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Fix ConcurrentBag yield spin loop with virtual threads #2399

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Fix ConcurrentBag yield spin loop with virtual threads #2399

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36 changes: 16 additions & 20 deletions src/main/java/com/zaxxer/hikari/util/ConcurrentBag.java
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Original file line number Diff line number Diff line change
Expand Up @@ -34,7 +34,6 @@
import static com.zaxxer.hikari.util.ConcurrentBag.IConcurrentBagEntry.*;
import static java.util.concurrent.TimeUnit.MICROSECONDS;
import static java.util.concurrent.TimeUnit.NANOSECONDS;
import static java.util.concurrent.locks.LockSupport.parkNanos;

/**
* This is a specialized concurrent bag that achieves superior performance
Expand Down Expand Up @@ -188,17 +187,16 @@ public void requite(final T bagEntry)
{
bagEntry.setState(STATE_NOT_IN_USE);

for (int i = 1, waiting = waiters.get(); waiting > 0; i++, waiting = waiters.get()) {
if (bagEntry.getState() != STATE_NOT_IN_USE || handoffQueue.offer(bagEntry)) {
return;
}
else if ((i & 0xff) == 0xff || (waiting > 1 && i % waiting == 0)) {
parkNanos(MICROSECONDS.toNanos(10));
}
else {
Thread.yield();
try {
while (waiters.get() > 0 && bagEntry.getState() == STATE_NOT_IN_USE) {
if (handoffQueue.offer(bagEntry, 10, MICROSECONDS)) {
return;
}
}
}
catch (InterruptedException ie) {
Thread.currentThread().interrupt();
}

final var threadLocalEntries = this.threadLocalList.get();
if (threadLocalEntries.size() < 16) {
Expand Down Expand Up @@ -318,18 +316,16 @@ public boolean reserve(final T bagEntry)
public void unreserve(final T bagEntry)
{
if (bagEntry.compareAndSet(STATE_RESERVED, STATE_NOT_IN_USE)) {
// spin until a thread takes it or none are waiting
for (int i = 1, waiting = waiters.get(); waiting > 0; i++, waiting = waiters.get()) {
if (bagEntry.getState() != STATE_NOT_IN_USE || handoffQueue.offer(bagEntry)) {
return;
}
else if ((i & 0xff) == 0xff || (waiting > 1 && i % waiting == 0)) {
parkNanos(MICROSECONDS.toNanos(10));
}
else {
Thread.yield();
try {
while (waiters.get() > 0 && bagEntry.getState() == STATE_NOT_IN_USE) {
if (handoffQueue.offer(bagEntry, 10, MICROSECONDS)) {
return;
}
}
}
catch (InterruptedException ie) {
Thread.currentThread().interrupt();
}
}
else {
LOGGER.warn("Attempt to relinquish an object to the bag that was not reserved: {}", bagEntry);
Expand Down