comparison src/os_cpu/solaris_sparc/vm/threadLS_solaris_sparc.hpp @ 0:a61af66fc99e jdk7-b24

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author duke
date Sat, 01 Dec 2007 00:00:00 +0000
parents
children c18cbe5936b8
comparison
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-1:000000000000 0:a61af66fc99e
1 /*
2 * Copyright 1998-2005 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 public:
26 // Java Thread - force inlining
27 static inline Thread* thread() ;
28
29 private:
30 static Thread* _get_thread_cache[]; // index by [(raw_id>>9)^(raw_id>>20) % _pd_cache_size]
31 static Thread* get_thread_via_cache_slowly(uintptr_t raw_id, int index);
32
33 NOT_PRODUCT(static int _tcacheHit;)
34 NOT_PRODUCT(static int _tcacheMiss;)
35
36 public:
37
38 // Print cache hit/miss statistics
39 static void print_statistics() PRODUCT_RETURN;
40
41 enum Constants {
42 _pd_cache_size = 256*2 // projected typical # of threads * 2
43 };
44
45 static void set_thread_in_slot (Thread *) ;
46
47 static uintptr_t pd_raw_thread_id() {
48 return _raw_thread_id();
49 }
50
51 static int pd_cache_index(uintptr_t raw_id) {
52 // Hash function: From email from Dave:
53 // The hash function deserves an explanation. %g7 points to libthread's
54 // "thread" structure. On T1 the thread structure is allocated on the
55 // user's stack (yes, really!) so the ">>20" handles T1 where the JVM's
56 // stack size is usually >= 1Mb. The ">>9" is for T2 where Roger allocates
57 // globs of thread blocks contiguously. The "9" has to do with the
58 // expected size of the T2 thread structure. If these constants are wrong
59 // the worst thing that'll happen is that the hit rate for heavily threaded
60 // apps won't be as good as it could be. If you want to burn another
61 // shift+xor you could mix together _all of the %g7 bits to form the hash,
62 // but I think that's excessive. Making the change above changed the
63 // T$ miss rate on SpecJBB (on a 16X system) from about 3% to imperceptible.
64 uintptr_t ix = (int) (((raw_id >> 9) ^ (raw_id >> 20)) % _pd_cache_size);
65 return ix;
66 }