| /* |
| * Copyright (c) 2015, 2020, 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/exceptionHandlerTable.hpp" |
| #include "code/scopeDesc.hpp" |
| #include "code/codeCache.hpp" |
| #include "code/icBuffer.hpp" |
| #include "gc/shared/barrierSet.hpp" |
| #include "gc/shared/barrierSetNMethod.hpp" |
| #include "gc/shared/gcBehaviours.hpp" |
| #include "interpreter/bytecode.inline.hpp" |
| #include "logging/log.hpp" |
| #include "logging/logTag.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "oops/methodData.hpp" |
| #include "oops/method.inline.hpp" |
| #include "prims/methodHandles.hpp" |
| #include "runtime/atomic.hpp" |
| #include "runtime/deoptimization.hpp" |
| #include "runtime/handles.inline.hpp" |
| #include "runtime/mutexLocker.hpp" |
| #include "runtime/sharedRuntime.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), |
| _mark_for_deoptimization_status(not_marked), |
| _method(method), |
| _gc_data(NULL) |
| { |
| 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), |
| _mark_for_deoptimization_status(not_marked), |
| _method(method), |
| _gc_data(NULL) |
| { |
| init_defaults(); |
| } |
| |
| void CompiledMethod::init_defaults() { |
| { // avoid uninitialized fields, even for short time periods |
| _is_far_code = false; |
| _scopes_data_begin = NULL; |
| _deopt_handler_begin = NULL; |
| _deopt_mh_handler_begin = NULL; |
| _exception_cache = NULL; |
| } |
| _has_unsafe_access = 0; |
| _has_method_handle_invokes = 0; |
| _has_wide_vectors = 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 not_installed: |
| return "not installed"; |
| 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::mark_for_deoptimization(bool inc_recompile_counts) { |
| MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, |
| Mutex::_no_safepoint_check_flag); |
| _mark_for_deoptimization_status = (inc_recompile_counts ? deoptimize : deoptimize_noupdate); |
| } |
| |
| //----------------------------------------------------------------------------- |
| |
| ExceptionCache* CompiledMethod::exception_cache_acquire() const { |
| return Atomic::load_acquire(&_exception_cache); |
| } |
| |
| 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"); |
| |
| for (;;) { |
| ExceptionCache *ec = exception_cache(); |
| if (ec != NULL) { |
| Klass* ex_klass = ec->exception_type(); |
| if (!ex_klass->is_loader_alive()) { |
| // We must guarantee that entries are not inserted with new next pointer |
| // edges to ExceptionCache entries with dead klasses, due to bad interactions |
| // with concurrent ExceptionCache cleanup. Therefore, the inserts roll |
| // the head pointer forward to the first live ExceptionCache, so that the new |
| // next pointers always point at live ExceptionCaches, that are not removed due |
| // to concurrent ExceptionCache cleanup. |
| ExceptionCache* next = ec->next(); |
| if (Atomic::cmpxchg(&_exception_cache, ec, next) == ec) { |
| CodeCache::release_exception_cache(ec); |
| } |
| continue; |
| } |
| ec = exception_cache(); |
| if (ec != NULL) { |
| new_entry->set_next(ec); |
| } |
| } |
| if (Atomic::cmpxchg(&_exception_cache, ec, new_entry) == ec) { |
| return; |
| } |
| } |
| } |
| |
| void CompiledMethod::clean_exception_cache() { |
| // For each nmethod, only a single thread may call this cleanup function |
| // at the same time, whether called in STW cleanup or concurrent cleanup. |
| // Note that if the GC is processing exception cache cleaning in a concurrent phase, |
| // then a single writer may contend with cleaning up the head pointer to the |
| // first ExceptionCache node that has a Klass* that is alive. That is fine, |
| // as long as there is no concurrent cleanup of next pointers from concurrent writers. |
| // And the concurrent writers do not clean up next pointers, only the head. |
| // Also note that concurent readers will walk through Klass* pointers that are not |
| // alive. That does not cause ABA problems, because Klass* is deleted after |
| // a handshake with all threads, after all stale ExceptionCaches have been |
| // unlinked. That is also when the CodeCache::exception_cache_purge_list() |
| // is deleted, with all ExceptionCache entries that were cleaned concurrently. |
| // That similarly implies that CAS operations on ExceptionCache entries do not |
| // suffer from ABA problems as unlinking and deletion is separated by a global |
| // handshake operation. |
| ExceptionCache* prev = NULL; |
| ExceptionCache* curr = exception_cache_acquire(); |
| |
| while (curr != NULL) { |
| ExceptionCache* next = curr->next(); |
| |
| if (!curr->exception_type()->is_loader_alive()) { |
| if (prev == NULL) { |
| // Try to clean head; this is contended by concurrent inserts, that |
| // both lazily clean the head, and insert entries at the head. If |
| // the CAS fails, the operation is restarted. |
| if (Atomic::cmpxchg(&_exception_cache, curr, next) != curr) { |
| prev = NULL; |
| curr = exception_cache_acquire(); |
| continue; |
| } |
| } else { |
| // It is impossible to during cleanup connect the next pointer to |
| // an ExceptionCache that has not been published before a safepoint |
| // prior to the cleanup. Therefore, release is not required. |
| prev->set_next(next); |
| } |
| // prev stays the same. |
| |
| CodeCache::release_exception_cache(curr); |
| } 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_acquire(); |
| 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); |
| } |
| } |
| |
| // 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_acquire(); |
| while (ec != NULL) { |
| if (ec->match_exception_with_space(exception)) { |
| return ec; |
| } |
| ec = ec->next(); |
| } |
| return NULL; |
| } |
| |
| //-------------end of code for ExceptionCache-------------- |
| |
| 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); |
| } |
| |
| 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); |
| } |
| |
| address CompiledMethod::oops_reloc_begin() const { |
| // 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. |
| if (frame_complete_offset() != CodeOffsets::frame_never_safe && |
| code_begin() + frame_complete_offset() > |
| verified_entry_point() + NativeJump::instruction_size) |
| { |
| // If we have a frame_complete_offset after the native jump, then there |
| // is no point trying to look for oops before that. This is a requirement |
| // for being allowed to scan oops concurrently. |
| return code_begin() + frame_complete_offset(); |
| } |
| |
| // It is not safe to read oops concurrently using entry barriers, if their |
| // location depend on whether the nmethod is entrant or not. |
| assert(BarrierSet::barrier_set()->barrier_set_nmethod() == NULL, "Not safe oop scan"); |
| |
| 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?? |
| } |
| return low_boundary; |
| } |
| |
| 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) { |
| if (method() != NULL && !method()->is_native()) { |
| address pc = fr.pc(); |
| SimpleScopeDesc ssd(this, pc); |
| Bytecode_invoke call(methodHandle(Thread::current(), 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); |
| } |
| } |
| |
| 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 IC callsites, releasing ICStubs of all compiled ICs |
| // as well as any associated CompiledICHolders. |
| void CompiledMethod::clear_ic_callsites() { |
| assert(CompiledICLocker::is_safe(this), "mt unsafe call"); |
| ResourceMark rm; |
| RelocIterator iter(this); |
| while(iter.next()) { |
| if (iter.type() == relocInfo::virtual_call_type) { |
| CompiledIC* ic = CompiledIC_at(&iter); |
| ic->set_to_clean(false); |
| } |
| } |
| } |
| |
| #ifdef ASSERT |
| // Check class_loader is alive for this bit of metadata. |
| class CheckClass : public MetadataClosure { |
| void do_metadata(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(), "must be alive"); |
| } |
| }; |
| #endif // ASSERT |
| |
| |
| bool CompiledMethod::clean_ic_if_metadata_is_dead(CompiledIC *ic) { |
| if (ic->is_clean()) { |
| return true; |
| } |
| if (ic->is_icholder_call()) { |
| // The only exception is compiledICHolder metdata which may |
| // yet be marked below. (We check this further below). |
| CompiledICHolder* cichk_metdata = ic->cached_icholder(); |
| |
| if (cichk_metdata->is_loader_alive()) { |
| return true; |
| } |
| } else { |
| Metadata* ic_metdata = ic->cached_metadata(); |
| if (ic_metdata != NULL) { |
| if (ic_metdata->is_klass()) { |
| if (((Klass*)ic_metdata)->is_loader_alive()) { |
| return true; |
| } |
| } else if (ic_metdata->is_method()) { |
| Method* method = (Method*)ic_metdata; |
| assert(!method->is_old(), "old method should have been cleaned"); |
| if (method->method_holder()->is_loader_alive()) { |
| return true; |
| } |
| } else { |
| ShouldNotReachHere(); |
| } |
| } |
| } |
| |
| return ic->set_to_clean(); |
| } |
| |
| // Clean references to unloaded nmethods at addr from this one, which is not unloaded. |
| template <class CompiledICorStaticCall> |
| static bool clean_if_nmethod_is_unloaded(CompiledICorStaticCall *ic, address addr, CompiledMethod* from, |
| bool clean_all) { |
| // 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) { |
| // Clean inline caches pointing to both zombie and not_entrant methods |
| if (clean_all || !nm->is_in_use() || nm->is_unloading() || (nm->method()->code() != nm)) { |
| // Inline cache cleaning should only be initiated on CompiledMethods that have been |
| // observed to be is_alive(). However, with concurrent code cache unloading, it is |
| // possible that by now, the state has become !is_alive. This can happen in two ways: |
| // 1) It can be racingly flipped to unloaded if the nmethod // being cleaned (from the |
| // sweeper) is_unloading(). This is fine, because if that happens, then the inline |
| // caches have already been cleaned under the same CompiledICLocker that we now hold during |
| // inline cache cleaning, and we will simply walk the inline caches again, and likely not |
| // find much of interest to clean. However, this race prevents us from asserting that the |
| // nmethod is_alive(). The is_unloading() function is completely monotonic; once set due |
| // to an oop dying, it remains set forever until freed. Because of that, all unloaded |
| // nmethods are is_unloading(), but notably, an unloaded nmethod may also subsequently |
| // become zombie (when the sweeper converts it to zombie). |
| // 2) It can be racingly flipped to zombie if the nmethod being cleaned (by the concurrent |
| // GC) cleans a zombie nmethod that is concurrently made zombie by the sweeper. In this |
| // scenario, the sweeper will first transition the nmethod to zombie, and then when |
| // unregistering from the GC, it will wait until the GC is done. The GC will then clean |
| // the inline caches *with IC stubs*, even though no IC stubs are needed. This is fine, |
| // as long as the IC stubs are guaranteed to be released until the next safepoint, where |
| // IC finalization requires live IC stubs to not be associated with zombie nmethods. |
| // This is guaranteed, because the sweeper does not have a single safepoint check until |
| // after it completes the whole transition function; it will wake up after the GC is |
| // done with concurrent code cache cleaning (which blocks out safepoints using the |
| // suspendible threads set), and then call clear_ic_callsites, which will release the |
| // associated IC stubs, before a subsequent safepoint poll can be reached. This |
| // guarantees that the spuriously created IC stubs are released appropriately before |
| // IC finalization in a safepoint gets to run. Therefore, this race is fine. This is also |
| // valid in a scenario where an inline cache of a zombie nmethod gets a spurious IC stub, |
| // and then when cleaning another inline cache, fails to request an IC stub because we |
| // exhausted the IC stub buffer. In this scenario, the GC will request a safepoint after |
| // yielding the suspendible therad set, effectively unblocking safepoints. Before such |
| // a safepoint can be reached, the sweeper similarly has to wake up, clear the IC stubs, |
| // and reach the next safepoint poll, after the whole transition function has completed. |
| // Due to the various races that can cause an nmethod to first be is_alive() and then |
| // racingly become !is_alive(), it is unfortunately not possible to assert the nmethod |
| // is_alive(), !is_unloaded() or !is_zombie() here. |
| if (!ic->set_to_clean(!from->is_unloading())) { |
| return false; |
| } |
| assert(ic->is_clean(), "nmethod " PTR_FORMAT "not clean %s", p2i(from), from->method()->name_and_sig_as_C_string()); |
| } |
| } |
| return true; |
| } |
| |
| static bool clean_if_nmethod_is_unloaded(CompiledIC *ic, CompiledMethod* from, |
| bool clean_all) { |
| return clean_if_nmethod_is_unloaded(ic, ic->ic_destination(), from, clean_all); |
| } |
| |
| static bool clean_if_nmethod_is_unloaded(CompiledStaticCall *csc, CompiledMethod* from, |
| bool clean_all) { |
| return clean_if_nmethod_is_unloaded(csc, csc->destination(), from, clean_all); |
| } |
| |
| // Cleans caches in nmethods that point to either classes that are unloaded |
| // or nmethods that are unloaded. |
| // |
| // Can be called either in parallel by G1 currently or after all |
| // nmethods are unloaded. Return postponed=true in the parallel case for |
| // inline caches found that point to nmethods that are not yet visited during |
| // the do_unloading walk. |
| bool CompiledMethod::unload_nmethod_caches(bool unloading_occurred) { |
| ResourceMark rm; |
| |
| // Exception cache only needs to be called if unloading occurred |
| if (unloading_occurred) { |
| clean_exception_cache(); |
| } |
| |
| if (!cleanup_inline_caches_impl(unloading_occurred, false)) { |
| return false; |
| } |
| |
| #ifdef ASSERT |
| // Check that the metadata embedded in the nmethod is alive |
| CheckClass check_class; |
| metadata_do(&check_class); |
| #endif |
| return true; |
| } |
| |
| void CompiledMethod::run_nmethod_entry_barrier() { |
| BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod(); |
| if (bs_nm != NULL) { |
| // We want to keep an invariant that nmethods found through iterations of a Thread's |
| // nmethods found in safepoints have gone through an entry barrier and are not armed. |
| // By calling this nmethod entry barrier, it plays along and acts |
| // like any other nmethod found on the stack of a thread (fewer surprises). |
| nmethod* nm = as_nmethod_or_null(); |
| if (nm != NULL) { |
| bool alive = bs_nm->nmethod_entry_barrier(nm); |
| assert(alive, "should be alive"); |
| } |
| } |
| } |
| |
| void CompiledMethod::cleanup_inline_caches(bool clean_all) { |
| for (;;) { |
| ICRefillVerifier ic_refill_verifier; |
| { CompiledICLocker ic_locker(this); |
| if (cleanup_inline_caches_impl(false, clean_all)) { |
| return; |
| } |
| } |
| // Call this nmethod entry barrier from the sweeper. |
| run_nmethod_entry_barrier(); |
| InlineCacheBuffer::refill_ic_stubs(); |
| } |
| } |
| |
| // Called to clean up after class unloading for live nmethods and from the sweeper |
| // for all methods. |
| bool CompiledMethod::cleanup_inline_caches_impl(bool unloading_occurred, bool clean_all) { |
| assert(CompiledICLocker::is_safe(this), "mt unsafe call"); |
| ResourceMark rm; |
| |
| // Find all calls in an nmethod and clear the ones that point to non-entrant, |
| // zombie and unloaded nmethods. |
| RelocIterator iter(this, oops_reloc_begin()); |
| bool is_in_static_stub = false; |
| while(iter.next()) { |
| |
| switch (iter.type()) { |
| |
| case relocInfo::virtual_call_type: |
| if (unloading_occurred) { |
| // If class unloading occurred we first clear ICs where the cached metadata |
| // is referring to an unloaded klass or method. |
| if (!clean_ic_if_metadata_is_dead(CompiledIC_at(&iter))) { |
| return false; |
| } |
| } |
| |
| if (!clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), this, clean_all)) { |
| return false; |
| } |
| break; |
| |
| case relocInfo::opt_virtual_call_type: |
| if (!clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), this, clean_all)) { |
| return false; |
| } |
| break; |
| |
| case relocInfo::static_call_type: |
| if (!clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), this, clean_all)) { |
| return false; |
| } |
| break; |
| |
| case relocInfo::static_stub_type: { |
| is_in_static_stub = true; |
| break; |
| } |
| |
| case relocInfo::metadata_type: { |
| // Only the metadata relocations contained in static/opt virtual call stubs |
| // contains the Method* passed to c2i adapters. It is the only metadata |
| // relocation that needs to be walked, as it is the one metadata relocation |
| // that violates the invariant that all metadata relocations have an oop |
| // in the compiled method (due to deferred resolution and code patching). |
| |
| // This causes dead metadata to remain in compiled methods that are not |
| // unloading. Unless these slippery metadata relocations of the static |
| // stubs are at least cleared, subsequent class redefinition operations |
| // will access potentially free memory, and JavaThread execution |
| // concurrent to class unloading may call c2i adapters with dead methods. |
| if (!is_in_static_stub) { |
| // The first metadata relocation after a static stub relocation is the |
| // metadata relocation of the static stub used to pass the Method* to |
| // c2i adapters. |
| continue; |
| } |
| is_in_static_stub = false; |
| if (is_unloading()) { |
| // If the nmethod itself is dying, then it may point at dead metadata. |
| // Nobody should follow that metadata; it is strictly unsafe. |
| continue; |
| } |
| metadata_Relocation* r = iter.metadata_reloc(); |
| Metadata* md = r->metadata_value(); |
| if (md != NULL && md->is_method()) { |
| Method* method = static_cast<Method*>(md); |
| if (!method->method_holder()->is_loader_alive()) { |
| Atomic::store(r->metadata_addr(), (Method*)NULL); |
| |
| if (!r->metadata_is_immediate()) { |
| r->fix_metadata_relocation(); |
| } |
| } |
| } |
| break; |
| } |
| |
| default: |
| break; |
| } |
| } |
| |
| return true; |
| } |
| |
| address CompiledMethod::continuation_for_implicit_exception(address pc, bool for_div0_check) { |
| // Exception happened outside inline-cache check code => we are inside |
| // an active nmethod => use cpc to determine a return address |
| int exception_offset = pc - code_begin(); |
| int cont_offset = ImplicitExceptionTable(this).continuation_offset( exception_offset ); |
| #ifdef ASSERT |
| if (cont_offset == 0) { |
| Thread* thread = Thread::current(); |
| ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY |
| HandleMark hm(thread); |
| ResourceMark rm(thread); |
| CodeBlob* cb = CodeCache::find_blob(pc); |
| assert(cb != NULL && cb == this, ""); |
| ttyLocker ttyl; |
| tty->print_cr("implicit exception happened at " INTPTR_FORMAT, p2i(pc)); |
| print(); |
| method()->print_codes(); |
| print_code(); |
| print_pcs(); |
| } |
| #endif |
| if (cont_offset == 0) { |
| // Let the normal error handling report the exception |
| return NULL; |
| } |
| if (cont_offset == exception_offset) { |
| #if INCLUDE_JVMCI |
| Deoptimization::DeoptReason deopt_reason = for_div0_check ? Deoptimization::Reason_div0_check : Deoptimization::Reason_null_check; |
| JavaThread *thread = JavaThread::current(); |
| thread->set_jvmci_implicit_exception_pc(pc); |
| thread->set_pending_deoptimization(Deoptimization::make_trap_request(deopt_reason, |
| Deoptimization::Action_reinterpret)); |
| return (SharedRuntime::deopt_blob()->implicit_exception_uncommon_trap()); |
| #else |
| ShouldNotReachHere(); |
| #endif |
| } |
| return code_begin() + cont_offset; |
| } |
| |
| class HasEvolDependency : public MetadataClosure { |
| bool _has_evol_dependency; |
| public: |
| HasEvolDependency() : _has_evol_dependency(false) {} |
| void do_metadata(Metadata* md) { |
| if (md->is_method()) { |
| Method* method = (Method*)md; |
| if (method->is_old()) { |
| _has_evol_dependency = true; |
| } |
| } |
| } |
| bool has_evol_dependency() const { return _has_evol_dependency; } |
| }; |
| |
| bool CompiledMethod::has_evol_metadata() { |
| // Check the metadata in relocIter and CompiledIC and also deoptimize |
| // any nmethod that has reference to old methods. |
| HasEvolDependency check_evol; |
| metadata_do(&check_evol); |
| if (check_evol.has_evol_dependency() && log_is_enabled(Debug, redefine, class, nmethod)) { |
| ResourceMark rm; |
| log_debug(redefine, class, nmethod) |
| ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on in nmethod metadata", |
| _method->method_holder()->external_name(), |
| _method->name()->as_C_string(), |
| _method->signature()->as_C_string(), |
| compile_id()); |
| } |
| return check_evol.has_evol_dependency(); |
| } |