diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/hotspot/share/code/compiledMethod.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/hotspot/share/code/compiledMethod.cpp Tue Sep 12 19:03:39 2017 +0200 @@ -0,0 +1,701 @@ +/* + * Copyright (c) 2015, 2017, 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 "code/compiledIC.hpp" +#include "code/compiledMethod.inline.hpp" +#include "code/scopeDesc.hpp" +#include "code/codeCache.hpp" +#include "prims/methodHandles.hpp" +#include "interpreter/bytecode.hpp" +#include "memory/resourceArea.hpp" +#include "runtime/mutexLocker.hpp" + +CompiledMethod::CompiledMethod(Method* method, const char* name, CompilerType type, const CodeBlobLayout& layout, int frame_complete_offset, int frame_size, ImmutableOopMapSet* oop_maps, bool caller_must_gc_arguments) + : CodeBlob(name, type, layout, frame_complete_offset, frame_size, oop_maps, caller_must_gc_arguments), + _method(method), _mark_for_deoptimization_status(not_marked) { + init_defaults(); +} + +CompiledMethod::CompiledMethod(Method* method, const char* name, CompilerType type, int size, int header_size, CodeBuffer* cb, int frame_complete_offset, int frame_size, OopMapSet* oop_maps, bool caller_must_gc_arguments) + : CodeBlob(name, type, CodeBlobLayout((address) this, size, header_size, cb), cb, frame_complete_offset, frame_size, oop_maps, caller_must_gc_arguments), + _method(method), _mark_for_deoptimization_status(not_marked) { + init_defaults(); +} + +void CompiledMethod::init_defaults() { + _has_unsafe_access = 0; + _has_method_handle_invokes = 0; + _lazy_critical_native = 0; + _has_wide_vectors = 0; + _unloading_clock = 0; +} + +bool CompiledMethod::is_method_handle_return(address return_pc) { + if (!has_method_handle_invokes()) return false; + PcDesc* pd = pc_desc_at(return_pc); + if (pd == NULL) + return false; + return pd->is_method_handle_invoke(); +} + +// Returns a string version of the method state. +const char* CompiledMethod::state() const { + int state = get_state(); + switch (state) { + case in_use: + return "in use"; + case not_used: + return "not_used"; + case not_entrant: + return "not_entrant"; + case zombie: + return "zombie"; + case unloaded: + return "unloaded"; + default: + fatal("unexpected method state: %d", state); + return NULL; + } +} + +//----------------------------------------------------------------------------- + +void CompiledMethod::add_exception_cache_entry(ExceptionCache* new_entry) { + assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock"); + assert(new_entry != NULL,"Must be non null"); + assert(new_entry->next() == NULL, "Must be null"); + + ExceptionCache *ec = exception_cache(); + if (ec != NULL) { + new_entry->set_next(ec); + } + release_set_exception_cache(new_entry); +} + +void CompiledMethod::clean_exception_cache(BoolObjectClosure* is_alive) { + ExceptionCache* prev = NULL; + ExceptionCache* curr = exception_cache(); + + while (curr != NULL) { + ExceptionCache* next = curr->next(); + + Klass* ex_klass = curr->exception_type(); + if (ex_klass != NULL && !ex_klass->is_loader_alive(is_alive)) { + if (prev == NULL) { + set_exception_cache(next); + } else { + prev->set_next(next); + } + delete curr; + // prev stays the same. + } else { + prev = curr; + } + + curr = next; + } +} + +// public method for accessing the exception cache +// These are the public access methods. +address CompiledMethod::handler_for_exception_and_pc(Handle exception, address pc) { + // We never grab a lock to read the exception cache, so we may + // have false negatives. This is okay, as it can only happen during + // the first few exception lookups for a given nmethod. + ExceptionCache* ec = exception_cache(); + while (ec != NULL) { + address ret_val; + if ((ret_val = ec->match(exception,pc)) != NULL) { + return ret_val; + } + ec = ec->next(); + } + return NULL; +} + +void CompiledMethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) { + // There are potential race conditions during exception cache updates, so we + // must own the ExceptionCache_lock before doing ANY modifications. Because + // we don't lock during reads, it is possible to have several threads attempt + // to update the cache with the same data. We need to check for already inserted + // copies of the current data before adding it. + + MutexLocker ml(ExceptionCache_lock); + ExceptionCache* target_entry = exception_cache_entry_for_exception(exception); + + if (target_entry == NULL || !target_entry->add_address_and_handler(pc,handler)) { + target_entry = new ExceptionCache(exception,pc,handler); + add_exception_cache_entry(target_entry); + } +} + +//-------------end of code for ExceptionCache-------------- + +// private method for handling exception cache +// These methods are private, and used to manipulate the exception cache +// directly. +ExceptionCache* CompiledMethod::exception_cache_entry_for_exception(Handle exception) { + ExceptionCache* ec = exception_cache(); + while (ec != NULL) { + if (ec->match_exception_with_space(exception)) { + return ec; + } + ec = ec->next(); + } + return NULL; +} + +bool CompiledMethod::is_at_poll_return(address pc) { + RelocIterator iter(this, pc, pc+1); + while (iter.next()) { + if (iter.type() == relocInfo::poll_return_type) + return true; + } + return false; +} + + +bool CompiledMethod::is_at_poll_or_poll_return(address pc) { + RelocIterator iter(this, pc, pc+1); + while (iter.next()) { + relocInfo::relocType t = iter.type(); + if (t == relocInfo::poll_return_type || t == relocInfo::poll_type) + return true; + } + return false; +} + +void CompiledMethod::verify_oop_relocations() { + // Ensure sure that the code matches the current oop values + RelocIterator iter(this, NULL, NULL); + while (iter.next()) { + if (iter.type() == relocInfo::oop_type) { + oop_Relocation* reloc = iter.oop_reloc(); + if (!reloc->oop_is_immediate()) { + reloc->verify_oop_relocation(); + } + } + } +} + + +ScopeDesc* CompiledMethod::scope_desc_at(address pc) { + PcDesc* pd = pc_desc_at(pc); + guarantee(pd != NULL, "scope must be present"); + return new ScopeDesc(this, pd->scope_decode_offset(), + pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(), + pd->return_oop()); +} + +ScopeDesc* CompiledMethod::scope_desc_near(address pc) { + PcDesc* pd = pc_desc_near(pc); + guarantee(pd != NULL, "scope must be present"); + return new ScopeDesc(this, pd->scope_decode_offset(), + pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(), + pd->return_oop()); +} + +void CompiledMethod::cleanup_inline_caches(bool clean_all/*=false*/) { + assert_locked_or_safepoint(CompiledIC_lock); + + // If the method is not entrant or zombie then a JMP is plastered over the + // first few bytes. If an oop in the old code was there, that oop + // should not get GC'd. Skip the first few bytes of oops on + // not-entrant methods. + address low_boundary = verified_entry_point(); + if (!is_in_use() && is_nmethod()) { + low_boundary += NativeJump::instruction_size; + // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump. + // This means that the low_boundary is going to be a little too high. + // This shouldn't matter, since oops of non-entrant methods are never used. + // In fact, why are we bothering to look at oops in a non-entrant method?? + } + + // Find all calls in an nmethod and clear the ones that point to non-entrant, + // zombie and unloaded nmethods. + ResourceMark rm; + RelocIterator iter(this, low_boundary); + while(iter.next()) { + switch(iter.type()) { + case relocInfo::virtual_call_type: + case relocInfo::opt_virtual_call_type: { + CompiledIC *ic = CompiledIC_at(&iter); + // Ok, to lookup references to zombies here + CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination()); + if( cb != NULL && cb->is_compiled() ) { + CompiledMethod* nm = cb->as_compiled_method(); + // Clean inline caches pointing to zombie, non-entrant and unloaded methods + if (clean_all || !nm->is_in_use() || (nm->method()->code() != nm)) ic->set_to_clean(is_alive()); + } + break; + } + case relocInfo::static_call_type: { + CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc()); + CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination()); + if( cb != NULL && cb->is_compiled() ) { + CompiledMethod* cm = cb->as_compiled_method(); + // Clean inline caches pointing to zombie, non-entrant and unloaded methods + if (clean_all || !cm->is_in_use() || (cm->method()->code() != cm)) { + csc->set_to_clean(); + } + } + break; + } + default: + break; + } + } +} + +int CompiledMethod::verify_icholder_relocations() { + ResourceMark rm; + int count = 0; + + RelocIterator iter(this); + while(iter.next()) { + if (iter.type() == relocInfo::virtual_call_type) { + if (CompiledIC::is_icholder_call_site(iter.virtual_call_reloc(), this)) { + CompiledIC *ic = CompiledIC_at(&iter); + if (TraceCompiledIC) { + tty->print("noticed icholder " INTPTR_FORMAT " ", p2i(ic->cached_icholder())); + ic->print(); + } + assert(ic->cached_icholder() != NULL, "must be non-NULL"); + count++; + } + } + } + + return count; +} + +// Method that knows how to preserve outgoing arguments at call. This method must be +// called with a frame corresponding to a Java invoke +void CompiledMethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) { +#ifndef SHARK + if (method() != NULL && !method()->is_native()) { + address pc = fr.pc(); + SimpleScopeDesc ssd(this, pc); + Bytecode_invoke call(ssd.method(), ssd.bci()); + bool has_receiver = call.has_receiver(); + bool has_appendix = call.has_appendix(); + Symbol* signature = call.signature(); + + // The method attached by JIT-compilers should be used, if present. + // Bytecode can be inaccurate in such case. + Method* callee = attached_method_before_pc(pc); + if (callee != NULL) { + has_receiver = !(callee->access_flags().is_static()); + has_appendix = false; + signature = callee->signature(); + } + + fr.oops_compiled_arguments_do(signature, has_receiver, has_appendix, reg_map, f); + } +#endif // !SHARK +} + +Method* CompiledMethod::attached_method(address call_instr) { + assert(code_contains(call_instr), "not part of the nmethod"); + RelocIterator iter(this, call_instr, call_instr + 1); + while (iter.next()) { + if (iter.addr() == call_instr) { + switch(iter.type()) { + case relocInfo::static_call_type: return iter.static_call_reloc()->method_value(); + case relocInfo::opt_virtual_call_type: return iter.opt_virtual_call_reloc()->method_value(); + case relocInfo::virtual_call_type: return iter.virtual_call_reloc()->method_value(); + default: break; + } + } + } + return NULL; // not found +} + +Method* CompiledMethod::attached_method_before_pc(address pc) { + if (NativeCall::is_call_before(pc)) { + NativeCall* ncall = nativeCall_before(pc); + return attached_method(ncall->instruction_address()); + } + return NULL; // not a call +} + +void CompiledMethod::clear_inline_caches() { + assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's only allowed at safepoint"); + if (is_zombie()) { + return; + } + + RelocIterator iter(this); + while (iter.next()) { + iter.reloc()->clear_inline_cache(); + } +} + +// Clear ICStubs of all compiled ICs +void CompiledMethod::clear_ic_stubs() { + assert_locked_or_safepoint(CompiledIC_lock); + RelocIterator iter(this); + while(iter.next()) { + if (iter.type() == relocInfo::virtual_call_type) { + CompiledIC* ic = CompiledIC_at(&iter); + ic->clear_ic_stub(); + } + } +} + +#ifdef ASSERT + +class CheckClass : AllStatic { + static BoolObjectClosure* _is_alive; + + // Check class_loader is alive for this bit of metadata. + static void check_class(Metadata* md) { + Klass* klass = NULL; + if (md->is_klass()) { + klass = ((Klass*)md); + } else if (md->is_method()) { + klass = ((Method*)md)->method_holder(); + } else if (md->is_methodData()) { + klass = ((MethodData*)md)->method()->method_holder(); + } else { + md->print(); + ShouldNotReachHere(); + } + assert(klass->is_loader_alive(_is_alive), "must be alive"); + } + public: + static void do_check_class(BoolObjectClosure* is_alive, CompiledMethod* nm) { + assert(SafepointSynchronize::is_at_safepoint(), "this is only ok at safepoint"); + _is_alive = is_alive; + nm->metadata_do(check_class); + } +}; + +// This is called during a safepoint so can use static data +BoolObjectClosure* CheckClass::_is_alive = NULL; +#endif // ASSERT + + +void CompiledMethod::clean_ic_if_metadata_is_dead(CompiledIC *ic, BoolObjectClosure *is_alive) { + if (ic->is_icholder_call()) { + // The only exception is compiledICHolder oops which may + // yet be marked below. (We check this further below). + CompiledICHolder* cichk_oop = ic->cached_icholder(); + + if (cichk_oop->holder_method()->method_holder()->is_loader_alive(is_alive) && + cichk_oop->holder_klass()->is_loader_alive(is_alive)) { + return; + } + } else { + Metadata* ic_oop = ic->cached_metadata(); + if (ic_oop != NULL) { + if (ic_oop->is_klass()) { + if (((Klass*)ic_oop)->is_loader_alive(is_alive)) { + return; + } + } else if (ic_oop->is_method()) { + if (((Method*)ic_oop)->method_holder()->is_loader_alive(is_alive)) { + return; + } + } else { + ShouldNotReachHere(); + } + } + } + + ic->set_to_clean(); +} + +unsigned char CompiledMethod::_global_unloading_clock = 0; + +void CompiledMethod::increase_unloading_clock() { + _global_unloading_clock++; + if (_global_unloading_clock == 0) { + // _nmethods are allocated with _unloading_clock == 0, + // so 0 is never used as a clock value. + _global_unloading_clock = 1; + } +} + +void CompiledMethod::set_unloading_clock(unsigned char unloading_clock) { + OrderAccess::release_store((volatile jubyte*)&_unloading_clock, unloading_clock); +} + +unsigned char CompiledMethod::unloading_clock() { + return (unsigned char)OrderAccess::load_acquire((volatile jubyte*)&_unloading_clock); +} + +// Processing of oop references should have been sufficient to keep +// all strong references alive. Any weak references should have been +// cleared as well. Visit all the metadata and ensure that it's +// really alive. +void CompiledMethod::verify_metadata_loaders(address low_boundary, BoolObjectClosure* is_alive) { +#ifdef ASSERT + RelocIterator iter(this, low_boundary); + while (iter.next()) { + // static_stub_Relocations may have dangling references to + // Method*s so trim them out here. Otherwise it looks like + // compiled code is maintaining a link to dead metadata. + address static_call_addr = NULL; + if (iter.type() == relocInfo::opt_virtual_call_type) { + CompiledIC* cic = CompiledIC_at(&iter); + if (!cic->is_call_to_interpreted()) { + static_call_addr = iter.addr(); + } + } else if (iter.type() == relocInfo::static_call_type) { + CompiledStaticCall* csc = compiledStaticCall_at(iter.reloc()); + if (!csc->is_call_to_interpreted()) { + static_call_addr = iter.addr(); + } + } + if (static_call_addr != NULL) { + RelocIterator sciter(this, low_boundary); + while (sciter.next()) { + if (sciter.type() == relocInfo::static_stub_type && + sciter.static_stub_reloc()->static_call() == static_call_addr) { + sciter.static_stub_reloc()->clear_inline_cache(); + } + } + } + } + // Check that the metadata embedded in the nmethod is alive + CheckClass::do_check_class(is_alive, this); +#endif +} + +// This is called at the end of the strong tracing/marking phase of a +// GC to unload an nmethod if it contains otherwise unreachable +// oops. + +void CompiledMethod::do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred) { + // Make sure the oop's ready to receive visitors + assert(!is_zombie() && !is_unloaded(), + "should not call follow on zombie or unloaded nmethod"); + + // If the method is not entrant then a JMP is plastered over the + // first few bytes. If an oop in the old code was there, that oop + // should not get GC'd. Skip the first few bytes of oops on + // not-entrant methods. + address low_boundary = verified_entry_point(); + if (is_not_entrant()) { + low_boundary += NativeJump::instruction_size; + // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump. + // (See comment above.) + } + + // The RedefineClasses() API can cause the class unloading invariant + // to no longer be true. See jvmtiExport.hpp for details. + // Also, leave a debugging breadcrumb in local flag. + if (JvmtiExport::has_redefined_a_class()) { + // This set of the unloading_occurred flag is done before the + // call to post_compiled_method_unload() so that the unloading + // of this nmethod is reported. + unloading_occurred = true; + } + + // Exception cache + clean_exception_cache(is_alive); + + // If class unloading occurred we first iterate over all inline caches and + // clear ICs where the cached oop is referring to an unloaded klass or method. + // The remaining live cached oops will be traversed in the relocInfo::oop_type + // iteration below. + if (unloading_occurred) { + RelocIterator iter(this, low_boundary); + while(iter.next()) { + if (iter.type() == relocInfo::virtual_call_type) { + CompiledIC *ic = CompiledIC_at(&iter); + clean_ic_if_metadata_is_dead(ic, is_alive); + } + } + } + + if (do_unloading_oops(low_boundary, is_alive, unloading_occurred)) { + return; + } + +#if INCLUDE_JVMCI + if (do_unloading_jvmci(is_alive, unloading_occurred)) { + return; + } +#endif + + // Ensure that all metadata is still alive + verify_metadata_loaders(low_boundary, is_alive); +} + +template +static bool clean_if_nmethod_is_unloaded(CompiledICorStaticCall *ic, address addr, BoolObjectClosure *is_alive, CompiledMethod* from) { + // Ok, to lookup references to zombies here + CodeBlob *cb = CodeCache::find_blob_unsafe(addr); + CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL; + if (nm != NULL) { + if (nm->unloading_clock() != CompiledMethod::global_unloading_clock()) { + // The nmethod has not been processed yet. + return true; + } + + // Clean inline caches pointing to both zombie and not_entrant methods + if (!nm->is_in_use() || (nm->method()->code() != nm)) { + ic->set_to_clean(); + assert(ic->is_clean(), "nmethod " PTR_FORMAT "not clean %s", p2i(from), from->method()->name_and_sig_as_C_string()); + } + } + + return false; +} + +static bool clean_if_nmethod_is_unloaded(CompiledIC *ic, BoolObjectClosure *is_alive, CompiledMethod* from) { + return clean_if_nmethod_is_unloaded(ic, ic->ic_destination(), is_alive, from); +} + +static bool clean_if_nmethod_is_unloaded(CompiledStaticCall *csc, BoolObjectClosure *is_alive, CompiledMethod* from) { + return clean_if_nmethod_is_unloaded(csc, csc->destination(), is_alive, from); +} + +bool CompiledMethod::do_unloading_parallel(BoolObjectClosure* is_alive, bool unloading_occurred) { + ResourceMark rm; + + // Make sure the oop's ready to receive visitors + assert(!is_zombie() && !is_unloaded(), + "should not call follow on zombie or unloaded nmethod"); + + // If the method is not entrant then a JMP is plastered over the + // first few bytes. If an oop in the old code was there, that oop + // should not get GC'd. Skip the first few bytes of oops on + // not-entrant methods. + address low_boundary = verified_entry_point(); + if (is_not_entrant()) { + low_boundary += NativeJump::instruction_size; + // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump. + // (See comment above.) + } + + // The RedefineClasses() API can cause the class unloading invariant + // to no longer be true. See jvmtiExport.hpp for details. + // Also, leave a debugging breadcrumb in local flag. + if (JvmtiExport::has_redefined_a_class()) { + // This set of the unloading_occurred flag is done before the + // call to post_compiled_method_unload() so that the unloading + // of this nmethod is reported. + unloading_occurred = true; + } + + // Exception cache + clean_exception_cache(is_alive); + + bool postponed = false; + + RelocIterator iter(this, low_boundary); + while(iter.next()) { + + switch (iter.type()) { + + case relocInfo::virtual_call_type: + if (unloading_occurred) { + // If class unloading occurred we first iterate over all inline caches and + // clear ICs where the cached oop is referring to an unloaded klass or method. + clean_ic_if_metadata_is_dead(CompiledIC_at(&iter), is_alive); + } + + postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this); + break; + + case relocInfo::opt_virtual_call_type: + postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this); + break; + + case relocInfo::static_call_type: + postponed |= clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), is_alive, this); + break; + + case relocInfo::oop_type: + // handled by do_unloading_oops below + break; + + case relocInfo::metadata_type: + break; // nothing to do. + + default: + break; + } + } + + if (do_unloading_oops(low_boundary, is_alive, unloading_occurred)) { + return postponed; + } + +#if INCLUDE_JVMCI + if (do_unloading_jvmci(is_alive, unloading_occurred)) { + return postponed; + } +#endif + + // Ensure that all metadata is still alive + verify_metadata_loaders(low_boundary, is_alive); + + return postponed; +} + +void CompiledMethod::do_unloading_parallel_postponed(BoolObjectClosure* is_alive, bool unloading_occurred) { + ResourceMark rm; + + // Make sure the oop's ready to receive visitors + assert(!is_zombie(), + "should not call follow on zombie nmethod"); + + // If the method is not entrant then a JMP is plastered over the + // first few bytes. If an oop in the old code was there, that oop + // should not get GC'd. Skip the first few bytes of oops on + // not-entrant methods. + address low_boundary = verified_entry_point(); + if (is_not_entrant()) { + low_boundary += NativeJump::instruction_size; + // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump. + // (See comment above.) + } + + RelocIterator iter(this, low_boundary); + while(iter.next()) { + + switch (iter.type()) { + + case relocInfo::virtual_call_type: + clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this); + break; + + case relocInfo::opt_virtual_call_type: + clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this); + break; + + case relocInfo::static_call_type: + clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), is_alive, this); + break; + + default: + break; + } + } +}