1 /*
2 * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
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).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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23 */
24
25 #ifndef SHARE_VM_RUNTIME_OSTHREAD_HPP
26 #define SHARE_VM_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
44 enum 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
56 // I'd make OSThread a ValueObj embedded in Thread to avoid an indirection, but
57 // the assembler test in java.cpp expects that it can install the OSThread of
58 // the main thread into its own Thread at will.
59
60
61 class OSThread: public CHeapObj<mtThread> {
62 friend class VMStructs;
63 friend class JVMCIVMStructs;
64 private:
65 OSThreadStartFunc _start_proc; // Thread start routine
66 void* _start_parm; // Thread start routine parameter
67 volatile ThreadState _state; // Thread state *hint*
68 volatile jint _interrupted; // Thread.isInterrupted state
69
70 // Note: _interrupted must be jint, so that Java intrinsics can access it.
71 // The value stored there must be either 0 or 1. It must be possible
72 // for Java to emulate Thread.currentThread().isInterrupted() by performing
73 // the double indirection Thread::current()->_osthread->_interrupted.
74
75 // Methods
76 public:
77 void set_state(ThreadState state) { _state = state; }
78 ThreadState get_state() { return _state; }
79
80 OSThread(OSThreadStartFunc start_proc, void* start_parm);
81 ~OSThread();
82
83 // Accessors
84 OSThreadStartFunc start_proc() const { return _start_proc; }
85 void set_start_proc(OSThreadStartFunc start_proc) { _start_proc = start_proc; }
86 void* start_parm() const { return _start_parm; }
87 void set_start_parm(void* start_parm) { _start_parm = start_parm; }
88
89 volatile bool interrupted() const { return _interrupted != 0; }
90 void set_interrupted(bool z) { _interrupted = z ? 1 : 0; }
91
92 // Printing
93 void print_on(outputStream* st) const;
94 void print() const { print_on(tty); }
95
96 // For java intrinsics:
97 static ByteSize interrupted_offset() { return byte_offset_of(OSThread, _interrupted); }
98
99 // Platform dependent stuff
100 #include OS_HEADER(osThread)
101
102 public:
103 static ByteSize thread_id_offset() { return byte_offset_of(OSThread, _thread_id); }
104 static size_t thread_id_size() { return sizeof(thread_id_t); }
105
106 thread_id_t thread_id() const { return _thread_id; }
107
108 void set_thread_id(thread_id_t id) { _thread_id = id; }
109
110 private:
111 // _thread_id is kernel thread id (similar to LWP id on Solaris). Each
112 // thread has a unique thread_id (BsdThreads or NPTL). It can be used
113 // to access /proc.
114 thread_id_t _thread_id;
115 };
116
117
118 // Utility class for use with condition variables:
119 class OSThreadWaitState : public StackObj {
120 OSThread* _osthread;
121 ThreadState _old_state;
122 public:
123 OSThreadWaitState(OSThread* osthread, bool is_object_wait) {
124 _osthread = osthread;
125 _old_state = osthread->get_state();
126 if (is_object_wait) {
127 osthread->set_state(OBJECT_WAIT);
128 } else {
129 osthread->set_state(CONDVAR_WAIT);
130 }
131 }
132 ~OSThreadWaitState() {
133 _osthread->set_state(_old_state);
134 }
135 };
136
137
138 // Utility class for use with contended monitors:
139 class OSThreadContendState : public StackObj {
140 OSThread* _osthread;
141 ThreadState _old_state;
142 public:
143 OSThreadContendState(OSThread* osthread) {
144 _osthread = osthread;
145 _old_state = osthread->get_state();
146 osthread->set_state(MONITOR_WAIT);
147 }
148 ~OSThreadContendState() {
149 _osthread->set_state(_old_state);
150 }
151 };
152
153 #endif // SHARE_VM_RUNTIME_OSTHREAD_HPP