Wed, 31 Jul 2019 14:28:51 -0400
8048556: Unnecessary GCLocker-initiated young GCs
Summary: Fixed recognition of unnecessary GCLocker collections.
Reviewed-by: pliden, tschatzl
Contributed-by: johnc@azul.com
ysr@777 | 1 | /* |
mikael@6198 | 2 | * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved. |
ysr@777 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
ysr@777 | 4 | * |
ysr@777 | 5 | * This code is free software; you can redistribute it and/or modify it |
ysr@777 | 6 | * under the terms of the GNU General Public License version 2 only, as |
ysr@777 | 7 | * published by the Free Software Foundation. |
ysr@777 | 8 | * |
ysr@777 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
ysr@777 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
ysr@777 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
ysr@777 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
ysr@777 | 13 | * accompanied this code). |
ysr@777 | 14 | * |
ysr@777 | 15 | * You should have received a copy of the GNU General Public License version |
ysr@777 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
ysr@777 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
ysr@777 | 18 | * |
trims@1907 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
trims@1907 | 20 | * or visit www.oracle.com if you need additional information or have any |
trims@1907 | 21 | * questions. |
ysr@777 | 22 | * |
ysr@777 | 23 | */ |
ysr@777 | 24 | |
stefank@2314 | 25 | #ifndef SHARE_VM_GC_IMPLEMENTATION_SHARED_CONCURRENTGCTHREAD_HPP |
stefank@2314 | 26 | #define SHARE_VM_GC_IMPLEMENTATION_SHARED_CONCURRENTGCTHREAD_HPP |
stefank@2314 | 27 | |
jprovino@4542 | 28 | #include "utilities/macros.hpp" |
pliden@6906 | 29 | #include "gc_implementation/shared/suspendibleThreadSet.hpp" |
stefank@2314 | 30 | #include "runtime/thread.hpp" |
ysr@777 | 31 | |
ysr@777 | 32 | class ConcurrentGCThread: public NamedThread { |
ysr@777 | 33 | friend class VMStructs; |
ysr@777 | 34 | |
ysr@777 | 35 | protected: |
iveresov@1229 | 36 | bool _should_terminate; |
iveresov@1229 | 37 | bool _has_terminated; |
ysr@777 | 38 | |
ysr@777 | 39 | enum CGC_flag_type { |
ysr@777 | 40 | CGC_nil = 0x0, |
ysr@777 | 41 | CGC_dont_suspend = 0x1, |
ysr@777 | 42 | CGC_CGC_safepoint = 0x2, |
ysr@777 | 43 | CGC_VM_safepoint = 0x4 |
ysr@777 | 44 | }; |
ysr@777 | 45 | |
ysr@777 | 46 | static int _CGC_flag; |
ysr@777 | 47 | |
ysr@777 | 48 | static bool CGC_flag_is_set(int b) { return (_CGC_flag & b) != 0; } |
ysr@777 | 49 | static int set_CGC_flag(int b) { return _CGC_flag |= b; } |
ysr@777 | 50 | static int reset_CGC_flag(int b) { return _CGC_flag &= ~b; } |
ysr@777 | 51 | |
ysr@777 | 52 | // Create and start the thread (setting it's priority high.) |
ysr@777 | 53 | void create_and_start(); |
ysr@777 | 54 | |
ysr@777 | 55 | // Do initialization steps in the thread: record stack base and size, |
ysr@777 | 56 | // init thread local storage, set JNI handle block. |
ysr@777 | 57 | void initialize_in_thread(); |
ysr@777 | 58 | |
ysr@777 | 59 | // Wait until Universe::is_fully_initialized(); |
ysr@777 | 60 | void wait_for_universe_init(); |
ysr@777 | 61 | |
ysr@777 | 62 | // Record that the current thread is terminating, and will do more |
ysr@777 | 63 | // concurrent work. |
ysr@777 | 64 | void terminate(); |
ysr@777 | 65 | |
ysr@777 | 66 | public: |
ysr@777 | 67 | // Constructor |
ysr@777 | 68 | |
ysr@777 | 69 | ConcurrentGCThread(); |
ysr@777 | 70 | ~ConcurrentGCThread() {} // Exists to call NamedThread destructor. |
ysr@777 | 71 | |
ysr@777 | 72 | // Tester |
ysr@777 | 73 | bool is_ConcurrentGC_thread() const { return true; } |
ysr@777 | 74 | }; |
ysr@777 | 75 | |
ysr@777 | 76 | // The SurrogateLockerThread is used by concurrent GC threads for |
ysr@777 | 77 | // manipulating Java monitors, in particular, currently for |
ysr@777 | 78 | // manipulating the pending_list_lock. XXX |
ysr@777 | 79 | class SurrogateLockerThread: public JavaThread { |
ysr@777 | 80 | friend class VMStructs; |
ysr@777 | 81 | public: |
ysr@777 | 82 | enum SLT_msg_type { |
ysr@777 | 83 | empty = 0, // no message |
ysr@777 | 84 | acquirePLL, // acquire pending list lock |
ysr@777 | 85 | releaseAndNotifyPLL // notify and release pending list lock |
ysr@777 | 86 | }; |
ysr@777 | 87 | private: |
ysr@777 | 88 | // the following are shared with the CMSThread |
ysr@777 | 89 | SLT_msg_type _buffer; // communication buffer |
ysr@777 | 90 | Monitor _monitor; // monitor controlling buffer |
ysr@777 | 91 | BasicLock _basicLock; // used for PLL locking |
ysr@777 | 92 | |
ysr@777 | 93 | public: |
ysr@777 | 94 | static SurrogateLockerThread* make(TRAPS); |
ysr@777 | 95 | |
kbarrett@7360 | 96 | // Terminate VM with error message that SLT needed but not yet created. |
kbarrett@7360 | 97 | static void report_missing_slt(); |
kbarrett@7360 | 98 | |
ysr@777 | 99 | SurrogateLockerThread(); |
ysr@777 | 100 | |
ysr@777 | 101 | bool is_hidden_from_external_view() const { return true; } |
ysr@777 | 102 | |
ysr@777 | 103 | void loop(); // main method |
ysr@777 | 104 | |
ysr@777 | 105 | void manipulatePLL(SLT_msg_type msg); |
ysr@777 | 106 | |
ysr@777 | 107 | }; |
stefank@2314 | 108 | |
stefank@2314 | 109 | #endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_CONCURRENTGCTHREAD_HPP |