Bug Summary

File:jdk/src/hotspot/cpu/x86/frame_x86.inline.hpp
Warning:line 235, column 42
Called C++ object pointer is null

Annotated Source Code

Press '?' to see keyboard shortcuts

clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name safepoint.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 2 -mthread-model posix -fno-delete-null-pointer-checks -mframe-pointer=all -relaxed-aliasing -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64 -dwarf-column-info -fno-split-dwarf-inlining -debugger-tuning=gdb -resource-dir /usr/lib/llvm-10/lib/clang/10.0.0 -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/hotspot/variant-server/libjvm/objs/precompiled -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -D __STDC_CONSTANT_MACROS -D _GNU_SOURCE -D _REENTRANT -D LIBC=gnu -D LINUX -D VM_LITTLE_ENDIAN -D _LP64=1 -D ASSERT -D CHECK_UNHANDLED_OOPS -D TARGET_ARCH_x86 -D INCLUDE_SUFFIX_OS=_linux -D INCLUDE_SUFFIX_CPU=_x86 -D INCLUDE_SUFFIX_COMPILER=_gcc -D TARGET_COMPILER_gcc -D AMD64 -D HOTSPOT_LIB_ARCH="amd64" -D COMPILER1 -D COMPILER2 -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/hotspot/variant-server/gensrc/adfiles -I /home/daniel/Projects/java/jdk/src/hotspot/share -I /home/daniel/Projects/java/jdk/src/hotspot/os/linux -I /home/daniel/Projects/java/jdk/src/hotspot/os/posix -I /home/daniel/Projects/java/jdk/src/hotspot/cpu/x86 -I /home/daniel/Projects/java/jdk/src/hotspot/os_cpu/linux_x86 -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/hotspot/variant-server/gensrc -I /home/daniel/Projects/java/jdk/src/hotspot/share/precompiled -I /home/daniel/Projects/java/jdk/src/hotspot/share/include -I /home/daniel/Projects/java/jdk/src/hotspot/os/posix/include -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/support/modules_include/java.base -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/support/modules_include/java.base/linux -I /home/daniel/Projects/java/jdk/src/java.base/share/native/libjimage -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/hotspot/variant-server/gensrc/adfiles -I /home/daniel/Projects/java/jdk/src/hotspot/share -I /home/daniel/Projects/java/jdk/src/hotspot/os/linux -I /home/daniel/Projects/java/jdk/src/hotspot/os/posix -I /home/daniel/Projects/java/jdk/src/hotspot/cpu/x86 -I /home/daniel/Projects/java/jdk/src/hotspot/os_cpu/linux_x86 -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/hotspot/variant-server/gensrc -D _FORTIFY_SOURCE=2 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.5.0/../../../../include/c++/7.5.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.5.0/../../../../include/x86_64-linux-gnu/c++/7.5.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.5.0/../../../../include/x86_64-linux-gnu/c++/7.5.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.5.0/../../../../include/c++/7.5.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-10/lib/clang/10.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O3 -Wno-format-zero-length -Wno-unused-parameter -Wno-unused -Wno-parentheses -Wno-comment -Wno-unknown-pragmas -Wno-address -Wno-delete-non-virtual-dtor -Wno-char-subscripts -Wno-array-bounds -Wno-int-in-bool-context -Wno-ignored-qualifiers -Wno-missing-field-initializers -Wno-implicit-fallthrough -Wno-empty-body -Wno-strict-overflow -Wno-sequence-point -Wno-maybe-uninitialized -Wno-misleading-indentation -Wno-cast-function-type -Wno-shift-negative-value -std=c++14 -fdeprecated-macro -fdebug-compilation-dir /home/daniel/Projects/java/jdk/make/hotspot -ferror-limit 19 -fmessage-length 0 -fvisibility hidden -stack-protector 1 -fno-rtti -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -faddrsig -o /home/daniel/Projects/java/scan/2021-12-21-193737-8510-1 -x c++ /home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp

/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp

→
1/*
2 * Copyright (c) 1997, 2021, 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#include "precompiled.hpp"
26#include "classfile/classLoaderDataGraph.hpp"
27#include "classfile/dictionary.hpp"
28#include "classfile/stringTable.hpp"
29#include "classfile/symbolTable.hpp"
30#include "code/codeCache.hpp"
31#include "code/icBuffer.hpp"
32#include "code/nmethod.hpp"
33#include "code/pcDesc.hpp"
34#include "code/scopeDesc.hpp"
35#include "compiler/compilationPolicy.hpp"
36#include "gc/shared/collectedHeap.hpp"
37#include "gc/shared/gcLocker.hpp"
38#include "gc/shared/oopStorage.hpp"
39#include "gc/shared/strongRootsScope.hpp"
40#include "gc/shared/workerThread.hpp"
41#include "gc/shared/workerUtils.hpp"
42#include "interpreter/interpreter.hpp"
43#include "jfr/jfrEvents.hpp"
44#include "logging/log.hpp"
45#include "logging/logStream.hpp"
46#include "memory/resourceArea.hpp"
47#include "memory/universe.hpp"
48#include "oops/oop.inline.hpp"
49#include "oops/symbol.hpp"
50#include "runtime/atomic.hpp"
51#include "runtime/deoptimization.hpp"
52#include "runtime/frame.inline.hpp"
53#include "runtime/handles.inline.hpp"
54#include "runtime/interfaceSupport.inline.hpp"
55#include "runtime/mutexLocker.hpp"
56#include "runtime/orderAccess.hpp"
57#include "runtime/osThread.hpp"
58#include "runtime/safepoint.hpp"
59#include "runtime/safepointMechanism.inline.hpp"
60#include "runtime/signature.hpp"
61#include "runtime/stackWatermarkSet.inline.hpp"
62#include "runtime/stubCodeGenerator.hpp"
63#include "runtime/stubRoutines.hpp"
64#include "runtime/sweeper.hpp"
65#include "runtime/synchronizer.hpp"
66#include "runtime/thread.inline.hpp"
67#include "runtime/threadSMR.hpp"
68#include "runtime/threadWXSetters.inline.hpp"
69#include "runtime/timerTrace.hpp"
70#include "services/runtimeService.hpp"
71#include "utilities/events.hpp"
72#include "utilities/macros.hpp"
73
74static void post_safepoint_begin_event(EventSafepointBegin& event,
75 uint64_t safepoint_id,
76 int thread_count,
77 int critical_thread_count) {
78 if (event.should_commit()) {
79 event.set_safepointId(safepoint_id);
80 event.set_totalThreadCount(thread_count);
81 event.set_jniCriticalThreadCount(critical_thread_count);
82 event.commit();
83 }
84}
85
86static void post_safepoint_cleanup_event(EventSafepointCleanup& event, uint64_t safepoint_id) {
87 if (event.should_commit()) {
88 event.set_safepointId(safepoint_id);
89 event.commit();
90 }
91}
92
93static void post_safepoint_synchronize_event(EventSafepointStateSynchronization& event,
94 uint64_t safepoint_id,
95 int initial_number_of_threads,
96 int threads_waiting_to_block,
97 uint64_t iterations) {
98 if (event.should_commit()) {
99 event.set_safepointId(safepoint_id);
100 event.set_initialThreadCount(initial_number_of_threads);
101 event.set_runningThreadCount(threads_waiting_to_block);
102 event.set_iterations(iterations);
103 event.commit();
104 }
105}
106
107static void post_safepoint_cleanup_task_event(EventSafepointCleanupTask& event,
108 uint64_t safepoint_id,
109 const char* name) {
110 if (event.should_commit()) {
111 event.set_safepointId(safepoint_id);
112 event.set_name(name);
113 event.commit();
114 }
115}
116
117static void post_safepoint_end_event(EventSafepointEnd& event, uint64_t safepoint_id) {
118 if (event.should_commit()) {
119 event.set_safepointId(safepoint_id);
120 event.commit();
121 }
122}
123
124// SafepointCheck
125SafepointStateTracker::SafepointStateTracker(uint64_t safepoint_id, bool at_safepoint)
126 : _safepoint_id(safepoint_id), _at_safepoint(at_safepoint) {}
127
128bool SafepointStateTracker::safepoint_state_changed() {
129 return _safepoint_id != SafepointSynchronize::safepoint_id() ||
130 _at_safepoint != SafepointSynchronize::is_at_safepoint();
131}
132
133// --------------------------------------------------------------------------------------------------
134// Implementation of Safepoint begin/end
135
136SafepointSynchronize::SynchronizeState volatile SafepointSynchronize::_state = SafepointSynchronize::_not_synchronized;
137int SafepointSynchronize::_waiting_to_block = 0;
138volatile uint64_t SafepointSynchronize::_safepoint_counter = 0;
139uint64_t SafepointSynchronize::_safepoint_id = 0;
140const uint64_t SafepointSynchronize::InactiveSafepointCounter = 0;
141int SafepointSynchronize::_current_jni_active_count = 0;
142
143WaitBarrier* SafepointSynchronize::_wait_barrier;
144
145static bool timeout_error_printed = false;
146
147// Statistic related
148static jlong _safepoint_begin_time = 0;
149static volatile int _nof_threads_hit_polling_page = 0;
150
151void SafepointSynchronize::init(Thread* vmthread) {
152 // WaitBarrier should never be destroyed since we will have
153 // threads waiting on it while exiting.
154 _wait_barrier = new WaitBarrier(vmthread);
155 SafepointTracing::init();
156}
157
158void SafepointSynchronize::increment_jni_active_count() {
159 assert(Thread::current()->is_VM_thread(), "Only VM thread may increment")do { if (!(Thread::current()->is_VM_thread())) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 159, "assert(" "Thread::current()->is_VM_thread()" ") failed"
, "Only VM thread may increment"); ::breakpoint(); } } while (
0);
160 ++_current_jni_active_count;
161}
162
163void SafepointSynchronize::decrement_waiting_to_block() {
164 assert(_waiting_to_block > 0, "sanity check")do { if (!(_waiting_to_block > 0)) { (*g_assert_poison) = 'X'
;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 164, "assert(" "_waiting_to_block > 0" ") failed", "sanity check"
); ::breakpoint(); } } while (0);
165 assert(Thread::current()->is_VM_thread(), "Only VM thread may decrement")do { if (!(Thread::current()->is_VM_thread())) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 165, "assert(" "Thread::current()->is_VM_thread()" ") failed"
, "Only VM thread may decrement"); ::breakpoint(); } } while (
0);
166 --_waiting_to_block;
167}
168
169bool SafepointSynchronize::thread_not_running(ThreadSafepointState *cur_state) {
170 if (!cur_state->is_running()) {
171 // Robustness: asserted in the caller, but handle/tolerate it for release bits.
172 LogTarget(Error, safepoint)LogTargetImpl<LogLevel::Error, (LogTag::_safepoint), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG), (LogTag::__NO_TAG)> lt;
173 if (lt.is_enabled()) {
174 ResourceMark rm;
175 LogStream ls(lt);
176 ls.print("Illegal initial state detected: ");
177 cur_state->print_on(&ls);
178 }
179 return true;
180 }
181 cur_state->examine_state_of_thread(SafepointSynchronize::safepoint_counter());
182 if (!cur_state->is_running()) {
183 return true;
184 }
185 LogTarget(Trace, safepoint)LogTargetImpl<LogLevel::Trace, (LogTag::_safepoint), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG), (LogTag::__NO_TAG)> lt;
186 if (lt.is_enabled()) {
187 ResourceMark rm;
188 LogStream ls(lt);
189 cur_state->print_on(&ls);
190 }
191 return false;
192}
193
194#ifdef ASSERT1
195static void assert_list_is_valid(const ThreadSafepointState* tss_head, int still_running) {
196 int a = 0;
197 const ThreadSafepointState *tmp_tss = tss_head;
198 while (tmp_tss != NULL__null) {
199 ++a;
200 assert(tmp_tss->is_running(), "Illegal initial state")do { if (!(tmp_tss->is_running())) { (*g_assert_poison) = 'X'
;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 200, "assert(" "tmp_tss->is_running()" ") failed", "Illegal initial state"
); ::breakpoint(); } } while (0);
201 tmp_tss = tmp_tss->get_next();
202 }
203 assert(a == still_running, "Must be the same")do { if (!(a == still_running)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 203, "assert(" "a == still_running" ") failed", "Must be the same"
); ::breakpoint(); } } while (0);
204}
205#endif // ASSERT
206
207static void back_off(int64_t start_time) {
208 // We start with fine-grained nanosleeping until a millisecond has
209 // passed, at which point we resort to plain naked_short_sleep.
210 if (os::javaTimeNanos() - start_time < NANOSECS_PER_MILLISEC) {
211 os::naked_short_nanosleep(10 * (NANOUNITS / MICROUNITS));
212 } else {
213 os::naked_short_sleep(1);
214 }
215}
216
217int SafepointSynchronize::synchronize_threads(jlong safepoint_limit_time, int nof_threads, int* initial_running)
218{
219 JavaThreadIteratorWithHandle jtiwh;
220
221#ifdef ASSERT1
222 for (; JavaThread *cur = jtiwh.next(); ) {
223 assert(cur->safepoint_state()->is_running(), "Illegal initial state")do { if (!(cur->safepoint_state()->is_running())) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 223, "assert(" "cur->safepoint_state()->is_running()"
") failed", "Illegal initial state"); ::breakpoint(); } } while
(0);
224 }
225 jtiwh.rewind();
226#endif // ASSERT
227
228 // Iterate through all threads until it has been determined how to stop them all at a safepoint.
229 int still_running = nof_threads;
230 ThreadSafepointState *tss_head = NULL__null;
231 ThreadSafepointState **p_prev = &tss_head;
232 for (; JavaThread *cur = jtiwh.next(); ) {
233 ThreadSafepointState *cur_tss = cur->safepoint_state();
234 assert(cur_tss->get_next() == NULL, "Must be NULL")do { if (!(cur_tss->get_next() == __null)) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 234, "assert(" "cur_tss->get_next() == __null" ") failed"
, "Must be NULL"); ::breakpoint(); } } while (0);
235 if (thread_not_running(cur_tss)) {
236 --still_running;
237 } else {
238 *p_prev = cur_tss;
239 p_prev = cur_tss->next_ptr();
240 }
241 }
242 *p_prev = NULL__null;
243
244 DEBUG_ONLY(assert_list_is_valid(tss_head, still_running);)assert_list_is_valid(tss_head, still_running);
245
246 *initial_running = still_running;
247
248 // If there is no thread still running, we are already done.
249 if (still_running <= 0) {
250 assert(tss_head == NULL, "Must be empty")do { if (!(tss_head == __null)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 250, "assert(" "tss_head == __null" ") failed", "Must be empty"
); ::breakpoint(); } } while (0);
251 return 1;
252 }
253
254 int iterations = 1; // The first iteration is above.
255 int64_t start_time = os::javaTimeNanos();
256
257 do {
258 // Check if this has taken too long:
259 if (SafepointTimeout && safepoint_limit_time < os::javaTimeNanos()) {
260 print_safepoint_timeout();
261 }
262
263 p_prev = &tss_head;
264 ThreadSafepointState *cur_tss = tss_head;
265 while (cur_tss != NULL__null) {
266 assert(cur_tss->is_running(), "Illegal initial state")do { if (!(cur_tss->is_running())) { (*g_assert_poison) = 'X'
;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 266, "assert(" "cur_tss->is_running()" ") failed", "Illegal initial state"
); ::breakpoint(); } } while (0);
267 if (thread_not_running(cur_tss)) {
268 --still_running;
269 *p_prev = NULL__null;
270 ThreadSafepointState *tmp = cur_tss;
271 cur_tss = cur_tss->get_next();
272 tmp->set_next(NULL__null);
273 } else {
274 *p_prev = cur_tss;
275 p_prev = cur_tss->next_ptr();
276 cur_tss = cur_tss->get_next();
277 }
278 }
279
280 DEBUG_ONLY(assert_list_is_valid(tss_head, still_running);)assert_list_is_valid(tss_head, still_running);
281
282 if (still_running > 0) {
283 back_off(start_time);
284 }
285
286 iterations++;
287 } while (still_running > 0);
288
289 assert(tss_head == NULL, "Must be empty")do { if (!(tss_head == __null)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 289, "assert(" "tss_head == __null" ") failed", "Must be empty"
); ::breakpoint(); } } while (0);
290
291 return iterations;
292}
293
294void SafepointSynchronize::arm_safepoint() {
295 // Begin the process of bringing the system to a safepoint.
296 // Java threads can be in several different states and are
297 // stopped by different mechanisms:
298 //
299 // 1. Running interpreted
300 // When executing branching/returning byte codes interpreter
301 // checks if the poll is armed, if so blocks in SS::block().
302 // 2. Running in native code
303 // When returning from the native code, a Java thread must check
304 // the safepoint _state to see if we must block. If the
305 // VM thread sees a Java thread in native, it does
306 // not wait for this thread to block. The order of the memory
307 // writes and reads of both the safepoint state and the Java
308 // threads state is critical. In order to guarantee that the
309 // memory writes are serialized with respect to each other,
310 // the VM thread issues a memory barrier instruction.
311 // 3. Running compiled Code
312 // Compiled code reads the local polling page that
313 // is set to fault if we are trying to get to a safepoint.
314 // 4. Blocked
315 // A thread which is blocked will not be allowed to return from the
316 // block condition until the safepoint operation is complete.
317 // 5. In VM or Transitioning between states
318 // If a Java thread is currently running in the VM or transitioning
319 // between states, the safepointing code will poll the thread state
320 // until the thread blocks itself when it attempts transitions to a
321 // new state or locking a safepoint checked monitor.
322
323 // We must never miss a thread with correct safepoint id, so we must make sure we arm
324 // the wait barrier for the next safepoint id/counter.
325 // Arming must be done after resetting _current_jni_active_count, _waiting_to_block.
326 _wait_barrier->arm(static_cast<int>(_safepoint_counter + 1));
327
328 assert((_safepoint_counter & 0x1) == 0, "must be even")do { if (!((_safepoint_counter & 0x1) == 0)) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 328, "assert(" "(_safepoint_counter & 0x1) == 0" ") failed"
, "must be even"); ::breakpoint(); } } while (0);
329 // The store to _safepoint_counter must happen after any stores in arming.
330 Atomic::release_store(&_safepoint_counter, _safepoint_counter + 1);
331
332 // We are synchronizing
333 OrderAccess::storestore(); // Ordered with _safepoint_counter
334 _state = _synchronizing;
335
336 // Arming the per thread poll while having _state != _not_synchronized means safepointing
337 log_trace(safepoint)(!(LogImpl<(LogTag::_safepoint), (LogTag::__NO_TAG), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG)>::is_level(LogLevel::Trace))) ? (void)0 : LogImpl
<(LogTag::_safepoint), (LogTag::__NO_TAG), (LogTag::__NO_TAG
), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG)
>::write<LogLevel::Trace>("Setting thread local yield flag for threads");
338 OrderAccess::storestore(); // storestore, global state -> local state
339 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *cur = jtiwh.next(); ) {
340 // Make sure the threads start polling, it is time to yield.
341 SafepointMechanism::arm_local_poll(cur);
342 }
343
344 OrderAccess::fence(); // storestore|storeload, global state -> local state
345}
346
347// Roll all threads forward to a safepoint and suspend them all
348void SafepointSynchronize::begin() {
349 assert(Thread::current()->is_VM_thread(), "Only VM thread may execute a safepoint")do { if (!(Thread::current()->is_VM_thread())) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 349, "assert(" "Thread::current()->is_VM_thread()" ") failed"
, "Only VM thread may execute a safepoint"); ::breakpoint(); }
} while (0);
350
351 EventSafepointBegin begin_event;
352 SafepointTracing::begin(VMThread::vm_op_type());
353
354 Universe::heap()->safepoint_synchronize_begin();
355
356 // By getting the Threads_lock, we assure that no threads are about to start or
357 // exit. It is released again in SafepointSynchronize::end().
358 Threads_lock->lock();
359
360 assert( _state == _not_synchronized, "trying to safepoint synchronize with wrong state")do { if (!(_state == _not_synchronized)) { (*g_assert_poison)
= 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 360, "assert(" "_state == _not_synchronized" ") failed", "trying to safepoint synchronize with wrong state"
); ::breakpoint(); } } while (0);
361
362 int nof_threads = Threads::number_of_threads();
363
364 _nof_threads_hit_polling_page = 0;
365
366 log_debug(safepoint)(!(LogImpl<(LogTag::_safepoint), (LogTag::__NO_TAG), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG)>::is_level(LogLevel::Debug))) ? (void)0 : LogImpl
<(LogTag::_safepoint), (LogTag::__NO_TAG), (LogTag::__NO_TAG
), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG)
>::write<LogLevel::Debug>("Safepoint synchronization initiated using %s wait barrier. (%d threads)", _wait_barrier->description(), nof_threads);
367
368 // Reset the count of active JNI critical threads
369 _current_jni_active_count = 0;
370
371 // Set number of threads to wait for
372 _waiting_to_block = nof_threads;
373
374 jlong safepoint_limit_time = 0;
375 if (SafepointTimeout) {
376 // Set the limit time, so that it can be compared to see if this has taken
377 // too long to complete.
378 safepoint_limit_time = SafepointTracing::start_of_safepoint() + (jlong)SafepointTimeoutDelay * (NANOUNITS / MILLIUNITS);
379 timeout_error_printed = false;
380 }
381
382 EventSafepointStateSynchronization sync_event;
383 int initial_running = 0;
384
385 // Arms the safepoint, _current_jni_active_count and _waiting_to_block must be set before.
386 arm_safepoint();
387
388 // Will spin until all threads are safe.
389 int iterations = synchronize_threads(safepoint_limit_time, nof_threads, &initial_running);
390 assert(_waiting_to_block == 0, "No thread should be running")do { if (!(_waiting_to_block == 0)) { (*g_assert_poison) = 'X'
;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 390, "assert(" "_waiting_to_block == 0" ") failed", "No thread should be running"
); ::breakpoint(); } } while (0);
391
392#ifndef PRODUCT
393 // Mark all threads
394 if (VerifyCrossModifyFence) {
395 JavaThreadIteratorWithHandle jtiwh;
396 for (; JavaThread *cur = jtiwh.next(); ) {
397 cur->set_requires_cross_modify_fence(true);
398 }
399 }
400
401 if (safepoint_limit_time != 0) {
402 jlong current_time = os::javaTimeNanos();
403 if (safepoint_limit_time < current_time) {
404 log_warning(safepoint)(!(LogImpl<(LogTag::_safepoint), (LogTag::__NO_TAG), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG)>::is_level(LogLevel::Warning))) ? (void)0 : LogImpl
<(LogTag::_safepoint), (LogTag::__NO_TAG), (LogTag::__NO_TAG
), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG)
>::write<LogLevel::Warning>("# SafepointSynchronize: Finished after "
405 INT64_FORMAT_W(6)"%" "6" "l" "d" " ms",
406 (int64_t)(current_time - SafepointTracing::start_of_safepoint()) / (NANOUNITS / MILLIUNITS));
407 }
408 }
409#endif
410
411 assert(Threads_lock->owned_by_self(), "must hold Threads_lock")do { if (!(Threads_lock->owned_by_self())) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 411, "assert(" "Threads_lock->owned_by_self()" ") failed"
, "must hold Threads_lock"); ::breakpoint(); } } while (0);
412
413 // Record state
414 _state = _synchronized;
415
416 OrderAccess::fence();
417
418 // Set the new id
419 ++_safepoint_id;
420
421#ifdef ASSERT1
422 // Make sure all the threads were visited.
423 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *cur = jtiwh.next(); ) {
424 assert(cur->was_visited_for_critical_count(_safepoint_counter), "missed a thread")do { if (!(cur->was_visited_for_critical_count(_safepoint_counter
))) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 424, "assert(" "cur->was_visited_for_critical_count(_safepoint_counter)"
") failed", "missed a thread"); ::breakpoint(); } } while (0
);
425 }
426#endif // ASSERT
427
428 // Update the count of active JNI critical regions
429 GCLocker::set_jni_lock_count(_current_jni_active_count);
430
431 post_safepoint_synchronize_event(sync_event,
432 _safepoint_id,
433 initial_running,
434 _waiting_to_block, iterations);
435
436 SafepointTracing::synchronized(nof_threads, initial_running, _nof_threads_hit_polling_page);
437
438 // We do the safepoint cleanup first since a GC related safepoint
439 // needs cleanup to be completed before running the GC op.
440 EventSafepointCleanup cleanup_event;
441 do_cleanup_tasks();
442 post_safepoint_cleanup_event(cleanup_event, _safepoint_id);
443
444 post_safepoint_begin_event(begin_event, _safepoint_id, nof_threads, _current_jni_active_count);
445 SafepointTracing::cleanup();
446}
447
448void SafepointSynchronize::disarm_safepoint() {
449 uint64_t active_safepoint_counter = _safepoint_counter;
450 {
451 JavaThreadIteratorWithHandle jtiwh;
452#ifdef ASSERT1
453 // A pending_exception cannot be installed during a safepoint. The threads
454 // may install an async exception after they come back from a safepoint into
455 // pending_exception after they unblock. But that should happen later.
456 for (; JavaThread *cur = jtiwh.next(); ) {
457 assert (!(cur->has_pending_exception() &&do { if (!(!(cur->has_pending_exception() && cur->
safepoint_state()->is_at_poll_safepoint()))) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 459, "assert(" "!(cur->has_pending_exception() && cur->safepoint_state()->is_at_poll_safepoint())"
") failed", "safepoint installed a pending exception"); ::breakpoint
(); } } while (0)
458 cur->safepoint_state()->is_at_poll_safepoint()),do { if (!(!(cur->has_pending_exception() && cur->
safepoint_state()->is_at_poll_safepoint()))) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 459, "assert(" "!(cur->has_pending_exception() && cur->safepoint_state()->is_at_poll_safepoint())"
") failed", "safepoint installed a pending exception"); ::breakpoint
(); } } while (0)
459 "safepoint installed a pending exception")do { if (!(!(cur->has_pending_exception() && cur->
safepoint_state()->is_at_poll_safepoint()))) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 459, "assert(" "!(cur->has_pending_exception() && cur->safepoint_state()->is_at_poll_safepoint())"
") failed", "safepoint installed a pending exception"); ::breakpoint
(); } } while (0);
460 }
461#endif // ASSERT
462
463 OrderAccess::fence(); // keep read and write of _state from floating up
464 assert(_state == _synchronized, "must be synchronized before ending safepoint synchronization")do { if (!(_state == _synchronized)) { (*g_assert_poison) = 'X'
;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 464, "assert(" "_state == _synchronized" ") failed", "must be synchronized before ending safepoint synchronization"
); ::breakpoint(); } } while (0);
465
466 // Change state first to _not_synchronized.
467 // No threads should see _synchronized when running.
468 _state = _not_synchronized;
469
470 // Set the next dormant (even) safepoint id.
471 assert((_safepoint_counter & 0x1) == 1, "must be odd")do { if (!((_safepoint_counter & 0x1) == 1)) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 471, "assert(" "(_safepoint_counter & 0x1) == 1" ") failed"
, "must be odd"); ::breakpoint(); } } while (0);
472 Atomic::release_store(&_safepoint_counter, _safepoint_counter + 1);
473
474 OrderAccess::fence(); // Keep the local state from floating up.
475
476 jtiwh.rewind();
477 for (; JavaThread *current = jtiwh.next(); ) {
478 // Clear the visited flag to ensure that the critical counts are collected properly.
479 DEBUG_ONLY(current->reset_visited_for_critical_count(active_safepoint_counter);)current->reset_visited_for_critical_count(active_safepoint_counter
);
480 ThreadSafepointState* cur_state = current->safepoint_state();
481 assert(!cur_state->is_running(), "Thread not suspended at safepoint")do { if (!(!cur_state->is_running())) { (*g_assert_poison)
= 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 481, "assert(" "!cur_state->is_running()" ") failed", "Thread not suspended at safepoint"
); ::breakpoint(); } } while (0);
482 cur_state->restart(); // TSS _running
483 assert(cur_state->is_running(), "safepoint state has not been reset")do { if (!(cur_state->is_running())) { (*g_assert_poison) =
'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 483, "assert(" "cur_state->is_running()" ") failed", "safepoint state has not been reset"
); ::breakpoint(); } } while (0);
484 }
485 } // ~JavaThreadIteratorWithHandle
486
487 // Release threads lock, so threads can be created/destroyed again.
488 Threads_lock->unlock();
489
490 // Wake threads after local state is correctly set.
491 _wait_barrier->disarm();
492}
493
494// Wake up all threads, so they are ready to resume execution after the safepoint
495// operation has been carried out
496void SafepointSynchronize::end() {
497 assert(Threads_lock->owned_by_self(), "must hold Threads_lock")do { if (!(Threads_lock->owned_by_self())) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 497, "assert(" "Threads_lock->owned_by_self()" ") failed"
, "must hold Threads_lock"); ::breakpoint(); } } while (0);
498 EventSafepointEnd event;
499 assert(Thread::current()->is_VM_thread(), "Only VM thread can execute a safepoint")do { if (!(Thread::current()->is_VM_thread())) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 499, "assert(" "Thread::current()->is_VM_thread()" ") failed"
, "Only VM thread can execute a safepoint"); ::breakpoint(); }
} while (0);
500
501 disarm_safepoint();
502
503 Universe::heap()->safepoint_synchronize_end();
504
505 SafepointTracing::end();
506
507 post_safepoint_end_event(event, safepoint_id());
508}
509
510bool SafepointSynchronize::is_cleanup_needed() {
511 // Need a safepoint if some inline cache buffers is non-empty
512 if (!InlineCacheBuffer::is_empty()) return true;
513 if (StringTable::needs_rehashing()) return true;
514 if (SymbolTable::needs_rehashing()) return true;
515 return false;
516}
517
518class ParallelSPCleanupThreadClosure : public ThreadClosure {
519public:
520 void do_thread(Thread* thread) {
521 if (thread->is_Java_thread()) {
522 StackWatermarkSet::start_processing(JavaThread::cast(thread), StackWatermarkKind::gc);
523 }
524 }
525};
526
527class ParallelSPCleanupTask : public WorkerTask {
528private:
529 SubTasksDone _subtasks;
530 uint _num_workers;
531 bool _do_lazy_roots;
532
533 class Tracer {
534 private:
535 const char* _name;
536 EventSafepointCleanupTask _event;
537 TraceTime _timer;
538
539 public:
540 Tracer(const char* name) :
541 _name(name),
542 _event(),
543 _timer(name, TRACETIME_LOG(Info, safepoint, cleanup)(LogImpl<(LogTag::_safepoint), (LogTag::_cleanup), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG)>::is_level(LogLevel::Info)) ? static_cast<TraceTimerLogPrintFunc
>(&LogImpl<(LogTag::_safepoint), (LogTag::_cleanup)
, (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG),
(LogTag::__NO_TAG)>::write<LogLevel::Info>) : (TraceTimerLogPrintFunc
)__null) {}
544 ~Tracer() {
545 post_safepoint_cleanup_task_event(_event, SafepointSynchronize::safepoint_id(), _name);
546 }
547 };
548
549public:
550 ParallelSPCleanupTask(uint num_workers) :
551 WorkerTask("Parallel Safepoint Cleanup"),
552 _subtasks(SafepointSynchronize::SAFEPOINT_CLEANUP_NUM_TASKS),
553 _num_workers(num_workers),
554 _do_lazy_roots(!VMThread::vm_operation()->skip_thread_oop_barriers() &&
555 Universe::heap()->uses_stack_watermark_barrier()) {}
556
557 void work(uint worker_id) {
558 if (_subtasks.try_claim_task(SafepointSynchronize::SAFEPOINT_CLEANUP_LAZY_ROOT_PROCESSING)) {
559 if (_do_lazy_roots) {
560 Tracer t("lazy partial thread root processing");
561 ParallelSPCleanupThreadClosure cl;
562 Threads::threads_do(&cl);
563 }
564 }
565
566 if (_subtasks.try_claim_task(SafepointSynchronize::SAFEPOINT_CLEANUP_UPDATE_INLINE_CACHES)) {
567 Tracer t("updating inline caches");
568 InlineCacheBuffer::update_inline_caches();
569 }
570
571 if (_subtasks.try_claim_task(SafepointSynchronize::SAFEPOINT_CLEANUP_COMPILATION_POLICY)) {
572 Tracer t("compilation policy safepoint handler");
573 CompilationPolicy::do_safepoint_work();
574 }
575
576 if (_subtasks.try_claim_task(SafepointSynchronize::SAFEPOINT_CLEANUP_SYMBOL_TABLE_REHASH)) {
577 if (SymbolTable::needs_rehashing()) {
578 Tracer t("rehashing symbol table");
579 SymbolTable::rehash_table();
580 }
581 }
582
583 if (_subtasks.try_claim_task(SafepointSynchronize::SAFEPOINT_CLEANUP_STRING_TABLE_REHASH)) {
584 if (StringTable::needs_rehashing()) {
585 Tracer t("rehashing string table");
586 StringTable::rehash_table();
587 }
588 }
589
590 if (_subtasks.try_claim_task(SafepointSynchronize::SAFEPOINT_CLEANUP_SYSTEM_DICTIONARY_RESIZE)) {
591 if (Dictionary::does_any_dictionary_needs_resizing()) {
592 Tracer t("resizing system dictionaries");
593 ClassLoaderDataGraph::resize_dictionaries();
594 }
595 }
596
597 if (_subtasks.try_claim_task(SafepointSynchronize::SAFEPOINT_CLEANUP_REQUEST_OOPSTORAGE_CLEANUP)) {
598 // Don't bother reporting event or time for this very short operation.
599 // To have any utility we'd also want to report whether needed.
600 OopStorage::trigger_cleanup_if_needed();
601 }
602
603 _subtasks.all_tasks_claimed();
604 }
605};
606
607// Various cleaning tasks that should be done periodically at safepoints.
608void SafepointSynchronize::do_cleanup_tasks() {
609
610 TraceTime timer("safepoint cleanup tasks", TRACETIME_LOG(Info, safepoint, cleanup)(LogImpl<(LogTag::_safepoint), (LogTag::_cleanup), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG)>::is_level(LogLevel::Info)) ? static_cast<TraceTimerLogPrintFunc
>(&LogImpl<(LogTag::_safepoint), (LogTag::_cleanup)
, (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG),
(LogTag::__NO_TAG)>::write<LogLevel::Info>) : (TraceTimerLogPrintFunc
)__null);
611
612 CollectedHeap* heap = Universe::heap();
613 assert(heap != NULL, "heap not initialized yet?")do { if (!(heap != __null)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 613, "assert(" "heap != __null" ") failed", "heap not initialized yet?"
); ::breakpoint(); } } while (0);
614 WorkerThreads* cleanup_workers = heap->safepoint_workers();
615 if (cleanup_workers != NULL__null) {
616 // Parallel cleanup using GC provided thread pool.
617 uint num_cleanup_workers = cleanup_workers->active_workers();
618 ParallelSPCleanupTask cleanup(num_cleanup_workers);
619 cleanup_workers->run_task(&cleanup);
620 } else {
621 // Serial cleanup using VMThread.
622 ParallelSPCleanupTask cleanup(1);
623 cleanup.work(0);
624 }
625
626 assert(InlineCacheBuffer::is_empty(), "should have cleaned up ICBuffer")do { if (!(InlineCacheBuffer::is_empty())) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 626, "assert(" "InlineCacheBuffer::is_empty()" ") failed", "should have cleaned up ICBuffer"
); ::breakpoint(); } } while (0);
627
628 if (log_is_enabled(Debug, monitorinflation)(LogImpl<(LogTag::_monitorinflation), (LogTag::__NO_TAG), (
LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag
::__NO_TAG)>::is_level(LogLevel::Debug))) {
629 // The VMThread calls do_final_audit_and_print_stats() which calls
630 // audit_and_print_stats() at the Info level at VM exit time.
631 ObjectSynchronizer::audit_and_print_stats(false /* on_exit */);
632 }
633}
634
635// Methods for determining if a JavaThread is safepoint safe.
636
637// False means unsafe with undetermined state.
638// True means a determined state, but it may be an unsafe state.
639// If called from a non-safepoint context safepoint_count MUST be InactiveSafepointCounter.
640bool SafepointSynchronize::try_stable_load_state(JavaThreadState *state, JavaThread *thread, uint64_t safepoint_count) {
641 assert((safepoint_count != InactiveSafepointCounter &&do { if (!((safepoint_count != InactiveSafepointCounter &&
Thread::current() == (Thread*)VMThread::vm_thread() &&
SafepointSynchronize::_state != _not_synchronized) || safepoint_count
== InactiveSafepointCounter)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 644, "assert(" "(safepoint_count != InactiveSafepointCounter && Thread::current() == (Thread*)VMThread::vm_thread() && SafepointSynchronize::_state != _not_synchronized) || safepoint_count == InactiveSafepointCounter"
") failed", "Invalid check"); ::breakpoint(); } } while (0)
642 Thread::current() == (Thread*)VMThread::vm_thread() &&do { if (!((safepoint_count != InactiveSafepointCounter &&
Thread::current() == (Thread*)VMThread::vm_thread() &&
SafepointSynchronize::_state != _not_synchronized) || safepoint_count
== InactiveSafepointCounter)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 644, "assert(" "(safepoint_count != InactiveSafepointCounter && Thread::current() == (Thread*)VMThread::vm_thread() && SafepointSynchronize::_state != _not_synchronized) || safepoint_count == InactiveSafepointCounter"
") failed", "Invalid check"); ::breakpoint(); } } while (0)
643 SafepointSynchronize::_state != _not_synchronized)do { if (!((safepoint_count != InactiveSafepointCounter &&
Thread::current() == (Thread*)VMThread::vm_thread() &&
SafepointSynchronize::_state != _not_synchronized) || safepoint_count
== InactiveSafepointCounter)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 644, "assert(" "(safepoint_count != InactiveSafepointCounter && Thread::current() == (Thread*)VMThread::vm_thread() && SafepointSynchronize::_state != _not_synchronized) || safepoint_count == InactiveSafepointCounter"
") failed", "Invalid check"); ::breakpoint(); } } while (0)
644 || safepoint_count == InactiveSafepointCounter, "Invalid check")do { if (!((safepoint_count != InactiveSafepointCounter &&
Thread::current() == (Thread*)VMThread::vm_thread() &&
SafepointSynchronize::_state != _not_synchronized) || safepoint_count
== InactiveSafepointCounter)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 644, "assert(" "(safepoint_count != InactiveSafepointCounter && Thread::current() == (Thread*)VMThread::vm_thread() && SafepointSynchronize::_state != _not_synchronized) || safepoint_count == InactiveSafepointCounter"
") failed", "Invalid check"); ::breakpoint(); } } while (0);
645
646 // To handle the thread_blocked state on the backedge of the WaitBarrier from
647 // previous safepoint and reading the reset value (0/InactiveSafepointCounter) we
648 // re-read state after we read thread safepoint id. The JavaThread changes its
649 // thread state from thread_blocked before resetting safepoint id to 0.
650 // This guarantees the second read will be from an updated thread state. It can
651 // either be different state making this an unsafe state or it can see blocked
652 // again. When we see blocked twice with a 0 safepoint id, either:
653 // - It is normally blocked, e.g. on Mutex, TBIVM.
654 // - It was in SS:block(), looped around to SS:block() and is blocked on the WaitBarrier.
655 // - It was in SS:block() but now on a Mutex.
656 // All of these cases are safe.
657
658 *state = thread->thread_state();
659 OrderAccess::loadload();
660 uint64_t sid = thread->safepoint_state()->get_safepoint_id(); // Load acquire
661 if (sid != InactiveSafepointCounter && sid != safepoint_count) {
662 // In an old safepoint, state not relevant.
663 return false;
664 }
665 return *state == thread->thread_state();
666}
667
668static bool safepoint_safe_with(JavaThread *thread, JavaThreadState state) {
669 switch(state) {
670 case _thread_in_native:
671 // native threads are safe if they have no java stack or have walkable stack
672 return !thread->has_last_Java_frame() || thread->frame_anchor()->walkable();
673
674 case _thread_blocked:
675 // On wait_barrier or blocked.
676 // Blocked threads should already have walkable stack.
677 assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "blocked and not walkable")do { if (!(!thread->has_last_Java_frame() || thread->frame_anchor
()->walkable())) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 677, "assert(" "!thread->has_last_Java_frame() || thread->frame_anchor()->walkable()"
") failed", "blocked and not walkable"); ::breakpoint(); } }
while (0);
678 return true;
679
680 default:
681 return false;
682 }
683}
684
685bool SafepointSynchronize::handshake_safe(JavaThread *thread) {
686 if (thread->is_terminated()) {
687 return true;
688 }
689 JavaThreadState stable_state;
690 if (try_stable_load_state(&stable_state, thread, InactiveSafepointCounter)) {
691 return safepoint_safe_with(thread, stable_state);
692 }
693 return false;
694}
695
696
697// -------------------------------------------------------------------------------------------------------
698// Implementation of Safepoint blocking point
699
700void SafepointSynchronize::block(JavaThread *thread) {
701 assert(thread != NULL, "thread must be set")do { if (!(thread != __null)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 701, "assert(" "thread != __null" ") failed", "thread must be set"
); ::breakpoint(); } } while (0);
702
703 // Threads shouldn't block if they are in the middle of printing, but...
704 ttyLocker::break_tty_lock_for_safepoint(os::current_thread_id());
705
706 // Only bail from the block() call if the thread is gone from the
707 // thread list; starting to exit should still block.
708 if (thread->is_terminated()) {
709 // block current thread if we come here from native code when VM is gone
710 thread->block_if_vm_exited();
711
712 // otherwise do nothing
713 return;
714 }
715
716 JavaThreadState state = thread->thread_state();
717 thread->frame_anchor()->make_walkable(thread);
718
719 uint64_t safepoint_id = SafepointSynchronize::safepoint_counter();
720
721 // We have no idea where the VMThread is, it might even be at next safepoint.
722 // So we can miss this poll, but stop at next.
723
724 // Load dependent store, it must not pass loading of safepoint_id.
725 thread->safepoint_state()->set_safepoint_id(safepoint_id); // Release store
726
727 // This part we can skip if we notice we miss or are in a future safepoint.
728 OrderAccess::storestore();
729 // Load in wait barrier should not float up
730 thread->set_thread_state_fence(_thread_blocked);
731
732 _wait_barrier->wait(static_cast<int>(safepoint_id));
733 assert(_state != _synchronized, "Can't be")do { if (!(_state != _synchronized)) { (*g_assert_poison) = 'X'
;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 733, "assert(" "_state != _synchronized" ") failed", "Can't be"
); ::breakpoint(); } } while (0);
734
735 // If barrier is disarmed stop store from floating above loads in barrier.
736 OrderAccess::loadstore();
737 thread->set_thread_state(state);
738
739 // Then we reset the safepoint id to inactive.
740 thread->safepoint_state()->reset_safepoint_id(); // Release store
741
742 OrderAccess::fence();
743
744 guarantee(thread->safepoint_state()->get_safepoint_id() == InactiveSafepointCounter,do { if (!(thread->safepoint_state()->get_safepoint_id(
) == InactiveSafepointCounter)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 745, "guarantee(" "thread->safepoint_state()->get_safepoint_id() == InactiveSafepointCounter"
") failed", "The safepoint id should be set only in block path"
); ::breakpoint(); } } while (0)
745 "The safepoint id should be set only in block path")do { if (!(thread->safepoint_state()->get_safepoint_id(
) == InactiveSafepointCounter)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 745, "guarantee(" "thread->safepoint_state()->get_safepoint_id() == InactiveSafepointCounter"
") failed", "The safepoint id should be set only in block path"
); ::breakpoint(); } } while (0);
746
747 // cross_modify_fence is done by SafepointMechanism::process_if_requested
748 // which is the only caller here.
749}
750
751// ------------------------------------------------------------------------------------------------------
752// Exception handlers
753
754
755void SafepointSynchronize::handle_polling_page_exception(JavaThread *thread) {
756 assert(thread->thread_state() == _thread_in_Java, "should come from Java code")do { if (!(thread->thread_state() == _thread_in_Java)) { (
*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 756, "assert(" "thread->thread_state() == _thread_in_Java"
") failed", "should come from Java code"); ::breakpoint(); }
} while (0);
1
Assuming the condition is true
→
2
←
Taking false branch
→
3
←
Loop condition is false. Exiting loop
→
757
758 // Enable WXWrite: the function is called implicitly from java code.
759 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread));
760
761 if (log_is_enabled(Info, safepoint, stats)(LogImpl<(LogTag::_safepoint), (LogTag::_stats), (LogTag::
__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG
)>::is_level(LogLevel::Info))) {
4
←
Assuming the condition is false
→
5
←
Taking false branch
→
762 Atomic::inc(&_nof_threads_hit_polling_page);
763 }
764
765 ThreadSafepointState* state = thread->safepoint_state();
766
767 state->handle_polling_page_exception();
6
←
Calling 'ThreadSafepointState::handle_polling_page_exception'
→
768}
769
770
771void SafepointSynchronize::print_safepoint_timeout() {
772 if (!timeout_error_printed) {
773 timeout_error_printed = true;
774 // Print out the thread info which didn't reach the safepoint for debugging
775 // purposes (useful when there are lots of threads in the debugger).
776 LogTarget(Warning, safepoint)LogTargetImpl<LogLevel::Warning, (LogTag::_safepoint), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG), (LogTag::__NO_TAG)> lt;
777 if (lt.is_enabled()) {
778 ResourceMark rm;
779 LogStream ls(lt);
780
781 ls.cr();
782 ls.print_cr("# SafepointSynchronize::begin: Timeout detected:");
783 ls.print_cr("# SafepointSynchronize::begin: Timed out while spinning to reach a safepoint.");
784 ls.print_cr("# SafepointSynchronize::begin: Threads which did not reach the safepoint:");
785 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *cur_thread = jtiwh.next(); ) {
786 if (cur_thread->safepoint_state()->is_running()) {
787 ls.print("# ");
788 cur_thread->print_on(&ls);
789 ls.cr();
790 }
791 }
792 ls.print_cr("# SafepointSynchronize::begin: (End of list)");
793 }
794 }
795
796 // To debug the long safepoint, specify both AbortVMOnSafepointTimeout &
797 // ShowMessageBoxOnError.
798 if (AbortVMOnSafepointTimeout) {
799 // Send the blocking thread a signal to terminate and write an error file.
800 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *cur_thread = jtiwh.next(); ) {
801 if (cur_thread->safepoint_state()->is_running()) {
802 if (!os::signal_thread(cur_thread, SIGILL4, "blocking a safepoint")) {
803 break; // Could not send signal. Report fatal error.
804 }
805 // Give cur_thread a chance to report the error and terminate the VM.
806 os::naked_sleep(3000);
807 }
808 }
809 fatal("Safepoint sync time longer than " INTX_FORMAT "ms detected when executing %s.",do { (*g_assert_poison) = 'X';; report_fatal(INTERNAL_ERROR, "/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 810, "Safepoint sync time longer than " "%" "l" "d" "ms detected when executing %s."
, SafepointTimeoutDelay, VMThread::vm_operation()->name())
; ::breakpoint(); } while (0)
810 SafepointTimeoutDelay, VMThread::vm_operation()->name())do { (*g_assert_poison) = 'X';; report_fatal(INTERNAL_ERROR, "/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 810, "Safepoint sync time longer than " "%" "l" "d" "ms detected when executing %s."
, SafepointTimeoutDelay, VMThread::vm_operation()->name())
; ::breakpoint(); } while (0);
811 }
812}
813
814// -------------------------------------------------------------------------------------------------------
815// Implementation of ThreadSafepointState
816
817ThreadSafepointState::ThreadSafepointState(JavaThread *thread)
818 : _at_poll_safepoint(false), _thread(thread), _safepoint_safe(false),
819 _safepoint_id(SafepointSynchronize::InactiveSafepointCounter), _next(NULL__null) {
820}
821
822void ThreadSafepointState::create(JavaThread *thread) {
823 ThreadSafepointState *state = new ThreadSafepointState(thread);
824 thread->set_safepoint_state(state);
825}
826
827void ThreadSafepointState::destroy(JavaThread *thread) {
828 if (thread->safepoint_state()) {
829 delete(thread->safepoint_state());
830 thread->set_safepoint_state(NULL__null);
831 }
832}
833
834uint64_t ThreadSafepointState::get_safepoint_id() const {
835 return Atomic::load_acquire(&_safepoint_id);
836}
837
838void ThreadSafepointState::reset_safepoint_id() {
839 Atomic::release_store(&_safepoint_id, SafepointSynchronize::InactiveSafepointCounter);
840}
841
842void ThreadSafepointState::set_safepoint_id(uint64_t safepoint_id) {
843 Atomic::release_store(&_safepoint_id, safepoint_id);
844}
845
846void ThreadSafepointState::examine_state_of_thread(uint64_t safepoint_count) {
847 assert(is_running(), "better be running or just have hit safepoint poll")do { if (!(is_running())) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 847, "assert(" "is_running()" ") failed", "better be running or just have hit safepoint poll"
); ::breakpoint(); } } while (0);
848
849 JavaThreadState stable_state;
850 if (!SafepointSynchronize::try_stable_load_state(&stable_state, _thread, safepoint_count)) {
851 // We could not get stable state of the JavaThread.
852 // Consider it running and just return.
853 return;
854 }
855
856 if (safepoint_safe_with(_thread, stable_state)) {
857 account_safe_thread();
858 return;
859 }
860
861 // All other thread states will continue to run until they
862 // transition and self-block in state _blocked
863 // Safepoint polling in compiled code causes the Java threads to do the same.
864 // Note: new threads may require a malloc so they must be allowed to finish
865
866 assert(is_running(), "examine_state_of_thread on non-running thread")do { if (!(is_running())) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 866, "assert(" "is_running()" ") failed", "examine_state_of_thread on non-running thread"
); ::breakpoint(); } } while (0);
867 return;
868}
869
870void ThreadSafepointState::account_safe_thread() {
871 SafepointSynchronize::decrement_waiting_to_block();
872 if (_thread->in_critical()) {
873 // Notice that this thread is in a critical section
874 SafepointSynchronize::increment_jni_active_count();
875 }
876 DEBUG_ONLY(_thread->set_visited_for_critical_count(SafepointSynchronize::safepoint_counter());)_thread->set_visited_for_critical_count(SafepointSynchronize
::safepoint_counter());
877 assert(!_safepoint_safe, "Must be unsafe before safe")do { if (!(!_safepoint_safe)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 877, "assert(" "!_safepoint_safe" ") failed", "Must be unsafe before safe"
); ::breakpoint(); } } while (0);
878 _safepoint_safe = true;
879}
880
881void ThreadSafepointState::restart() {
882 assert(_safepoint_safe, "Must be safe before unsafe")do { if (!(_safepoint_safe)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 882, "assert(" "_safepoint_safe" ") failed", "Must be safe before unsafe"
); ::breakpoint(); } } while (0);
883 _safepoint_safe = false;
884}
885
886void ThreadSafepointState::print_on(outputStream *st) const {
887 const char *s = _safepoint_safe ? "_at_safepoint" : "_running";
888
889 st->print_cr("Thread: " INTPTR_FORMAT"0x%016" "l" "x"
890 " [0x%2x] State: %s _at_poll_safepoint %d",
891 p2i(_thread), _thread->osthread()->thread_id(), s, _at_poll_safepoint);
892
893 _thread->print_thread_state_on(st);
894}
895
896// ---------------------------------------------------------------------------------------------------------------------
897
898// Process pending operation.
899void ThreadSafepointState::handle_polling_page_exception() {
900 JavaThread* self = thread();
901 assert(self == JavaThread::current(), "must be self")do { if (!(self == JavaThread::current())) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 901, "assert(" "self == JavaThread::current()" ") failed", "must be self"
); ::breakpoint(); } } while (0);
7
←
Assuming the condition is true
→
8
←
Taking false branch
→
9
←
Loop condition is false. Exiting loop
→
902
903 // Step 1: Find the nmethod from the return address
904 address real_return_addr = self->saved_exception_pc();
905
906 CodeBlob *cb = CodeCache::find_blob(real_return_addr);
907 assert(cb != NULL && cb->is_compiled(), "return address should be in nmethod")do { if (!(cb != __null && cb->is_compiled())) { (
*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 907, "assert(" "cb != __null && cb->is_compiled()"
") failed", "return address should be in nmethod"); ::breakpoint
(); } } while (0);
10
←
Assuming the condition is true
→
11
←
Assuming the condition is false
→
12
←
Taking false branch
→
13
←
Loop condition is false. Exiting loop
→
908 CompiledMethod* nm = (CompiledMethod*)cb;
909
910 // Find frame of caller
911 frame stub_fr = self->last_frame();
912 CodeBlob* stub_cb = stub_fr.cb();
913 assert(stub_cb->is_safepoint_stub(), "must be a safepoint stub")do { if (!(stub_cb->is_safepoint_stub())) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 913, "assert(" "stub_cb->is_safepoint_stub()" ") failed"
, "must be a safepoint stub"); ::breakpoint(); } } while (0);
14
←
Assuming the condition is false
→
15
←
Taking false branch
→
16
←
Loop condition is false. Exiting loop
→
914 RegisterMap map(self, true, false);
915 frame caller_fr = stub_fr.sender(&map);
916
917 // Should only be poll_return or poll
918 assert( nm->is_at_poll_or_poll_return(real_return_addr), "should not be at call" )do { if (!(nm->is_at_poll_or_poll_return(real_return_addr)
)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 918, "assert(" "nm->is_at_poll_or_poll_return(real_return_addr)"
") failed", "should not be at call"); ::breakpoint(); } } while
(0);
17
←
Assuming the condition is false
→
18
←
Taking false branch
→
19
←
Loop condition is false. Exiting loop
→
919
920 // This is a poll immediately before a return. The exception handling code
921 // has already had the effect of causing the return to occur, so the execution
922 // will continue immediately after the call. In addition, the oopmap at the
923 // return point does not mark the return value as an oop (if it is), so
924 // it needs a handle here to be updated.
925 if( nm->is_at_poll_return(real_return_addr) ) {
20
←
Assuming the condition is true
→
21
←
Taking true branch
→
926 // See if return type is an oop.
927 bool return_oop = nm->method()->is_returning_oop();
928 HandleMark hm(self);
929 Handle return_value;
930 if (return_oop
21.1
'return_oop' is true
21.1
'return_oop' is true
) {
22
←
Taking true branch
→
931 // The oop result has been saved on the stack together with all
932 // the other registers. In order to preserve it over GCs we need
933 // to keep it in a handle.
934 oop result = caller_fr.saved_oop_result(&map);
23
←
Calling 'frame::saved_oop_result'
→
935 assert(oopDesc::is_oop_or_null(result), "must be oop")do { if (!(oopDesc::is_oop_or_null(result))) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 935, "assert(" "oopDesc::is_oop_or_null(result)" ") failed"
, "must be oop"); ::breakpoint(); } } while (0);
936 return_value = Handle(self, result);
937 assert(Universe::heap()->is_in_or_null(result), "must be heap pointer")do { if (!(Universe::heap()->is_in_or_null(result))) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 937, "assert(" "Universe::heap()->is_in_or_null(result)"
") failed", "must be heap pointer"); ::breakpoint(); } } while
(0);
938 }
939
940 // We get here if compiled return polls found a reason to call into the VM.
941 // One condition for that is that the top frame is not yet safe to use.
942 // The following stack watermark barrier poll will catch such situations.
943 StackWatermarkSet::after_unwind(self);
944
945 // Process pending operation
946 SafepointMechanism::process_if_requested_with_exit_check(self, true /* check asyncs */);
947
948 // restore oop result, if any
949 if (return_oop) {
950 caller_fr.set_saved_oop_result(&map, return_value());
951 }
952 }
953
954 // This is a safepoint poll. Verify the return address and block.
955 else {
956
957 // verify the blob built the "return address" correctly
958 assert(real_return_addr == caller_fr.pc(), "must match")do { if (!(real_return_addr == caller_fr.pc())) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 958, "assert(" "real_return_addr == caller_fr.pc()" ") failed"
, "must match"); ::breakpoint(); } } while (0);
959
960 set_at_poll_safepoint(true);
961 // Process pending operation
962 // We never deliver an async exception at a polling point as the
963 // compiler may not have an exception handler for it. The polling
964 // code will notice the pending async exception, deoptimize and
965 // the exception will be delivered. (Polling at a return point
966 // is ok though). Sure is a lot of bother for a deprecated feature...
967 SafepointMechanism::process_if_requested_with_exit_check(self, false /* check asyncs */);
968 set_at_poll_safepoint(false);
969
970 // If we have a pending async exception deoptimize the frame
971 // as otherwise we may never deliver it.
972 if (self->has_async_exception_condition()) {
973 ThreadInVMfromJava __tiv(self, false /* check asyncs */);
974 Deoptimization::deoptimize_frame(self, caller_fr.id());
975 }
976
977 // If an exception has been installed we must check for a pending deoptimization
978 // Deoptimize frame if exception has been thrown.
979
980 if (self->has_pending_exception() ) {
981 RegisterMap map(self, true, false);
982 frame caller_fr = stub_fr.sender(&map);
983 if (caller_fr.is_deoptimized_frame()) {
984 // The exception patch will destroy registers that are still
985 // live and will be needed during deoptimization. Defer the
986 // Async exception should have deferred the exception until the
987 // next safepoint which will be detected when we get into
988 // the interpreter so if we have an exception now things
989 // are messed up.
990
991 fatal("Exception installed and deoptimization is pending")do { (*g_assert_poison) = 'X';; report_fatal(INTERNAL_ERROR, "/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 991, "Exception installed and deoptimization is pending"); ::
breakpoint(); } while (0);
992 }
993 }
994 }
995}
996
997
998// -------------------------------------------------------------------------------------------------------
999// Implementation of SafepointTracing
1000
1001jlong SafepointTracing::_last_safepoint_begin_time_ns = 0;
1002jlong SafepointTracing::_last_safepoint_sync_time_ns = 0;
1003jlong SafepointTracing::_last_safepoint_cleanup_time_ns = 0;
1004jlong SafepointTracing::_last_safepoint_end_time_ns = 0;
1005jlong SafepointTracing::_last_app_time_ns = 0;
1006int SafepointTracing::_nof_threads = 0;
1007int SafepointTracing::_nof_running = 0;
1008int SafepointTracing::_page_trap = 0;
1009VM_Operation::VMOp_Type SafepointTracing::_current_type;
1010jlong SafepointTracing::_max_sync_time = 0;
1011jlong SafepointTracing::_max_vmop_time = 0;
1012uint64_t SafepointTracing::_op_count[VM_Operation::VMOp_Terminating] = {0};
1013
1014void SafepointTracing::init() {
1015 // Application start
1016 _last_safepoint_end_time_ns = os::javaTimeNanos();
1017}
1018
1019// Helper method to print the header.
1020static void print_header(outputStream* st) {
1021 // The number of spaces is significant here, and should match the format
1022 // specifiers in print_statistics().
1023
1024 st->print("VM Operation "
1025 "[ threads: total initial_running ]"
1026 "[ time: sync cleanup vmop total ]");
1027
1028 st->print_cr(" page_trap_count");
1029}
1030
1031// This prints a nice table. To get the statistics to not shift due to the logging uptime
1032// decorator, use the option as: -Xlog:safepoint+stats:[outputfile]:none
1033void SafepointTracing::statistics_log() {
1034 LogTarget(Info, safepoint, stats)LogTargetImpl<LogLevel::Info, (LogTag::_safepoint), (LogTag
::_stats), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG
), (LogTag::__NO_TAG)> lt;
1035 assert (lt.is_enabled(), "should only be called when printing statistics is enabled")do { if (!(lt.is_enabled())) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/runtime/safepoint.cpp"
, 1035, "assert(" "lt.is_enabled()" ") failed", "should only be called when printing statistics is enabled"
); ::breakpoint(); } } while (0);
1036 LogStream ls(lt);
1037
1038 static int _cur_stat_index = 0;
1039
1040 // Print header every 30 entries
1041 if ((_cur_stat_index % 30) == 0) {
1042 print_header(&ls);
1043 _cur_stat_index = 1; // wrap
1044 } else {
1045 _cur_stat_index++;
1046 }
1047
1048 ls.print("%-28s [ "
1049 INT32_FORMAT_W(8)"%" "8" "d" " " INT32_FORMAT_W(8)"%" "8" "d" " "
1050 "]",
1051 VM_Operation::name(_current_type),
1052 _nof_threads,
1053 _nof_running);
1054 ls.print("[ "
1055 INT64_FORMAT_W(10)"%" "10" "l" "d" " " INT64_FORMAT_W(10)"%" "10" "l" "d" " "
1056 INT64_FORMAT_W(10)"%" "10" "l" "d" " " INT64_FORMAT_W(10)"%" "10" "l" "d" " ]",
1057 (int64_t)(_last_safepoint_sync_time_ns - _last_safepoint_begin_time_ns),
1058 (int64_t)(_last_safepoint_cleanup_time_ns - _last_safepoint_sync_time_ns),
1059 (int64_t)(_last_safepoint_end_time_ns - _last_safepoint_cleanup_time_ns),
1060 (int64_t)(_last_safepoint_end_time_ns - _last_safepoint_begin_time_ns));
1061
1062 ls.print_cr(INT32_FORMAT_W(16)"%" "16" "d", _page_trap);
1063}
1064
1065// This method will be called when VM exits. This tries to summarize the sampling.
1066// Current thread may already be deleted, so don't use ResourceMark.
1067void SafepointTracing::statistics_exit_log() {
1068 if (!log_is_enabled(Info, safepoint, stats)(LogImpl<(LogTag::_safepoint), (LogTag::_stats), (LogTag::
__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG
)>::is_level(LogLevel::Info))) {
1069 return;
1070 }
1071 for (int index = 0; index < VM_Operation::VMOp_Terminating; index++) {
1072 if (_op_count[index] != 0) {
1073 log_info(safepoint, stats)(!(LogImpl<(LogTag::_safepoint), (LogTag::_stats), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG)>::is_level(LogLevel::Info))) ? (void)0 : LogImpl
<(LogTag::_safepoint), (LogTag::_stats), (LogTag::__NO_TAG
), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG)
>::write<LogLevel::Info>("%-28s" UINT64_FORMAT_W(10)"%" "10" "l" "u", VM_Operation::name(index),
1074 _op_count[index]);
1075 }
1076 }
1077
1078 log_info(safepoint, stats)(!(LogImpl<(LogTag::_safepoint), (LogTag::_stats), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG)>::is_level(LogLevel::Info))) ? (void)0 : LogImpl
<(LogTag::_safepoint), (LogTag::_stats), (LogTag::__NO_TAG
), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG)
>::write<LogLevel::Info>("Maximum sync time " INT64_FORMAT"%" "l" "d"" ns",
1079 (int64_t)(_max_sync_time));
1080 log_info(safepoint, stats)(!(LogImpl<(LogTag::_safepoint), (LogTag::_stats), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG)>::is_level(LogLevel::Info))) ? (void)0 : LogImpl
<(LogTag::_safepoint), (LogTag::_stats), (LogTag::__NO_TAG
), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG)
>::write<LogLevel::Info>("Maximum vm operation time (except for Exit VM operation) "
1081 INT64_FORMAT"%" "l" "d" " ns",
1082 (int64_t)(_max_vmop_time));
1083}
1084
1085void SafepointTracing::begin(VM_Operation::VMOp_Type type) {
1086 _op_count[type]++;
1087 _current_type = type;
1088
1089 // update the time stamp to begin recording safepoint time
1090 _last_safepoint_begin_time_ns = os::javaTimeNanos();
1091 _last_safepoint_sync_time_ns = 0;
1092 _last_safepoint_cleanup_time_ns = 0;
1093
1094 _last_app_time_ns = _last_safepoint_begin_time_ns - _last_safepoint_end_time_ns;
1095 _last_safepoint_end_time_ns = 0;
1096
1097 RuntimeService::record_safepoint_begin(_last_app_time_ns);
1098}
1099
1100void SafepointTracing::synchronized(int nof_threads, int nof_running, int traps) {
1101 _last_safepoint_sync_time_ns = os::javaTimeNanos();
1102 _nof_threads = nof_threads;
1103 _nof_running = nof_running;
1104 _page_trap = traps;
1105 RuntimeService::record_safepoint_synchronized(_last_safepoint_sync_time_ns - _last_safepoint_begin_time_ns);
1106}
1107
1108void SafepointTracing::cleanup() {
1109 _last_safepoint_cleanup_time_ns = os::javaTimeNanos();
1110}
1111
1112void SafepointTracing::end() {
1113 _last_safepoint_end_time_ns = os::javaTimeNanos();
1114
1115 if (_max_sync_time < (_last_safepoint_sync_time_ns - _last_safepoint_begin_time_ns)) {
1116 _max_sync_time = _last_safepoint_sync_time_ns - _last_safepoint_begin_time_ns;
1117 }
1118 if (_max_vmop_time < (_last_safepoint_end_time_ns - _last_safepoint_sync_time_ns)) {
1119 _max_vmop_time = _last_safepoint_end_time_ns - _last_safepoint_sync_time_ns;
1120 }
1121 if (log_is_enabled(Info, safepoint, stats)(LogImpl<(LogTag::_safepoint), (LogTag::_stats), (LogTag::
__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG
)>::is_level(LogLevel::Info))) {
1122 statistics_log();
1123 }
1124
1125 log_info(safepoint)(!(LogImpl<(LogTag::_safepoint), (LogTag::__NO_TAG), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG)>::is_level(LogLevel::Info))) ? (void)0 : LogImpl
<(LogTag::_safepoint), (LogTag::__NO_TAG), (LogTag::__NO_TAG
), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG)
>::write<LogLevel::Info>(
1126 "Safepoint \"%s\", "
1127 "Time since last: " JLONG_FORMAT"%" "l" "d" " ns, "
1128 "Reaching safepoint: " JLONG_FORMAT"%" "l" "d" " ns, "
1129 "At safepoint: " JLONG_FORMAT"%" "l" "d" " ns, "
1130 "Total: " JLONG_FORMAT"%" "l" "d" " ns",
1131 VM_Operation::name(_current_type),
1132 _last_app_time_ns,
1133 _last_safepoint_cleanup_time_ns - _last_safepoint_begin_time_ns,
1134 _last_safepoint_end_time_ns - _last_safepoint_cleanup_time_ns,
1135 _last_safepoint_end_time_ns - _last_safepoint_begin_time_ns
1136 );
1137
1138 RuntimeService::record_safepoint_end(_last_safepoint_end_time_ns - _last_safepoint_cleanup_time_ns);
1139}
←

/home/daniel/Projects/java/jdk/src/hotspot/cpu/x86/frame_x86.inline.hpp

1/*
2 * Copyright (c) 1997, 2021, 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 CPU_X86_FRAME_X86_INLINE_HPP
26#define CPU_X86_FRAME_X86_INLINE_HPP
27
28#include "code/codeCache.hpp"
29#include "code/vmreg.inline.hpp"
30#include "runtime/registerMap.hpp"
31
32// Inline functions for Intel frames:
33
34// Constructors:
35
36inline frame::frame() {
37 _pc = NULL__null;
38 _sp = NULL__null;
39 _unextended_sp = NULL__null;
40 _fp = NULL__null;
41 _cb = NULL__null;
42 _deopt_state = unknown;
43}
44
45inline void frame::init(intptr_t* sp, intptr_t* fp, address pc) {
46 _sp = sp;
47 _unextended_sp = sp;
48 _fp = fp;
49 _pc = pc;
50 assert(pc != NULL, "no pc?")do { if (!(pc != __null)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/cpu/x86/frame_x86.inline.hpp"
, 50, "assert(" "pc != __null" ") failed", "no pc?"); ::breakpoint
(); } } while (0);
51 _cb = CodeCache::find_blob(pc);
52 adjust_unextended_sp();
53
54 address original_pc = CompiledMethod::get_deopt_original_pc(this);
55 if (original_pc != NULL__null) {
56 _pc = original_pc;
57 _deopt_state = is_deoptimized;
58 } else {
59 _deopt_state = not_deoptimized;
60 }
61}
62
63inline frame::frame(intptr_t* sp, intptr_t* fp, address pc) {
64 init(sp, fp, pc);
65}
66
67inline frame::frame(intptr_t* sp, intptr_t* unextended_sp, intptr_t* fp, address pc) {
68 _sp = sp;
69 _unextended_sp = unextended_sp;
70 _fp = fp;
71 _pc = pc;
72 assert(pc != NULL, "no pc?")do { if (!(pc != __null)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/cpu/x86/frame_x86.inline.hpp"
, 72, "assert(" "pc != __null" ") failed", "no pc?"); ::breakpoint
(); } } while (0);
73 _cb = CodeCache::find_blob(pc);
74 adjust_unextended_sp();
75
76 address original_pc = CompiledMethod::get_deopt_original_pc(this);
77 if (original_pc != NULL__null) {
78 _pc = original_pc;
79 assert(_cb->as_compiled_method()->insts_contains_inclusive(_pc),do { if (!(_cb->as_compiled_method()->insts_contains_inclusive
(_pc))) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/cpu/x86/frame_x86.inline.hpp"
, 80, "assert(" "_cb->as_compiled_method()->insts_contains_inclusive(_pc)"
") failed", "original PC must be in the main code section of the the compiled method (or must be immediately following it)"
); ::breakpoint(); } } while (0)
80 "original PC must be in the main code section of the the compiled method (or must be immediately following it)")do { if (!(_cb->as_compiled_method()->insts_contains_inclusive
(_pc))) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/cpu/x86/frame_x86.inline.hpp"
, 80, "assert(" "_cb->as_compiled_method()->insts_contains_inclusive(_pc)"
") failed", "original PC must be in the main code section of the the compiled method (or must be immediately following it)"
); ::breakpoint(); } } while (0);
81 _deopt_state = is_deoptimized;
82 } else {
83 if (_cb->is_deoptimization_stub()) {
84 _deopt_state = is_deoptimized;
85 } else {
86 _deopt_state = not_deoptimized;
87 }
88 }
89}
90
91inline frame::frame(intptr_t* sp, intptr_t* fp) {
92 _sp = sp;
93 _unextended_sp = sp;
94 _fp = fp;
95 _pc = (address)(sp[-1]);
96
97 // Here's a sticky one. This constructor can be called via AsyncGetCallTrace
98 // when last_Java_sp is non-null but the pc fetched is junk. If we are truly
99 // unlucky the junk value could be to a zombied method and we'll die on the
100 // find_blob call. This is also why we can have no asserts on the validity
101 // of the pc we find here. AsyncGetCallTrace -> pd_get_top_frame_for_signal_handler
102 // -> pd_last_frame should use a specialized version of pd_last_frame which could
103 // call a specialized frame constructor instead of this one.
104 // Then we could use the assert below. However this assert is of somewhat dubious
105 // value.
106 // UPDATE: this constructor is only used by trace_method_handle_stub() now.
107 // assert(_pc != NULL, "no pc?");
108
109 _cb = CodeCache::find_blob(_pc);
110 adjust_unextended_sp();
111
112 address original_pc = CompiledMethod::get_deopt_original_pc(this);
113 if (original_pc != NULL__null) {
114 _pc = original_pc;
115 _deopt_state = is_deoptimized;
116 } else {
117 _deopt_state = not_deoptimized;
118 }
119}
120
121// Accessors
122
123inline bool frame::equal(frame other) const {
124 bool ret = sp() == other.sp()
125 && unextended_sp() == other.unextended_sp()
126 && fp() == other.fp()
127 && pc() == other.pc();
128 assert(!ret || ret && cb() == other.cb() && _deopt_state == other._deopt_state, "inconsistent construction")do { if (!(!ret || ret && cb() == other.cb() &&
_deopt_state == other._deopt_state)) { (*g_assert_poison) = 'X'
;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/cpu/x86/frame_x86.inline.hpp"
, 128, "assert(" "!ret || ret && cb() == other.cb() && _deopt_state == other._deopt_state"
") failed", "inconsistent construction"); ::breakpoint(); } }
while (0);
129 return ret;
130}
131
132// Return unique id for this frame. The id must have a value where we can distinguish
133// identity and younger/older relationship. NULL represents an invalid (incomparable)
134// frame.
135inline intptr_t* frame::id(void) const { return unextended_sp(); }
136
137// Return true if the frame is older (less recent activation) than the frame represented by id
138inline bool frame::is_older(intptr_t* id) const { assert(this->id() != NULL && id != NULL, "NULL frame id")do { if (!(this->id() != __null && id != __null)) {
(*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/cpu/x86/frame_x86.inline.hpp"
, 138, "assert(" "this->id() != __null && id != __null"
") failed", "NULL frame id"); ::breakpoint(); } } while (0);
139 return this->id() > id ; }
140
141
142
143inline intptr_t* frame::link() const { return (intptr_t*) *(intptr_t **)addr_at(link_offset); }
144
145inline intptr_t* frame::unextended_sp() const { return _unextended_sp; }
146
147// Return address:
148
149inline address* frame::sender_pc_addr() const { return (address*) addr_at( return_addr_offset); }
150inline address frame::sender_pc() const { return *sender_pc_addr(); }
151
152inline intptr_t* frame::sender_sp() const { return addr_at( sender_sp_offset); }
153
154inline intptr_t** frame::interpreter_frame_locals_addr() const {
155 return (intptr_t**)addr_at(interpreter_frame_locals_offset);
156}
157
158inline intptr_t* frame::interpreter_frame_last_sp() const {
159 return *(intptr_t**)addr_at(interpreter_frame_last_sp_offset);
160}
161
162inline intptr_t* frame::interpreter_frame_bcp_addr() const {
163 return (intptr_t*)addr_at(interpreter_frame_bcp_offset);
164}
165
166
167inline intptr_t* frame::interpreter_frame_mdp_addr() const {
168 return (intptr_t*)addr_at(interpreter_frame_mdp_offset);
169}
170
171
172
173// Constant pool cache
174
175inline ConstantPoolCache** frame::interpreter_frame_cache_addr() const {
176 return (ConstantPoolCache**)addr_at(interpreter_frame_cache_offset);
177}
178
179// Method
180
181inline Method** frame::interpreter_frame_method_addr() const {
182 return (Method**)addr_at(interpreter_frame_method_offset);
183}
184
185// Mirror
186
187inline oop* frame::interpreter_frame_mirror_addr() const {
188 return (oop*)addr_at(interpreter_frame_mirror_offset);
189}
190
191// top of expression stack
192inline intptr_t* frame::interpreter_frame_tos_address() const {
193 intptr_t* last_sp = interpreter_frame_last_sp();
194 if (last_sp == NULL__null) {
195 return sp();
196 } else {
197 // sp() may have been extended or shrunk by an adapter. At least
198 // check that we don't fall behind the legal region.
199 // For top deoptimized frame last_sp == interpreter_frame_monitor_end.
200 assert(last_sp <= (intptr_t*) interpreter_frame_monitor_end(), "bad tos")do { if (!(last_sp <= (intptr_t*) interpreter_frame_monitor_end
())) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/cpu/x86/frame_x86.inline.hpp"
, 200, "assert(" "last_sp <= (intptr_t*) interpreter_frame_monitor_end()"
") failed", "bad tos"); ::breakpoint(); } } while (0);
201 return last_sp;
202 }
203}
204
205inline oop* frame::interpreter_frame_temp_oop_addr() const {
206 return (oop *)(fp() + interpreter_frame_oop_temp_offset);
207}
208
209inline int frame::interpreter_frame_monitor_size() {
210 return BasicObjectLock::size();
211}
212
213
214// expression stack
215// (the max_stack arguments are used by the GC; see class FrameClosure)
216
217inline intptr_t* frame::interpreter_frame_expression_stack() const {
218 intptr_t* monitor_end = (intptr_t*) interpreter_frame_monitor_end();
219 return monitor_end-1;
220}
221
222// Entry frames
223
224inline JavaCallWrapper** frame::entry_frame_call_wrapper_addr() const {
225 return (JavaCallWrapper**)addr_at(entry_frame_call_wrapper_offset);
226}
227
228// Compiled frames
229
230// Register is a class, but it would be assigned numerical value.
231// "0" is assigned for rax. Thus we need to ignore -Wnonnull.
232PRAGMA_DIAG_PUSHGCC diagnostic push
233PRAGMA_NONNULL_IGNOREDGCC diagnostic ignored "-Wnonnull"
234inline oop frame::saved_oop_result(RegisterMap* map) const {
235 oop* result_adr = (oop *)map->location(rax->as_VMReg());
24
←
Called C++ object pointer is null
236 guarantee(result_adr != NULL, "bad register save location")do { if (!(result_adr != __null)) { (*g_assert_poison) = 'X';
; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/cpu/x86/frame_x86.inline.hpp"
, 236, "guarantee(" "result_adr != NULL" ") failed", "bad register save location"
); ::breakpoint(); } } while (0);
237
238 return (*result_adr);
239}
240
241inline void frame::set_saved_oop_result(RegisterMap* map, oop obj) {
242 oop* result_adr = (oop *)map->location(rax->as_VMReg());
243 guarantee(result_adr != NULL, "bad register save location")do { if (!(result_adr != __null)) { (*g_assert_poison) = 'X';
; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/cpu/x86/frame_x86.inline.hpp"
, 243, "guarantee(" "result_adr != NULL" ") failed", "bad register save location"
); ::breakpoint(); } } while (0);
244
245 *result_adr = obj;
246}
247PRAGMA_DIAG_POPGCC diagnostic pop
248
249#endif // CPU_X86_FRAME_X86_INLINE_HPP