org.checkerframework.checker.lock.qual.GuardedBy Maven / Gradle / Ivy
package org.checkerframework.checker.lock.qual;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import org.checkerframework.framework.qual.DefaultFor;
import org.checkerframework.framework.qual.DefaultQualifierInHierarchy;
import org.checkerframework.framework.qual.JavaExpression;
import org.checkerframework.framework.qual.SubtypeOf;
import org.checkerframework.framework.qual.TypeKind;
import org.checkerframework.framework.qual.TypeUseLocation;
import org.checkerframework.framework.qual.UpperBoundFor;
/**
* Indicates that a thread may dereference the value referred to by the annotated variable only if
* the thread holds all the given lock expressions.
*
* {@code @GuardedBy({})} is the default type qualifier.
*
*
The argument is a string or set of strings that indicates the expression(s) that must be held,
* using the syntax of
* Java expressions described in the manual. The expressions evaluate to an intrinsic (built-in,
* synchronization) monitor or an explicit {@link java.util.concurrent.locks.Lock}. The expression
* {@code ""} is also permitted; the type {@code @GuardedBy("") Object o} indicates that
* the value referenced by {@code o} is guarded by the intrinsic (monitor) lock of the value
* referenced by {@code o}.
*
* Two {@code @GuardedBy} annotations with different argument expressions are unrelated by
* subtyping.
*
* @see Holding
* @checker_framework.manual #lock-checker Lock Checker
* @checker_framework.manual #lock-examples-guardedby Example use of @GuardedBy
*/
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE_USE, ElementType.TYPE_PARAMETER})
@SubtypeOf(GuardedByUnknown.class)
@DefaultQualifierInHierarchy
// These are required because the default for local variables is @GuardedByUnknown, but if the local
// variable is one of these type kinds, the default should be @GuardedByUnknown.
@DefaultFor(
value = {TypeUseLocation.EXCEPTION_PARAMETER, TypeUseLocation.UPPER_BOUND},
typeKinds = {
TypeKind.BOOLEAN,
TypeKind.BYTE,
TypeKind.CHAR,
TypeKind.DOUBLE,
TypeKind.FLOAT,
TypeKind.INT,
TypeKind.LONG,
TypeKind.SHORT
},
types = {String.class, Void.class})
@UpperBoundFor(
typeKinds = {
TypeKind.BOOLEAN,
TypeKind.BYTE,
TypeKind.CHAR,
TypeKind.DOUBLE,
TypeKind.FLOAT,
TypeKind.INT,
TypeKind.LONG,
TypeKind.SHORT
},
types = String.class)
public @interface GuardedBy {
/**
* The Java value expressions that need to be held.
*
* @see Syntax of
* Java expressions
*/
@JavaExpression
String[] value() default {};
}