• file
• revisions
• annotate
• diff
• comparison
• raw

src/share/vm/code/stubs.cpp@b1f619d38249 (annotated)

src/share/vm/code/stubs.cpp

Tue, 05 Jan 2010 16:12:26 -0800

author

never

date

Tue, 05 Jan 2010 16:12:26 -0800

changeset 1576

b1f619d38249

parent 435

a61af66fc99e

child 1845

f03d0a26bf83

permissions

-rw-r--r--

6914002: unsigned compare problem after 5057818
Reviewed-by: kvn, twisti

duke@435	1	/*
duke@435	2	* Copyright 1997-2005 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/_stubs.cpp.incl"
duke@435	27
duke@435	28
duke@435	29	// Implementation of StubQueue
duke@435	30	//
duke@435	31	// Standard wrap-around queue implementation; the queue dimensions
duke@435	32	// are specified by the _queue_begin & _queue_end indices. The queue
duke@435	33	// can be in two states (transparent to the outside):
duke@435	34	//
duke@435	35	// a) contiguous state: all queue entries in one block (or empty)
duke@435	36	//
duke@435	37	// Queue: |...|XXXXXXX|...............|
duke@435	38	// ^0 ^begin ^end ^size = limit
duke@435	39	// |_______|
duke@435	40	// one block
duke@435	41	//
duke@435	42	// b) non-contiguous state: queue entries in two blocks
duke@435	43	//
duke@435	44	// Queue: |XXX|.......|XXXXXXX|.......|
duke@435	45	// ^0 ^end ^begin ^limit ^size
duke@435	46	// |___| |_______|
duke@435	47	// 1st block 2nd block
duke@435	48	//
duke@435	49	// In the non-contiguous state, the wrap-around point is
duke@435	50	// indicated via the _buffer_limit index since the last
duke@435	51	// queue entry may not fill up the queue completely in
duke@435	52	// which case we need to know where the 2nd block's end
duke@435	53	// is to do the proper wrap-around. When removing the
duke@435	54	// last entry of the 2nd block, _buffer_limit is reset
duke@435	55	// to _buffer_size.
duke@435	56	//
duke@435	57	// CAUTION: DO NOT MESS WITH THIS CODE IF YOU CANNOT PROVE
duke@435	58	// ITS CORRECTNESS! THIS CODE IS MORE SUBTLE THAN IT LOOKS!
duke@435	59
duke@435	60
duke@435	61	StubQueue::StubQueue(StubInterface* stub_interface, int buffer_size,
duke@435	62	Mutex* lock, const char* name) : _mutex(lock) {
duke@435	63	intptr_t size = round_to(buffer_size, 2*BytesPerWord);
duke@435	64	BufferBlob* blob = BufferBlob::create(name, size);
duke@435	65	if( blob == NULL ) vm_exit_out_of_memory1(size, "CodeCache: no room for %s", name);
duke@435	66	_stub_interface = stub_interface;
duke@435	67	_buffer_size = blob->instructions_size();
duke@435	68	_buffer_limit = blob->instructions_size();
duke@435	69	_stub_buffer = blob->instructions_begin();
duke@435	70	_queue_begin = 0;
duke@435	71	_queue_end = 0;
duke@435	72	_number_of_stubs = 0;
duke@435	73	register_queue(this);
duke@435	74	}
duke@435	75
duke@435	76
duke@435	77	StubQueue::~StubQueue() {
duke@435	78	// Note: Currently StubQueues are never destroyed so nothing needs to be done here.
duke@435	79	// If we want to implement the destructor, we need to release the BufferBlob
duke@435	80	// allocated in the constructor (i.e., we need to keep it around or look it
duke@435	81	// up via CodeCache::find_blob(...).
duke@435	82	Unimplemented();
duke@435	83	}
duke@435	84
duke@435	85
duke@435	86	Stub* StubQueue::stub_containing(address pc) const {
duke@435	87	if (contains(pc)) {
duke@435	88	for (Stub* s = first(); s != NULL; s = next(s)) {
duke@435	89	if (stub_contains(s, pc)) return s;
duke@435	90	}
duke@435	91	}
duke@435	92	return NULL;
duke@435	93	}
duke@435	94
duke@435	95
duke@435	96	Stub* StubQueue::request_committed(int code_size) {
duke@435	97	Stub* s = request(code_size);
duke@435	98	if (s != NULL) commit(code_size);
duke@435	99	return s;
duke@435	100	}
duke@435	101
duke@435	102
duke@435	103	Stub* StubQueue::request(int requested_code_size) {
duke@435	104	assert(requested_code_size > 0, "requested_code_size must be > 0");
duke@435	105	if (_mutex != NULL) _mutex->lock();
duke@435	106	Stub* s = current_stub();
duke@435	107	int requested_size = round_to(stub_code_size_to_size(requested_code_size), CodeEntryAlignment);
duke@435	108	if (requested_size <= available_space()) {
duke@435	109	if (is_contiguous()) {
duke@435	110	// Queue: |...|XXXXXXX|.............|
duke@435	111	// ^0 ^begin ^end ^size = limit
duke@435	112	assert(_buffer_limit == _buffer_size, "buffer must be fully usable");
duke@435	113	if (_queue_end + requested_size <= _buffer_size) {
duke@435	114	// code fits in at the end => nothing to do
duke@435	115	stub_initialize(s, requested_size);
duke@435	116	return s;
duke@435	117	} else {
duke@435	118	// stub doesn't fit in at the queue end
duke@435	119	// => reduce buffer limit & wrap around
duke@435	120	assert(!is_empty(), "just checkin'");
duke@435	121	_buffer_limit = _queue_end;
duke@435	122	_queue_end = 0;
duke@435	123	}
duke@435	124	}
duke@435	125	}
duke@435	126	if (requested_size <= available_space()) {
duke@435	127	assert(!is_contiguous(), "just checkin'");
duke@435	128	assert(_buffer_limit <= _buffer_size, "queue invariant broken");
duke@435	129	// Queue: |XXX|.......|XXXXXXX|.......|
duke@435	130	// ^0 ^end ^begin ^limit ^size
duke@435	131	s = current_stub();
duke@435	132	stub_initialize(s, requested_size);
duke@435	133	return s;
duke@435	134	}
duke@435	135	// Not enough space left
duke@435	136	if (_mutex != NULL) _mutex->unlock();
duke@435	137	return NULL;
duke@435	138	}
duke@435	139
duke@435	140
duke@435	141	void StubQueue::commit(int committed_code_size) {
duke@435	142	assert(committed_code_size > 0, "committed_code_size must be > 0");
duke@435	143	int committed_size = round_to(stub_code_size_to_size(committed_code_size), CodeEntryAlignment);
duke@435	144	Stub* s = current_stub();
duke@435	145	assert(committed_size <= stub_size(s), "committed size must not exceed requested size");
duke@435	146	stub_initialize(s, committed_size);
duke@435	147	_queue_end += committed_size;
duke@435	148	_number_of_stubs++;
duke@435	149	if (_mutex != NULL) _mutex->unlock();
duke@435	150	debug_only(stub_verify(s);)
duke@435	151	}
duke@435	152
duke@435	153
duke@435	154	void StubQueue::remove_first() {
duke@435	155	if (number_of_stubs() == 0) return;
duke@435	156	Stub* s = first();
duke@435	157	debug_only(stub_verify(s);)
duke@435	158	stub_finalize(s);
duke@435	159	_queue_begin += stub_size(s);
duke@435	160	assert(_queue_begin <= _buffer_limit, "sanity check");
duke@435	161	if (_queue_begin == _queue_end) {
duke@435	162	// buffer empty
duke@435	163	// => reset queue indices
duke@435	164	_queue_begin = 0;
duke@435	165	_queue_end = 0;
duke@435	166	_buffer_limit = _buffer_size;
duke@435	167	} else if (_queue_begin == _buffer_limit) {
duke@435	168	// buffer limit reached
duke@435	169	// => reset buffer limit & wrap around
duke@435	170	_buffer_limit = _buffer_size;
duke@435	171	_queue_begin = 0;
duke@435	172	}
duke@435	173	_number_of_stubs--;
duke@435	174	}
duke@435	175
duke@435	176
duke@435	177	void StubQueue::remove_first(int n) {
duke@435	178	int i = MIN2(n, number_of_stubs());
duke@435	179	while (i-- > 0) remove_first();
duke@435	180	}
duke@435	181
duke@435	182
duke@435	183	void StubQueue::remove_all(){
duke@435	184	debug_only(verify();)
duke@435	185	remove_first(number_of_stubs());
duke@435	186	assert(number_of_stubs() == 0, "sanity check");
duke@435	187	}
duke@435	188
duke@435	189
duke@435	190	enum { StubQueueLimit = 10 }; // there are only a few in the world
duke@435	191	static StubQueue* registered_stub_queues[StubQueueLimit];
duke@435	192
duke@435	193	void StubQueue::register_queue(StubQueue* sq) {
duke@435	194	for (int i = 0; i < StubQueueLimit; i++) {
duke@435	195	if (registered_stub_queues[i] == NULL) {
duke@435	196	registered_stub_queues[i] = sq;
duke@435	197	return;
duke@435	198	}
duke@435	199	}
duke@435	200	ShouldNotReachHere();
duke@435	201	}
duke@435	202
duke@435	203
duke@435	204	void StubQueue::queues_do(void f(StubQueue* sq)) {
duke@435	205	for (int i = 0; i < StubQueueLimit; i++) {
duke@435	206	if (registered_stub_queues[i] != NULL) {
duke@435	207	f(registered_stub_queues[i]);
duke@435	208	}
duke@435	209	}
duke@435	210	}
duke@435	211
duke@435	212
duke@435	213	void StubQueue::stubs_do(void f(Stub* s)) {
duke@435	214	debug_only(verify();)
duke@435	215	MutexLockerEx lock(_mutex);
duke@435	216	for (Stub* s = first(); s != NULL; s = next(s)) f(s);
duke@435	217	}
duke@435	218
duke@435	219
duke@435	220	void StubQueue::verify() {
duke@435	221	// verify only if initialized
duke@435	222	if (_stub_buffer == NULL) return;
duke@435	223	MutexLockerEx lock(_mutex);
duke@435	224	// verify index boundaries
duke@435	225	guarantee(0 <= _buffer_size, "buffer size must be positive");
duke@435	226	guarantee(0 <= _buffer_limit && _buffer_limit <= _buffer_size , "_buffer_limit out of bounds");
duke@435	227	guarantee(0 <= _queue_begin && _queue_begin < _buffer_limit, "_queue_begin out of bounds");
duke@435	228	guarantee(0 <= _queue_end && _queue_end <= _buffer_limit, "_queue_end out of bounds");
duke@435	229	// verify alignment
duke@435	230	guarantee(_buffer_size % CodeEntryAlignment == 0, "_buffer_size not aligned");
duke@435	231	guarantee(_buffer_limit % CodeEntryAlignment == 0, "_buffer_limit not aligned");
duke@435	232	guarantee(_queue_begin % CodeEntryAlignment == 0, "_queue_begin not aligned");
duke@435	233	guarantee(_queue_end % CodeEntryAlignment == 0, "_queue_end not aligned");
duke@435	234	// verify buffer limit/size relationship
duke@435	235	if (is_contiguous()) {
duke@435	236	guarantee(_buffer_limit == _buffer_size, "_buffer_limit must equal _buffer_size");
duke@435	237	}
duke@435	238	// verify contents
duke@435	239	int n = 0;
duke@435	240	for (Stub* s = first(); s != NULL; s = next(s)) {
duke@435	241	stub_verify(s);
duke@435	242	n++;
duke@435	243	}
duke@435	244	guarantee(n == number_of_stubs(), "number of stubs inconsistent");
duke@435	245	guarantee(_queue_begin != _queue_end || n == 0, "buffer indices must be the same");
duke@435	246	}
duke@435	247
duke@435	248
duke@435	249	void StubQueue::print() {
duke@435	250	MutexLockerEx lock(_mutex);
duke@435	251	for (Stub* s = first(); s != NULL; s = next(s)) {
duke@435	252	stub_print(s);
duke@435	253	}
duke@435	254	}