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 /* 25 * Per-thread blocking support for JSR166. See the Java-level 26 * Documentation for rationale. Basically, park acts like wait, unpark 27 * like notify. 28 * 29 * 6271289 -- 30 * To avoid errors where an os thread expires but the JavaThread still 31 * exists, Parkers are immortal (type-stable) and are recycled across 32 * new threads. This parallels the ParkEvent implementation. 33 * Because park-unpark allow spurious wakeups it is harmless if an 34 * unpark call unparks a new thread using the old Parker reference. 35 * 36 * In the future we'll want to think about eliminating Parker and using 37 * ParkEvent instead. There's considerable duplication between the two 38 * services. 39 * 40 */ 41 42 class Parker : public os::PlatformParker { 43 private: 150 FreeNext = NULL ; 151 ListNext = NULL ; 152 ListPrev = NULL ; 153 OnList = 0 ; 154 TState = 0 ; 155 Notified = 0 ; 156 IsWaiting = 0 ; 157 } 158 159 // We use placement-new to force ParkEvent instances to be 160 // aligned on 256-byte address boundaries. This ensures that the least 161 // significant byte of a ParkEvent address is always 0. 162 163 void * operator new (size_t sz) ; 164 void operator delete (void * a) ; 165 166 public: 167 static ParkEvent * Allocate (Thread * t) ; 168 static void Release (ParkEvent * e) ; 169 } ; | 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 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" 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: 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. 168 169 void * operator new (size_t sz) ; 170 void operator delete (void * a) ; 171 172 public: 173 static ParkEvent * Allocate (Thread * t) ; 174 static void Release (ParkEvent * e) ; 175 } ; 176 177 #endif // SHARE_VM_RUNTIME_PARK_HPP |