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src/share/vm/runtime/sweeper.hpp@d13d7aba8c12 (annotated)

src/share/vm/runtime/sweeper.hpp

Wed, 09 Oct 2013 16:32:21 +0200

author

roland

date

Wed, 09 Oct 2013 16:32:21 +0200

changeset 5914

d13d7aba8c12

parent 5792

510fbd28919c

child 6099

78da3894b86f

permissions

-rw-r--r--

8023657: New type profiling points: arguments to call
Summary: x86 interpreter and c1 type profiling for arguments at calls
Reviewed-by: kvn, twisti

duke@435	1	/*
sla@5237	2	* Copyright (c) 1997, 2013, Oracle and/or its affiliates. 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	*
trims@1907	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907	20	* or visit www.oracle.com if you need additional information or have any
trims@1907	21	* questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
stefank@2314	25	#ifndef SHARE_VM_RUNTIME_SWEEPER_HPP
stefank@2314	26	#define SHARE_VM_RUNTIME_SWEEPER_HPP
stefank@2314	27
duke@435	28	// An NmethodSweeper is an incremental cleaner for:
duke@435	29	// - cleanup inline caches
anoll@5792	30	// - reclamation of nmethods
anoll@5792	31	// Removing nmethods from the code cache includes two operations
anoll@5792	32	// 1) mark active nmethods
anoll@5792	33	// Is done in 'mark_active_nmethods()'. This function is called at a
anoll@5792	34	// safepoint and marks all nmethods that are active on a thread's stack.
anoll@5792	35	// 2) sweep nmethods
anoll@5792	36	// Is done in sweep_code_cache(). This function is the only place in the
anoll@5792	37	// sweeper where memory is reclaimed. Note that sweep_code_cache() is not
anoll@5792	38	// called at a safepoint. However, sweep_code_cache() stops executing if
anoll@5792	39	// another thread requests a safepoint. Consequently, 'mark_active_nmethods()'
anoll@5792	40	// and sweep_code_cache() cannot execute at the same time.
anoll@5792	41	// To reclaim memory, nmethods are first marked as 'not-entrant'. Methods can
anoll@5792	42	// be made not-entrant by (i) the sweeper, (ii) deoptimization, (iii) dependency
anoll@5792	43	// invalidation, and (iv) being replaced be a different method version (tiered
anoll@5792	44	// compilation). Not-entrant nmethod cannot be called by Java threads, but they
anoll@5792	45	// can still be active on the stack. To ensure that active nmethod are not reclaimed,
anoll@5792	46	// we have to wait until the next marking phase has completed. If a not-entrant
anoll@5792	47	// nmethod was NOT marked as active, it can be converted to 'zombie' state. To safely
anoll@5792	48	// remove the nmethod, all inline caches (IC) that point to the the nmethod must be
anoll@5792	49	// cleared. After that, the nmethod can be evicted from the code cache. Each nmethod's
anoll@5792	50	// state change happens during separate sweeps. It may take at least 3 sweeps before an
anoll@5792	51	// nmethod's space is freed. Sweeping is currently done by compiler threads between
anoll@5792	52	// compilations or at least each 5 sec (NmethodSweepCheckInterval) when the code cache
anoll@5792	53	// is full.
duke@435	54
duke@435	55	class NMethodSweeper : public AllStatic {
sla@5237	56	static long _traversals; // Stack scan count, also sweep ID.
sla@5237	57	static nmethod* _current; // Current nmethod
sla@5237	58	static int _seen; // Nof. nmethod we have currently processed in current pass of CodeCache
sla@5237	59	static int _flushed_count; // Nof. nmethods flushed in current sweep
sla@5237	60	static int _zombified_count; // Nof. nmethods made zombie in current sweep
sla@5237	61	static int _marked_count; // Nof. nmethods marked for reclaim in current sweep
never@1999	62
neliasso@5038	63	static volatile int _invocations; // No. of invocations left until we are completed with this pass
neliasso@5038	64	static volatile int _sweep_started; // Flag to control conc sweeper
duke@435	65
anoll@5792	66	//The following are reset in mark_active_nmethods and synchronized by the safepoint
anoll@5792	67	static bool _request_mark_phase; // Indicates that a change has happend and we need another mark pahse,
anoll@5792	68	// always checked and reset at a safepoint so memory will be in sync.
anoll@5792	69	static int _locked_seen; // Number of locked nmethods encountered during the scan
duke@435	70	static int _not_entrant_seen_on_stack; // Number of not entrant nmethod were are still on stack
duke@435	71
sla@5237	72	// Stat counters
sla@5237	73	static int _total_nof_methods_reclaimed; // Accumulated nof methods flushed
sla@5237	74	static jlong _total_time_sweeping; // Accumulated time sweeping
sla@5237	75	static jlong _total_time_this_sweep; // Total time this sweep
sla@5237	76	static jlong _peak_sweep_time; // Peak time for a full sweep
sla@5237	77	static jlong _peak_sweep_fraction_time; // Peak time sweeping one fraction
sla@5237	78
anoll@5792	79	static int process_nmethod(nmethod *nm);
coleenp@4037	80	static void release_nmethod(nmethod* nm);
coleenp@4037	81
neliasso@5038	82	static bool sweep_in_progress();
anoll@5792	83	static void sweep_code_cache();
anoll@5792	84	static void request_nmethod_marking() { _request_mark_phase = true; }
anoll@5792	85	static void reset_nmethod_marking() { _request_mark_phase = false; }
anoll@5792	86	static bool need_marking_phase() { return _request_mark_phase; }
anoll@5792	87
anoll@5792	88	static int _hotness_counter_reset_val;
never@1999	89
duke@435	90	public:
sla@5237	91	static long traversal_count() { return _traversals; }
sla@5237	92	static int total_nof_methods_reclaimed() { return _total_nof_methods_reclaimed; }
sla@5237	93	static jlong total_time_sweeping() { return _total_time_sweeping; }
sla@5237	94	static jlong peak_sweep_time() { return _peak_sweep_time; }
sla@5237	95	static jlong peak_sweep_fraction_time() { return _peak_sweep_fraction_time; }
anoll@5792	96	static void log_sweep(const char* msg, const char* format = NULL, ...);
anoll@5792	97
duke@435	98
never@2916	99	#ifdef ASSERT
johnc@5548	100	static bool is_sweeping(nmethod* which) { return _current == which; }
never@2916	101	// Keep track of sweeper activity in the ring buffer
never@2916	102	static void record_sweep(nmethod* nm, int line);
never@2916	103	static void report_events(int id, address entry);
never@2916	104	static void report_events();
never@2916	105	#endif
never@2916	106
anoll@5792	107	static void mark_active_nmethods(); // Invoked at the end of each safepoint
anoll@5792	108	static void possibly_sweep(); // Compiler threads call this to sweep
duke@435	109
anoll@5792	110	static int sort_nmethods_by_hotness(nmethod** nm1, nmethod** nm2);
anoll@5792	111	static int hotness_counter_reset_val();
anoll@5792	112
anoll@5792	113	static void notify() {
neliasso@5038	114	// Request a new sweep of the code cache from the beginning. No
duke@435	115	// need to synchronize the setting of this flag since it only
duke@435	116	// changes to false at safepoint so we can never overwrite it with false.
anoll@5792	117	request_nmethod_marking();
duke@435	118	}
duke@435	119	};
stefank@2314	120
stefank@2314	121	#endif // SHARE_VM_RUNTIME_SWEEPER_HPP