author | stefank |
Mon, 25 Nov 2019 12:31:39 +0100 | |
changeset 59249 | 29b0d0b61615 |
parent 59247 | 56bf71d64d51 |
child 59290 | 97d13893ec3c |
permissions | -rw-r--r-- |
49800 | 1 |
/* |
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* Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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* |
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*/ |
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#include "precompiled.hpp" |
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#include "utilities/globalCounter.hpp" |
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50429
83aec1d357d4
8204301: Make OrderAccess functions available to hpp rather than inline.hpp files
coleenp
parents:
50029
diff
changeset
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#include "runtime/orderAccess.hpp" |
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#include "runtime/thread.hpp" |
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#include "runtime/threadSMR.inline.hpp" |
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#include "runtime/vmThread.hpp" |
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#include "utilities/spinYield.hpp" |
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GlobalCounter::PaddedCounter GlobalCounter::_global_counter; |
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class GlobalCounter::CounterThreadCheck : public ThreadClosure { |
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private: |
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uintx _gbl_cnt; |
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public: |
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CounterThreadCheck(uintx gbl_cnt) : _gbl_cnt(gbl_cnt) {} |
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void do_thread(Thread* thread) { |
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SpinYield yield; |
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// Loops on this thread until it has exited the critical read section. |
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while(true) { |
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59247
56bf71d64d51
8234562: Move OrderAccess::release_store*/load_acquire to Atomic
stefank
parents:
52452
diff
changeset
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uintx cnt = Atomic::load_acquire(thread->get_rcu_counter()); |
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// This checks if the thread's counter is active. And if so is the counter |
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// for a pre-existing reader (belongs to this grace period). A pre-existing |
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// reader will have a lower counter than the global counter version for this |
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// generation. If the counter is larger than the global counter version this |
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// is a new reader and we can continue. |
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if (((cnt & COUNTER_ACTIVE) != 0) && (cnt - _gbl_cnt) > (max_uintx / 2)) { |
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yield.wait(); |
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} else { |
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break; |
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} |
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} |
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} |
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}; |
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void GlobalCounter::write_synchronize() { |
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assert((*Thread::current()->get_rcu_counter() & COUNTER_ACTIVE) == 0x0, "must be outside a critcal section"); |
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// Atomic::add must provide fence since we have storeload dependency. |
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59249
29b0d0b61615
8234737: Harmonize parameter order in Atomic - add
stefank
parents:
59247
diff
changeset
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uintx gbl_cnt = Atomic::add(&_global_counter._counter, COUNTER_INCREMENT); |
52332
d2a3503c72f7
8212827: GlobalCounter should support nested critical sections
kbarrett
parents:
51548
diff
changeset
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// Do all RCU threads. |
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CounterThreadCheck ctc(gbl_cnt); |
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for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) { |
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ctc.do_thread(thread); |
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} |
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for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) { |
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ctc.do_thread(njti.current()); |
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eb8d5aeabab3
8209850: Allow NamedThreads to use GlobalCounter critical sections
kbarrett
parents:
51405
diff
changeset
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} |
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} |