Mercurial > hg > graal-compiler
annotate src/share/vm/runtime/park.hpp @ 14495:cd5d10655495
8027754: Enable loop optimizations for loops with MathExact inside
Reviewed-by: kvn, iveresov
author | rbackman |
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date | Thu, 23 Jan 2014 12:08:28 +0100 |
parents | 9758d9f36299 |
children |
rev | line source |
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1878 | 1 /* |
12146
9758d9f36299
8021954: VM SIGSEGV during classloading on MacOS; hs_err_pid file produced
coleenp
parents:
1972
diff
changeset
|
2 * Copyright (c) 1997, 2013, 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 */ | |
1972 | 24 |
25 #ifndef SHARE_VM_RUNTIME_PARK_HPP | |
26 #define SHARE_VM_RUNTIME_PARK_HPP | |
27 | |
28 #include "utilities/debug.hpp" | |
29 #include "utilities/globalDefinitions.hpp" | |
1878 | 30 /* |
31 * Per-thread blocking support for JSR166. See the Java-level | |
32 * Documentation for rationale. Basically, park acts like wait, unpark | |
33 * like notify. | |
34 * | |
35 * 6271289 -- | |
36 * To avoid errors where an os thread expires but the JavaThread still | |
37 * exists, Parkers are immortal (type-stable) and are recycled across | |
38 * new threads. This parallels the ParkEvent implementation. | |
39 * Because park-unpark allow spurious wakeups it is harmless if an | |
40 * unpark call unparks a new thread using the old Parker reference. | |
41 * | |
42 * In the future we'll want to think about eliminating Parker and using | |
43 * ParkEvent instead. There's considerable duplication between the two | |
44 * services. | |
45 * | |
46 */ | |
47 | |
48 class Parker : public os::PlatformParker { | |
49 private: | |
50 volatile int _counter ; | |
51 Parker * FreeNext ; | |
52 JavaThread * AssociatedWith ; // Current association | |
53 | |
54 public: | |
55 Parker() : PlatformParker() { | |
56 _counter = 0 ; | |
57 FreeNext = NULL ; | |
58 AssociatedWith = NULL ; | |
59 } | |
60 protected: | |
61 ~Parker() { ShouldNotReachHere(); } | |
62 public: | |
63 // For simplicity of interface with Java, all forms of park (indefinite, | |
64 // relative, and absolute) are multiplexed into one call. | |
65 void park(bool isAbsolute, jlong time); | |
66 void unpark(); | |
67 | |
68 // Lifecycle operators | |
69 static Parker * Allocate (JavaThread * t) ; | |
70 static void Release (Parker * e) ; | |
71 private: | |
72 static Parker * volatile FreeList ; | |
73 static volatile int ListLock ; | |
74 | |
75 }; | |
76 | |
77 ///////////////////////////////////////////////////////////// | |
78 // | |
79 // ParkEvents are type-stable and immortal. | |
80 // | |
81 // Lifecycle: Once a ParkEvent is associated with a thread that ParkEvent remains | |
82 // associated with the thread for the thread's entire lifetime - the relationship is | |
83 // stable. A thread will be associated at most one ParkEvent. When the thread | |
84 // expires, the ParkEvent moves to the EventFreeList. New threads attempt to allocate from | |
85 // the EventFreeList before creating a new Event. Type-stability frees us from | |
86 // worrying about stale Event or Thread references in the objectMonitor subsystem. | |
87 // (A reference to ParkEvent is always valid, even though the event may no longer be associated | |
88 // with the desired or expected thread. A key aspect of this design is that the callers of | |
89 // park, unpark, etc must tolerate stale references and spurious wakeups). | |
90 // | |
91 // Only the "associated" thread can block (park) on the ParkEvent, although | |
92 // any other thread can unpark a reachable parkevent. Park() is allowed to | |
93 // return spuriously. In fact park-unpark a really just an optimization to | |
94 // avoid unbounded spinning and surrender the CPU to be a polite system citizen. | |
95 // A degenerate albeit "impolite" park-unpark implementation could simply return. | |
96 // See http://blogs.sun.com/dave for more details. | |
97 // | |
98 // Eventually I'd like to eliminate Events and ObjectWaiters, both of which serve as | |
99 // thread proxies, and simply make the THREAD structure type-stable and persistent. | |
100 // Currently, we unpark events associated with threads, but ideally we'd just | |
101 // unpark threads. | |
102 // | |
103 // The base-class, PlatformEvent, is platform-specific while the ParkEvent is | |
104 // platform-independent. PlatformEvent provides park(), unpark(), etc., and | |
105 // is abstract -- that is, a PlatformEvent should never be instantiated except | |
106 // as part of a ParkEvent. | |
107 // Equivalently we could have defined a platform-independent base-class that | |
108 // exported Allocate(), Release(), etc. The platform-specific class would extend | |
109 // that base-class, adding park(), unpark(), etc. | |
110 // | |
111 // A word of caution: The JVM uses 2 very similar constructs: | |
112 // 1. ParkEvent are used for Java-level "monitor" synchronization. | |
113 // 2. Parkers are used by JSR166-JUC park-unpark. | |
114 // | |
115 // We'll want to eventually merge these redundant facilities and use ParkEvent. | |
116 | |
117 | |
118 class ParkEvent : public os::PlatformEvent { | |
119 private: | |
120 ParkEvent * FreeNext ; | |
121 | |
122 // Current association | |
123 Thread * AssociatedWith ; | |
124 intptr_t RawThreadIdentity ; // LWPID etc | |
125 volatile int Incarnation ; | |
126 | |
127 // diagnostic : keep track of last thread to wake this thread. | |
128 // this is useful for construction of dependency graphs. | |
129 void * LastWaker ; | |
130 | |
131 public: | |
132 // MCS-CLH list linkage and Native Mutex/Monitor | |
133 ParkEvent * volatile ListNext ; | |
134 ParkEvent * volatile ListPrev ; | |
135 volatile intptr_t OnList ; | |
136 volatile int TState ; | |
137 volatile int Notified ; // for native monitor construct | |
138 volatile int IsWaiting ; // Enqueued on WaitSet | |
139 | |
140 | |
141 private: | |
142 static ParkEvent * volatile FreeList ; | |
143 static volatile int ListLock ; | |
144 | |
145 // It's prudent to mark the dtor as "private" | |
146 // ensuring that it's not visible outside the package. | |
147 // Unfortunately gcc warns about such usage, so | |
148 // we revert to the less desirable "protected" visibility. | |
149 // The other compilers accept private dtors. | |
150 | |
151 protected: // Ensure dtor is never invoked | |
152 ~ParkEvent() { guarantee (0, "invariant") ; } | |
153 | |
154 ParkEvent() : PlatformEvent() { | |
155 AssociatedWith = NULL ; | |
156 FreeNext = NULL ; | |
157 ListNext = NULL ; | |
158 ListPrev = NULL ; | |
159 OnList = 0 ; | |
160 TState = 0 ; | |
161 Notified = 0 ; | |
162 IsWaiting = 0 ; | |
163 } | |
164 | |
165 // We use placement-new to force ParkEvent instances to be | |
166 // aligned on 256-byte address boundaries. This ensures that the least | |
167 // significant byte of a ParkEvent address is always 0. | |
168 | |
12146
9758d9f36299
8021954: VM SIGSEGV during classloading on MacOS; hs_err_pid file produced
coleenp
parents:
1972
diff
changeset
|
169 void * operator new (size_t sz) throw(); |
1878 | 170 void operator delete (void * a) ; |
171 | |
172 public: | |
173 static ParkEvent * Allocate (Thread * t) ; | |
174 static void Release (ParkEvent * e) ; | |
175 } ; | |
1972 | 176 |
177 #endif // SHARE_VM_RUNTIME_PARK_HPP |