Mercurial > hg > graal-jvmci-8
annotate src/share/vm/runtime/park.cpp @ 7588:f9eb431c3efe
8006005: Fix constant pool index validation and alignment trap for method parameter reflection
Summary: This patch addresses an alignment trap due to the storage format of method parameters data in constMethod. It also adds code to validate constant pool indexes for method parameters data.
Reviewed-by: jrose, dholmes
Contributed-by: eric.mccorkle@oracle.com
author | coleenp |
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date | Mon, 14 Jan 2013 11:01:39 -0500 |
parents | b9a9ed0f8eeb |
children | 9758d9f36299 |
rev | line source |
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1878 | 1 /* |
6842
b9a9ed0f8eeb
7197424: update copyright year to match last edit in jdk8 hotspot repository
mikael
parents:
6197
diff
changeset
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2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved. |
1878 | 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
20 * or visit www.oracle.com if you need additional information or have any | |
21 * questions. | |
22 * | |
23 */ | |
24 | |
1972 | 25 #include "precompiled.hpp" |
26 #include "runtime/thread.hpp" | |
1878 | 27 |
28 | |
29 | |
30 // Lifecycle management for TSM ParkEvents. | |
31 // ParkEvents are type-stable (TSM). | |
32 // In our particular implementation they happen to be immortal. | |
33 // | |
34 // We manage concurrency on the FreeList with a CAS-based | |
35 // detach-modify-reattach idiom that avoids the ABA problems | |
36 // that would otherwise be present in a simple CAS-based | |
37 // push-pop implementation. (push-one and pop-all) | |
38 // | |
39 // Caveat: Allocate() and Release() may be called from threads | |
40 // other than the thread associated with the Event! | |
41 // If we need to call Allocate() when running as the thread in | |
42 // question then look for the PD calls to initialize native TLS. | |
43 // Native TLS (Win32/Linux/Solaris) can only be initialized or | |
44 // accessed by the associated thread. | |
45 // See also pd_initialize(). | |
46 // | |
47 // Note that we could defer associating a ParkEvent with a thread | |
48 // until the 1st time the thread calls park(). unpark() calls to | |
49 // an unprovisioned thread would be ignored. The first park() call | |
50 // for a thread would allocate and associate a ParkEvent and return | |
51 // immediately. | |
52 | |
53 volatile int ParkEvent::ListLock = 0 ; | |
54 ParkEvent * volatile ParkEvent::FreeList = NULL ; | |
55 | |
56 ParkEvent * ParkEvent::Allocate (Thread * t) { | |
57 // In rare cases -- JVM_RawMonitor* operations -- we can find t == null. | |
58 ParkEvent * ev ; | |
59 | |
60 // Start by trying to recycle an existing but unassociated | |
61 // ParkEvent from the global free list. | |
62 for (;;) { | |
63 ev = FreeList ; | |
64 if (ev == NULL) break ; | |
65 // 1: Detach - sequester or privatize the list | |
66 // Tantamount to ev = Swap (&FreeList, NULL) | |
67 if (Atomic::cmpxchg_ptr (NULL, &FreeList, ev) != ev) { | |
68 continue ; | |
69 } | |
70 | |
71 // We've detached the list. The list in-hand is now | |
72 // local to this thread. This thread can operate on the | |
73 // list without risk of interference from other threads. | |
74 // 2: Extract -- pop the 1st element from the list. | |
75 ParkEvent * List = ev->FreeNext ; | |
76 if (List == NULL) break ; | |
77 for (;;) { | |
78 // 3: Try to reattach the residual list | |
79 guarantee (List != NULL, "invariant") ; | |
80 ParkEvent * Arv = (ParkEvent *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ; | |
81 if (Arv == NULL) break ; | |
82 | |
83 // New nodes arrived. Try to detach the recent arrivals. | |
84 if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) { | |
85 continue ; | |
86 } | |
87 guarantee (Arv != NULL, "invariant") ; | |
88 // 4: Merge Arv into List | |
89 ParkEvent * Tail = List ; | |
90 while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ; | |
91 Tail->FreeNext = Arv ; | |
92 } | |
93 break ; | |
94 } | |
95 | |
96 if (ev != NULL) { | |
97 guarantee (ev->AssociatedWith == NULL, "invariant") ; | |
98 } else { | |
99 // Do this the hard way -- materialize a new ParkEvent. | |
100 // In rare cases an allocating thread might detach a long list -- | |
101 // installing null into FreeList -- and then stall or be obstructed. | |
102 // A 2nd thread calling Allocate() would see FreeList == null. | |
103 // The list held privately by the 1st thread is unavailable to the 2nd thread. | |
104 // In that case the 2nd thread would have to materialize a new ParkEvent, | |
105 // even though free ParkEvents existed in the system. In this case we end up | |
106 // with more ParkEvents in circulation than we need, but the race is | |
107 // rare and the outcome is benign. Ideally, the # of extant ParkEvents | |
108 // is equal to the maximum # of threads that existed at any one time. | |
109 // Because of the race mentioned above, segments of the freelist | |
110 // can be transiently inaccessible. At worst we may end up with the | |
111 // # of ParkEvents in circulation slightly above the ideal. | |
112 // Note that if we didn't have the TSM/immortal constraint, then | |
113 // when reattaching, above, we could trim the list. | |
114 ev = new ParkEvent () ; | |
115 guarantee ((intptr_t(ev) & 0xFF) == 0, "invariant") ; | |
116 } | |
117 ev->reset() ; // courtesy to caller | |
118 ev->AssociatedWith = t ; // Associate ev with t | |
119 ev->FreeNext = NULL ; | |
120 return ev ; | |
121 } | |
122 | |
123 void ParkEvent::Release (ParkEvent * ev) { | |
124 if (ev == NULL) return ; | |
125 guarantee (ev->FreeNext == NULL , "invariant") ; | |
126 ev->AssociatedWith = NULL ; | |
127 for (;;) { | |
128 // Push ev onto FreeList | |
129 // The mechanism is "half" lock-free. | |
130 ParkEvent * List = FreeList ; | |
131 ev->FreeNext = List ; | |
132 if (Atomic::cmpxchg_ptr (ev, &FreeList, List) == List) break ; | |
133 } | |
134 } | |
135 | |
136 // Override operator new and delete so we can ensure that the | |
137 // least significant byte of ParkEvent addresses is 0. | |
138 // Beware that excessive address alignment is undesirable | |
139 // as it can result in D$ index usage imbalance as | |
140 // well as bank access imbalance on Niagara-like platforms, | |
141 // although Niagara's hash function should help. | |
142 | |
143 void * ParkEvent::operator new (size_t sz) { | |
6197 | 144 return (void *) ((intptr_t (AllocateHeap(sz + 256, mtInternal, CALLER_PC)) + 256) & -256) ; |
1878 | 145 } |
146 | |
147 void ParkEvent::operator delete (void * a) { | |
148 // ParkEvents are type-stable and immortal ... | |
149 ShouldNotReachHere(); | |
150 } | |
151 | |
152 | |
153 // 6399321 As a temporary measure we copied & modified the ParkEvent:: | |
154 // allocate() and release() code for use by Parkers. The Parker:: forms | |
155 // will eventually be removed as we consolide and shift over to ParkEvents | |
156 // for both builtin synchronization and JSR166 operations. | |
157 | |
158 volatile int Parker::ListLock = 0 ; | |
159 Parker * volatile Parker::FreeList = NULL ; | |
160 | |
161 Parker * Parker::Allocate (JavaThread * t) { | |
162 guarantee (t != NULL, "invariant") ; | |
163 Parker * p ; | |
164 | |
165 // Start by trying to recycle an existing but unassociated | |
166 // Parker from the global free list. | |
167 for (;;) { | |
168 p = FreeList ; | |
169 if (p == NULL) break ; | |
170 // 1: Detach | |
171 // Tantamount to p = Swap (&FreeList, NULL) | |
172 if (Atomic::cmpxchg_ptr (NULL, &FreeList, p) != p) { | |
173 continue ; | |
174 } | |
175 | |
176 // We've detached the list. The list in-hand is now | |
177 // local to this thread. This thread can operate on the | |
178 // list without risk of interference from other threads. | |
179 // 2: Extract -- pop the 1st element from the list. | |
180 Parker * List = p->FreeNext ; | |
181 if (List == NULL) break ; | |
182 for (;;) { | |
183 // 3: Try to reattach the residual list | |
184 guarantee (List != NULL, "invariant") ; | |
185 Parker * Arv = (Parker *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ; | |
186 if (Arv == NULL) break ; | |
187 | |
188 // New nodes arrived. Try to detach the recent arrivals. | |
189 if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) { | |
190 continue ; | |
191 } | |
192 guarantee (Arv != NULL, "invariant") ; | |
193 // 4: Merge Arv into List | |
194 Parker * Tail = List ; | |
195 while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ; | |
196 Tail->FreeNext = Arv ; | |
197 } | |
198 break ; | |
199 } | |
200 | |
201 if (p != NULL) { | |
202 guarantee (p->AssociatedWith == NULL, "invariant") ; | |
203 } else { | |
204 // Do this the hard way -- materialize a new Parker.. | |
205 // In rare cases an allocating thread might detach | |
206 // a long list -- installing null into FreeList --and | |
207 // then stall. Another thread calling Allocate() would see | |
208 // FreeList == null and then invoke the ctor. In this case we | |
209 // end up with more Parkers in circulation than we need, but | |
210 // the race is rare and the outcome is benign. | |
211 // Ideally, the # of extant Parkers is equal to the | |
212 // maximum # of threads that existed at any one time. | |
213 // Because of the race mentioned above, segments of the | |
214 // freelist can be transiently inaccessible. At worst | |
215 // we may end up with the # of Parkers in circulation | |
216 // slightly above the ideal. | |
217 p = new Parker() ; | |
218 } | |
219 p->AssociatedWith = t ; // Associate p with t | |
220 p->FreeNext = NULL ; | |
221 return p ; | |
222 } | |
223 | |
224 | |
225 void Parker::Release (Parker * p) { | |
226 if (p == NULL) return ; | |
227 guarantee (p->AssociatedWith != NULL, "invariant") ; | |
228 guarantee (p->FreeNext == NULL , "invariant") ; | |
229 p->AssociatedWith = NULL ; | |
230 for (;;) { | |
231 // Push p onto FreeList | |
232 Parker * List = FreeList ; | |
233 p->FreeNext = List ; | |
234 if (Atomic::cmpxchg_ptr (p, &FreeList, List) == List) break ; | |
235 } | |
236 } | |
237 |