) static_bound: The call can be static bound (i.e, no need to use // inline cache) void CompiledIC::compute_monomorphic_entry(methodHandle method, KlassHandle receiver_klass, bool is_optimized, bool static_bound, CompiledICInfo& info, TRAPS) { nmethod* method_code = method->code(); address entry = NULL; if (method_code != NULL && method_code->is_in_use()) { // Call to compiled code if (static_bound || is_optimized) { entry = method_code->verified_entry_point(); } else { entry = method_code->entry_point(); } } if (entry != NULL) { // Call to compiled code info.set_compiled_entry(entry, (static_bound || is_optimized) ? NULL : receiver_klass(), is_optimized); } else { // Note: the following problem exists with Compiler1: // - at compile time we may or may not know if the destination is final // - if we know that the destination is final, we will emit an optimized // virtual call (no inline cache), and need a Method* to make a call // to the interpreter // - if we do not know if the destination is final, we emit a standard // virtual call, and use CompiledICHolder to call interpreted code // (no static call stub has been generated) // However in that case we will now notice it is static_bound // and convert the call into what looks to be an optimized // virtual call. This causes problems in verifying the IC because // it look vanilla but is optimized. Code in is_call_to_interpreted // is aware of this and weakens its asserts. // static_bound should imply is_optimized -- otherwise we have a // performance bug (statically-bindable method is called via // dynamically-dispatched call note: the reverse implication isn't // necessarily true -- the call may have been optimized based on compiler // analysis (static_bound is only based on "final" etc.) #ifdef COMPILER2 #ifdef TIERED #if defined(ASSERT) // can't check the assert because we don't have the CompiledIC with which to // find the address if the call instruction. // // CodeBlob* cb = find_blob_unsafe(instruction_address()); // assert(cb->is_compiled_by_c1() || !static_bound || is_optimized, "static_bound should imply is_optimized"); #endif // ASSERT #else assert(!static_bound || is_optimized, "static_bound should imply is_optimized"); #endif // TIERED #endif // COMPILER2 if (is_optimized) { // Use stub entry info.set_interpreter_entry(method()->get_c2i_entry(), method()); } else { // Use icholder entry CompiledICHolder* holder = new CompiledICHolder(method(), receiver_klass()); info.set_icholder_entry(method()->get_c2i_unverified_entry(), holder); } } assert(info.is_optimized() == is_optimized, "must agree"); } bool CompiledIC::is_icholder_entry(address entry) { CodeBlob* cb = CodeCache::find_blob_unsafe(entry); return (cb != NULL && cb->is_adapter_blob()); } // ---------------------------------------------------------------------------- void CompiledStaticCall::set_to_clean() { assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call"); // Reset call site MutexLockerEx pl(SafepointSynchronize::is_at_safepoint() ? NULL : Patching_lock, Mutex::_no_safepoint_check_flag); #ifdef ASSERT CodeBlob* cb = CodeCache::find_blob_unsafe(this); assert(cb != NULL && cb->is_nmethod(), "must be nmethod"); #endif set_destination_mt_safe(SharedRuntime::get_resolve_static_call_stub()); // Do not reset stub here: It is too expensive to call find_stub. // Instead, rely on caller (nmethod::clear_inline_caches) to clear // both the call and its stub. } bool CompiledStaticCall::is_clean() const { return destination() == SharedRuntime::get_resolve_static_call_stub(); } bool CompiledStaticCall::is_call_to_compiled() const { return CodeCache::contains(destination()); } bool CompiledStaticCall::is_call_to_interpreted() const { // It is a call to interpreted, if it calls to a stub. Hence, the destination // must be in the stub part of the nmethod that contains the call nmethod* nm = CodeCache::find_nmethod(instruction_address()); return nm->stub_contains(destination()); } void CompiledStaticCall::set(const StaticCallInfo& info) { assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call"); MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag); // Updating a cache to the wrong entry can cause bugs that are very hard // to track down - if cache entry gets invalid - we just clean it. In // this way it is always the same code path that is responsible for // updating and resolving an inline cache assert(is_clean(), "do not update a call entry - use clean"); if (info._to_interpreter) { // Call to interpreted code set_to_interpreted(info.callee(), info.entry()); } else { if (TraceICs) { ResourceMark rm; tty->print_cr("CompiledStaticCall@" INTPTR_FORMAT ": set_to_compiled " INTPTR_FORMAT, p2i(instruction_address()), p2i(info.entry())); } // Call to compiled code assert (CodeCache::contains(info.entry()), "wrong entry point"); set_destination_mt_safe(info.entry()); } } // Compute settings for a CompiledStaticCall. Since we might have to set // the stub when calling to the interpreter, we need to return arguments. void CompiledStaticCall::compute_entry(methodHandle m, StaticCallInfo& info) { nmethod* m_code = m->code(); info._callee = m; if (m_code != NULL && m_code->is_in_use()) { info._to_interpreter = false; info._entry = m_code->verified_entry_point(); } else { // Callee is interpreted code. In any case entering the interpreter // puts a converter-frame on the stack to save arguments. assert(!m->is_method_handle_intrinsic(), "Compiled code should never call interpreter MH intrinsics"); info._to_interpreter = true; info._entry = m()->get_c2i_entry(); } } address CompiledStaticCall::find_stub() { // Find reloc. information containing this call-site RelocIterator iter((nmethod*)NULL, instruction_address()); while (iter.next()) { if (iter.addr() == instruction_address()) { switch(iter.type()) { case relocInfo::static_call_type: return iter.static_call_reloc()->static_stub(); // We check here for opt_virtual_call_type, since we reuse the code // from the CompiledIC implementation case relocInfo::opt_virtual_call_type: return iter.opt_virtual_call_reloc()->static_stub(); case relocInfo::poll_type: case relocInfo::poll_return_type: // A safepoint can't overlap a call. default: ShouldNotReachHere(); } } } return NULL; } //----------------------------------------------------------------------------- // Non-product mode code #ifndef PRODUCT void CompiledIC::verify() { // make sure code pattern is actually a call imm32 instruction _ic_call->verify(); if (os::is_MP()) { _ic_call->verify_alignment(); } assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted() || is_optimized() || is_megamorphic(), "sanity check"); } void CompiledIC::print() { print_compiled_ic(); tty->cr(); } void CompiledIC::print_compiled_ic() { tty->print("Inline cache at " INTPTR_FORMAT ", calling %s " INTPTR_FORMAT " cached_value " INTPTR_FORMAT, p2i(instruction_address()), is_call_to_interpreted() ? "interpreted " : "", p2i(ic_destination()), p2i(is_optimized() ? NULL : cached_value())); } void CompiledStaticCall::print() { tty->print("static call at " INTPTR_FORMAT " -> ", p2i(instruction_address())); if (is_clean()) { tty->print("clean"); } else if (is_call_to_compiled()) { tty->print("compiled"); } else if (is_call_to_interpreted()) { tty->print("interpreted"); } tty->cr(); } #endif // !PRODUCT