Avoid circularity through class loading in circularity lock locking m…

…echanism.

byte-buddy-dep/src/main/java/net/bytebuddy/agent/builder/AgentBuilder.java

@@ -2585,20 +2585,31 @@ class Default implements CircularityLock {
  private final ConcurrentMap<Thread, Boolean> threads = new ConcurrentHashMap<Thread, Boolean>();
 
  /**
- * Creates a default circularity lock. The constructor invokes all methods that are used by
- * the lock to avoid that using this lock triggers class loading under use.
+ * An additional global lock that avoids circularity errors cause by class loading
+ * by the locking mechanism.
+ */
+ private final AtomicBoolean open = new AtomicBoolean();
+
+ /**
+ * Creates a default circularity lock.
  */
  public Default() {
- Thread thread = Thread.currentThread();
- threads.putIfAbsent(thread, true);
- threads.remove(thread);
+ open.compareAndSet(false, true); // trigger expected class loading
  }
 
  /**
  * {@inheritDoc}
  */
  public boolean acquire() {
- return threads.putIfAbsent(Thread.currentThread(), true) == null;
+ if (open.compareAndSet(true, false)) {
+ try {
+ return threads.putIfAbsent(Thread.currentThread(), true) == null;
+ } finally {
+ open.set(true);
+ }
+ } else {
+ return false;
+ }
  }
 
  /**
@@ -2639,6 +2650,12 @@ class Global implements CircularityLock {
  */
  private final TimeUnit timeUnit;
 
+ /**
+ * An additional global lock that avoids circularity errors cause by class loading
+ * by the locking mechanism.
+ */
+ private final AtomicBoolean open = new AtomicBoolean();
+
  /**
  * Creates a new global circularity lock that does not wait for a release.
  */
@@ -2656,26 +2673,24 @@ public Global(long time, TimeUnit timeUnit) {
  lock = new ReentrantLock();
  this.time = time;
  this.timeUnit = timeUnit;
- try {
- if (!(time == 0 ? lock.tryLock() : lock.tryLock(time, timeUnit))) {
- throw new IllegalStateException();
- }
- } catch (InterruptedException ignored) {
- Thread.currentThread().interrupt();
- return;
- }
- lock.unlock();
+ open.compareAndSet(false, true); // trigger expected class loading
  }
 
  /**
  * {@inheritDoc}
  */
  public boolean acquire() {
- try {
- return time == 0
- ? lock.tryLock()
- : lock.tryLock(time, timeUnit);
- } catch (InterruptedException ignored) {
+ if (open.compareAndSet(true, false)) {
+ try {
+ return time == 0
+ ? lock.tryLock()
+ : lock.tryLock(time, timeUnit);
+ } catch (InterruptedException ignored) {
+ return false;
+ } finally {
+ open.set(true);
+ }
+ } else {
  return false;
  }
  }