/*
* 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) {
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);
}
}
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 <class CompiledICorStaticCall>
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;
}
}
}