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