Microtasking: Serial Section

• code block between SERIAL and END SERIAL is executed only by one task

• other tasks are waiting until the serial block execution is completed

• example: reduction ( s = s + a(:) )

subroutine parsum(a,n,sum)

real a(n)

*pdir serial

sum=0.0

*pdir end serial

sumlocal = 0.0

*pdir pardo for, nobarr=(entry,exit)

do i = 1, n

sumlocal = sumlocal + a(i)

end do

*pdir critical

sum = sum + sumlocal

*pdir end critical

return

end

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