8268638: semaphores of AsyncLogWriter may be broken when JVM is exiting.
Backport-of: fa3b44d43811dca8c609d6c61a58680835abf8e3
diff --git a/src/hotspot/share/logging/logAsyncWriter.cpp b/src/hotspot/share/logging/logAsyncWriter.cpp
index b3b61f8..f46fc1c 100644
--- a/src/hotspot/share/logging/logAsyncWriter.cpp
+++ b/src/hotspot/share/logging/logAsyncWriter.cpp
@@ -28,24 +28,18 @@
#include "logging/logHandle.hpp"
#include "runtime/atomic.hpp"
-Semaphore AsyncLogWriter::_sem(0);
-Semaphore AsyncLogWriter::_io_sem(1);
-
-class AsyncLogLocker : public StackObj {
- private:
- static Semaphore _lock;
+class AsyncLogWriter::AsyncLogLocker : public StackObj {
public:
AsyncLogLocker() {
- _lock.wait();
+ assert(_instance != nullptr, "AsyncLogWriter::_lock is unavailable");
+ _instance->_lock.wait();
}
~AsyncLogLocker() {
- _lock.signal();
+ _instance->_lock.signal();
}
};
-Semaphore AsyncLogLocker::_lock(1);
-
void AsyncLogWriter::enqueue_locked(const AsyncLogMessage& msg) {
if (_buffer.size() >= _buffer_max_size) {
bool p_created;
@@ -64,7 +58,7 @@
AsyncLogMessage m(output, decorations, os::strdup(msg));
{ // critical area
- AsyncLogLocker lock;
+ AsyncLogLocker locker;
enqueue_locked(m);
}
}
@@ -72,7 +66,7 @@
// LogMessageBuffer consists of a multiple-part/multiple-line messsage.
// The lock here guarantees its integrity.
void AsyncLogWriter::enqueue(LogFileOutput& output, LogMessageBuffer::Iterator msg_iterator) {
- AsyncLogLocker lock;
+ AsyncLogLocker locker;
for (; !msg_iterator.is_at_end(); msg_iterator++) {
AsyncLogMessage m(output, msg_iterator.decorations(), os::strdup(msg_iterator.message()));
@@ -81,7 +75,8 @@
}
AsyncLogWriter::AsyncLogWriter()
- : _initialized(false),
+ : _lock(1), _sem(0), _io_sem(1),
+ _initialized(false),
_stats(17 /*table_size*/) {
if (os::create_thread(this, os::asynclog_thread)) {
_initialized = true;
@@ -125,7 +120,7 @@
bool own_io = false;
{ // critical region
- AsyncLogLocker lock;
+ AsyncLogLocker locker;
_buffer.pop_all(&logs);
// append meta-messages of dropped counters
diff --git a/src/hotspot/share/logging/logAsyncWriter.hpp b/src/hotspot/share/logging/logAsyncWriter.hpp
index 736a957..23c92c5 100644
--- a/src/hotspot/share/logging/logAsyncWriter.hpp
+++ b/src/hotspot/share/logging/logAsyncWriter.hpp
@@ -133,12 +133,16 @@
// times. It is no-op if async logging is not established.
//
class AsyncLogWriter : public NonJavaThread {
+ class AsyncLogLocker;
+
static AsyncLogWriter* _instance;
+ // _lock(1) denotes a critional region.
+ Semaphore _lock;
// _sem is a semaphore whose value denotes how many messages have been enqueued.
// It decreases in AsyncLogWriter::run()
- static Semaphore _sem;
+ Semaphore _sem;
// A lock of IO
- static Semaphore _io_sem;
+ Semaphore _io_sem;
volatile bool _initialized;
AsyncLogMap _stats; // statistics for dropped messages
