codeql/java/ql/test/query-tests/ThreadSafe/examples/FlawedSemaphore.java

package examples;

@ThreadSafe
public class FlawedSemaphore {
  private final int capacity;
  private int state;

  public FlawedSemaphore(int c) {
    capacity = c;
    state = 0;
  }

  public void acquire() {
    try {
      while (state == capacity) { // $ Alert
        this.wait();
      }
      state++; // $ Alert
    } catch (InterruptedException e) {
      e.printStackTrace();
    }
  }

  public void release() {
    synchronized (this) {
      state--; // State can become negative
      this.notifyAll();
    }
  }
}