Hi Igor (and all),
Here is the output from the compiler:
dhu...@oscnet166 125%> x10c++ -STATIC_CALLS -o Driver Driver.x10 PrefixSum.x10
AsyncPrefixSum.x10 DistPrefixSum.x10
/Users/dhudak/osc/research/x10/tutorial/examples/GoodPrefixSum/src/AsyncPrefixSum.x10:48:
Place type error: either method target should be local or method should be
global.
Method target: AsyncPrefixSum.this.a_prefix_sum
Method target place: null
Current place: AsyncPrefixSum#this.home
Method: size
/Users/dhudak/osc/research/x10/tutorial/examples/GoodPrefixSum/src/AsyncPrefixSum.x10:49:
Place type error: either method target should be local or method should be
global.
Method target: AsyncPrefixSum.this.a_prefix_sum
Method target place: null
Current place: AsyncPrefixSum#this.home
Method: size
/Users/dhudak/osc/research/x10/tutorial/examples/GoodPrefixSum/src/PrefixSum.x10:42:
Place type error: either method target should be local or method should be
global.
Method target: PrefixSum.this.a_prefix_sum
Method target place: null
Current place: PrefixSum#this.home
Method: size
/Users/dhudak/osc/research/x10/tutorial/examples/GoodPrefixSum/src/DistPrefixSum.x10:61:
Place type error: either method target should be local or method should be
global.
Method target: DistPrefixSum.this
Method target place: null
Current place: p
Method: place_str
4 errors.
Let's focus on the third error, since that is from the "easiest" implementation
(single activity, single place). The code is attached. I think my problem
boils down to a lack of understanding about referencing an object's fields and
exactly what "this" means.
I start out by declaring a class whose objects will allocate an array. I
provide 3 constructors (a default and 2 initialization constructors).
Constructors seem to use "this" for their definition - is that correct?
public class PrefixSum {
val a_prefix_sum: Array[Int](1);
public def this() {
a_prefix_sum = new Array[Int]([1..2], (Point)=>0);
}
public def this(length:Int) {
a_prefix_sum = new Array[Int]([1..length], (Point)=>0);
for ((i) in a_prefix_sum) {
a_prefix_sum([i]) = i;
}
}
public def this(a:Array[Int](1))
{
a_prefix_sum = new Array[Int](a.region, (Point)=>0);
for ((i) in a_prefix_sum) {
a_prefix_sum([i]) = a([i]);
}
}
...then, I get the following error on the following code:
/Users/dhudak/osc/research/x10/tutorial/examples/GoodPrefixSum/src/PrefixSum.x10:42:
Place type error: either method target should be local or method should be
global.
Method target: PrefixSum.this.a_prefix_sum
Method target place: null
Current place: PrefixSum#this.home
Method: size
public def str_end():String
{
return a_prefix_sum([a_prefix_sum.size()]).toString();
}
So, it looks like accessing the "size" field of a_prefix_sum goes through
"this" - which is the class PrefixSum???
Thanks,
Dave
On Jul 29, 2010, at 3:08 PM, Igor Peshansky wrote:
> Hi, Dave,
>
> You're accessing a field (or calling a method) of a remote object
> reference. If you ran the compiler with the -STATIC_CALLS flag,
> you would have gotten a compile-time error. As it is, the
> compiler inserts a dynamic check for you, which then fails at
> runtime.
>
> Try compiling your program with -STATIC_CALLS, and see what the
> compiler reports.
>
> Hope this helps,
> Igor
> P.S. Judging by your stack trace, you seem to be running on a Mac.
> There was a bug with printing Mac stack traces in X10 2.0.5 which
> is fixed in SVN HEAD (so it will work better in the next release).
>
> Dave Hudak <dhu...@osc.edu> wrote on 07/29/2010 12:53:18 PM:
>
>> Hi All,
>>
>> I took Igor's advice on using a cell to pass results back to the
>> calling place. I recoded my function for translating a distarray into
>> a string as follows. The "boo/hoo" statements are line counters:
>>
>> public def place_str(): String
>> {
>> Console.OUT.println("hoo");
>> var s : String = ""; //var is mutable
>> Console.OUT.println("hoo1");
>> var first : Boolean = true; //var
>> declaration must include type
>> Console.OUT.println("place_str "+here.id);
>> for (pt in a_prefix_sum | here) {
>> if (first) {
>> first = false;
>> }
>> else {
>> s += ", ";
>> }
>> Console.OUT.println("place_str point = "+pt);
>> s += a_prefix_sum(pt).toString(); //works because
>> toString is global
>> }
>> return s;
>> }
>>
>> public def str():String
>> {
>> var s : String = ""; //var is mutable
>> for (p in a_prefix_sum.dist.places()) {
>> Console.OUT.println("str "+p.id);
>> val z = new Cell[String](null);
>> Console.OUT.println("boo");
>> val h = here;
>> Console.OUT.println("boo2");
>> at (p) {
>> Console.OUT.println("boo3");
>> val q = place_str();
>> Console.OUT.println("boo4");
>> at (h) z.set(q);
>> Console.OUT.println("boo5");
>> }
>> s += z();
>> if (p.id != (Place.MAX_PLACES - 1)) {
>> s += ", ";
>> } //if
>> Console.OUT.println("s = "+s);
>> } //for i
>> return s;
>> }
>>
>> I am causing an exception when I call the place_str method from any
>> place other that place 0. Here is the output:
>>
>> dhu...@oscnet166 77%> mpirun -np 8 Driver
>> <...snip>
>> str 0
>> boo
>> boo2
>> boo3
>> hoo
>> hoo1
>> place_str 0
>> place_str point = (1)
>> place_str point = (2)
>> place_str point = (3)
>> place_str point = (4)
>> boo4
>> boo5
>> s = 1, 2, 3, 4,
>> str 1
>> boo
>> boo2
>> boo3
>> Uncaught exception at place 0: x10.lang.ClassCastException (home==1):
>> DistPrefixSum{self.home==here}
>> x10.lang.ClassCastException (home==1): DistPrefixSum{self.home==here}
>> at x10::lang::Throwable::fillInStackTrace()
>>
>> Any ideas?
>>
>> Thanks,
>> Dave
>> On Jul 28, 2010, at 8:05 PM, Igor Peshansky wrote:
>>
>>> Igor Peshansky/Watson/i...@ibmus wrote on 07/28/2010 07:15:02 PM:
>>>
>>>> Dave Hudak <dhu...@osc.edu> wrote on 07/28/2010 02:37:22 PM:
>>>>
>>>>> Hi All,
>>>>>
>>>>> I am trying to write a class that will do a prefix sum on an array.
> I
>>>>> have written the single-place version and a single-place version
> that
>>>>> uses multiple activities to compute the sums. I am now trying to
>>>>> write the distributed version. Both classes are included (I will
>>>>> eventually write an interface for these classes).
>>>>>
>>>>> I have been able to write the constructors and call them without
> run-
>>>>> time exceptions occurring. Now, I want to write a function that
>>>>> returns a single string representation of a dist array. I wrote a
>>>>> function that should create a string representation of all dist
> array
>>>>> elements at a given location (I called it place_str), and then I
> want
>>>>> to loop over all places:
>>>>>
>>>>> (from DistPrefixSum.x10):
>>>>>
>>>>> public def str():String
>>>>> {
>>>>> var s : String = ""; //var is mutable
>>>>> for (var place_id:int=0; place_id<Place.MAX_PLACES; place_id++)
>
>>> {
>>>>> s += at (Place.places(place_id)) place_str();
>>>>> if (place_id != (Place.MAX_PLACES - 1)) {
>>>>> s += ", ";
>>>>> } //if
>>>>> } //for i
>>>>> return s;
>>>>> }
>>>>>
>>>>> My error occurs on the at statement:
>>>>>
>>>>> dhu...@oscnet166 35%> x10c++ -O -o Driver Driver.x10 PrefixSum.x10
>>>>> AsyncPrefixSum.x10 DistPrefixSum.x10
>>>>>
>>>>
>>>
>>
> /Users/dhudak/osc/research/x10/tutorial/examples/GoodPrefixSum/src/DistPrefixSum.
>>>>> x10:49: Local variable "place_id" is accessed from an inner class or
> a
>>>>> closure, and must be declared final or shared.
>>>>> 1 error.
>>>>>
>>>>> Does anyone have any recommendations? Creating a single string from
> a
>>>>> dist array of integers is a reduction just like finding the sum or
> max
>>>>> of the entries, so I figure its well understood...
>>>>
>>>> Dave,
>>>>
>>>> This is a bug in the typechecking of at expressions. You can work
>>> around
>>>> this by changing the body of the for loop to
>>>>
>>>> val z = new Cell[String](null);
>>>> val h = here;
>>>> at (Place.places(place_id)) { val q = place_str(); at (h)
>>> z.set(q);
>>>> }
>>>> s += z();
>>>> if (place_id != (Place.MAX_PLACES - 1)) {
>>>> s += ", ";
>>>> } //if
>>>>
>>>> The above code is less efficient, but it should work.
>>>> I've opened a JIRA issue:
> http://jira.codehaus.org/browse/XTENLANG-1632
>>> .
>>>> Please watch that issue for updates on the fix.
>>>> Igor
>>>
>>> Dave,
>>>
>>> The fix turned out to be simple. This is now fixed in SVN HEAD
> (r15224),
>>> and will be available in the next X10 release (or you can build from
> SVN
>>> to pick up the fix).
>>> Igor
> --
> Igor Peshansky (note the spelling change!)
> IBM T.J. Watson Research Center
> X10: Parallel Productivity and Performance (http://x10-lang.org/)
> XJ: No More Pain for XML's Gain (http://www.research.ibm.com/xj/)
> "I hear and I forget. I see and I remember. I do and I understand" --
> Confucius
>
>
> ------------------------------------------------------------------------------
> The Palm PDK Hot Apps Program offers developers who use the
> Plug-In Development Kit to bring their C/C++ apps to Palm for a share
> of $1 Million in cash or HP Products. Visit us here for more details:
> http://p.sf.net/sfu/dev2dev-palm
> _______________________________________________
> X10-users mailing list
> X10-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/x10-users
---
David E. Hudak, Ph.D. dhu...@osc.edu
Program Director, HPC Engineering
Ohio Supercomputer Center
http://www.osc.edu
------------------------------------------------------------------------------
The Palm PDK Hot Apps Program offers developers who use the
Plug-In Development Kit to bring their C/C++ apps to Palm for a share
of $1 Million in cash or HP Products. Visit us here for more details:
http://p.sf.net/sfu/dev2dev-palm
_______________________________________________
X10-users mailing list
X10-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/x10-users
