Deadlock/2

- if lcka is set in the first section and the if statement branches around the unset lock, threads running the other sections will deadlock waiting forever for the lock to be released
- make sure locks are always released

call omp_init_lock(lcka)

C$omp parallel sections

c$omp section

call omp_set_lock(lcka)

ival = dowork()

if(ival.EQ.TOL) then

call omp_unset_lock(lcka)

else

call error(ival)

endif

c$omp section

call omp_set_lock(lcka)

call use_B_and_A(res)

call omp_unset_lock(lcka)

c$omp end parallel sections

Often deadlock condition arises from error processing: