eldo_user

Eldo Control Language
Parallel Operation
Example: use of ijob() inside a step parallel loop:
.define_task t_step_para
set i = 0
para_step (type=step,
+ param=i,
+ start=100k,
+ stop=10k,
+ step=-10k)
fprint(stdout,
+ "Beginning run %d with i=%.2g.\n",
+ ijob(),
+ i)
end_para_step
.end_define_task
.t_step_para
The output of this example may be:
Beginning run 1 with i=1e+05.
Beginning run 3 with i=8e+04.
Beginning run 2 with i=9e+04.
Beginning run 4 with i=7e+04.
Beginning run 6 with i=5e+04.
Beginning run 5 with i=6e+04.
Beginning run 7 with i=4e+04.
Beginning run 9 with i=2e+04.
Beginning run 8 with i=3e+04.
Beginning run 10 with i=1e+04.
Concurrency Issues
To prevent concurrency issues from occurring, ECL is very strict about code that is allowed to
be parallelized inside loops. By default, no scalar variable can be assigned inside a parallel loop
(otherwise a syntax error is generated). It is only possible to store values inside arrays. During
execution, ECL checks that no value of an array is accessed by more than one job in write mode.
If more than one job accesses the same value (inside an array) in write mode, then an error
occurs at run time. It is strongly recommended to store results inside arrays indexed by the
index of the current job.
Example: a step parallel loop running simulations:
Eldo® User's Manual, 15.3 1047