1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/runtime/vmThread.hpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,155 @@
1.4 +/*
1.5 + * Copyright (c) 1998, 2012, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#ifndef SHARE_VM_RUNTIME_VMTHREAD_HPP
1.29 +#define SHARE_VM_RUNTIME_VMTHREAD_HPP
1.30 +
1.31 +#include "runtime/perfData.hpp"
1.32 +#include "runtime/thread.inline.hpp"
1.33 +#include "runtime/vm_operations.hpp"
1.34 +
1.35 +//
1.36 +// Prioritized queue of VM operations.
1.37 +//
1.38 +// Encapsulates both queue management and
1.39 +// and priority policy
1.40 +//
1.41 +class VMOperationQueue : public CHeapObj<mtInternal> {
1.42 + private:
1.43 + enum Priorities {
1.44 + SafepointPriority, // Highest priority (operation executed at a safepoint)
1.45 + MediumPriority, // Medium priority
1.46 + nof_priorities
1.47 + };
1.48 +
1.49 + // We maintain a doubled linked list, with explicit count.
1.50 + int _queue_length[nof_priorities];
1.51 + int _queue_counter;
1.52 + VM_Operation* _queue [nof_priorities];
1.53 + // we also allow the vmThread to register the ops it has drained so we
1.54 + // can scan them from oops_do
1.55 + VM_Operation* _drain_list;
1.56 +
1.57 + // Double-linked non-empty list insert.
1.58 + void insert(VM_Operation* q,VM_Operation* n);
1.59 + void unlink(VM_Operation* q);
1.60 +
1.61 + // Basic queue manipulation
1.62 + bool queue_empty (int prio);
1.63 + void queue_add_front (int prio, VM_Operation *op);
1.64 + void queue_add_back (int prio, VM_Operation *op);
1.65 + VM_Operation* queue_remove_front(int prio);
1.66 + void queue_oops_do(int queue, OopClosure* f);
1.67 + void drain_list_oops_do(OopClosure* f);
1.68 + VM_Operation* queue_drain(int prio);
1.69 + // lock-free query: may return the wrong answer but must not break
1.70 + bool queue_peek(int prio) { return _queue_length[prio] > 0; }
1.71 +
1.72 + public:
1.73 + VMOperationQueue();
1.74 +
1.75 + // Highlevel operations. Encapsulates policy
1.76 + bool add(VM_Operation *op);
1.77 + VM_Operation* remove_next(); // Returns next or null
1.78 + VM_Operation* remove_next_at_safepoint_priority() { return queue_remove_front(SafepointPriority); }
1.79 + VM_Operation* drain_at_safepoint_priority() { return queue_drain(SafepointPriority); }
1.80 + void set_drain_list(VM_Operation* list) { _drain_list = list; }
1.81 + bool peek_at_safepoint_priority() { return queue_peek(SafepointPriority); }
1.82 +
1.83 + // GC support
1.84 + void oops_do(OopClosure* f);
1.85 +
1.86 + void verify_queue(int prio) PRODUCT_RETURN;
1.87 +};
1.88 +
1.89 +
1.90 +//
1.91 +// A single VMThread (the primordial thread) spawns all other threads
1.92 +// and is itself used by other threads to offload heavy vm operations
1.93 +// like scavenge, garbage_collect etc.
1.94 +//
1.95 +
1.96 +class VMThread: public NamedThread {
1.97 + private:
1.98 + static ThreadPriority _current_priority;
1.99 +
1.100 + static bool _should_terminate;
1.101 + static bool _terminated;
1.102 + static Monitor * _terminate_lock;
1.103 + static PerfCounter* _perf_accumulated_vm_operation_time;
1.104 +
1.105 + void evaluate_operation(VM_Operation* op);
1.106 + public:
1.107 + // Constructor
1.108 + VMThread();
1.109 +
1.110 + // Tester
1.111 + bool is_VM_thread() const { return true; }
1.112 + bool is_GC_thread() const { return true; }
1.113 +
1.114 + // The ever running loop for the VMThread
1.115 + void loop();
1.116 +
1.117 + // Called to stop the VM thread
1.118 + static void wait_for_vm_thread_exit();
1.119 + static bool should_terminate() { return _should_terminate; }
1.120 + static bool is_terminated() { return _terminated == true; }
1.121 +
1.122 + // Execution of vm operation
1.123 + static void execute(VM_Operation* op);
1.124 +
1.125 + // Returns the current vm operation if any.
1.126 + static VM_Operation* vm_operation() { return _cur_vm_operation; }
1.127 +
1.128 + // Returns the single instance of VMThread.
1.129 + static VMThread* vm_thread() { return _vm_thread; }
1.130 +
1.131 + // GC support
1.132 + void oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf);
1.133 +
1.134 + // Debugging
1.135 + void print_on(outputStream* st) const;
1.136 + void print() const { print_on(tty); }
1.137 + void verify();
1.138 +
1.139 + // Performance measurement
1.140 + static PerfCounter* perf_accumulated_vm_operation_time() { return _perf_accumulated_vm_operation_time; }
1.141 +
1.142 + // Entry for starting vm thread
1.143 + virtual void run();
1.144 +
1.145 + // Creations/Destructions
1.146 + static void create();
1.147 + static void destroy();
1.148 +
1.149 + private:
1.150 + // VM_Operation support
1.151 + static VM_Operation* _cur_vm_operation; // Current VM operation
1.152 + static VMOperationQueue* _vm_queue; // Queue (w/ policy) of VM operations
1.153 +
1.154 + // Pointer to single-instance of VM thread
1.155 + static VMThread* _vm_thread;
1.156 +};
1.157 +
1.158 +#endif // SHARE_VM_RUNTIME_VMTHREAD_HPP
