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src/share/vm/code/vtableStubs.cpp@1d037ecd7960 (annotated)

src/share/vm/code/vtableStubs.cpp

Wed, 08 Apr 2009 00:12:59 -0700

author

jrose

date

Wed, 08 Apr 2009 00:12:59 -0700

changeset 1144

1d037ecd7960

parent 435

a61af66fc99e

child 1279

bd02caa94611

permissions

-rw-r--r--

6827505: sizing logic for vtable and itable stubs needs self-check
Summary: Asserts and comments to help maintain the correct sizing of certain stubs
Reviewed-by: kvn

duke@435	1	/*
duke@435	2	* Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
duke@435	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435	4	*
duke@435	5	* This code is free software; you can redistribute it and/or modify it
duke@435	6	* under the terms of the GNU General Public License version 2 only, as
duke@435	7	* published by the Free Software Foundation.
duke@435	8	*
duke@435	9	* This code is distributed in the hope that it will be useful, but WITHOUT
duke@435	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435	12	* version 2 for more details (a copy is included in the LICENSE file that
duke@435	13	* accompanied this code).
duke@435	14	*
duke@435	15	* You should have received a copy of the GNU General Public License version
duke@435	16	* 2 along with this work; if not, write to the Free Software Foundation,
duke@435	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435	18	*
duke@435	19	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435	20	* CA 95054 USA or visit www.sun.com if you need additional information or
duke@435	21	* have any questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
duke@435	25	#include "incls/_precompiled.incl"
duke@435	26	#include "incls/_vtableStubs.cpp.incl"
duke@435	27
duke@435	28	// -----------------------------------------------------------------------------------------
duke@435	29	// Implementation of VtableStub
duke@435	30
duke@435	31	address VtableStub::_chunk = NULL;
duke@435	32	address VtableStub::_chunk_end = NULL;
duke@435	33	VMReg VtableStub::_receiver_location = VMRegImpl::Bad();
duke@435	34
duke@435	35	static int num_vtable_chunks = 0;
duke@435	36
duke@435	37
duke@435	38	void* VtableStub::operator new(size_t size, int code_size) {
duke@435	39	assert(size == sizeof(VtableStub), "mismatched size");
duke@435	40	num_vtable_chunks++;
duke@435	41	// compute real VtableStub size (rounded to nearest word)
duke@435	42	const int real_size = round_to(code_size + sizeof(VtableStub), wordSize);
duke@435	43	// malloc them in chunks to minimize header overhead
duke@435	44	const int chunk_factor = 32;
duke@435	45	if (_chunk == NULL || _chunk + real_size > _chunk_end) {
duke@435	46	const int bytes = chunk_factor * real_size + pd_code_alignment();
duke@435	47	BufferBlob* blob = BufferBlob::create("vtable chunks", bytes);
duke@435	48	if( blob == NULL ) vm_exit_out_of_memory1(bytes, "CodeCache: no room for %s", "vtable chunks");
duke@435	49	_chunk = blob->instructions_begin();
duke@435	50	_chunk_end = _chunk + bytes;
duke@435	51	VTune::register_stub("vtable stub", _chunk, _chunk_end);
duke@435	52	Forte::register_stub("vtable stub", _chunk, _chunk_end);
duke@435	53	// Notify JVMTI about this stub. The event will be recorded by the enclosing
duke@435	54	// JvmtiDynamicCodeEventCollector and posted when this thread has released
duke@435	55	// all locks.
duke@435	56	if (JvmtiExport::should_post_dynamic_code_generated()) {
duke@435	57	JvmtiExport::post_dynamic_code_generated_while_holding_locks("vtable stub", _chunk, _chunk_end);
duke@435	58	}
duke@435	59	align_chunk();
duke@435	60	}
duke@435	61	assert(_chunk + real_size <= _chunk_end, "bad allocation");
duke@435	62	void* res = _chunk;
duke@435	63	_chunk += real_size;
duke@435	64	align_chunk();
duke@435	65	return res;
duke@435	66	}
duke@435	67
duke@435	68
duke@435	69	void VtableStub::print() {
duke@435	70	tty->print("vtable stub (index = %d, receiver_location = %d, code = [" INTPTR_FORMAT ", " INTPTR_FORMAT "[)",
duke@435	71	index(), receiver_location(), code_begin(), code_end());
duke@435	72	}
duke@435	73
duke@435	74
duke@435	75	// -----------------------------------------------------------------------------------------
duke@435	76	// Implementation of VtableStubs
duke@435	77	//
duke@435	78	// For each hash value there's a linked list of vtable stubs (with that
duke@435	79	// hash value). Each list is anchored in a little hash _table, indexed
duke@435	80	// by that hash value.
duke@435	81
duke@435	82	VtableStub* VtableStubs::_table[VtableStubs::N];
duke@435	83	int VtableStubs::_number_of_vtable_stubs = 0;
duke@435	84
duke@435	85
duke@435	86	void VtableStubs::initialize() {
duke@435	87	VtableStub::_receiver_location = SharedRuntime::name_for_receiver();
duke@435	88	{
duke@435	89	MutexLocker ml(VtableStubs_lock);
duke@435	90	assert(_number_of_vtable_stubs == 0, "potential performance bug: VtableStubs initialized more than once");
duke@435	91	assert(is_power_of_2(N), "N must be a power of 2");
duke@435	92	for (int i = 0; i < N; i++) {
duke@435	93	_table[i] = NULL;
duke@435	94	}
duke@435	95	}
duke@435	96	}
duke@435	97
duke@435	98
duke@435	99	address VtableStubs::create_stub(bool is_vtable_stub, int vtable_index, methodOop method) {
duke@435	100	assert(vtable_index >= 0, "must be positive");
duke@435	101
duke@435	102	VtableStub* s = ShareVtableStubs ? lookup(is_vtable_stub, vtable_index) : NULL;
duke@435	103	if (s == NULL) {
duke@435	104	if (is_vtable_stub) {
duke@435	105	s = create_vtable_stub(vtable_index);
duke@435	106	} else {
duke@435	107	s = create_itable_stub(vtable_index);
duke@435	108	}
duke@435	109	enter(is_vtable_stub, vtable_index, s);
duke@435	110	if (PrintAdapterHandlers) {
duke@435	111	tty->print_cr("Decoding VtableStub %s[%d]@%d",
duke@435	112	is_vtable_stub? "vtbl": "itbl", vtable_index, VtableStub::receiver_location());
duke@435	113	Disassembler::decode(s->code_begin(), s->code_end());
duke@435	114	}
duke@435	115	}
duke@435	116	return s->entry_point();
duke@435	117	}
duke@435	118
duke@435	119
duke@435	120	inline uint VtableStubs::hash(bool is_vtable_stub, int vtable_index){
duke@435	121	// Assumption: receiver_location < 4 in most cases.
duke@435	122	int hash = ((vtable_index << 2) ^ VtableStub::receiver_location()->value()) + vtable_index;
duke@435	123	return (is_vtable_stub ? ~hash : hash) & mask;
duke@435	124	}
duke@435	125
duke@435	126
duke@435	127	VtableStub* VtableStubs::lookup(bool is_vtable_stub, int vtable_index) {
duke@435	128	MutexLocker ml(VtableStubs_lock);
duke@435	129	unsigned hash = VtableStubs::hash(is_vtable_stub, vtable_index);
duke@435	130	VtableStub* s = _table[hash];
duke@435	131	while( s && !s->matches(is_vtable_stub, vtable_index)) s = s->next();
duke@435	132	return s;
duke@435	133	}
duke@435	134
duke@435	135
duke@435	136	void VtableStubs::enter(bool is_vtable_stub, int vtable_index, VtableStub* s) {
duke@435	137	MutexLocker ml(VtableStubs_lock);
duke@435	138	assert(s->matches(is_vtable_stub, vtable_index), "bad vtable stub");
duke@435	139	unsigned int h = VtableStubs::hash(is_vtable_stub, vtable_index);
duke@435	140	// enter s at the beginning of the corresponding list
duke@435	141	s->set_next(_table[h]);
duke@435	142	_table[h] = s;
duke@435	143	_number_of_vtable_stubs++;
duke@435	144	}
duke@435	145
duke@435	146
duke@435	147	bool VtableStubs::is_entry_point(address pc) {
duke@435	148	MutexLocker ml(VtableStubs_lock);
duke@435	149	VtableStub* stub = (VtableStub*)(pc - VtableStub::entry_offset());
duke@435	150	uint hash = VtableStubs::hash(stub->is_vtable_stub(), stub->index());
duke@435	151	VtableStub* s;
duke@435	152	for (s = _table[hash]; s != NULL && s != stub; s = s->next()) {}
duke@435	153	return s == stub;
duke@435	154	}
duke@435	155
duke@435	156
duke@435	157	bool VtableStubs::contains(address pc) {
duke@435	158	// simple solution for now - we may want to use
duke@435	159	// a faster way if this function is called often
duke@435	160	return stub_containing(pc) != NULL;
duke@435	161	}
duke@435	162
duke@435	163
duke@435	164	VtableStub* VtableStubs::stub_containing(address pc) {
duke@435	165	// Note: No locking needed since any change to the data structure
duke@435	166	// happens with an atomic store into it (we don't care about
duke@435	167	// consistency with the _number_of_vtable_stubs counter).
duke@435	168	for (int i = 0; i < N; i++) {
duke@435	169	for (VtableStub* s = _table[i]; s != NULL; s = s->next()) {
duke@435	170	if (s->contains(pc)) return s;
duke@435	171	}
duke@435	172	}
duke@435	173	return NULL;
duke@435	174	}
duke@435	175
duke@435	176	void vtableStubs_init() {
duke@435	177	VtableStubs::initialize();
duke@435	178	}
duke@435	179
duke@435	180
duke@435	181	//-----------------------------------------------------------------------------------------------------
duke@435	182	// Non-product code
duke@435	183	#ifndef PRODUCT
duke@435	184
duke@435	185	extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index) {
duke@435	186	ResourceMark rm;
duke@435	187	HandleMark hm;
duke@435	188	klassOop klass = receiver->klass();
duke@435	189	instanceKlass* ik = instanceKlass::cast(klass);
duke@435	190	klassVtable* vt = ik->vtable();
duke@435	191	klass->print();
duke@435	192	fatal3("bad compiled vtable dispatch: receiver " INTPTR_FORMAT ", index %d (vtable length %d)", (address)receiver, index, vt->length());
duke@435	193	}
duke@435	194
duke@435	195	#endif // Product