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src/share/vm/memory/threadLocalAllocBuffer.inline.hpp@7b0e9cba0307 (annotated)

src/share/vm/memory/threadLocalAllocBuffer.inline.hpp

Wed, 13 Jan 2010 15:26:39 -0800

author

ysr

date

Wed, 13 Jan 2010 15:26:39 -0800

changeset 1601

7b0e9cba0307

parent 1600

2dd52dea6d28

child 1907

c18cbe5936b8

child 1926

2d127394260e

permissions

-rw-r--r--

6896647: card marks can be deferred too long
Summary: Deferred card marks are now flushed during the gc prologue. Parallel[Scavege,OldGC] and SerialGC no longer defer card marks generated by COMPILER2 as a result of ReduceInitialCardMarks. For these cases, introduced a diagnostic option to defer the card marks, only for the purposes of testing and diagnostics. CMS and G1 continue to defer card marks. Potential performance concern related to single-threaded flushing of deferred card marks in the gc prologue will be addressed in the future.
Reviewed-by: never, johnc

duke@435	1	/*
johnc@1600	2	* Copyright 1999-2009 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	inline HeapWord* ThreadLocalAllocBuffer::allocate(size_t size) {
duke@435	26	invariants();
duke@435	27	HeapWord* obj = top();
duke@435	28	if (pointer_delta(end(), obj) >= size) {
duke@435	29	// successful thread-local allocation
johnc@1600	30	#ifdef ASSERT
johnc@1600	31	// Skip mangling the space corresponding to the object header to
johnc@1600	32	// ensure that the returned space is not considered parsable by
johnc@1600	33	// any concurrent GC thread.
johnc@1600	34	size_t hdr_size = CollectedHeap::min_fill_size();
johnc@1600	35	Copy::fill_to_words(obj + hdr_size, size - hdr_size, badHeapWordVal);
johnc@1600	36	#endif // ASSERT
duke@435	37	// This addition is safe because we know that top is
duke@435	38	// at least size below end, so the add can't wrap.
duke@435	39	set_top(obj + size);
duke@435	40
duke@435	41	invariants();
duke@435	42	return obj;
duke@435	43	}
duke@435	44	return NULL;
duke@435	45	}
duke@435	46
duke@435	47	inline size_t ThreadLocalAllocBuffer::compute_size(size_t obj_size) {
duke@435	48	const size_t aligned_obj_size = align_object_size(obj_size);
duke@435	49
duke@435	50	// Compute the size for the new TLAB.
duke@435	51	// The "last" tlab may be smaller to reduce fragmentation.
duke@435	52	// unsafe_max_tlab_alloc is just a hint.
duke@435	53	const size_t available_size = Universe::heap()->unsafe_max_tlab_alloc(myThread()) /
duke@435	54	HeapWordSize;
duke@435	55	size_t new_tlab_size = MIN2(available_size, desired_size() + aligned_obj_size);
duke@435	56
duke@435	57	// Make sure there's enough room for object and filler int[].
duke@435	58	const size_t obj_plus_filler_size = aligned_obj_size + alignment_reserve();
duke@435	59	if (new_tlab_size < obj_plus_filler_size) {
duke@435	60	// If there isn't enough room for the allocation, return failure.
duke@435	61	if (PrintTLAB && Verbose) {
duke@435	62	gclog_or_tty->print_cr("ThreadLocalAllocBuffer::compute_size(" SIZE_FORMAT ")"
duke@435	63	" returns failure",
duke@435	64	obj_size);
duke@435	65	}
duke@435	66	return 0;
duke@435	67	}
duke@435	68	if (PrintTLAB && Verbose) {
duke@435	69	gclog_or_tty->print_cr("ThreadLocalAllocBuffer::compute_size(" SIZE_FORMAT ")"
duke@435	70	" returns " SIZE_FORMAT,
duke@435	71	obj_size, new_tlab_size);
duke@435	72	}
duke@435	73	return new_tlab_size;
duke@435	74	}
duke@435	75
duke@435	76
duke@435	77	void ThreadLocalAllocBuffer::record_slow_allocation(size_t obj_size) {
duke@435	78	// Raise size required to bypass TLAB next time. Why? Else there's
duke@435	79	// a risk that a thread that repeatedly allocates objects of one
duke@435	80	// size will get stuck on this slow path.
duke@435	81
duke@435	82	set_refill_waste_limit(refill_waste_limit() + refill_waste_limit_increment());
duke@435	83
duke@435	84	_slow_allocations++;
duke@435	85
duke@435	86	if (PrintTLAB && Verbose) {
duke@435	87	Thread* thrd = myThread();
duke@435	88	gclog_or_tty->print("TLAB: %s thread: "INTPTR_FORMAT" [id: %2d]"
duke@435	89	" obj: "SIZE_FORMAT
duke@435	90	" free: "SIZE_FORMAT
duke@435	91	" waste: "SIZE_FORMAT"\n",
duke@435	92	"slow", thrd, thrd->osthread()->thread_id(),
duke@435	93	obj_size, free(), refill_waste_limit());
duke@435	94	}
duke@435	95	}