archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-08-26 22:34:27 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions
jdk/src/hotspot/share/code/dependencies.cpp
Jesper Wilhelmsson c36755dedf Merge
2021-07-22 00:46:18 +00:00

2258 lines
79 KiB
C++
Raw Blame History

/*
* Copyright (c) 2005, 2021, 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 "ci/ciArrayKlass.hpp"
#include "ci/ciEnv.hpp"
#include "ci/ciKlass.hpp"
#include "ci/ciMethod.hpp"
#include "classfile/javaClasses.inline.hpp"
#include "classfile/vmClasses.hpp"
#include "code/dependencies.hpp"
#include "compiler/compileLog.hpp"
#include "compiler/compileBroker.hpp"
#include "compiler/compileTask.hpp"
#include "memory/resourceArea.hpp"
#include "oops/klass.hpp"
#include "oops/oop.inline.hpp"
#include "oops/objArrayKlass.hpp"
#include "runtime/flags/flagSetting.hpp"
#include "runtime/handles.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/jniHandles.inline.hpp"
#include "runtime/perfData.hpp"
#include "runtime/thread.inline.hpp"
#include "runtime/vmThread.hpp"
#include "utilities/copy.hpp"
#ifdef ASSERT
static bool must_be_in_vm() {
Thread* thread = Thread::current();
if (thread->is_Java_thread()) {
return JavaThread::cast(thread)->thread_state() == _thread_in_vm;
} else {
return true; // Could be VMThread or GC thread
}
}
#endif //ASSERT
void Dependencies::initialize(ciEnv* env) {
Arena* arena = env->arena();
_oop_recorder = env->oop_recorder();
_log = env->log();
_dep_seen = new(arena) GrowableArray<int>(arena, 500, 0, 0);
#if INCLUDE_JVMCI
_using_dep_values = false;
#endif
DEBUG_ONLY(_deps[end_marker] = NULL);
for (int i = (int)FIRST_TYPE; i < (int)TYPE_LIMIT; i++) {
_deps[i] = new(arena) GrowableArray<ciBaseObject*>(arena, 10, 0, 0);
}
_content_bytes = NULL;
_size_in_bytes = (size_t)-1;
assert(TYPE_LIMIT <= (1<<LG2_TYPE_LIMIT), "sanity");
}
void Dependencies::assert_evol_method(ciMethod* m) {
assert_common_1(evol_method, m);
}
void Dependencies::assert_leaf_type(ciKlass* ctxk) {
if (ctxk->is_array_klass()) {
// As a special case, support this assertion on an array type,
// which reduces to an assertion on its element type.
// Note that this cannot be done with assertions that
// relate to concreteness or abstractness.
ciType* elemt = ctxk->as_array_klass()->base_element_type();
if (!elemt->is_instance_klass()) return; // Ex: int[][]
ctxk = elemt->as_instance_klass();
//if (ctxk->is_final()) return; // Ex: String[][]
}
check_ctxk(ctxk);
assert_common_1(leaf_type, ctxk);
}
void Dependencies::assert_abstract_with_unique_concrete_subtype(ciKlass* ctxk, ciKlass* conck) {
check_ctxk_abstract(ctxk);
assert_common_2(abstract_with_unique_concrete_subtype, ctxk, conck);
}
void Dependencies::assert_unique_concrete_method(ciKlass* ctxk, ciMethod* uniqm) {
check_ctxk(ctxk);
check_unique_method(ctxk, uniqm);
assert_common_2(unique_concrete_method_2, ctxk, uniqm);
}
void Dependencies::assert_unique_concrete_method(ciKlass* ctxk, ciMethod* uniqm, ciKlass* resolved_klass, ciMethod* resolved_method) {
check_ctxk(ctxk);
check_unique_method(ctxk, uniqm);
if (UseVtableBasedCHA) {
assert_common_4(unique_concrete_method_4, ctxk, uniqm, resolved_klass, resolved_method);
} else {
assert_common_2(unique_concrete_method_2, ctxk, uniqm);
}
}
void Dependencies::assert_has_no_finalizable_subclasses(ciKlass* ctxk) {
check_ctxk(ctxk);
assert_common_1(no_finalizable_subclasses, ctxk);
}
void Dependencies::assert_call_site_target_value(ciCallSite* call_site, ciMethodHandle* method_handle) {
assert_common_2(call_site_target_value, call_site, method_handle);
}
#if INCLUDE_JVMCI
Dependencies::Dependencies(Arena* arena, OopRecorder* oop_recorder, CompileLog* log) {
_oop_recorder = oop_recorder;
_log = log;
_dep_seen = new(arena) GrowableArray<int>(arena, 500, 0, 0);
_using_dep_values = true;
DEBUG_ONLY(_dep_values[end_marker] = NULL);
for (int i = (int)FIRST_TYPE; i < (int)TYPE_LIMIT; i++) {
_dep_values[i] = new(arena) GrowableArray<DepValue>(arena, 10, 0, DepValue());
}
_content_bytes = NULL;
_size_in_bytes = (size_t)-1;
assert(TYPE_LIMIT <= (1<<LG2_TYPE_LIMIT), "sanity");
}
void Dependencies::assert_evol_method(Method* m) {
assert_common_1(evol_method, DepValue(_oop_recorder, m));
}
void Dependencies::assert_has_no_finalizable_subclasses(Klass* ctxk) {
check_ctxk(ctxk);
assert_common_1(no_finalizable_subclasses, DepValue(_oop_recorder, ctxk));
}
void Dependencies::assert_leaf_type(Klass* ctxk) {
if (ctxk->is_array_klass()) {
// As a special case, support this assertion on an array type,
// which reduces to an assertion on its element type.
// Note that this cannot be done with assertions that
// relate to concreteness or abstractness.
BasicType elemt = ArrayKlass::cast(ctxk)->element_type();
if (is_java_primitive(elemt)) return; // Ex: int[][]
ctxk = ObjArrayKlass::cast(ctxk)->bottom_klass();
//if (ctxk->is_final()) return; // Ex: String[][]
}
check_ctxk(ctxk);
assert_common_1(leaf_type, DepValue(_oop_recorder, ctxk));
}
void Dependencies::assert_abstract_with_unique_concrete_subtype(Klass* ctxk, Klass* conck) {
check_ctxk_abstract(ctxk);
DepValue ctxk_dv(_oop_recorder, ctxk);
DepValue conck_dv(_oop_recorder, conck, &ctxk_dv);
assert_common_2(abstract_with_unique_concrete_subtype, ctxk_dv, conck_dv);
}
void Dependencies::assert_unique_concrete_method(Klass* ctxk, Method* uniqm) {
check_ctxk(ctxk);
check_unique_method(ctxk, uniqm);
assert_common_2(unique_concrete_method_2, DepValue(_oop_recorder, ctxk), DepValue(_oop_recorder, uniqm));
}
void Dependencies::assert_call_site_target_value(oop call_site, oop method_handle) {
assert_common_2(call_site_target_value, DepValue(_oop_recorder, JNIHandles::make_local(call_site)), DepValue(_oop_recorder, JNIHandles::make_local(method_handle)));
}
#endif // INCLUDE_JVMCI
// Helper function. If we are adding a new dep. under ctxk2,
// try to find an old dep. under a broader* ctxk1. If there is
//
bool Dependencies::maybe_merge_ctxk(GrowableArray<ciBaseObject*>* deps,
int ctxk_i, ciKlass* ctxk2) {
ciKlass* ctxk1 = deps->at(ctxk_i)->as_metadata()->as_klass();
if (ctxk2->is_subtype_of(ctxk1)) {
return true; // success, and no need to change
} else if (ctxk1->is_subtype_of(ctxk2)) {
// new context class fully subsumes previous one
deps->at_put(ctxk_i, ctxk2);
return true;
} else {
return false;
}
}
void Dependencies::assert_common_1(DepType dept, ciBaseObject* x) {
assert(dep_args(dept) == 1, "sanity");
log_dependency(dept, x);
GrowableArray<ciBaseObject*>* deps = _deps[dept];
// see if the same (or a similar) dep is already recorded
if (note_dep_seen(dept, x)) {
assert(deps->find(x) >= 0, "sanity");
} else {
deps->append(x);
}
}
void Dependencies::assert_common_2(DepType dept,
ciBaseObject* x0, ciBaseObject* x1) {
assert(dep_args(dept) == 2, "sanity");
log_dependency(dept, x0, x1);
GrowableArray<ciBaseObject*>* deps = _deps[dept];
// see if the same (or a similar) dep is already recorded
bool has_ctxk = has_explicit_context_arg(dept);
if (has_ctxk) {
assert(dep_context_arg(dept) == 0, "sanity");
if (note_dep_seen(dept, x1)) {
// look in this bucket for redundant assertions
const int stride = 2;
for (int i = deps->length(); (i -= stride) >= 0; ) {
ciBaseObject* y1 = deps->at(i+1);
if (x1 == y1) { // same subject; check the context
if (maybe_merge_ctxk(deps, i+0, x0->as_metadata()->as_klass())) {
return;
}
}
}
}
} else {
if (note_dep_seen(dept, x0) && note_dep_seen(dept, x1)) {
// look in this bucket for redundant assertions
const int stride = 2;
for (int i = deps->length(); (i -= stride) >= 0; ) {
ciBaseObject* y0 = deps->at(i+0);
ciBaseObject* y1 = deps->at(i+1);
if (x0 == y0 && x1 == y1) {
return;
}
}
}
}
// append the assertion in the correct bucket:
deps->append(x0);
deps->append(x1);
}
void Dependencies::assert_common_4(DepType dept,
ciKlass* ctxk, ciBaseObject* x1, ciBaseObject* x2, ciBaseObject* x3) {
assert(has_explicit_context_arg(dept), "sanity");
assert(dep_context_arg(dept) == 0, "sanity");
assert(dep_args(dept) == 4, "sanity");
log_dependency(dept, ctxk, x1, x2, x3);
GrowableArray<ciBaseObject*>* deps = _deps[dept];
// see if the same (or a similar) dep is already recorded
if (note_dep_seen(dept, x1) && note_dep_seen(dept, x2) && note_dep_seen(dept, x3)) {
// look in this bucket for redundant assertions
const int stride = 4;
for (int i = deps->length(); (i -= stride) >= 0; ) {
ciBaseObject* y1 = deps->at(i+1);
ciBaseObject* y2 = deps->at(i+2);
ciBaseObject* y3 = deps->at(i+3);
if (x1 == y1 && x2 == y2 && x3 == y3) { // same subjects; check the context
if (maybe_merge_ctxk(deps, i+0, ctxk)) {
return;
}
}
}
}
// append the assertion in the correct bucket:
deps->append(ctxk);
deps->append(x1);
deps->append(x2);
deps->append(x3);
}
#if INCLUDE_JVMCI
bool Dependencies::maybe_merge_ctxk(GrowableArray<DepValue>* deps,
int ctxk_i, DepValue ctxk2_dv) {
Klass* ctxk1 = deps->at(ctxk_i).as_klass(_oop_recorder);
Klass* ctxk2 = ctxk2_dv.as_klass(_oop_recorder);
if (ctxk2->is_subtype_of(ctxk1)) {
return true; // success, and no need to change
} else if (ctxk1->is_subtype_of(ctxk2)) {
// new context class fully subsumes previous one
deps->at_put(ctxk_i, ctxk2_dv);
return true;
} else {
return false;
}
}
void Dependencies::assert_common_1(DepType dept, DepValue x) {
assert(dep_args(dept) == 1, "sanity");
//log_dependency(dept, x);
GrowableArray<DepValue>* deps = _dep_values[dept];
// see if the same (or a similar) dep is already recorded
if (note_dep_seen(dept, x)) {
assert(deps->find(x) >= 0, "sanity");
} else {
deps->append(x);
}
}
void Dependencies::assert_common_2(DepType dept,
DepValue x0, DepValue x1) {
assert(dep_args(dept) == 2, "sanity");
//log_dependency(dept, x0, x1);
GrowableArray<DepValue>* deps = _dep_values[dept];
// see if the same (or a similar) dep is already recorded
bool has_ctxk = has_explicit_context_arg(dept);
if (has_ctxk) {
assert(dep_context_arg(dept) == 0, "sanity");
if (note_dep_seen(dept, x1)) {
// look in this bucket for redundant assertions
const int stride = 2;
for (int i = deps->length(); (i -= stride) >= 0; ) {
DepValue y1 = deps->at(i+1);
if (x1 == y1) { // same subject; check the context
if (maybe_merge_ctxk(deps, i+0, x0)) {
return;
}
}
}
}
} else {
if (note_dep_seen(dept, x0) && note_dep_seen(dept, x1)) {
// look in this bucket for redundant assertions
const int stride = 2;
for (int i = deps->length(); (i -= stride) >= 0; ) {
DepValue y0 = deps->at(i+0);
DepValue y1 = deps->at(i+1);
if (x0 == y0 && x1 == y1) {
return;
}
}
}
}
// append the assertion in the correct bucket:
deps->append(x0);
deps->append(x1);
}
#endif // INCLUDE_JVMCI
/// Support for encoding dependencies into an nmethod:
void Dependencies::copy_to(nmethod* nm) {
address beg = nm->dependencies_begin();
address end = nm->dependencies_end();
guarantee(end - beg >= (ptrdiff_t) size_in_bytes(), "bad sizing");
Copy::disjoint_words((HeapWord*) content_bytes(),
(HeapWord*) beg,
size_in_bytes() / sizeof(HeapWord));
assert(size_in_bytes() % sizeof(HeapWord) == 0, "copy by words");
}
static int sort_dep(ciBaseObject** p1, ciBaseObject** p2, int narg) {
for (int i = 0; i < narg; i++) {
int diff = p1[i]->ident() - p2[i]->ident();
if (diff != 0) return diff;
}
return 0;
}
static int sort_dep_arg_1(ciBaseObject** p1, ciBaseObject** p2)
{ return sort_dep(p1, p2, 1); }
static int sort_dep_arg_2(ciBaseObject** p1, ciBaseObject** p2)
{ return sort_dep(p1, p2, 2); }
static int sort_dep_arg_3(ciBaseObject** p1, ciBaseObject** p2)
{ return sort_dep(p1, p2, 3); }
static int sort_dep_arg_4(ciBaseObject** p1, ciBaseObject** p2)
{ return sort_dep(p1, p2, 4); }
#if INCLUDE_JVMCI
// metadata deps are sorted before object deps
static int sort_dep_value(Dependencies::DepValue* p1, Dependencies::DepValue* p2, int narg) {
for (int i = 0; i < narg; i++) {
int diff = p1[i].sort_key() - p2[i].sort_key();
if (diff != 0) return diff;
}
return 0;
}
static int sort_dep_value_arg_1(Dependencies::DepValue* p1, Dependencies::DepValue* p2)
{ return sort_dep_value(p1, p2, 1); }
static int sort_dep_value_arg_2(Dependencies::DepValue* p1, Dependencies::DepValue* p2)
{ return sort_dep_value(p1, p2, 2); }
static int sort_dep_value_arg_3(Dependencies::DepValue* p1, Dependencies::DepValue* p2)
{ return sort_dep_value(p1, p2, 3); }
#endif // INCLUDE_JVMCI
void Dependencies::sort_all_deps() {
#if INCLUDE_JVMCI
if (_using_dep_values) {
for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
DepType dept = (DepType)deptv;
GrowableArray<DepValue>* deps = _dep_values[dept];
if (deps->length() <= 1) continue;
switch (dep_args(dept)) {
case 1: deps->sort(sort_dep_value_arg_1, 1); break;
case 2: deps->sort(sort_dep_value_arg_2, 2); break;
case 3: deps->sort(sort_dep_value_arg_3, 3); break;
default: ShouldNotReachHere(); break;
}
}
return;
}
#endif // INCLUDE_JVMCI
for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
DepType dept = (DepType)deptv;
GrowableArray<ciBaseObject*>* deps = _deps[dept];
if (deps->length() <= 1) continue;
switch (dep_args(dept)) {
case 1: deps->sort(sort_dep_arg_1, 1); break;
case 2: deps->sort(sort_dep_arg_2, 2); break;
case 3: deps->sort(sort_dep_arg_3, 3); break;
case 4: deps->sort(sort_dep_arg_4, 4); break;
default: ShouldNotReachHere(); break;
}
}
}
size_t Dependencies::estimate_size_in_bytes() {
size_t est_size = 100;
#if INCLUDE_JVMCI
if (_using_dep_values) {
for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
DepType dept = (DepType)deptv;
GrowableArray<DepValue>* deps = _dep_values[dept];
est_size += deps->length() * 2; // tags and argument(s)
}
return est_size;
}
#endif // INCLUDE_JVMCI
for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
DepType dept = (DepType)deptv;
GrowableArray<ciBaseObject*>* deps = _deps[dept];
est_size += deps->length()*2; // tags and argument(s)
}
return est_size;
}
ciKlass* Dependencies::ctxk_encoded_as_null(DepType dept, ciBaseObject* x) {
switch (dept) {
case unique_concrete_method_2:
case unique_concrete_method_4:
return x->as_metadata()->as_method()->holder();
default:
return NULL; // let NULL be NULL
}
}
Klass* Dependencies::ctxk_encoded_as_null(DepType dept, Metadata* x) {
assert(must_be_in_vm(), "raw oops here");
switch (dept) {
case unique_concrete_method_2:
case unique_concrete_method_4:
assert(x->is_method(), "sanity");
return ((Method*)x)->method_holder();
default:
return NULL; // let NULL be NULL
}
}
void Dependencies::encode_content_bytes() {
sort_all_deps();
// cast is safe, no deps can overflow INT_MAX
CompressedWriteStream bytes((int)estimate_size_in_bytes());
#if INCLUDE_JVMCI
if (_using_dep_values) {
for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
DepType dept = (DepType)deptv;
GrowableArray<DepValue>* deps = _dep_values[dept];
if (deps->length() == 0) continue;
int stride = dep_args(dept);
int ctxkj = dep_context_arg(dept); // -1 if no context arg
assert(stride > 0, "sanity");
for (int i = 0; i < deps->length(); i += stride) {
jbyte code_byte = (jbyte)dept;
int skipj = -1;
if (ctxkj >= 0 && ctxkj+1 < stride) {
Klass* ctxk = deps->at(i+ctxkj+0).as_klass(_oop_recorder);
DepValue x = deps->at(i+ctxkj+1); // following argument
if (ctxk == ctxk_encoded_as_null(dept, x.as_metadata(_oop_recorder))) {
skipj = ctxkj; // we win: maybe one less oop to keep track of
code_byte |= default_context_type_bit;
}
}
bytes.write_byte(code_byte);
for (int j = 0; j < stride; j++) {
if (j == skipj) continue;
DepValue v = deps->at(i+j);
int idx = v.index();
bytes.write_int(idx);
}
}
}
} else {
#endif // INCLUDE_JVMCI
for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
DepType dept = (DepType)deptv;
GrowableArray<ciBaseObject*>* deps = _deps[dept];
if (deps->length() == 0) continue;
int stride = dep_args(dept);
int ctxkj = dep_context_arg(dept); // -1 if no context arg
assert(stride > 0, "sanity");
for (int i = 0; i < deps->length(); i += stride) {
jbyte code_byte = (jbyte)dept;
int skipj = -1;
if (ctxkj >= 0 && ctxkj+1 < stride) {
ciKlass* ctxk = deps->at(i+ctxkj+0)->as_metadata()->as_klass();
ciBaseObject* x = deps->at(i+ctxkj+1); // following argument
if (ctxk == ctxk_encoded_as_null(dept, x)) {
skipj = ctxkj; // we win: maybe one less oop to keep track of
code_byte |= default_context_type_bit;
}
}
bytes.write_byte(code_byte);
for (int j = 0; j < stride; j++) {
if (j == skipj) continue;
ciBaseObject* v = deps->at(i+j);
int idx;
if (v->is_object()) {
idx = _oop_recorder->find_index(v->as_object()->constant_encoding());
} else {
ciMetadata* meta = v->as_metadata();
idx = _oop_recorder->find_index(meta->constant_encoding());
}
bytes.write_int(idx);
}
}
}
#if INCLUDE_JVMCI
}
#endif
// write a sentinel byte to mark the end
bytes.write_byte(end_marker);
// round it out to a word boundary
while (bytes.position() % sizeof(HeapWord) != 0) {
bytes.write_byte(end_marker);
}
// check whether the dept byte encoding really works
assert((jbyte)default_context_type_bit != 0, "byte overflow");
_content_bytes = bytes.buffer();
_size_in_bytes = bytes.position();
}
const char* Dependencies::_dep_name[TYPE_LIMIT] = {
"end_marker",
"evol_method",
"leaf_type",
"abstract_with_unique_concrete_subtype",
"unique_concrete_method_2",
"unique_concrete_method_4",
"no_finalizable_subclasses",
"call_site_target_value"
};
int Dependencies::_dep_args[TYPE_LIMIT] = {
-1,// end_marker
1, // evol_method m
1, // leaf_type ctxk
2, // abstract_with_unique_concrete_subtype ctxk, k
2, // unique_concrete_method_2 ctxk, m
4, // unique_concrete_method_4 ctxk, m, resolved_klass, resolved_method
1, // no_finalizable_subclasses ctxk
2 // call_site_target_value call_site, method_handle
};
const char* Dependencies::dep_name(Dependencies::DepType dept) {
if (!dept_in_mask(dept, all_types)) return "?bad-dep?";
return _dep_name[dept];
}
int Dependencies::dep_args(Dependencies::DepType dept) {
if (!dept_in_mask(dept, all_types)) return -1;
return _dep_args[dept];
}
void Dependencies::check_valid_dependency_type(DepType dept) {
guarantee(FIRST_TYPE <= dept && dept < TYPE_LIMIT, "invalid dependency type: %d", (int) dept);
}
Dependencies::DepType Dependencies::validate_dependencies(CompileTask* task, char** failure_detail) {
int klass_violations = 0;
DepType result = end_marker;
for (Dependencies::DepStream deps(this); deps.next(); ) {
Klass* witness = deps.check_dependency();
if (witness != NULL) {
if (klass_violations == 0) {
result = deps.type();
if (failure_detail != NULL && klass_violations == 0) {
// Use a fixed size buffer to prevent the string stream from
// resizing in the context of an inner resource mark.
char* buffer = NEW_RESOURCE_ARRAY(char, O_BUFLEN);
stringStream st(buffer, O_BUFLEN);
deps.print_dependency(witness, true, &st);
*failure_detail = st.as_string();
}
}
klass_violations++;
if (xtty == NULL) {
// If we're not logging then a single violation is sufficient,
// otherwise we want to log all the dependences which were
// violated.
break;
}
}
}
return result;
}
// for the sake of the compiler log, print out current dependencies:
void Dependencies::log_all_dependencies() {
if (log() == NULL) return;
ResourceMark rm;
for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
DepType dept = (DepType)deptv;
GrowableArray<ciBaseObject*>* deps = _deps[dept];
int deplen = deps->length();
if (deplen == 0) {
continue;
}
int stride = dep_args(dept);
GrowableArray<ciBaseObject*>* ciargs = new GrowableArray<ciBaseObject*>(stride);
for (int i = 0; i < deps->length(); i += stride) {
for (int j = 0; j < stride; j++) {
// flush out the identities before printing
ciargs->push(deps->at(i+j));
}
write_dependency_to(log(), dept, ciargs);
ciargs->clear();
}
guarantee(deplen == deps->length(), "deps array cannot grow inside nested ResoureMark scope");
}
}
void Dependencies::write_dependency_to(CompileLog* log,
DepType dept,
GrowableArray<DepArgument>* args,
Klass* witness) {
if (log == NULL) {
return;
}
ResourceMark rm;
ciEnv* env = ciEnv::current();
GrowableArray<ciBaseObject*>* ciargs = new GrowableArray<ciBaseObject*>(args->length());
for (GrowableArrayIterator<DepArgument> it = args->begin(); it != args->end(); ++it) {
DepArgument arg = *it;
if (arg.is_oop()) {
ciargs->push(env->get_object(arg.oop_value()));
} else {
ciargs->push(env->get_metadata(arg.metadata_value()));
}
}
int argslen = ciargs->length();
Dependencies::write_dependency_to(log, dept, ciargs, witness);
guarantee(argslen == ciargs->length(), "ciargs array cannot grow inside nested ResoureMark scope");
}
void Dependencies::write_dependency_to(CompileLog* log,
DepType dept,
GrowableArray<ciBaseObject*>* args,
Klass* witness) {
if (log == NULL) {
return;
}
ResourceMark rm;
GrowableArray<int>* argids = new GrowableArray<int>(args->length());
for (GrowableArrayIterator<ciBaseObject*> it = args->begin(); it != args->end(); ++it) {
ciBaseObject* obj = *it;
if (obj->is_object()) {
argids->push(log->identify(obj->as_object()));
} else {
argids->push(log->identify(obj->as_metadata()));
}
}
if (witness != NULL) {
log->begin_elem("dependency_failed");
} else {
log->begin_elem("dependency");
}
log->print(" type='%s'", dep_name(dept));
const int ctxkj = dep_context_arg(dept); // -1 if no context arg
if (ctxkj >= 0 && ctxkj < argids->length()) {
log->print(" ctxk='%d'", argids->at(ctxkj));
}
// write remaining arguments, if any.
for (int j = 0; j < argids->length(); j++) {
if (j == ctxkj) continue; // already logged
if (j == 1) {
log->print( " x='%d'", argids->at(j));
} else {
log->print(" x%d='%d'", j, argids->at(j));
}
}
if (witness != NULL) {
log->object("witness", witness);
log->stamp();
}
log->end_elem();
}
void Dependencies::write_dependency_to(xmlStream* xtty,
DepType dept,
GrowableArray<DepArgument>* args,
Klass* witness) {
if (xtty == NULL) {
return;
}
Thread* thread = Thread::current();
HandleMark rm(thread);
ttyLocker ttyl;
int ctxkj = dep_context_arg(dept); // -1 if no context arg
if (witness != NULL) {
xtty->begin_elem("dependency_failed");
} else {
xtty->begin_elem("dependency");
}
xtty->print(" type='%s'", dep_name(dept));
if (ctxkj >= 0) {
xtty->object("ctxk", args->at(ctxkj).metadata_value());
}
// write remaining arguments, if any.
for (int j = 0; j < args->length(); j++) {
if (j == ctxkj) continue; // already logged
DepArgument arg = args->at(j);
if (j == 1) {
if (arg.is_oop()) {
xtty->object("x", Handle(thread, arg.oop_value()));
} else {
xtty->object("x", arg.metadata_value());
}
} else {
char xn[12]; sprintf(xn, "x%d", j);
if (arg.is_oop()) {
xtty->object(xn, Handle(thread, arg.oop_value()));
} else {
xtty->object(xn, arg.metadata_value());
}
}
}
if (witness != NULL) {
xtty->object("witness", witness);
xtty->stamp();
}
xtty->end_elem();
}
void Dependencies::print_dependency(DepType dept, GrowableArray<DepArgument>* args,
Klass* witness, outputStream* st) {
ResourceMark rm;
ttyLocker ttyl; // keep the following output all in one block
st->print_cr("%s of type %s",
(witness == NULL)? "Dependency": "Failed dependency",
dep_name(dept));
// print arguments
int ctxkj = dep_context_arg(dept); // -1 if no context arg
for (int j = 0; j < args->length(); j++) {
DepArgument arg = args->at(j);
bool put_star = false;
if (arg.is_null()) continue;
const char* what;
if (j == ctxkj) {
assert(arg.is_metadata(), "must be");
what = "context";
put_star = !Dependencies::is_concrete_klass((Klass*)arg.metadata_value());
} else if (arg.is_method()) {
what = "method ";
put_star = !Dependencies::is_concrete_method((Method*)arg.metadata_value(), NULL);
} else if (arg.is_klass()) {
what = "class ";
} else {
what = "object ";
}
st->print(" %s = %s", what, (put_star? "*": ""));
if (arg.is_klass()) {
st->print("%s", ((Klass*)arg.metadata_value())->external_name());
} else if (arg.is_method()) {
((Method*)arg.metadata_value())->print_value_on(st);
} else if (arg.is_oop()) {
arg.oop_value()->print_value_on(st);
} else {
ShouldNotReachHere(); // Provide impl for this type.
}
st->cr();
}
if (witness != NULL) {
bool put_star = !Dependencies::is_concrete_klass(witness);
st->print_cr(" witness = %s%s",
(put_star? "*": ""),
witness->external_name());
}
}
void Dependencies::DepStream::log_dependency(Klass* witness) {
if (_deps == NULL && xtty == NULL) return; // fast cutout for runtime
ResourceMark rm;
const int nargs = argument_count();
GrowableArray<DepArgument>* args = new GrowableArray<DepArgument>(nargs);
for (int j = 0; j < nargs; j++) {
if (is_oop_argument(j)) {
args->push(argument_oop(j));
} else {
args->push(argument(j));
}
}
int argslen = args->length();
if (_deps != NULL && _deps->log() != NULL) {
if (ciEnv::current() != NULL) {
Dependencies::write_dependency_to(_deps->log(), type(), args, witness);
} else {
// Treat the CompileLog as an xmlstream instead
Dependencies::write_dependency_to((xmlStream*)_deps->log(), type(), args, witness);
}
} else {
Dependencies::write_dependency_to(xtty, type(), args, witness);
}
guarantee(argslen == args->length(), "args array cannot grow inside nested ResoureMark scope");
}
void Dependencies::DepStream::print_dependency(Klass* witness, bool verbose, outputStream* st) {
ResourceMark rm;
int nargs = argument_count();
GrowableArray<DepArgument>* args = new GrowableArray<DepArgument>(nargs);
for (int j = 0; j < nargs; j++) {
if (is_oop_argument(j)) {
args->push(argument_oop(j));
} else {
args->push(argument(j));
}
}
int argslen = args->length();
Dependencies::print_dependency(type(), args, witness, st);
if (verbose) {
if (_code != NULL) {
st->print(" code: ");
_code->print_value_on(st);
st->cr();
}
}
guarantee(argslen == args->length(), "args array cannot grow inside nested ResoureMark scope");
}
/// Dependency stream support (decodes dependencies from an nmethod):
#ifdef ASSERT
void Dependencies::DepStream::initial_asserts(size_t byte_limit) {
assert(must_be_in_vm(), "raw oops here");
_byte_limit = byte_limit;
_type = (DepType)(end_marker-1); // defeat "already at end" assert
assert((_code!=NULL) + (_deps!=NULL) == 1, "one or t'other");
}
#endif //ASSERT
bool Dependencies::DepStream::next() {
assert(_type != end_marker, "already at end");
if (_bytes.position() == 0 && _code != NULL
&& _code->dependencies_size() == 0) {
// Method has no dependencies at all.
return false;
}
int code_byte = (_bytes.read_byte() & 0xFF);
if (code_byte == end_marker) {
DEBUG_ONLY(_type = end_marker);
return false;
} else {
int ctxk_bit = (code_byte & Dependencies::default_context_type_bit);
code_byte -= ctxk_bit;
DepType dept = (DepType)code_byte;
_type = dept;
Dependencies::check_valid_dependency_type(dept);
int stride = _dep_args[dept];
assert(stride == dep_args(dept), "sanity");
int skipj = -1;
if (ctxk_bit != 0) {
skipj = 0; // currently the only context argument is at zero
assert(skipj == dep_context_arg(dept), "zero arg always ctxk");
}
for (int j = 0; j < stride; j++) {
_xi[j] = (j == skipj)? 0: _bytes.read_int();
}
DEBUG_ONLY(_xi[stride] = -1); // help detect overruns
return true;
}
}
inline Metadata* Dependencies::DepStream::recorded_metadata_at(int i) {
Metadata* o = NULL;
if (_code != NULL) {
o = _code->metadata_at(i);
} else {
o = _deps->oop_recorder()->metadata_at(i);
}
return o;
}
inline oop Dependencies::DepStream::recorded_oop_at(int i) {
return (_code != NULL)
? _code->oop_at(i)
: JNIHandles::resolve(_deps->oop_recorder()->oop_at(i));
}
Metadata* Dependencies::DepStream::argument(int i) {
Metadata* result = recorded_metadata_at(argument_index(i));
if (result == NULL) { // Explicit context argument can be compressed
int ctxkj = dep_context_arg(type()); // -1 if no explicit context arg
if (ctxkj >= 0 && i == ctxkj && ctxkj+1 < argument_count()) {
result = ctxk_encoded_as_null(type(), argument(ctxkj+1));
}
}
assert(result == NULL || result->is_klass() || result->is_method(), "must be");
return result;
}
/**
* Returns a unique identifier for each dependency argument.
*/
uintptr_t Dependencies::DepStream::get_identifier(int i) {
if (is_oop_argument(i)) {
return (uintptr_t)(oopDesc*)argument_oop(i);
} else {
return (uintptr_t)argument(i);
}
}
oop Dependencies::DepStream::argument_oop(int i) {
oop result = recorded_oop_at(argument_index(i));
assert(oopDesc::is_oop_or_null(result), "must be");
return result;
}
InstanceKlass* Dependencies::DepStream::context_type() {
assert(must_be_in_vm(), "raw oops here");
// Most dependencies have an explicit context type argument.
{
int ctxkj = dep_context_arg(type()); // -1 if no explicit context arg
if (ctxkj >= 0) {
Metadata* k = argument(ctxkj);
assert(k != NULL && k->is_klass(), "type check");
return InstanceKlass::cast((Klass*)k);
}
}
// Some dependencies are using the klass of the first object
// argument as implicit context type.
{
int ctxkj = dep_implicit_context_arg(type());
if (ctxkj >= 0) {
Klass* k = argument_oop(ctxkj)->klass();
assert(k != NULL, "type check");
return InstanceKlass::cast(k);
}
}
// And some dependencies don't have a context type at all,
// e.g. evol_method.
return NULL;
}
// ----------------- DependencySignature --------------------------------------
bool DependencySignature::equals(DependencySignature const& s1, DependencySignature const& s2) {
if ((s1.type() != s2.type()) || (s1.args_count() != s2.args_count())) {
return false;
}
for (int i = 0; i < s1.args_count(); i++) {
if (s1.arg(i) != s2.arg(i)) {
return false;
}
}
return true;
}
/// Checking dependencies
// This hierarchy walker inspects subtypes of a given type, trying to find a "bad" class which breaks a dependency.
// Such a class is called a "witness" to the broken dependency.
// While searching around, we ignore "participants", which are already known to the dependency.
class AbstractClassHierarchyWalker {
public:
enum { PARTICIPANT_LIMIT = 3 };
private:
// if non-zero, tells how many witnesses to convert to participants
uint _record_witnesses;
// special classes which are not allowed to be witnesses:
Klass* _participants[PARTICIPANT_LIMIT+1];
uint _num_participants;
#ifdef ASSERT
uint _nof_requests; // one-shot walker
#endif // ASSERT
static PerfCounter* _perf_find_witness_anywhere_calls_count;
static PerfCounter* _perf_find_witness_anywhere_steps_count;
static PerfCounter* _perf_find_witness_in_calls_count;
protected:
virtual Klass* find_witness_in(KlassDepChange& changes) = 0;
virtual Klass* find_witness_anywhere(InstanceKlass* context_type) = 0;
AbstractClassHierarchyWalker(Klass* participant) : _record_witnesses(0), _num_participants(0)
#ifdef ASSERT
, _nof_requests(0)
#endif // ASSERT
{
for (uint i = 0; i < PARTICIPANT_LIMIT+1; i++) {
_participants[i] = NULL;
}
if (participant != NULL) {
add_participant(participant);
}
}
bool is_participant(Klass* k) {
for (uint i = 0; i < _num_participants; i++) {
if (_participants[i] == k) {
return true;
}
}
return false;
}
bool record_witness(Klass* witness) {
if (_record_witnesses > 0) {
--_record_witnesses;
add_participant(witness);
return false; // not a witness
} else {
return true; // is a witness
}
}
class CountingClassHierarchyIterator : public ClassHierarchyIterator {
private:
jlong _nof_steps;
public:
CountingClassHierarchyIterator(InstanceKlass* root) : ClassHierarchyIterator(root), _nof_steps(0) {}
void next() {
_nof_steps++;
ClassHierarchyIterator::next();
}
~CountingClassHierarchyIterator() {
if (UsePerfData) {
_perf_find_witness_anywhere_steps_count->inc(_nof_steps);
}
}
};
public:
uint num_participants() { return _num_participants; }
Klass* participant(uint n) {
assert(n <= _num_participants, "oob");
if (n < _num_participants) {
return _participants[n];
} else {
return NULL;
}
}
void add_participant(Klass* participant) {
assert(!is_participant(participant), "sanity");
assert(_num_participants + _record_witnesses < PARTICIPANT_LIMIT, "oob");
uint np = _num_participants++;
_participants[np] = participant;
}
void record_witnesses(uint add) {
if (add > PARTICIPANT_LIMIT) add = PARTICIPANT_LIMIT;
assert(_num_participants + add < PARTICIPANT_LIMIT, "oob");
_record_witnesses = add;
}
Klass* find_witness(InstanceKlass* context_type, KlassDepChange* changes = NULL);
static void init();
static void print_statistics();
};
PerfCounter* AbstractClassHierarchyWalker::_perf_find_witness_anywhere_calls_count = NULL;
PerfCounter* AbstractClassHierarchyWalker::_perf_find_witness_anywhere_steps_count = NULL;
PerfCounter* AbstractClassHierarchyWalker::_perf_find_witness_in_calls_count = NULL;
void AbstractClassHierarchyWalker::init() {
if (UsePerfData) {
EXCEPTION_MARK;
_perf_find_witness_anywhere_calls_count =
PerfDataManager::create_counter(SUN_CI, "findWitnessAnywhere", PerfData::U_Events, CHECK);
_perf_find_witness_anywhere_steps_count =
PerfDataManager::create_counter(SUN_CI, "findWitnessAnywhereSteps", PerfData::U_Events, CHECK);
_perf_find_witness_in_calls_count =
PerfDataManager::create_counter(SUN_CI, "findWitnessIn", PerfData::U_Events, CHECK);
}
}
Klass* AbstractClassHierarchyWalker::find_witness(InstanceKlass* context_type, KlassDepChange* changes) {
// Current thread must be in VM (not native mode, as in CI):
assert(must_be_in_vm(), "raw oops here");
// Must not move the class hierarchy during this check:
assert_locked_or_safepoint(Compile_lock);
assert(_nof_requests++ == 0, "repeated requests are not supported");
assert(changes == NULL || changes->involves_context(context_type), "irrelevant dependency");
// (Note: Interfaces do not have subclasses.)
// If it is an interface, search its direct implementors.
// (Their subclasses are additional indirect implementors. See InstanceKlass::add_implementor().)
if (context_type->is_interface()) {
int nof_impls = context_type->nof_implementors();
if (nof_impls == 0) {
return NULL; // no implementors
} else if (nof_impls == 1) { // unique implementor
assert(context_type != context_type->implementor(), "not unique");
context_type = InstanceKlass::cast(context_type->implementor());
} else { // nof_impls >= 2
// Avoid this case: *I.m > { A.m, C }; B.m > C
// Here, I.m has 2 concrete implementations, but m appears unique
// as A.m, because the search misses B.m when checking C.
// The inherited method B.m was getting missed by the walker
// when interface 'I' was the starting point.
// %%% Until this is fixed more systematically, bail out.
return context_type;
}
}
assert(!context_type->is_interface(), "no interfaces allowed");
if (changes != NULL) {
if (UsePerfData) {
_perf_find_witness_in_calls_count->inc();
}
return find_witness_in(*changes);
} else {
if (UsePerfData) {
_perf_find_witness_anywhere_calls_count->inc();
}
return find_witness_anywhere(context_type);
}
}
class ConcreteSubtypeFinder : public AbstractClassHierarchyWalker {
private:
bool is_witness(Klass* k);
protected:
virtual Klass* find_witness_in(KlassDepChange& changes);
virtual Klass* find_witness_anywhere(InstanceKlass* context_type);
public:
ConcreteSubtypeFinder(Klass* participant = NULL) : AbstractClassHierarchyWalker(participant) {}
};
bool ConcreteSubtypeFinder::is_witness(Klass* k) {
if (Dependencies::is_concrete_klass(k)) {
return record_witness(k); // concrete subtype
} else {
return false; // not a concrete class
}
}
Klass* ConcreteSubtypeFinder::find_witness_in(KlassDepChange& changes) {
// When looking for unexpected concrete types, do not look beneath expected ones:
// * CX > CC > C' is OK, even if C' is new.
// * CX > { CC, C' } is not OK if C' is new, and C' is the witness.
Klass* new_type = changes.as_new_klass_change()->new_type();
assert(!is_participant(new_type), "only old classes are participants");
// If the new type is a subtype of a participant, we are done.
for (uint i = 0; i < num_participants(); i++) {
if (changes.involves_context(participant(i))) {
// new guy is protected from this check by previous participant
return NULL;
}
}
if (is_witness(new_type)) {
return new_type;
}
// No witness found. The dependency remains unbroken.
return NULL;
}
Klass* ConcreteSubtypeFinder::find_witness_anywhere(InstanceKlass* context_type) {
for (CountingClassHierarchyIterator iter(context_type); !iter.done(); iter.next()) {
Klass* sub = iter.klass();
// Do not report participant types.
if (is_participant(sub)) {
// Don't walk beneath a participant since it hides witnesses.
iter.skip_subclasses();
} else if (is_witness(sub)) {
return sub; // found a witness
}
}
// No witness found. The dependency remains unbroken.
return NULL;
}
class ConcreteMethodFinder : public AbstractClassHierarchyWalker {
private:
Symbol* _name;
Symbol* _signature;
// cache of method lookups
Method* _found_methods[PARTICIPANT_LIMIT+1];
bool is_witness(Klass* k);
protected:
virtual Klass* find_witness_in(KlassDepChange& changes);
virtual Klass* find_witness_anywhere(InstanceKlass* context_type);
public:
bool witnessed_reabstraction_in_supers(Klass* k);
ConcreteMethodFinder(Method* m, Klass* participant = NULL) : AbstractClassHierarchyWalker(participant) {
assert(m != NULL && m->is_method(), "sanity");
_name = m->name();
_signature = m->signature();
for (int i = 0; i < PARTICIPANT_LIMIT+1; i++) {
_found_methods[i] = NULL;
}
}
// Note: If n==num_participants, returns NULL.
Method* found_method(uint n) {
assert(n <= num_participants(), "oob");
Method* fm = _found_methods[n];
assert(n == num_participants() || fm != NULL, "proper usage");
if (fm != NULL && fm->method_holder() != participant(n)) {
// Default methods from interfaces can be added to classes. In
// that case the holder of the method is not the class but the
// interface where it's defined.
assert(fm->is_default_method(), "sanity");
return NULL;
}
return fm;
}
void add_participant(Klass* participant) {
AbstractClassHierarchyWalker::add_participant(participant);
_found_methods[num_participants()] = NULL;
}
bool record_witness(Klass* witness, Method* m) {
_found_methods[num_participants()] = m;
return AbstractClassHierarchyWalker::record_witness(witness);
}
private:
static PerfCounter* _perf_find_witness_anywhere_calls_count;
static PerfCounter* _perf_find_witness_anywhere_steps_count;
static PerfCounter* _perf_find_witness_in_calls_count;
public:
static void init();
static void print_statistics();
};
bool ConcreteMethodFinder::is_witness(Klass* k) {
if (is_participant(k)) {
return false; // do not report participant types
}
if (k->is_instance_klass()) {
InstanceKlass* ik = InstanceKlass::cast(k);
// Search class hierarchy first, skipping private implementations
// as they never override any inherited methods
Method* m = ik->find_instance_method(_name, _signature, Klass::PrivateLookupMode::skip);
if (Dependencies::is_concrete_method(m, ik)) {
return record_witness(k, m); // concrete method found
} else {
// Check for re-abstraction of method
if (!ik->is_interface() && m != NULL && m->is_abstract()) {
// Found a matching abstract method 'm' in the class hierarchy.
// This is fine iff 'k' is an abstract class and all concrete subtypes
// of 'k' override 'm' and are participates of the current search.
ConcreteSubtypeFinder wf;
for (uint i = 0; i < num_participants(); i++) {
Klass* p = participant(i);
wf.add_participant(p);
}
Klass* w = wf.find_witness(ik);
if (w != NULL) {
Method* wm = InstanceKlass::cast(w)->find_instance_method(_name, _signature, Klass::PrivateLookupMode::skip);
if (!Dependencies::is_concrete_method(wm, w)) {
// Found a concrete subtype 'w' which does not override abstract method 'm'.
// Bail out because 'm' could be called with 'w' as receiver (leading to an
// AbstractMethodError) and thus the method we are looking for is not unique.
return record_witness(k, m);
}
}
}
// Check interface defaults also, if any exist.
Array<Method*>* default_methods = ik->default_methods();
if (default_methods != NULL) {
Method* dm = ik->find_method(default_methods, _name, _signature);
if (Dependencies::is_concrete_method(dm, NULL)) {
return record_witness(k, dm); // default method found
}
}
return false; // no concrete method found
}
} else {
return false; // no methods to find in an array type
}
}
Klass* ConcreteMethodFinder::find_witness_in(KlassDepChange& changes) {
// When looking for unexpected concrete methods, look beneath expected ones, to see if there are overrides.
// * CX.m > CC.m > C'.m is not OK, if C'.m is new, and C' is the witness.
Klass* new_type = changes.as_new_klass_change()->new_type();
assert(!is_participant(new_type), "only old classes are participants");
if (is_witness(new_type)) {
return new_type;
} else {
// No witness found, but is_witness() doesn't detect method re-abstraction in case of spot-checking.
if (witnessed_reabstraction_in_supers(new_type)) {
return new_type;
}
}
// No witness found. The dependency remains unbroken.
return NULL;
}
bool ConcreteMethodFinder::witnessed_reabstraction_in_supers(Klass* k) {
if (!k->is_instance_klass()) {
return false; // no methods to find in an array type
} else {
// Looking for a case when an abstract method is inherited into a concrete class.
if (Dependencies::is_concrete_klass(k) && !k->is_interface()) {
Method* m = InstanceKlass::cast(k)->find_instance_method(_name, _signature, Klass::PrivateLookupMode::skip);
if (m != NULL) {
return false; // no reabstraction possible: local method found
}
for (InstanceKlass* super = k->java_super(); super != NULL; super = super->java_super()) {
m = super->find_instance_method(_name, _signature, Klass::PrivateLookupMode::skip);
if (m != NULL) { // inherited method found
if (m->is_abstract() || m->is_overpass()) {
return record_witness(super, m); // abstract method found
}
return false;
}
}
// Miranda.
return true;
}
return false;
}
}
Klass* ConcreteMethodFinder::find_witness_anywhere(InstanceKlass* context_type) {
// Walk hierarchy under a context type, looking for unexpected types.
for (CountingClassHierarchyIterator iter(context_type); !iter.done(); iter.next()) {
Klass* sub = iter.klass();
if (is_witness(sub)) {
return sub; // found a witness
}
}
// No witness found. The dependency remains unbroken.
return NULL;
}
// For some method m and some class ctxk (subclass of method holder),
// enumerate all distinct overrides of m in concrete subclasses of ctxk.
// It relies on vtable/itable information to perform method selection on each linked subclass
// and ignores all non yet linked ones (speculatively treat them as "effectively abstract").
class LinkedConcreteMethodFinder : public AbstractClassHierarchyWalker {
private:
InstanceKlass* _resolved_klass; // resolved class (JVMS-5.4.3.1)
InstanceKlass* _declaring_klass; // the holder of resolved method (JVMS-5.4.3.3)
int _vtable_index; // vtable/itable index of the resolved method
bool _do_itable_lookup; // choose between itable and vtable lookup logic
// cache of method lookups
Method* _found_methods[PARTICIPANT_LIMIT+1];
bool is_witness(Klass* k);
Method* select_method(InstanceKlass* recv_klass);
static int compute_vtable_index(InstanceKlass* resolved_klass, Method* resolved_method, bool& is_itable_index);
static bool is_concrete_klass(InstanceKlass* ik);
void add_participant(Method* m, Klass* participant) {
uint np = num_participants();
AbstractClassHierarchyWalker::add_participant(participant);
assert(np + 1 == num_participants(), "sanity");
_found_methods[np] = m; // record the method for the participant
}
bool record_witness(Klass* witness, Method* m) {
for (uint i = 0; i < num_participants(); i++) {
if (found_method(i) == m) {
return false; // already recorded
}
}
// Record not yet seen method.
_found_methods[num_participants()] = m;
return AbstractClassHierarchyWalker::record_witness(witness);
}
void initialize(Method* participant) {
for (uint i = 0; i < PARTICIPANT_LIMIT+1; i++) {
_found_methods[i] = NULL;
}
if (participant != NULL) {
add_participant(participant, participant->method_holder());
}
}
protected:
virtual Klass* find_witness_in(KlassDepChange& changes);
virtual Klass* find_witness_anywhere(InstanceKlass* context_type);
public:
// In order to perform method selection, the following info is needed:
// (1) interface or virtual call;
// (2) vtable/itable index;
// (3) declaring class (in case of interface call).
//
// It is prepared based on the results of method resolution: resolved class and resolved method (as specified in JVMS-5.4.3.3).
// Optionally, a method which was previously determined as a unique target (uniqm) is added as a participant
// to enable dependency spot-checking and speed up the search.
LinkedConcreteMethodFinder(InstanceKlass* resolved_klass, Method* resolved_method, Method* uniqm = NULL) : AbstractClassHierarchyWalker(NULL) {
assert(UseVtableBasedCHA, "required");
assert(resolved_klass->is_linked(), "required");
assert(resolved_method->method_holder()->is_linked(), "required");
assert(!resolved_method->can_be_statically_bound(), "no vtable index available");
_resolved_klass = resolved_klass;
_declaring_klass = resolved_method->method_holder();
_vtable_index = compute_vtable_index(resolved_klass, resolved_method,
_do_itable_lookup); // out parameter
assert(_vtable_index >= 0, "invalid vtable index");
initialize(uniqm);
}
// Note: If n==num_participants, returns NULL.
Method* found_method(uint n) {
assert(n <= num_participants(), "oob");
assert(participant(n) != NULL || n == num_participants(), "proper usage");
return _found_methods[n];
}
};
Klass* LinkedConcreteMethodFinder::find_witness_in(KlassDepChange& changes) {
Klass* type = changes.type();
assert(!is_participant(type), "only old classes are participants");
if (is_witness(type)) {
return type;
}
return NULL; // No witness found. The dependency remains unbroken.
}
Klass* LinkedConcreteMethodFinder::find_witness_anywhere(InstanceKlass* context_type) {
for (CountingClassHierarchyIterator iter(context_type); !iter.done(); iter.next()) {
Klass* sub = iter.klass();
if (is_witness(sub)) {
return sub;
}
if (sub->is_instance_klass() && !InstanceKlass::cast(sub)->is_linked()) {
iter.skip_subclasses(); // ignore not yet linked classes
}
}
return NULL; // No witness found. The dependency remains unbroken.
}
bool LinkedConcreteMethodFinder::is_witness(Klass* k) {
if (is_participant(k)) {
return false; // do not report participant types
} else if (k->is_instance_klass()) {
InstanceKlass* ik = InstanceKlass::cast(k);
if (is_concrete_klass(ik)) {
Method* m = select_method(ik);
return record_witness(ik, m);
} else {
return false; // ignore non-concrete holder class
}
} else {
return false; // no methods to find in an array type
}
}
Method* LinkedConcreteMethodFinder::select_method(InstanceKlass* recv_klass) {
Method* selected_method = NULL;
if (_do_itable_lookup) {
assert(_declaring_klass->is_interface(), "sanity");
bool implements_interface; // initialized by method_at_itable_or_null()
selected_method = recv_klass->method_at_itable_or_null(_declaring_klass, _vtable_index,
implements_interface); // out parameter
assert(implements_interface, "not implemented");
} else {
selected_method = recv_klass->method_at_vtable(_vtable_index);
}
return selected_method; // NULL when corresponding slot is empty (AbstractMethodError case)
}
int LinkedConcreteMethodFinder::compute_vtable_index(InstanceKlass* resolved_klass, Method* resolved_method,
// out parameter
bool& is_itable_index) {
if (resolved_klass->is_interface() && resolved_method->has_itable_index()) {
is_itable_index = true;
return resolved_method->itable_index();
}
// Check for default or miranda method first.
InstanceKlass* declaring_klass = resolved_method->method_holder();
if (!resolved_klass->is_interface() && declaring_klass->is_interface()) {
is_itable_index = false;
return resolved_klass->vtable_index_of_interface_method(resolved_method);
}
// At this point we are sure that resolved_method is virtual and not
// a default or miranda method; therefore, it must have a valid vtable index.
assert(resolved_method->has_vtable_index(), "");
is_itable_index = false;
return resolved_method->vtable_index();
}
bool LinkedConcreteMethodFinder::is_concrete_klass(InstanceKlass* ik) {
if (!Dependencies::is_concrete_klass(ik)) {
return false; // not concrete
}
if (ik->is_interface()) {
return false; // interfaces aren't concrete
}
if (!ik->is_linked()) {
return false; // not yet linked classes don't have instances
}
return true;
}
#ifdef ASSERT
// Assert that m is inherited into ctxk, without intervening overrides.
// (May return true even if this is not true, in corner cases where we punt.)
bool Dependencies::verify_method_context(InstanceKlass* ctxk, Method* m) {
if (m->is_private()) {
return false; // Quick lose. Should not happen.
}
if (m->method_holder() == ctxk) {
return true; // Quick win.
}
if (!(m->is_public() || m->is_protected())) {
// The override story is complex when packages get involved.
return true; // Must punt the assertion to true.
}
Method* lm = ctxk->lookup_method(m->name(), m->signature());
if (lm == NULL && ctxk->is_instance_klass()) {
// It might be an interface method
lm = InstanceKlass::cast(ctxk)->lookup_method_in_ordered_interfaces(m->name(),
m->signature());
}
if (lm == m) {
// Method m is inherited into ctxk.
return true;
}
if (lm != NULL) {
if (!(lm->is_public() || lm->is_protected())) {
// Method is [package-]private, so the override story is complex.
return true; // Must punt the assertion to true.
}
if (lm->is_static()) {
// Static methods don't override non-static so punt
return true;
}
if (!Dependencies::is_concrete_method(lm, ctxk) &&
!Dependencies::is_concrete_method(m, ctxk)) {
// They are both non-concrete
if (lm->method_holder()->is_subtype_of(m->method_holder())) {
// Method m is overridden by lm, but both are non-concrete.
return true;
}
if (lm->method_holder()->is_interface() && m->method_holder()->is_interface() &&
ctxk->is_subtype_of(m->method_holder()) && ctxk->is_subtype_of(lm->method_holder())) {
// Interface method defined in multiple super interfaces
return true;
}
}
}
ResourceMark rm;
tty->print_cr("Dependency method not found in the associated context:");
tty->print_cr(" context = %s", ctxk->external_name());
tty->print( " method = "); m->print_short_name(tty); tty->cr();
if (lm != NULL) {
tty->print( " found = "); lm->print_short_name(tty); tty->cr();
}
return false;
}
#endif // ASSERT
bool Dependencies::is_concrete_klass(Klass* k) {
if (k->is_abstract()) return false;
// %%% We could treat classes which are concrete but
// have not yet been instantiated as virtually abstract.
// This would require a deoptimization barrier on first instantiation.
//if (k->is_not_instantiated()) return false;
return true;
}
bool Dependencies::is_concrete_method(Method* m, Klass* k) {
// NULL is not a concrete method.
if (m == NULL) {
return false;
}
// Statics are irrelevant to virtual call sites.
if (m->is_static()) {
return false;
}
// Abstract methods are not concrete.
if (m->is_abstract()) {
return false;
}
// Overpass (error) methods are not concrete if k is abstract.
if (m->is_overpass() && k != NULL) {
return !k->is_abstract();
}
// Note "true" is conservative answer: overpass clause is false if k == NULL,
// implies return true if answer depends on overpass clause.
return true;
}
Klass* Dependencies::find_finalizable_subclass(InstanceKlass* ik) {
for (ClassHierarchyIterator iter(ik); !iter.done(); iter.next()) {
Klass* sub = iter.klass();
if (sub->has_finalizer() && !sub->is_interface()) {
return sub;
}
}
return NULL; // not found
}
bool Dependencies::is_concrete_klass(ciInstanceKlass* k) {
if (k->is_abstract()) return false;
// We could also return false if k does not yet appear to be
// instantiated, if the VM version supports this distinction also.
//if (k->is_not_instantiated()) return false;
return true;
}
bool Dependencies::has_finalizable_subclass(ciInstanceKlass* k) {
return k->has_finalizable_subclass();
}
// Any use of the contents (bytecodes) of a method must be
// marked by an "evol_method" dependency, if those contents
// can change. (Note: A method is always dependent on itself.)
Klass* Dependencies::check_evol_method(Method* m) {
assert(must_be_in_vm(), "raw oops here");
// Did somebody do a JVMTI RedefineClasses while our backs were turned?
// Or is there a now a breakpoint?
// (Assumes compiled code cannot handle bkpts; change if UseFastBreakpoints.)
if (m->is_old()
|| m->number_of_breakpoints() > 0) {
return m->method_holder();
} else {
return NULL;
}
}
// This is a strong assertion: It is that the given type
// has no subtypes whatever. It is most useful for
// optimizing checks on reflected types or on array types.
// (Checks on types which are derived from real instances
// can be optimized more strongly than this, because we
// know that the checked type comes from a concrete type,
// and therefore we can disregard abstract types.)
Klass* Dependencies::check_leaf_type(InstanceKlass* ctxk) {
assert(must_be_in_vm(), "raw oops here");
assert_locked_or_safepoint(Compile_lock);
Klass* sub = ctxk->subklass();
if (sub != NULL) {
return sub;
} else if (ctxk->nof_implementors() != 0) {
// if it is an interface, it must be unimplemented
// (if it is not an interface, nof_implementors is always zero)
InstanceKlass* impl = ctxk->implementor();
assert(impl != NULL, "must be set");
return impl;
} else {
return NULL;
}
}
// Test the assertion that conck is the only concrete subtype* of ctxk.
// The type conck itself is allowed to have have further concrete subtypes.
// This allows the compiler to narrow occurrences of ctxk by conck,
// when dealing with the types of actual instances.
Klass* Dependencies::check_abstract_with_unique_concrete_subtype(InstanceKlass* ctxk,
Klass* conck,
NewKlassDepChange* changes) {
ConcreteSubtypeFinder wf(conck);
Klass* k = wf.find_witness(ctxk, changes);
return k;
}
// Find the unique concrete proper subtype of ctxk, or NULL if there
// is more than one concrete proper subtype. If there are no concrete
// proper subtypes, return ctxk itself, whether it is concrete or not.
// The returned subtype is allowed to have have further concrete subtypes.
// That is, return CC1 for CX > CC1 > CC2, but NULL for CX > { CC1, CC2 }.
Klass* Dependencies::find_unique_concrete_subtype(InstanceKlass* ctxk) {
ConcreteSubtypeFinder wf(ctxk); // Ignore ctxk when walking.
wf.record_witnesses(1); // Record one other witness when walking.
Klass* wit = wf.find_witness(ctxk);
if (wit != NULL) return NULL; // Too many witnesses.
Klass* conck = wf.participant(0);
if (conck == NULL) {
return ctxk; // Return ctxk as a flag for "no subtypes".
} else {
#ifndef PRODUCT
// Make sure the dependency mechanism will pass this discovery:
if (VerifyDependencies) {
// Turn off dependency tracing while actually testing deps.
FlagSetting fs(TraceDependencies, false);
if (!Dependencies::is_concrete_klass(ctxk)) {
guarantee(NULL == (void *)
check_abstract_with_unique_concrete_subtype(ctxk, conck),
"verify dep.");
}
}
#endif //PRODUCT
return conck;
}
}
// Try to determine whether root method in some context is concrete or not based on the information about the unique method
// in that context. It exploits the fact that concrete root method is always inherited into the context when there's a unique method.
// Hence, unique method holder is always a supertype of the context class when root method is concrete.
// Examples for concrete_root_method
// C (C.m uniqm)
// |
// CX (ctxk) uniqm is inherited into context.
//
// CX (ctxk) (CX.m uniqm) here uniqm is defined in ctxk.
// Examples for !concrete_root_method
// CX (ctxk)
// |
// C (C.m uniqm) uniqm is in subtype of ctxk.
bool Dependencies::is_concrete_root_method(Method* uniqm, InstanceKlass* ctxk) {
if (uniqm == NULL) {
return false; // match Dependencies::is_concrete_method() behavior
}
// Theoretically, the "direction" of subtype check matters here.
// On one hand, in case of interface context with a single implementor, uniqm can be in a superclass of the implementor which
// is not related to context class.
// On another hand, uniqm could come from an interface unrelated to the context class, but right now it is not possible:
// it is required that uniqm->method_holder() is the participant (uniqm->method_holder() <: ctxk), hence a default method
// can't be used as unique.
if (ctxk->is_interface()) {
InstanceKlass* implementor = ctxk->implementor();
assert(implementor != ctxk, "single implementor only"); // should have been invalidated earlier
ctxk = implementor;
}
InstanceKlass* holder = uniqm->method_holder();
assert(!holder->is_interface(), "no default methods allowed");
assert(ctxk->is_subclass_of(holder) || holder->is_subclass_of(ctxk), "not related");
return ctxk->is_subclass_of(holder);
}
// If a class (or interface) has a unique concrete method uniqm, return NULL.
// Otherwise, return a class that contains an interfering method.
Klass* Dependencies::check_unique_concrete_method(InstanceKlass* ctxk,
Method* uniqm,
NewKlassDepChange* changes) {
ConcreteMethodFinder wf(uniqm, uniqm->method_holder());
Klass* k = wf.find_witness(ctxk, changes);
if (k != NULL) {
return k;
}
if (!Dependencies::is_concrete_root_method(uniqm, ctxk) || changes != NULL) {
Klass* conck = find_witness_AME(ctxk, uniqm, changes);
if (conck != NULL) {
// Found a concrete subtype 'conck' which does not override abstract root method.
return conck;
}
}
return NULL;
}
// Search for AME.
// There are two version of checks.
// 1) Spot checking version(Classload time). Newly added class is checked for AME.
// Checks whether abstract/overpass method is inherited into/declared in newly added concrete class.
// 2) Compile time analysis for abstract/overpass(abstract klass) root_m. The non uniqm subtrees are checked for concrete classes.
Klass* Dependencies::find_witness_AME(InstanceKlass* ctxk, Method* m, KlassDepChange* changes) {
if (m != NULL) {
if (changes != NULL) {
// Spot checking version.
ConcreteMethodFinder wf(m);
Klass* new_type = changes->as_new_klass_change()->new_type();
if (wf.witnessed_reabstraction_in_supers(new_type)) {
return new_type;
}
} else {
// Note: It is required that uniqm->method_holder() is the participant (see ClassHierarchyWalker::found_method()).
ConcreteSubtypeFinder wf(m->method_holder());
Klass* conck = wf.find_witness(ctxk);
if (conck != NULL) {
Method* cm = InstanceKlass::cast(conck)->find_instance_method(m->name(), m->signature(), Klass::PrivateLookupMode::skip);
if (!Dependencies::is_concrete_method(cm, conck)) {
return conck;
}
}
}
}
return NULL;
}
// Find the set of all non-abstract methods under ctxk that match m.
// (The method m must be defined or inherited in ctxk.)
// Include m itself in the set, unless it is abstract.
// If this set has exactly one element, return that element.
Method* Dependencies::find_unique_concrete_method(InstanceKlass* ctxk, Method* m, Klass** participant) {
// Return NULL if m is marked old; must have been a redefined method.
if (m->is_old()) {
return NULL;
}
if (m->is_default_method()) {
return NULL; // not supported
}
assert(verify_method_context(ctxk, m), "proper context");
ConcreteMethodFinder wf(m);
wf.record_witnesses(1);
Klass* wit = wf.find_witness(ctxk);
if (wit != NULL) return NULL; // Too many witnesses.
Method* fm = wf.found_method(0); // Will be NULL if num_parts == 0.
if (participant != NULL) {
(*participant) = wf.participant(0);
}
if (!Dependencies::is_concrete_method(fm, NULL)) {
fm = NULL; // ignore abstract methods
}
if (Dependencies::is_concrete_method(m, ctxk)) {
if (fm == NULL) {
// It turns out that m was always the only implementation.
fm = m;
} else if (fm != m) {
// Two conflicting implementations after all.
// (This can happen if m is inherited into ctxk and fm overrides it.)
return NULL;
}
} else if (Dependencies::find_witness_AME(ctxk, fm) != NULL) {
// Found a concrete subtype which does not override abstract root method.
return NULL;
}
assert(Dependencies::is_concrete_root_method(fm, ctxk) == Dependencies::is_concrete_method(m, ctxk), "mismatch");
#ifndef PRODUCT
// Make sure the dependency mechanism will pass this discovery:
if (VerifyDependencies && fm != NULL) {
guarantee(NULL == (void *)check_unique_concrete_method(ctxk, fm),
"verify dep.");
}
#endif //PRODUCT
return fm;
}
// If a class (or interface) has a unique concrete method uniqm, return NULL.
// Otherwise, return a class that contains an interfering method.
Klass* Dependencies::check_unique_concrete_method(InstanceKlass* ctxk,
Method* uniqm,
Klass* resolved_klass,
Method* resolved_method,
KlassDepChange* changes) {
assert(UseVtableBasedCHA, "required");
assert(!ctxk->is_interface() || ctxk == resolved_klass, "sanity");
assert(!resolved_method->can_be_statically_bound() || resolved_method == uniqm, "sanity");
assert(resolved_klass->is_subtype_of(resolved_method->method_holder()), "sanity");
if (!InstanceKlass::cast(resolved_klass)->is_linked() ||
!resolved_method->method_holder()->is_linked() ||
resolved_method->can_be_statically_bound()) {
// Dependency is redundant, but benign. Just keep it to avoid unnecessary recompilation.
return NULL; // no vtable index available
}
LinkedConcreteMethodFinder mf(InstanceKlass::cast(resolved_klass), resolved_method, uniqm);
return mf.find_witness(ctxk, changes);
}
// Find the set of all non-abstract methods under ctxk that match m.
// (The method m must be defined or inherited in ctxk.)
// Include m itself in the set, unless it is abstract.
// If this set has exactly one element, return that element.
// Not yet linked subclasses of ctxk are ignored since they don't have any instances yet.
// Additionally, resolved_klass and resolved_method complete the description of the call site being analyzed.
Method* Dependencies::find_unique_concrete_method(InstanceKlass* ctxk, Method* m, Klass* resolved_klass, Method* resolved_method) {
// Return NULL if m is marked old; must have been a redefined method.
if (m->is_old()) {
return NULL;
}
if (!InstanceKlass::cast(resolved_klass)->is_linked() ||
!resolved_method->method_holder()->is_linked() ||
resolved_method->can_be_statically_bound()) {
return m; // nothing to do: no witness under ctxk
}
LinkedConcreteMethodFinder wf(InstanceKlass::cast(resolved_klass), resolved_method);
assert(Dependencies::verify_method_context(ctxk, m), "proper context");
wf.record_witnesses(1);
Klass* wit = wf.find_witness(ctxk);
if (wit != NULL) {
return NULL; // Too many witnesses.
}
// p == NULL when no participants are found (wf.num_participants() == 0).
// fm == NULL case has 2 meanings:
// * when p == NULL: no method found;
// * when p != NULL: AbstractMethodError-throwing method found.
// Also, found method should always be accompanied by a participant class.
Klass* p = wf.participant(0);
Method* fm = wf.found_method(0);
assert(fm == NULL || p != NULL, "no participant");
// Normalize all error-throwing cases to NULL.
if (fm == Universe::throw_illegal_access_error() ||
fm == Universe::throw_no_such_method_error() ||
!Dependencies::is_concrete_method(fm, p)) {
fm = NULL; // error-throwing method
}
if (Dependencies::is_concrete_method(m, ctxk)) {
if (p == NULL) {
// It turns out that m was always the only implementation.
assert(fm == NULL, "sanity");
fm = m;
}
}
#ifndef PRODUCT
// Make sure the dependency mechanism will pass this discovery:
if (VerifyDependencies && fm != NULL) {
guarantee(NULL == check_unique_concrete_method(ctxk, fm, resolved_klass, resolved_method),
"verify dep.");
}
#endif // PRODUCT
assert(fm == NULL || !fm->is_abstract(), "sanity");
// Old CHA conservatively reports concrete methods in abstract classes
// irrespective of whether they have concrete subclasses or not.
// Also, abstract root method case is not fully supported.
#ifdef ASSERT
Klass* uniqp = NULL;
Method* uniqm = Dependencies::find_unique_concrete_method(ctxk, m, &uniqp);
assert(uniqm == NULL || uniqm == fm ||
m->is_abstract() ||
uniqm->method_holder()->is_abstract() ||
(fm == NULL && uniqm != NULL && uniqp != NULL && !InstanceKlass::cast(uniqp)->is_linked()),
"sanity");
#endif // ASSERT
return fm;
}
Klass* Dependencies::check_has_no_finalizable_subclasses(InstanceKlass* ctxk, NewKlassDepChange* changes) {
InstanceKlass* search_at = ctxk;
if (changes != NULL) {
search_at = changes->new_type(); // just look at the new bit
}
return find_finalizable_subclass(search_at);
}
Klass* Dependencies::check_call_site_target_value(oop call_site, oop method_handle, CallSiteDepChange* changes) {
assert(call_site != NULL, "sanity");
assert(method_handle != NULL, "sanity");
assert(call_site->is_a(vmClasses::CallSite_klass()), "sanity");
if (changes == NULL) {
// Validate all CallSites
if (java_lang_invoke_CallSite::target(call_site) != method_handle)
return call_site->klass(); // assertion failed
} else {
// Validate the given CallSite
if (call_site == changes->call_site() && java_lang_invoke_CallSite::target(call_site) != changes->method_handle()) {
assert(method_handle != changes->method_handle(), "must be");
return call_site->klass(); // assertion failed
}
}
return NULL; // assertion still valid
}
void Dependencies::DepStream::trace_and_log_witness(Klass* witness) {
if (witness != NULL) {
if (TraceDependencies) {
print_dependency(witness, /*verbose=*/ true);
}
// The following is a no-op unless logging is enabled:
log_dependency(witness);
}
}
Klass* Dependencies::DepStream::check_new_klass_dependency(NewKlassDepChange* changes) {
assert_locked_or_safepoint(Compile_lock);
Dependencies::check_valid_dependency_type(type());
Klass* witness = NULL;
switch (type()) {
case evol_method:
witness = check_evol_method(method_argument(0));
break;
case leaf_type:
witness = check_leaf_type(context_type());
break;
case abstract_with_unique_concrete_subtype:
witness = check_abstract_with_unique_concrete_subtype(context_type(), type_argument(1), changes);
break;
case unique_concrete_method_2:
witness = check_unique_concrete_method(context_type(), method_argument(1), changes);
break;
case unique_concrete_method_4:
witness = check_unique_concrete_method(context_type(), method_argument(1), type_argument(2), method_argument(3), changes);
break;
case no_finalizable_subclasses:
witness = check_has_no_finalizable_subclasses(context_type(), changes);
break;
default:
witness = NULL;
break;
}
trace_and_log_witness(witness);
return witness;
}
Klass* Dependencies::DepStream::check_klass_init_dependency(KlassInitDepChange* changes) {
assert_locked_or_safepoint(Compile_lock);
Dependencies::check_valid_dependency_type(type());
// No new types added. Only unique_concrete_method_4 is sensitive to class initialization changes.
Klass* witness = NULL;
switch (type()) {
case unique_concrete_method_4:
witness = check_unique_concrete_method(context_type(), method_argument(1), type_argument(2), method_argument(3), changes);
break;
default:
witness = NULL;
break;
}
trace_and_log_witness(witness);
return witness;
}
Klass* Dependencies::DepStream::check_klass_dependency(KlassDepChange* changes) {
assert_locked_or_safepoint(Compile_lock);
Dependencies::check_valid_dependency_type(type());
if (changes != NULL) {
if (UseVtableBasedCHA && changes->is_klass_init_change()) {
return check_klass_init_dependency(changes->as_klass_init_change());
} else {
return check_new_klass_dependency(changes->as_new_klass_change());
}
} else {
Klass* witness = check_new_klass_dependency(NULL);
// check_klass_init_dependency duplicates check_new_klass_dependency checks when class hierarchy change info is absent.
assert(witness != NULL || check_klass_init_dependency(NULL) == NULL, "missed dependency");
return witness;
}
}
Klass* Dependencies::DepStream::check_call_site_dependency(CallSiteDepChange* changes) {
assert_locked_or_safepoint(Compile_lock);
Dependencies::check_valid_dependency_type(type());
Klass* witness = NULL;
switch (type()) {
case call_site_target_value:
witness = check_call_site_target_value(argument_oop(0), argument_oop(1), changes);
break;
default:
witness = NULL;
break;
}
trace_and_log_witness(witness);
return witness;
}
Klass* Dependencies::DepStream::spot_check_dependency_at(DepChange& changes) {
// Handle klass dependency
if (changes.is_klass_change() && changes.as_klass_change()->involves_context(context_type()))
return check_klass_dependency(changes.as_klass_change());
// Handle CallSite dependency
if (changes.is_call_site_change())
return check_call_site_dependency(changes.as_call_site_change());
// irrelevant dependency; skip it
return NULL;
}
void DepChange::print() {
int nsup = 0, nint = 0;
for (ContextStream str(*this); str.next(); ) {
Klass* k = str.klass();
switch (str.change_type()) {
case Change_new_type:
tty->print_cr(" dependee = %s", k->external_name());
break;
case Change_new_sub:
if (!WizardMode) {
++nsup;
} else {
tty->print_cr(" context super = %s", k->external_name());
}
break;
case Change_new_impl:
if (!WizardMode) {
++nint;
} else {
tty->print_cr(" context interface = %s", k->external_name());
}
break;
default:
break;
}
}
if (nsup + nint != 0) {
tty->print_cr(" context supers = %d, interfaces = %d", nsup, nint);
}
}
void DepChange::ContextStream::start() {
Klass* type = (_changes.is_klass_change() ? _changes.as_klass_change()->type() : (Klass*) NULL);
_change_type = (type == NULL ? NO_CHANGE : Start_Klass);
_klass = type;
_ti_base = NULL;
_ti_index = 0;
_ti_limit = 0;
}
bool DepChange::ContextStream::next() {
switch (_change_type) {
case Start_Klass: // initial state; _klass is the new type
_ti_base = InstanceKlass::cast(_klass)->transitive_interfaces();
_ti_index = 0;
_change_type = Change_new_type;
return true;
case Change_new_type:
// fall through:
_change_type = Change_new_sub;
case Change_new_sub:
// 6598190: brackets workaround Sun Studio C++ compiler bug 6629277
{
_klass = _klass->super();
if (_klass != NULL) {
return true;
}
}
// else set up _ti_limit and fall through:
_ti_limit = (_ti_base == NULL) ? 0 : _ti_base->length();
_change_type = Change_new_impl;
case Change_new_impl:
if (_ti_index < _ti_limit) {
_klass = _ti_base->at(_ti_index++);
return true;
}
// fall through:
_change_type = NO_CHANGE; // iterator is exhausted
case NO_CHANGE:
break;
default:
ShouldNotReachHere();
}
return false;
}
void KlassDepChange::initialize() {
// entire transaction must be under this lock:
assert_lock_strong(Compile_lock);
// Mark all dependee and all its superclasses
// Mark transitive interfaces
for (ContextStream str(*this); str.next(); ) {
Klass* d = str.klass();
assert(!InstanceKlass::cast(d)->is_marked_dependent(), "checking");
InstanceKlass::cast(d)->set_is_marked_dependent(true);
}
}
KlassDepChange::~KlassDepChange() {
// Unmark all dependee and all its superclasses
// Unmark transitive interfaces
for (ContextStream str(*this); str.next(); ) {
Klass* d = str.klass();
InstanceKlass::cast(d)->set_is_marked_dependent(false);
}
}
bool KlassDepChange::involves_context(Klass* k) {
if (k == NULL || !k->is_instance_klass()) {
return false;
}
InstanceKlass* ik = InstanceKlass::cast(k);
bool is_contained = ik->is_marked_dependent();
assert(is_contained == type()->is_subtype_of(k),
"correct marking of potential context types");
return is_contained;
}
void Dependencies::print_statistics() {
AbstractClassHierarchyWalker::print_statistics();
}
void AbstractClassHierarchyWalker::print_statistics() {
if (UsePerfData) {
jlong deps_find_witness_calls = _perf_find_witness_anywhere_calls_count->get_value();
jlong deps_find_witness_steps = _perf_find_witness_anywhere_steps_count->get_value();
jlong deps_find_witness_singles = _perf_find_witness_in_calls_count->get_value();
ttyLocker ttyl;
tty->print_cr("Dependency check (find_witness) "
"calls=" JLONG_FORMAT ", steps=" JLONG_FORMAT " (avg=%.1f), singles=" JLONG_FORMAT,
deps_find_witness_calls,
deps_find_witness_steps,
(double)deps_find_witness_steps / deps_find_witness_calls,
deps_find_witness_singles);
if (xtty != NULL) {
xtty->elem("deps_find_witness calls='" JLONG_FORMAT "' steps='" JLONG_FORMAT "' singles='" JLONG_FORMAT "'",
deps_find_witness_calls,
deps_find_witness_steps,
deps_find_witness_singles);
}
}
}
CallSiteDepChange::CallSiteDepChange(Handle call_site, Handle method_handle) :
_call_site(call_site),
_method_handle(method_handle) {
assert(_call_site()->is_a(vmClasses::CallSite_klass()), "must be");
assert(_method_handle.is_null() || _method_handle()->is_a(vmClasses::MethodHandle_klass()), "must be");
}
void dependencies_init() {
AbstractClassHierarchyWalker::init();
}
Reference in a new issue View git blame Copy permalink