1 /*
2 * Copyright (c) 1997, 2022, 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
6 * under the terms of the GNU General Public License version 2 only, as
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.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
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 "runtime/suspendedThreadTask.hpp"
33 #include "utilities/macros.hpp"
34
35 #if defined(LINUX) || defined(AIX) || defined(BSD)
36 #include "suspendResume_posix.hpp"
37 #endif
38
39 class Monitor;
40
41 // The OSThread class holds OS-specific thread information. It is equivalent
42 // to the sys_thread_t structure of the classic JVM implementation.
43
44 // The thread states represented by the ThreadState values are platform-specific
45 // and are likely to be only approximate, because most OSes don't give you access
46 // to precise thread state information.
47
48 // Note: the ThreadState is legacy code and is not correctly implemented.
49 // Uses of ThreadState need to be replaced by the state in the JavaThread.
50
51 enum ThreadState {
52 ALLOCATED, // Memory has been allocated but not initialized
53 INITIALIZED, // The thread has been initialized but yet started
54 RUNNABLE, // Has been started and is runnable, but not necessarily running
55 MONITOR_WAIT, // Waiting on a contended monitor lock
56 CONDVAR_WAIT, // Waiting on a condition variable
57 OBJECT_WAIT, // Waiting on an Object.wait() call
58 BREAKPOINTED, // Suspended at breakpoint
59 SLEEPING, // Thread.sleep()
60 ZOMBIE // All done, but not reclaimed yet
61 };
62
63 typedef int (*OSThreadStartFunc)(void*);
64
65 class OSThread: public CHeapObj<mtThread> {
66 friend class VMStructs;
67 friend class JVMCIVMStructs;
68 private:
69 volatile ThreadState _state; // Thread state *hint*
70
71 // Methods
72 public:
73 void set_state(ThreadState state) { _state = state; }
74 ThreadState get_state() { return _state; }
75
76 OSThread();
77 ~OSThread();
78
79 // Printing
80 void print_on(outputStream* st) const;
81 void print() const;
82
83 // Platform dependent stuff
84 #include OS_HEADER(osThread)
85
86 public:
87
88 thread_id_t thread_id() const { return _thread_id; }
89
90 void set_thread_id(thread_id_t id) { _thread_id = id; }
91
92 private:
93 // _thread_id is kernel thread id (similar to LWP id on Solaris). Each
94 // thread has a unique thread_id (BsdThreads or NPTL). It can be used
95 // to access /proc.
96 thread_id_t _thread_id;
97 };
98
99
100 // Utility class for use with condition variables:
101 class OSThreadWaitState : public StackObj {
102 OSThread* _osthread;
103 ThreadState _old_state;
104 public:
105 OSThreadWaitState(OSThread* osthread, bool is_object_wait) {
106 _osthread = osthread;
107 _old_state = osthread->get_state();
108 if (is_object_wait) {
109 osthread->set_state(OBJECT_WAIT);
110 } else {
111 osthread->set_state(CONDVAR_WAIT);
112 }
113 }
114 ~OSThreadWaitState() {
115 _osthread->set_state(_old_state);
116 }
117 };
118
119
120 // Utility class for use with contended monitors:
121 class OSThreadContendState : public StackObj {
122 OSThread* _osthread;
123 ThreadState _old_state;
124 public:
125 OSThreadContendState(OSThread* osthread) {
126 _osthread = osthread;
127 _old_state = osthread->get_state();
128 osthread->set_state(MONITOR_WAIT);
129 }
130 ~OSThreadContendState() {
131 _osthread->set_state(_old_state);
132 }
133 };
134
135 #endif // SHARE_RUNTIME_OSTHREAD_HPP