checker/tests/lock/LockEffectAnnotations.java

import java.util.concurrent.locks.ReentrantLock;
import org.checkerframework.checker.lock.qual.GuardSatisfied;
import org.checkerframework.checker.lock.qual.GuardedBy;
import org.checkerframework.checker.lock.qual.GuardedByBottom;
import org.checkerframework.checker.lock.qual.GuardedByUnknown;
import org.checkerframework.checker.lock.qual.LockingFree;
import org.checkerframework.checker.lock.qual.MayReleaseLocks;
import org.checkerframework.checker.lock.qual.ReleasesNoLocks;
import org.checkerframework.dataflow.qual.Pure;
import org.checkerframework.dataflow.qual.SideEffectFree;

public class LockEffectAnnotations {
  class MyClass {
    Object field = new Object();
  }

  private @GuardedBy({}) MyClass myField;

  private final ReentrantLock myLock2 = new ReentrantLock();
  private @GuardedBy("myLock2") MyClass x3;

  // This method does not use locks or synchronization but cannot
  // be annotated as @SideEffectFree since it alters myField.
  @LockingFree
  void myMethod5() {
    myField = new MyClass();
  }

  @SideEffectFree
  int mySideEffectFreeMethod() {
    return 0;
  }

  @MayReleaseLocks
  void myUnlockingMethod() {
    myLock2.unlock();
  }

  @MayReleaseLocks
  void myReleaseLocksEmptyMethod() {}

  @MayReleaseLocks
  // :: error: (guardsatisfied.with.mayreleaselocks)
  void methodGuardSatisfiedReceiver(@GuardSatisfied LockEffectAnnotations this) {}

  @MayReleaseLocks
  // :: error: (guardsatisfied.with.mayreleaselocks)
  void methodGuardSatisfiedParameter(@GuardSatisfied Object o) {}

  @MayReleaseLocks
  void myOtherMethod() {
    if (myLock2.tryLock()) {
      x3.field = new Object(); // OK: the lock is held
      myMethod5();
      x3.field = new Object(); // OK: the lock is still held since myMethod is locking-free
      mySideEffectFreeMethod();
      x3.field = new Object(); // OK: the lock is still held since mySideEffectFreeMethod is
      // side-effect-free
      myUnlockingMethod();
      // :: error: (lock.not.held)
      x3.field = new Object(); // ILLEGAL: myLockingMethod is not locking-free
    }
    if (myLock2.tryLock()) {
      x3.field = new Object(); // OK: the lock is held
      myReleaseLocksEmptyMethod();
      // :: error: (lock.not.held)
      x3.field = new Object(); // ILLEGAL: even though myUnannotatedEmptyMethod is empty, since
      // myReleaseLocksEmptyMethod() is annotated with @MayReleaseLocks and the Lock Checker
      // no longer knows the state of the lock.
      if (myLock2.isHeldByCurrentThread()) {
        x3.field = new Object(); // OK: the lock is known to be held
      }
    }
  }

  @ReleasesNoLocks
  void innerClassTest() {
    class InnerClass {
      @MayReleaseLocks
      void innerClassMethod() {}
    }

    InnerClass ic = new InnerClass();
    // :: error: (method.guarantee.violated)
    ic.innerClassMethod();
  }

  @MayReleaseLocks
  synchronized void mayReleaseLocksSynchronizedMethod() {}

  @ReleasesNoLocks
  synchronized void releasesNoLocksSynchronizedMethod() {}

  @LockingFree
  // :: error: (lockingfree.synchronized.method)
  synchronized void lockingFreeSynchronizedMethod() {}

  @SideEffectFree
  // :: error: (lockingfree.synchronized.method)
  synchronized void sideEffectFreeSynchronizedMethod() {}

  @Pure
  // :: error: (lockingfree.synchronized.method)
  synchronized void pureSynchronizedMethod() {}

  @MayReleaseLocks
  void mayReleaseLocksMethodWithSynchronizedBlock() {
    synchronized (this) {
    }
  }

  @ReleasesNoLocks
  void releasesNoLocksMethodWithSynchronizedBlock() {
    synchronized (this) {
    }
  }

  @LockingFree
  void lockingFreeMethodWithSynchronizedBlock() {
    // :: error: (synchronized.block.in.lockingfree.method)
    synchronized (this) {
    }
  }

  @SideEffectFree
  void sideEffectFreeMethodWithSynchronizedBlock() {
    // :: error: (synchronized.block.in.lockingfree.method)
    synchronized (this) {
    }
  }

  @Pure
  void pureMethodWithSynchronizedBlock() {
    // :: error: (synchronized.block.in.lockingfree.method)
    synchronized (this) {
    }
  }

  @GuardedByUnknown class MyClass2 {}

  // :: error: (expression.unparsable) :: error: (super.invocation)
  // :: warning: (inconsistent.constructor.type)
  @GuardedBy("lock") class MyClass3 {}

  @GuardedBy({}) class MyClass4 {}
  // :: error: (guardsatisfied.location.disallowed) :: error: (super.invocation)
  // :: warning: (inconsistent.constructor.type)
  @GuardSatisfied class MyClass5 {}

  // :: error: (super.invocation) :: warning: (inconsistent.constructor.type)
  @GuardedByBottom class MyClass6 {}
}