Par

Syntax

par p from a to b
{
par body
};

Semantics

The parallel equivalent of the for loop, each iteration will execute concurrently on different processes. This allows the programmer to write code MPMD style, with the limitation that bounds a and b must be known during compilation. Variables declared to be multiply allocated within parallel scope, such as a par block, will automatically be allocated just to the subgroup of processes within that scope.

Note: There is no guarantee as to the ranks of the processes involved within a par block and such as block will be distributed over the ranks which are most appropriate at that time.

Example

#include <io>
var p;
par p from 0 to 9 {
   print("Hello world\n");
};

The code fragment will involve 10 processes (0 to 9 inclusive) and each will display a Hello world message.