Re: Defining block size during runtime

From: sainath l (ls.sainath_at_gmail_dot_com)
Date: Thu Jul 23 2009 - 16:45:04 PDT

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    Its not possible  to deallocate memory using upc_free for the derived data
    type that is given in Gary's example .
    ALthough the code compiles without any noise during compile time it breaks.
    Could someone tell me as to why this is the case. And also is there a way to
    deallocate the memory for the array of structures in Gary's Example.
    
    cheers,
    sainath
    
    On Fri, Jul 24, 2009 at 12:23 AM, sainath l <ls.sainath_at_gmail_dot_com> wrote:
    
    > Hello ,
    >
    > Thanks again Gary.
    >
    >
    > Cheers,
    > sainath
    >
    >
    >
    >
    >
    >
    > On Thu, Jul 23, 2009 at 6:19 AM, Gary Funck <gary_at_intrepid_dot_com> wrote:
    >
    >> On 07/23/09 02:00:02, sainath l wrote:
    >> >    I am very much interested in knowing any workaround, if possible, for
    >> >    dynamically allocating an array with variable block size at runtime.
    >> >
    >> >    Lets say I want to know if it is possible to create the following
    >> array
    >> >    dynamically where N and M are some variables. If yes then how can we
    >> do
    >> >    it.
    >> >
    >> >    shared [M] int A[N][M];
    >>
    >> Sainath,
    >> I'm not sure if this is what you're asking about, but attached is
    >> a program that uses a "trick" to ensure that each row of the array
    >> has affinity to a single thread, in a thread-cyclic fashion.
    >>
    >> The trick is that by placing the row vector 'y' inside of
    >> struct, we ensure that y is allocated contiguously on a
    >> given thread.  And for each a[i+1] (based upon UPC's
    >> indexing rules) we know that it will be allocated on
    >> the next thread (in cyclic order) after thread 'i'.
    >>
    >> $ upc alloc_row_struct.upc -o alloc_row_struct
    >> $ alloc_row_struct -n 4 4 5
    >> threadof a[0].y[0] = 0
    >> threadof a[0].y[1] = 0
    >> threadof a[0].y[2] = 0
    >> threadof a[0].y[3] = 0
    >> threadof a[0].y[4] = 0
    >> threadof a[1].y[0] = 1
    >> threadof a[1].y[1] = 1
    >> threadof a[1].y[2] = 1
    >> threadof a[1].y[3] = 1
    >> threadof a[1].y[4] = 1
    >> threadof a[2].y[0] = 2
    >> threadof a[2].y[1] = 2
    >> threadof a[2].y[2] = 2
    >> threadof a[2].y[3] = 2
    >> threadof a[2].y[4] = 2
    >> threadof a[3].y[0] = 3
    >> threadof a[3].y[1] = 3
    >> threadof a[3].y[2] = 3
    >> threadof a[3].y[3] = 3
    >> threadof a[3].y[4] = 3
    >>
    >> Above '-n 4' indicates that the program will run on 4 threads.
    >> That number was chosen to agree with the value of N (also 4)
    >> given above, but in fact could be any number.
    >>
    >> Whether this is the best method, or even a recommended practice,
    >> for accomplishing your objective, I'm not sure.  Perhaps others
    >> on the list can offer some comment or suggest alternative
    >> methods?
    >>
    >> - Gary
    >>
    >
    >
    

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