1 /*
2 * Copyright (c) 2012, 2025, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #ifndef SHARE_RUNTIME_JAVATHREAD_INLINE_HPP
27 #define SHARE_RUNTIME_JAVATHREAD_INLINE_HPP
28
29 #include "runtime/javaThread.hpp"
30
31 #include "classfile/javaClasses.hpp"
32 #include "gc/shared/tlab_globals.hpp"
33 #include "memory/universe.hpp"
34 #include "oops/instanceKlass.hpp"
35 #include "oops/oopHandle.inline.hpp"
36 #include "runtime/atomic.hpp"
37 #include "runtime/continuation.hpp"
38 #include "runtime/continuationEntry.inline.hpp"
39 #include "runtime/lockStack.inline.hpp"
40 #include "runtime/nonJavaThread.hpp"
41 #include "runtime/objectMonitor.inline.hpp"
42 #include "runtime/orderAccess.hpp"
43 #include "runtime/safepoint.hpp"
44
45 inline void JavaThread::set_suspend_flag(SuspendFlags f) {
46 uint32_t flags;
47 do {
48 flags = _suspend_flags;
49 }
50 while (Atomic::cmpxchg(&_suspend_flags, flags, (flags | f)) != flags);
51 }
52 inline void JavaThread::clear_suspend_flag(SuspendFlags f) {
53 uint32_t flags;
54 do {
55 flags = _suspend_flags;
56 }
57 while (Atomic::cmpxchg(&_suspend_flags, flags, (flags & ~f)) != flags);
58 }
59
60 inline void JavaThread::set_obj_deopt_flag() {
61 set_suspend_flag(_obj_deopt);
62 }
63 inline void JavaThread::clear_obj_deopt_flag() {
64 clear_suspend_flag(_obj_deopt);
65 }
66
67 #if INCLUDE_JVMTI
68 inline bool JavaThread::set_carrier_thread_suspended() {
69 return Atomic::cmpxchg(&_carrier_thread_suspended, false, true) == false;
70 }
71 inline bool JavaThread::clear_carrier_thread_suspended() {
72 return Atomic::cmpxchg(&_carrier_thread_suspended, true, false) == true;
73 }
74 #endif
75
76 class AsyncExceptionHandshake : public AsyncHandshakeClosure {
77 OopHandle _exception;
78 public:
79 AsyncExceptionHandshake(OopHandle& o, const char* name = "AsyncExceptionHandshake")
80 : AsyncHandshakeClosure(name), _exception(o) { }
81
82 ~AsyncExceptionHandshake() {
83 Thread* current = Thread::current();
84 // Can get here from the VMThread via install_async_exception() bail out.
85 if (current->is_Java_thread()) {
86 guarantee(JavaThread::cast(current)->is_oop_safe(),
87 "JavaThread cannot touch oops after its GC barrier is detached.");
88 }
89 assert(!_exception.is_empty(), "invariant");
90 _exception.release(Universe::vm_global());
91 }
92
93 void do_thread(Thread* thr) {
94 JavaThread* self = JavaThread::cast(thr);
95 assert(self == JavaThread::current(), "must be");
96
97 self->handle_async_exception(exception());
98 }
99 oop exception() {
100 assert(!_exception.is_empty(), "invariant");
101 return _exception.resolve();
102 }
103 bool is_async_exception() { return true; }
104 };
105
106 class UnsafeAccessErrorHandshake : public AsyncHandshakeClosure {
107 public:
108 UnsafeAccessErrorHandshake() : AsyncHandshakeClosure("UnsafeAccessErrorHandshake") {}
109 void do_thread(Thread* thr) {
110 JavaThread* self = JavaThread::cast(thr);
111 assert(self == JavaThread::current(), "must be");
112
113 self->handshake_state()->handle_unsafe_access_error();
114 }
115 bool is_async_exception() { return true; }
116 };
117
118 inline void JavaThread::set_pending_unsafe_access_error() {
119 if (!has_async_exception_condition()) {
120 Handshake::execute(new UnsafeAccessErrorHandshake(), this);
121 }
122 }
123
124 inline bool JavaThread::has_async_exception_condition() {
125 return handshake_state()->has_async_exception_operation();
126 }
127
128 inline JavaThread::NoAsyncExceptionDeliveryMark::NoAsyncExceptionDeliveryMark(JavaThread *t) : _target(t) {
129 assert(!_target->handshake_state()->async_exceptions_blocked(), "Nesting is not supported");
130 _target->handshake_state()->set_async_exceptions_blocked(true);
131 }
132 inline JavaThread::NoAsyncExceptionDeliveryMark::~NoAsyncExceptionDeliveryMark() {
133 _target->handshake_state()->set_async_exceptions_blocked(false);
134 }
135
136 inline JavaThreadState JavaThread::thread_state() const {
137 #if defined(PPC64) || defined (AARCH64) || defined(RISCV64)
138 // Use membars when accessing volatile _thread_state. See
139 // Threads::create_vm() for size checks.
140 return Atomic::load_acquire(&_thread_state);
141 #else
142 return Atomic::load(&_thread_state);
143 #endif
144 }
145
146 inline void JavaThread::set_thread_state(JavaThreadState s) {
147 assert(current_or_null() == nullptr || current_or_null() == this,
148 "state change should only be called by the current thread");
149 #if defined(PPC64) || defined (AARCH64) || defined(RISCV64)
150 // Use membars when accessing volatile _thread_state. See
151 // Threads::create_vm() for size checks.
152 Atomic::release_store(&_thread_state, s);
153 #else
154 Atomic::store(&_thread_state, s);
155 #endif
156 }
157
158 inline void JavaThread::set_thread_state_fence(JavaThreadState s) {
159 set_thread_state(s);
160 OrderAccess::fence();
161 }
162
163 ThreadSafepointState* JavaThread::safepoint_state() const {
164 return _safepoint_state;
165 }
166
167 void JavaThread::set_safepoint_state(ThreadSafepointState *state) {
168 _safepoint_state = state;
169 }
170
171 bool JavaThread::is_at_poll_safepoint() {
172 return _safepoint_state->is_at_poll_safepoint();
173 }
174
175 bool JavaThread::is_vthread_mounted() const {
176 return vthread_continuation() != nullptr;
177 }
178
179 const ContinuationEntry* JavaThread::vthread_continuation() const {
180 for (ContinuationEntry* c = last_continuation(); c != nullptr; c = c->parent()) {
181 if (c->is_virtual_thread())
182 return c;
183 }
184 return nullptr;
185 }
186
187 void JavaThread::enter_critical() {
188 assert(Thread::current() == this ||
189 (Thread::current()->is_VM_thread() &&
190 SafepointSynchronize::is_synchronizing()),
191 "this must be current thread or synchronizing");
192 _jni_active_critical++;
193 }
194
195 inline void JavaThread::set_done_attaching_via_jni() {
196 _jni_attach_state = _attached_via_jni;
197 OrderAccess::fence();
198 }
199
200 inline bool JavaThread::is_exiting() const {
201 TerminatedTypes l_terminated = Atomic::load_acquire(&_terminated);
202 return l_terminated == _thread_exiting ||
203 l_terminated == _thread_gc_barrier_detached ||
204 check_is_terminated(l_terminated);
205 }
206
207 inline bool JavaThread::is_oop_safe() const {
208 TerminatedTypes l_terminated = Atomic::load_acquire(&_terminated);
209 return l_terminated != _thread_gc_barrier_detached &&
210 !check_is_terminated(l_terminated);
211 }
212
213 inline bool JavaThread::is_terminated() const {
214 TerminatedTypes l_terminated = Atomic::load_acquire(&_terminated);
215 return check_is_terminated(l_terminated);
216 }
217
218 inline void JavaThread::set_terminated(TerminatedTypes t) {
219 Atomic::release_store(&_terminated, t);
220 }
221
222 inline bool JavaThread::is_active_Java_thread() const {
223 return on_thread_list() && !is_terminated();
224 }
225
226 // Allow tracking of class initialization monitor use
227 inline void JavaThread::set_class_to_be_initialized(InstanceKlass* k) {
228 assert((k == nullptr && _class_to_be_initialized != nullptr) ||
229 (k != nullptr && _class_to_be_initialized == nullptr), "incorrect usage");
230 assert(this == Thread::current(), "Only the current thread can set this field");
231 _class_to_be_initialized = k;
232 }
233
234 inline InstanceKlass* JavaThread::class_to_be_initialized() const {
235 return _class_to_be_initialized;
236 }
237
238 inline InstanceKlass* JavaThread::set_class_being_initialized(InstanceKlass* k) {
239 assert(this == Thread::current(), "Only the current thread can set this field");
240 InstanceKlass* prev = _class_being_initialized;
241 _class_being_initialized = k;
242 return prev;
243 }
244
245 inline InstanceKlass* JavaThread::class_being_initialized() const {
246 assert(this == Thread::current(), "Only the current thread can get this field");
247 return _class_being_initialized;
248 }
249
250 inline void JavaThread::om_set_monitor_cache(ObjectMonitor* monitor) {
251 assert(UseObjectMonitorTable, "must be");
252 assert(monitor != nullptr, "use om_clear_monitor_cache to clear");
253 assert(this == current() || monitor->has_owner(this), "only add owned monitors for other threads");
254 assert(this == current() || is_obj_deopt_suspend(), "thread must not run concurrently");
255
256 _om_cache.set_monitor(monitor);
257 }
258
259 inline void JavaThread::om_clear_monitor_cache() {
260 if (UseObjectMonitorTable) {
261 _om_cache.clear();
262 }
263 }
264
265 inline ObjectMonitor* JavaThread::om_get_from_monitor_cache(oop obj) {
266 assert(obj != nullptr, "do not look for null objects");
267 assert(this == current(), "only get own thread locals");
268 return _om_cache.get_monitor(obj);
269 }
270
271 #endif // SHARE_RUNTIME_JAVATHREAD_INLINE_HPP