Kotlin 如果带注释的成员未被特定块包围，则发出 IDE 警告

我认为这是一种黑客行为，但使用context receivers可能会奏效.不过，我认为它们不是以这种方式使用的.

您可以声明一个伪object作为上下文接收方，并将其作为上下文接收方添加到属性中:

object ReadLock

class ExampleResource : LockableProjectItem {
    override val readWriteLock: ReadWriteLock = ReentrantReadWriteLock()

    // properties with context receivers cannot have a backing field, so we need to explicitly declare this
    private val nonThreadSafeMemberField: String = ""

    context(ReadLock)
    val nonThreadSafeMember: String
        get() = nonThreadSafeMemberField
}

然后在readLock，你通过了object:

fun <T : LockableProjectItem, Out> T.readLock(block: context(ReadLock) T.() -> Out): Out {
    try {
        readWriteLock.readLock().lock()
        return block(ReadLock, this)
    } finally {
        readWriteLock.readLock().unlock()
    }
}

备注:

• 如果您try 在没有上下文接收方的情况下访问nonThreadSafeMember，则会出现错误:

  val resource = ExampleResource()
  val readResult = resource.nonThreadSafeMember //error
  

• 您仍然可以通过执行以下操作来访问nonThreadSafeMember，而无需获取读锁定:

  with(ReadLock) { // with(ReadLock) doesn't acquire the lock, just gets the context receiver
      resource.nonThreadSafeMember // no error
  }
  

  但要accidentally%写这样的东西要难得多，我认为这就是你试图阻止的.

• 如果您调用readLock内的另一个函数，并且想要访问该函数内的nonThreadSafeMember，则也应该将该函数标记为context(ReadLock).例如:

  fun main() {
      val resource = ExampleResource()
      val readResult = resource.readLock {
          foo(this)
      }
  }
  
  context(ReadLock)
  fun foo(x: ExampleResource) {
      x.nonThreadSafeMember
  }
  

  上下文接收器被传播通过.