Question

我现在正在玩X10，我有多个例外。这是我创建的代码：

Main.x10

public class Main {

// main Method for the Main class
public static def main(argv:Rail[String]) {
    Console.OUT.println("This is the main place. (ID="+here.id+")");
    val dataItem = new Data();
    // no global reference, data is copied to each place.
    finish for (p in Place.places()) {
        at (p) async {
            Console.OUT.println("This is place no: "+here.id+". The value of dataItem is "+dataItem.getValue()+".");
            dataItem.incValue();
        }
    }
    Console.OUT.println("Final value of dataItem without GlobalRef in multiple places at place "+here.id+": "+dataItem.getValue());
    dataItem.setValue(0);
    finish for (p in Place.places()) {
        async {
            Console.OUT.println("This is place no: "+here.id+". The value of dataItem is "+dataItem.getValue()+".");
            dataItem.incValue();
        }
    }
    Console.OUT.println("Final value of dataItem without GlobalRef in one place at place "+here.id+": "+dataItem.getValue());
    dataItem.setValue(0);
    val globalRefDataItem = GlobalRef[Data](dataItem);
    finish for (p in Place.places()) {
        at (p) async {
            val globalDataItemUnwrapped = globalRefDataItem();
            Console.OUT.println("This is place no: "+here.id+". The value of dataItem is "+globalDataItemUnwrapped.getValue()+".");
            atomic globalDataItemUnwrapped.incValue();
        }
    }
    Console.OUT.println("Final value of dataItem with GlobalRef in multiple places at place "+here.id+": "+dataItem.getValue());
}

}

Data.x10

public class Data{
private var value:Long;
def getValue():Long{
    return value;
}
def setValue(value:long){
    this.value = value;
}
def incValue(){
    this.value = this.value+1;
}
}

X10DT中的输出如下：

This is the main place. (ID=0)
This is place no: 3. The value of dataItem is 0.
This is place no: 1. The value of dataItem is 0.
This is place no: 2. The value of dataItem is 0.
This is place no: 0. The value of dataItem is 0.
Final value of dataItem without GlobalRef in multiple places at place 0: 0
This is place no: 0. The value of dataItem is 0.
This is place no: 0. The value of dataItem is 1.
This is place no: 0. The value of dataItem is 2.
This is place no: 0. The value of dataItem is 3.
Final value of dataItem without GlobalRef in one place at place 0: 4
This is place no: 0. The value of dataItem is 0.
Command used: /home/martze/x10dt/workspace/Example/bin/Main
Uncaught exception at place 0: x10.lang.MultipleExceptions
x10.lang.FailedDynamicCheckException: !(here == x$0.home)
at x10aux::throwException(x10::lang::CheckedThrowable*)
at Main__closure__3::__apply()
at x10::lang::Activity::run()
at x10::lang::Runtime__Worker::loop()
at x10::lang::Runtime__Worker::__apply()
at x10::lang::Runtime__Pool::run()
at 
at GC_inner_start_routine
at GC_call_with_stack_base
at 
at clone
x10.lang.FailedDynamicCheckException: !(here == x$0.home)
at x10aux::throwException(x10::lang::CheckedThrowable*)
at Main__closure__3::__apply()
at x10::lang::Activity::run()
at x10::lang::Runtime__Worker::loop()
at x10::lang::Runtime__Worker::__apply()
at x10::lang::Runtime__Pool::run()
at 
at GC_inner_start_routine
at GC_call_with_stack_base
at 
at clone
x10.lang.FailedDynamicCheckException: !(here == x$0.home)
at x10aux::throwException(x10::lang::CheckedThrowable*)
at Main__closure__3::__apply()
at x10::lang::Activity::run()
at x10::lang::Runtime__Worker::loop()
at x10::lang::Runtime__Worker::__apply()
at x10::lang::Runtime__Pool::run()
at 
at GC_inner_start_routine
at GC_call_with_stack_base
at 
at clone

我尝试使用谷歌搜索，但结果只是指向一些根本没有帮助我的文档。我的环境变量设置为X10_NTHREADS = 1，我将位数设置为4.我正在使用Ubuntu，我正在使用C ++后端。

我该怎么办？这个错误是什么意思？

Answer 1

GlobalRef是对特定地点的对象的全局有意义的引用。它可能只在创建它的地方（“家”）被取消引用。在GlobalRef的解除引用（'展开'）时会抛出异常：

val globalRefDataItem = GlobalRef[Data](dataItem);
finish for (p in Place.places()) {
  at (p) async {
    val globalDataItemUnwrapped = globalRefDataItem();
    ...
  }
}

{0}在地点0处创建，但在地点GlobalRef被取消引用（globalRefDataItem()）。如果它出现错误将更容易理解：

要访问x10.lang.FailedDynamicCheckException: (here != globalRefDataItem.home)引用的对象，活动必须将位置更改回原位。例如：

GlobalRef

这通常被称为“乒乓”成语 - 活动变为远程位置，然后再次变回原来的位置。

在您的程序中，还需要在增加之前打印dataItem 的值。要执行此操作，请在表达式（X10 language spec§13.3）中使用从远程位置返回值，例如：

val globalRefDataItem = GlobalRef[Data](dataItem); finish for (p in Place.places()) { at (p) async { at(globalRefDataItem.home) { atomic globalDataItemUnwrapped.incValue(); } } }

注意，我对原始代码进行了重要更改，以便在单个finish for (p in Place.places()) { at (p) async { val currentValue = at(globalRefDataItem.home) { val globalDataItemUnwrapped = globalRefDataItem(); var valueBeforeInc:Long = 0; atomic { valueBeforeInc = globalDataItemUnwrapped.getValue(); globalDataItemUnwrapped.incValue(); } valueBeforeInc }; Console.OUT.println("This is place no: "+here.id+". The value of dataItem is "+currentValue+"."); } }块中组合值的获取和增量。如果没有此更改，则另一个活动可能会增加这两个语句之间的值。 X10提供原子类型（例如atomic），它提供了这样的原子x10.util.concurrent.AtomicLong操作。

X10 x10.lang.FailedDynamicCheckException：！（这里== x $ 0.home）C ++后端

1 个答案: