1/*
2 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
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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).
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23 */
24
25#ifndef SHARE_RUNTIME_OSTHREAD_HPP
26#define SHARE_RUNTIME_OSTHREAD_HPP
27
28#include "runtime/frame.hpp"
29#include "runtime/handles.hpp"
30#include "runtime/javaFrameAnchor.hpp"
31#include "runtime/objectMonitor.hpp"
32#include "utilities/macros.hpp"
33
34// The OSThread class holds OS-specific thread information. It is equivalent
35// to the sys_thread_t structure of the classic JVM implementation.
36
37// The thread states represented by the ThreadState values are platform-specific
38// and are likely to be only approximate, because most OSes don't give you access
39// to precise thread state information.
40
41// Note: the ThreadState is legacy code and is not correctly implemented.
42// Uses of ThreadState need to be replaced by the state in the JavaThread.
43
44enum ThreadState {
45 ALLOCATED, // Memory has been allocated but not initialized
46 INITIALIZED, // The thread has been initialized but yet started
47 RUNNABLE, // Has been started and is runnable, but not necessarily running
48 MONITOR_WAIT, // Waiting on a contended monitor lock
49 CONDVAR_WAIT, // Waiting on a condition variable
50 OBJECT_WAIT, // Waiting on an Object.wait() call
51 BREAKPOINTED, // Suspended at breakpoint
52 SLEEPING, // Thread.sleep()
53 ZOMBIE // All done, but not reclaimed yet
54};
55
56typedef int (*OSThreadStartFunc)(void*);
57
58class OSThread: public CHeapObj<mtThread> {
59 friend class VMStructs;
60 friend class JVMCIVMStructs;
61 private:
62 OSThreadStartFunc _start_proc; // Thread start routine
63 void* _start_parm; // Thread start routine parameter
64 volatile ThreadState _state; // Thread state *hint*
65 volatile jint _interrupted; // Thread.isInterrupted state
66
67 // Note: _interrupted must be jint, so that Java intrinsics can access it.
68 // The value stored there must be either 0 or 1. It must be possible
69 // for Java to emulate Thread.currentThread().isInterrupted() by performing
70 // the double indirection Thread::current()->_osthread->_interrupted.
71
72 // Methods
73 public:
74 void set_state(ThreadState state) { _state = state; }
75 ThreadState get_state() { return _state; }
76
77 OSThread(OSThreadStartFunc start_proc, void* start_parm);
78 ~OSThread();
79
80 // Accessors
81 OSThreadStartFunc start_proc() const { return _start_proc; }
82 void set_start_proc(OSThreadStartFunc start_proc) { _start_proc = start_proc; }
83 void* start_parm() const { return _start_parm; }
84 void set_start_parm(void* start_parm) { _start_parm = start_parm; }
85
86 volatile bool interrupted() const { return _interrupted != 0; }
87 void set_interrupted(bool z) { _interrupted = z ? 1 : 0; }
88
89 // Printing
90 void print_on(outputStream* st) const;
91 void print() const;
92
93 // For java intrinsics:
94 static ByteSize interrupted_offset() { return byte_offset_of(OSThread, _interrupted); }
95
96 // Platform dependent stuff
97#include OS_HEADER(osThread)
98
99 public:
100 static ByteSize thread_id_offset() { return byte_offset_of(OSThread, _thread_id); }
101 static size_t thread_id_size() { return sizeof(thread_id_t); }
102
103 thread_id_t thread_id() const { return _thread_id; }
104
105 void set_thread_id(thread_id_t id) { _thread_id = id; }
106
107 private:
108 // _thread_id is kernel thread id (similar to LWP id on Solaris). Each
109 // thread has a unique thread_id (BsdThreads or NPTL). It can be used
110 // to access /proc.
111 thread_id_t _thread_id;
112};
113
114
115// Utility class for use with condition variables:
116class OSThreadWaitState : public StackObj {
117 OSThread* _osthread;
118 ThreadState _old_state;
119 public:
120 OSThreadWaitState(OSThread* osthread, bool is_object_wait) {
121 _osthread = osthread;
122 _old_state = osthread->get_state();
123 if (is_object_wait) {
124 osthread->set_state(OBJECT_WAIT);
125 } else {
126 osthread->set_state(CONDVAR_WAIT);
127 }
128 }
129 ~OSThreadWaitState() {
130 _osthread->set_state(_old_state);
131 }
132};
133
134
135// Utility class for use with contended monitors:
136class OSThreadContendState : public StackObj {
137 OSThread* _osthread;
138 ThreadState _old_state;
139 public:
140 OSThreadContendState(OSThread* osthread) {
141 _osthread = osthread;
142 _old_state = osthread->get_state();
143 osthread->set_state(MONITOR_WAIT);
144 }
145 ~OSThreadContendState() {
146 _osthread->set_state(_old_state);
147 }
148};
149
150#endif // SHARE_RUNTIME_OSTHREAD_HPP
151