--- a/src/hotspot/share/runtime/globals.hpp Tue Mar 26 07:09:10 2019 -0400
+++ b/src/hotspot/share/runtime/globals.hpp Tue Mar 26 12:08:51 2019 +0100
@@ -371,6 +371,10 @@
"Generate a lot of safepoints. This works with " \
"GuaranteedSafepointInterval") \
\
+ diagnostic(bool, HandshakeALot, false, \
+ "Generate a lot of handshakes. This works with " \
+ "GuaranteedSafepointInterval") \
+ \
product_pd(bool, BackgroundCompilation, \
"A thread requesting compilation is not blocked during " \
"compilation") \
--- a/src/hotspot/share/runtime/thread.cpp Tue Mar 26 07:09:10 2019 -0400
+++ b/src/hotspot/share/runtime/thread.cpp Tue Mar 26 12:08:51 2019 +0100
@@ -2928,9 +2928,21 @@
}
}
+#ifdef ASSERT
+void JavaThread::verify_states_for_handshake() {
+ // This checks that the thread has a correct frame state during a handshake.
+ assert((!has_last_Java_frame() && java_call_counter() == 0) ||
+ (has_last_Java_frame() && java_call_counter() > 0),
+ "unexpected frame info: has_last_frame=%d, java_call_counter=%d",
+ has_last_Java_frame(), java_call_counter());
+}
+#endif
+
void JavaThread::nmethods_do(CodeBlobClosure* cf) {
assert((!has_last_Java_frame() && java_call_counter() == 0) ||
- (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
+ (has_last_Java_frame() && java_call_counter() > 0),
+ "unexpected frame info: has_last_frame=%d, java_call_counter=%d",
+ has_last_Java_frame(), java_call_counter());
if (has_last_Java_frame()) {
// Traverse the execution stack
--- a/src/hotspot/share/runtime/thread.hpp Tue Mar 26 07:09:10 2019 -0400
+++ b/src/hotspot/share/runtime/thread.hpp Tue Mar 26 12:08:51 2019 +0100
@@ -1874,6 +1874,9 @@
// RedefineClasses Support
void metadata_do(MetadataClosure* f);
+ // Debug method asserting thread states are correct during a handshake operation.
+ DEBUG_ONLY(void verify_states_for_handshake();)
+
// Misc. operations
char* name() const { return (char*)get_thread_name(); }
void print_on(outputStream* st, bool print_extended_info) const;
--- a/src/hotspot/share/runtime/vmThread.cpp Tue Mar 26 07:09:10 2019 -0400
+++ b/src/hotspot/share/runtime/vmThread.cpp Tue Mar 26 12:08:51 2019 +0100
@@ -434,22 +434,35 @@
static VM_None safepointALot_op("SafepointALot");
static VM_Cleanup cleanup_op;
-VM_Operation* VMThread::no_op_safepoint(bool check_time) {
+class HandshakeALotTC : public ThreadClosure {
+ public:
+ virtual void do_thread(Thread* thread) {
+#ifdef ASSERT
+ assert(thread->is_Java_thread(), "must be");
+ JavaThread* jt = (JavaThread*)thread;
+ jt->verify_states_for_handshake();
+#endif
+ }
+};
+
+VM_Operation* VMThread::no_op_safepoint() {
+ // Check for handshakes first since we may need to return a VMop.
+ if (HandshakeALot) {
+ HandshakeALotTC haltc;
+ Handshake::execute(&haltc);
+ }
+ // Check for a cleanup before SafepointALot to keep stats correct.
+ long interval_ms = SafepointTracing::time_since_last_safepoint_ms();
+ bool max_time_exceeded = GuaranteedSafepointInterval != 0 &&
+ (interval_ms >= GuaranteedSafepointInterval);
+ if (max_time_exceeded && SafepointSynchronize::is_cleanup_needed()) {
+ return &cleanup_op;
+ }
if (SafepointALot) {
return &safepointALot_op;
}
- if (!SafepointSynchronize::is_cleanup_needed()) {
- return NULL;
- }
- if (check_time) {
- long interval_ms = SafepointTracing::time_since_last_safepoint_ms();
- bool max_time_exceeded = GuaranteedSafepointInterval != 0 &&
- (interval_ms > GuaranteedSafepointInterval);
- if (!max_time_exceeded) {
- return NULL;
- }
- }
- return &cleanup_op;
+ // Nothing to be done.
+ return NULL;
}
void VMThread::loop() {
@@ -491,19 +504,22 @@
exit(-1);
}
- if (timedout && (_cur_vm_operation = VMThread::no_op_safepoint(false)) != NULL) {
- MutexUnlockerEx mul(VMOperationQueue_lock,
- Mutex::_no_safepoint_check_flag);
- // Force a safepoint since we have not had one for at least
- // 'GuaranteedSafepointInterval' milliseconds. This will run all
- // the clean-up processing that needs to be done regularly at a
- // safepoint
- SafepointSynchronize::begin();
- #ifdef ASSERT
+ if (timedout) {
+ // Have to unlock VMOperationQueue_lock just in case no_op_safepoint()
+ // has to do a handshake.
+ MutexUnlockerEx mul(VMOperationQueue_lock, Mutex::_no_safepoint_check_flag);
+ if ((_cur_vm_operation = VMThread::no_op_safepoint()) != NULL) {
+ // Force a safepoint since we have not had one for at least
+ // 'GuaranteedSafepointInterval' milliseconds and we need to clean
+ // something. This will run all the clean-up processing that needs
+ // to be done at a safepoint.
+ SafepointSynchronize::begin();
+ #ifdef ASSERT
if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot();
- #endif
- SafepointSynchronize::end();
- _cur_vm_operation = NULL;
+ #endif
+ SafepointSynchronize::end();
+ _cur_vm_operation = NULL;
+ }
}
_cur_vm_operation = _vm_queue->remove_next();
@@ -615,10 +631,9 @@
VMOperationRequest_lock->notify_all();
}
- //
- // We want to make sure that we get to a safepoint regularly.
- //
- if ((_cur_vm_operation = VMThread::no_op_safepoint(false)) != NULL) {
+ // We want to make sure that we get to a safepoint regularly
+ // even when executing VMops that don't require safepoints.
+ if ((_cur_vm_operation = VMThread::no_op_safepoint()) != NULL) {
HandleMark hm(VMThread::vm_thread());
SafepointSynchronize::begin();
SafepointSynchronize::end();
--- a/src/hotspot/share/runtime/vmThread.hpp Tue Mar 26 07:09:10 2019 -0400
+++ b/src/hotspot/share/runtime/vmThread.hpp Tue Mar 26 12:08:51 2019 +0100
@@ -123,7 +123,7 @@
static VMOperationTimeoutTask* _timeout_task;
- static VM_Operation* no_op_safepoint(bool check_time);
+ static VM_Operation* no_op_safepoint();
void evaluate_operation(VM_Operation* op);
--- a/test/hotspot/jtreg/ProblemList.txt Tue Mar 26 07:09:10 2019 -0400
+++ b/test/hotspot/jtreg/ProblemList.txt Tue Mar 26 12:08:51 2019 +0100
@@ -80,7 +80,6 @@
# :hotspot_runtime
-runtime/handshake/HandshakeWalkSuspendExitTest.java 8214174 generic-all
runtime/NMT/CheckForProperDetailStackTrace.java 8218458 generic-all
runtime/SharedArchiveFile/SASymbolTableTest.java 8193639 solaris-all
runtime/containers/docker/TestCPUSets.java 8220672 generic-all
--- a/test/hotspot/jtreg/runtime/Thread/SuspendAtExit.java Tue Mar 26 07:09:10 2019 -0400
+++ b/test/hotspot/jtreg/runtime/Thread/SuspendAtExit.java Tue Mar 26 12:08:51 2019 +0100
@@ -26,6 +26,7 @@
* @bug 8167108
* @summary Stress test java.lang.Thread.suspend() at thread exit.
* @run main/othervm -Xlog:thread+smr=debug SuspendAtExit
+ * @run main/othervm -Xlog:thread+smr=debug -XX:+UnlockDiagnosticVMOptions -XX:GuaranteedSafepointInterval=1 -XX:+HandshakeALot SuspendAtExit
*/
import java.util.concurrent.CountDownLatch;
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/handshake/HandshakeSuspendExitTest.java Tue Mar 26 12:08:51 2019 +0100
@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+/*
+ * @test HandshakeSuspendExitTest
+ * @summary This test tries to stress the handshakes with new and exiting threads while suspending them.
+ * @library /testlibrary /test/lib
+ * @build HandshakeSuspendExitTest
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:GuaranteedSafepointInterval=1 -XX:+HandshakeALot HandshakeSuspendExitTest
+ */
+
+public class HandshakeSuspendExitTest implements Runnable {
+
+ static Thread[] _suspend_threads = new Thread[16];
+ static volatile boolean _exit_now = false;
+ static java.util.concurrent.Semaphore _sem = new java.util.concurrent.Semaphore(0);
+
+ @Override
+ public void run() {
+ _sem.release();
+ while (!_exit_now) {
+ // Leave last 2 threads running.
+ for (int i = 0; i < _suspend_threads.length - 2; i++) {
+ if (Thread.currentThread() != thr) {
+ thr.suspend();
+ thr.resume();
+ }
+ }
+ }
+ _sem.release();
+ }
+
+ public static void main(String... args) throws Exception {
+ HandshakeSuspendExitTest test = new HandshakeSuspendExitTest();
+ // Fire-up suspend threads.
+ for (int i = 0; i < _suspend_threads.length; i++) {
+ _suspend_threads[i] = new Thread(test);
+ }
+ for (int i = 0; i < _suspend_threads.length; i++) {
+ _suspend_threads[i].start();
+ }
+ // Wait for all suspend-threads to start looping.
+ for (Thread thr : _suspend_threads) {
+ _sem.acquire();
+ }
+
+ // Fire-up exiting threads.
+ Thread[] exit_threads = new Thread[128];
+ for (int i = 0; i < exit_threads.length; i++) {
+ exit_threads[i] = new Thread();
+ exit_threads[i].start();
+ }
+
+ // Try to suspend them.
+ for (Thread thr : exit_threads) {
+ thr.suspend();
+ }
+ for (Thread thr : exit_threads) {
+ thr.resume();
+ }
+
+ // Start exit and join.
+ _exit_now = true;
+ int waiting = _suspend_threads.length;
+ do {
+ // Resume any worker threads that might have suspended
+ // each other at exactly the same time so they can see
+ // _exit_now and check in via the semaphore.
+ for (Thread thr : _suspend_threads) {
+ thr.resume();
+ }
+ while (_sem.tryAcquire()) {
+ --waiting;
+ }
+ } while (waiting > 0);
+ for (Thread thr : _suspend_threads) {
+ thr.join();
+ }
+ for (Thread thr : exit_threads) {
+ thr.join();
+ }
+ }
+}
--- a/test/hotspot/jtreg/runtime/handshake/HandshakeTransitionTest.java Tue Mar 26 07:09:10 2019 -0400
+++ b/test/hotspot/jtreg/runtime/handshake/HandshakeTransitionTest.java Tue Mar 26 12:08:51 2019 +0100
@@ -62,6 +62,7 @@
true,
"-Djava.library.path=" + lib,
"-XX:+SafepointALot",
+ "-XX:+HandshakeALot",
"-XX:GuaranteedSafepointInterval=20",
"-Xlog:ergo*",
"-XX:ParallelGCThreads=1",
--- a/test/hotspot/jtreg/runtime/handshake/HandshakeWalkSuspendExitTest.java Tue Mar 26 07:09:10 2019 -0400
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,93 +0,0 @@
-/*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-
-/*
- * @test HandshakeWalkSuspendExitTest
- * @summary This test tries to stress the handshakes with new and exiting threads while suspending them.
- * @library /testlibrary /test/lib
- * @build HandshakeWalkSuspendExitTest
- * @run driver ClassFileInstaller sun.hotspot.WhiteBox
- * sun.hotspot.WhiteBox$WhiteBoxPermission
- * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI HandshakeWalkSuspendExitTest
- */
-
-import jdk.test.lib.Asserts;
-import sun.hotspot.WhiteBox;
-
-public class HandshakeWalkSuspendExitTest implements Runnable {
-
- static final int _test_threads = 8;
- static final int _test_exit_threads = 128;
- static Thread[] _threads = new Thread[_test_threads];
- static volatile boolean exit_now = false;
- static java.util.concurrent.Semaphore _sem = new java.util.concurrent.Semaphore(0);
-
- @Override
- public void run() {
- WhiteBox wb = WhiteBox.getWhiteBox();
- while (!exit_now) {
- _sem.release();
- // We only suspend threads on even index and not ourself.
- // Otherwise we can accidentially suspend all threads.
- for (int i = 0; i < _threads.length; i += 2) {
- wb.handshakeWalkStack(null /* ignored */, true /* stackwalk all threads */);
- if (Thread.currentThread() != _threads[i]) {
- _threads[i].suspend();
- _threads[i].resume();
- }
- }
- for (int i = 0; i < _threads.length; i += 2) {
- wb.handshakeWalkStack(_threads[i] /* thread to stackwalk */, false /* stackwalk one thread */);
- if (Thread.currentThread() != _threads[i]) {
- _threads[i].suspend();
- _threads[i].resume();
- }
- }
- }
- }
-
- public static void main(String... args) throws Exception {
- HandshakeWalkSuspendExitTest test = new HandshakeWalkSuspendExitTest();
-
- for (int i = 0; i < _threads.length; i++) {
- _threads[i] = new Thread(test);
- _threads[i].start();
- }
- for (int i = 0; i < _test_threads; i++) {
- _sem.acquire();
- }
- Thread[] exit_threads = new Thread[_test_exit_threads];
- for (int i = 0; i < _test_exit_threads; i++) {
- exit_threads[i] = new Thread(new Runnable() { public void run() {} });
- exit_threads[i].start();
- }
- exit_now = true;
- for (int i = 0; i < _threads.length; i++) {
- _threads[i].join();
- }
- for (int i = 0; i < exit_threads.length; i++) {
- exit_threads[i].join();
- }
- }
-}