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/*
* Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "code/vtableStubs.hpp"
#include "compiler/disassembler.hpp"
#include "memory/allocation.inline.hpp"
#include "memory/resourceArea.hpp"
#include "oops/instanceKlass.hpp"
#include "oops/klassVtable.hpp"
#include "oops/oop.inline.hpp"
#include "prims/forte.hpp"
#include "prims/jvmtiExport.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/sharedRuntime.hpp"
#ifdef COMPILER2
#include "opto/matcher.hpp"
#endif
PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
// -----------------------------------------------------------------------------------------
// Implementation of VtableStub
address VtableStub::_chunk = NULL;
address VtableStub::_chunk_end = NULL;
VMReg VtableStub::_receiver_location = VMRegImpl::Bad();
void* VtableStub::operator new(size_t size, int code_size) throw() {
assert(size == sizeof(VtableStub), "mismatched size");
// compute real VtableStub size (rounded to nearest word)
const int real_size = round_to(code_size + sizeof(VtableStub), wordSize);
// malloc them in chunks to minimize header overhead
const int chunk_factor = 32;
if (_chunk == NULL || _chunk + real_size > _chunk_end) {
const int bytes = chunk_factor * real_size + pd_code_alignment();
// There is a dependency on the name of the blob in src/share/vm/prims/jvmtiCodeBlobEvents.cpp
// If changing the name, update the other file accordingly.
BufferBlob* blob = BufferBlob::create("vtable chunks", bytes);
if (blob == NULL) {
return NULL;
}
_chunk = blob->content_begin();
_chunk_end = _chunk + bytes;
Forte::register_stub("vtable stub", _chunk, _chunk_end);
align_chunk();
}
assert(_chunk + real_size <= _chunk_end, "bad allocation");
void* res = _chunk;
_chunk += real_size;
align_chunk();
return res;
}
void VtableStub::print_on(outputStream* st) const {
st->print("vtable stub (index = %d, receiver_location = %d, code = [" INTPTR_FORMAT ", " INTPTR_FORMAT "[)",
index(), receiver_location(), code_begin(), code_end());
}
// -----------------------------------------------------------------------------------------
// Implementation of VtableStubs
//
// For each hash value there's a linked list of vtable stubs (with that
// hash value). Each list is anchored in a little hash _table, indexed
// by that hash value.
VtableStub* VtableStubs::_table[VtableStubs::N];
int VtableStubs::_number_of_vtable_stubs = 0;
void VtableStubs::initialize() {
VtableStub::_receiver_location = SharedRuntime::name_for_receiver();
{
MutexLocker ml(VtableStubs_lock);
assert(_number_of_vtable_stubs == 0, "potential performance bug: VtableStubs initialized more than once");
assert(is_power_of_2(N), "N must be a power of 2");
for (int i = 0; i < N; i++) {
_table[i] = NULL;
}
}
}
address VtableStubs::find_stub(bool is_vtable_stub, int vtable_index) {
assert(vtable_index >= 0, "must be positive");
VtableStub* s = ShareVtableStubs ? lookup(is_vtable_stub, vtable_index) : NULL;
if (s == NULL) {
if (is_vtable_stub) {
s = create_vtable_stub(vtable_index);
} else {
s = create_itable_stub(vtable_index);
}
// Creation of vtable or itable can fail if there is not enough free space in the code cache.
if (s == NULL) {
return NULL;
}
enter(is_vtable_stub, vtable_index, s);
if (PrintAdapterHandlers) {
tty->print_cr("Decoding VtableStub %s[%d]@%d",
is_vtable_stub? "vtbl": "itbl", vtable_index, VtableStub::receiver_location());
Disassembler::decode(s->code_begin(), s->code_end());
}
// Notify JVMTI about this stub. The event will be recorded by the enclosing
// JvmtiDynamicCodeEventCollector and posted when this thread has released
// all locks.
if (JvmtiExport::should_post_dynamic_code_generated()) {
JvmtiExport::post_dynamic_code_generated_while_holding_locks(is_vtable_stub? "vtable stub": "itable stub",
s->code_begin(), s->code_end());
}
}
return s->entry_point();
}
inline uint VtableStubs::hash(bool is_vtable_stub, int vtable_index){
// Assumption: receiver_location < 4 in most cases.
int hash = ((vtable_index << 2) ^ VtableStub::receiver_location()->value()) + vtable_index;
return (is_vtable_stub ? ~hash : hash) & mask;
}
VtableStub* VtableStubs::lookup(bool is_vtable_stub, int vtable_index) {
MutexLocker ml(VtableStubs_lock);
unsigned hash = VtableStubs::hash(is_vtable_stub, vtable_index);
VtableStub* s = _table[hash];
while( s && !s->matches(is_vtable_stub, vtable_index)) s = s->next();
return s;
}
void VtableStubs::enter(bool is_vtable_stub, int vtable_index, VtableStub* s) {
MutexLocker ml(VtableStubs_lock);
assert(s->matches(is_vtable_stub, vtable_index), "bad vtable stub");
unsigned int h = VtableStubs::hash(is_vtable_stub, vtable_index);
// enter s at the beginning of the corresponding list
s->set_next(_table[h]);
_table[h] = s;
_number_of_vtable_stubs++;
}
bool VtableStubs::is_entry_point(address pc) {
MutexLocker ml(VtableStubs_lock);
VtableStub* stub = (VtableStub*)(pc - VtableStub::entry_offset());
uint hash = VtableStubs::hash(stub->is_vtable_stub(), stub->index());
VtableStub* s;
for (s = _table[hash]; s != NULL && s != stub; s = s->next()) {}
return s == stub;
}
bool VtableStubs::contains(address pc) {
// simple solution for now - we may want to use
// a faster way if this function is called often
return stub_containing(pc) != NULL;
}
VtableStub* VtableStubs::stub_containing(address pc) {
// Note: No locking needed since any change to the data structure
// happens with an atomic store into it (we don't care about
// consistency with the _number_of_vtable_stubs counter).
for (int i = 0; i < N; i++) {
for (VtableStub* s = _table[i]; s != NULL; s = s->next()) {
if (s->contains(pc)) return s;
}
}
return NULL;
}
void vtableStubs_init() {
VtableStubs::initialize();
}
void VtableStubs::vtable_stub_do(void f(VtableStub*)) {
for (int i = 0; i < N; i++) {
for (VtableStub* s = _table[i]; s != NULL; s = s->next()) {
f(s);
}
}
}
//-----------------------------------------------------------------------------------------------------
// Non-product code
#ifndef PRODUCT
extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index) {
ResourceMark rm;
HandleMark hm;
Klass* klass = receiver->klass();
InstanceKlass* ik = InstanceKlass::cast(klass);
klassVtable* vt = ik->vtable();
ik->print();
fatal(err_msg("bad compiled vtable dispatch: receiver " INTPTR_FORMAT ", "
"index %d (vtable length %d)",
(address)receiver, index, vt->length()));
}
#endif // Product
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