Mercurial > hg > truffle
annotate src/share/vm/runtime/park.hpp @ 12146:9758d9f36299
8021954: VM SIGSEGV during classloading on MacOS; hs_err_pid file produced
Summary: declare all user-defined operator new()s within Hotspot code with the empty throw() exception specification
Reviewed-by: coleenp, twisti, dholmes, hseigel, dcubed, kvn, ccheung
Contributed-by: lois.foltan@oracle.com
| author | coleenp |
|---|---|
| date | Thu, 29 Aug 2013 18:56:29 -0400 |
| parents | f95d63e2154a |
| children |
| rev | line source |
|---|---|
| 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 |