| /* |
| * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #ifndef SHARE_VM_GC_CONCURRENTGCPHASEMANAGER_HPP |
| #define SHARE_VM_GC_CONCURRENTGCPHASEMANAGER_HPP |
| |
| #include "memory/allocation.hpp" |
| |
| // Manage concurrent phase information, to support WhiteBox testing. |
| // Managers are stack allocated. Managers may be nested, to support |
| // nested subphases. |
| class ConcurrentGCPhaseManager : public StackObj { |
| public: |
| |
| // Special phase ids used by all GC's that use this facility. |
| static const int UNCONSTRAINED_PHASE = 0; // Unconstrained or no request. |
| static const int IDLE_PHASE = 1; // Concurrent processing is idle. |
| |
| // Stack of phase managers. |
| class Stack VALUE_OBJ_CLASS_SPEC { |
| friend class ConcurrentGCPhaseManager; |
| |
| public: |
| // Create an empty stack of phase managers. |
| Stack(); |
| |
| private: |
| int _requested_phase; |
| ConcurrentGCPhaseManager* _top; |
| |
| // Non-copyable - never defined. |
| Stack(const Stack&); |
| Stack& operator=(const Stack&); |
| }; |
| |
| // Construct and push a new manager on the stack, activating phase. |
| // Notifies callers in wait_for_phase of the phase change. |
| // |
| // Preconditions: |
| // - Calling thread must be a ConcurrentGC thread |
| // - phase != UNCONSTRAINED_PHASE |
| // - stack != NULL |
| // - other managers on stack must all be active. |
| ConcurrentGCPhaseManager(int phase, Stack* stack); |
| |
| // Pop this manager off the stack, deactivating phase. Before |
| // changing phases, if is_requested() is true, wait until the |
| // request is changed. After changing phases, notifies callers of |
| // wait_for_phase of the phase change. |
| // |
| // Preconditions: |
| // - Calling thread must be a ConcurrentGC thread |
| // - this must be the current top of the manager stack |
| ~ConcurrentGCPhaseManager(); |
| |
| // Returns true if this phase is active and is currently requested. |
| // |
| // Preconditions: |
| // - Calling thread must be a ConcurrentGC thread |
| // - this must be the current top of manager stack |
| bool is_requested() const; |
| |
| // Wait until is_requested() is false. Returns true if waited. |
| // |
| // Preconditions: |
| // - Calling thread must be a ConcurrentGC thread |
| // - this must be the current top of manager stack |
| bool wait_when_requested() const; |
| |
| // Directly step from one phase to another, without needing to pop a |
| // manager from the stack and allocate a new one. Before changing |
| // phases, if is_requested() is true and force is false, wait until |
| // the request is changed. After changing phases, notifies callers |
| // of wait_for_phase of the phase change. |
| // |
| // Preconditions: |
| // - Calling thread must be a ConcurrentGC thread |
| // - phase != UNCONSTRAINED_PHASE |
| // - this must be the current top of manager stack |
| void set_phase(int phase, bool force); |
| |
| // Deactivate the manager. An inactive manager no longer blocks |
| // transitions out of the associated phase when that phase has been |
| // requested. |
| // |
| // Preconditions: |
| // - Calling thread must be a ConcurrentGC thread |
| // - this must be the current top of manager stack |
| void deactivate(); |
| |
| // Used to implement CollectorPolicy::request_concurrent_phase(). |
| // Updates request to the new phase, and notifies threads blocked on |
| // the old request of the change. Returns true if the phase is |
| // UNCONSTRAINED_PHASE. Otherwise, waits until an active phase is |
| // the requested phase (returning true) or IDLE_PHASE (returning |
| // false if not also the requested phase). |
| // |
| // Preconditions: |
| // - Calling thread must be a Java thread |
| // - stack must be non-NULL |
| static bool wait_for_phase(int phase, Stack* stack); |
| |
| private: |
| int _phase; |
| bool _active; |
| ConcurrentGCPhaseManager* _prev; |
| Stack* _stack; |
| |
| // Non-copyable - never defined. |
| ConcurrentGCPhaseManager(const ConcurrentGCPhaseManager&); |
| ConcurrentGCPhaseManager& operator=(const ConcurrentGCPhaseManager&); |
| |
| bool wait_when_requested_impl() const; |
| }; |
| |
| #endif // include guard |