8294759: Print actual lock/monitor ranking

Reviewed-by: coleenp, dholmes
This commit is contained in:
Aleksey Shipilev 2022-10-06 07:57:54 +00:00
parent 7012d4ba55
commit e38ae8a651
4 changed files with 104 additions and 0 deletions
src/hotspot/share/runtime
test/hotspot/jtreg/runtime/logging

@ -24,6 +24,9 @@
#include "precompiled.hpp"
#include "gc/shared/gc_globals.hpp"
#include "logging/log.hpp"
#include "logging/logStream.hpp"
#include "memory/resourceArea.hpp"
#include "memory/universe.hpp"
#include "runtime/javaThread.hpp"
#include "runtime/mutexLocker.hpp"
@ -380,6 +383,16 @@ void mutex_init() {
#endif
}
void MutexLocker::post_initialize() {
// Print mutex ranks if requested.
LogTarget(Info, vmmutex) lt;
if (lt.is_enabled()) {
ResourceMark rm;
LogStream ls(lt);
print_lock_ranks(&ls);
}
}
GCMutexLocker::GCMutexLocker(Mutex* mutex) {
if (SafepointSynchronize::is_at_safepoint()) {
_locked = false;
@ -409,3 +422,39 @@ void print_owned_locks_on_error(outputStream* st) {
}
if (none) st->print_cr("None");
}
void print_lock_ranks(outputStream* st) {
st->print_cr("VM Mutex/Monitor ranks: ");
#ifdef ASSERT
// Be extra defensive and figure out the bounds on
// ranks right here. This also saves a bit of time
// in the #ranks*#mutexes loop below.
int min_rank = INT_MAX;
int max_rank = INT_MIN;
for (int i = 0; i < _num_mutex; i++) {
Mutex* m = _mutex_array[i];
int r = (int) m->rank();
if (min_rank > r) min_rank = r;
if (max_rank < r) max_rank = r;
}
// Print the listings rank by rank
for (int r = min_rank; r <= max_rank; r++) {
bool first = true;
for (int i = 0; i < _num_mutex; i++) {
Mutex* m = _mutex_array[i];
if (r != (int) m->rank()) continue;
if (first) {
st->cr();
st->print_cr("Rank \"%s\":", m->rank_name());
first = false;
}
st->print_cr(" %s", m->name());
}
}
#else
st->print_cr(" Only known in debug builds.");
#endif // ASSERT
}

@ -175,6 +175,7 @@ extern Mutex* tty_lock; // lock to synchronize output.
// Print all mutexes/monitors that are currently owned by a thread; called
// by fatal error handler.
void print_owned_locks_on_error(outputStream* st);
void print_lock_ranks(outputStream* st);
char *lock_name(Mutex *mutex);
@ -225,6 +226,8 @@ class MutexLocker: public StackObj {
_mutex->unlock();
}
}
static void post_initialize();
};
// A MonitorLocker is like a MutexLocker above, except it allows

@ -647,6 +647,7 @@ jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
LogConfiguration::post_initialize();
Metaspace::post_initialize();
MutexLocker::post_initialize();
HOTSPOT_VM_INIT_END();

@ -0,0 +1,51 @@
/*
* Copyright (c) 2022, Red Hat, Inc. 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
* @bug 8294759
* @summary Verify mutex rank logging works
* @requires vm.flagless
* @library /test/lib
* @run driver MutexRankTest
*/
import jdk.test.lib.process.OutputAnalyzer;
import jdk.test.lib.process.ProcessTools;
import jdk.test.lib.Platform;
public class MutexRankTest {
public static void main(String[] args) throws Exception {
ProcessBuilder pb = ProcessTools.createJavaProcessBuilder("-Xlog:vmmutex",
"-version");
OutputAnalyzer oa = new OutputAnalyzer(pb.start());
oa.shouldContain("VM Mutex/Monitor ranks:");
if (Platform.isDebugBuild()) {
oa.shouldContain("Rank \"safepoint\"");
oa.shouldContain("Heap_lock");
} else {
oa.shouldContain("Only known in debug builds");
}
oa.shouldHaveExitValue(0);
}
}