Avoid repeated ESMF initialization in unittestTimeManagerMod.F90

ESMF was being repeatedly initialized in unittestTimeManagerMod.F90,
which is an error. This led to unit tests failing silently. This commit
fixes the issue by checking if ESMF is already initialized before
calling ESMF_Initialize, and not calling ESMF_Finalize at the end of
each unit test.

Currently this skips any calls to ESMF_Finalize, as it is an error to
re-call ESMF_Initialize after calling ESMF_Finalize. A better solution
would be to only call ESMF_Initialize and ESMF_Finalize once per unit
test executable. I am looking into whether that's possible. I'm not sure
if it will cause any problems to not do the ESMF_Finalize.

See #3015 (comment)
for details.

Resolves #3015

Author: billsacks

src/unit_test_shr/unittestTimeManagerMod.F90

@@ -48,7 +48,7 @@ subroutine unittest_timemgr_setup(dtime, use_gregorian_calendar)
     ! Should be called once for every test that uses the time manager.
     !
     ! !USES:
-    use ESMF, only : ESMF_Initialize, ESMF_SUCCESS
+    use ESMF, only : ESMF_Initialize, ESMF_IsInitialized, ESMF_SUCCESS
     use clm_time_manager, only : set_timemgr_init, timemgr_init, NO_LEAP_C, GREGORIAN_C
     !
     ! !ARGUMENTS:
@@ -59,6 +59,7 @@ subroutine unittest_timemgr_setup(dtime, use_gregorian_calendar)
     integer :: l_dtime  ! local version of dtime
     logical :: l_use_gregorian_calendar  ! local version of use_gregorian_calendar
     character(len=:), allocatable :: calendar
+    logical :: esmf_is_initialized
     integer :: rc ! return code
 
     integer, parameter :: dtime_default = 1800  ! time step (seconds)
@@ -89,9 +90,15 @@ subroutine unittest_timemgr_setup(dtime, use_gregorian_calendar)
        l_use_gregorian_calendar = .false.
     end if
 
-    call ESMF_Initialize(rc=rc)
+    esmf_is_initialized = ESMF_IsInitialized(rc=rc)
     if (rc /= ESMF_SUCCESS) then
-       stop 'Error in ESMF_Initialize'
+       stop 'Error in ESMF_IsInitialized'
+    end if
+    if (.not. esmf_is_initialized) then
+       call ESMF_Initialize(rc=rc)
+       if (rc /= ESMF_SUCCESS) then
+          stop 'Error in ESMF_Initialize'
+       end if
     end if
 
     if (l_use_gregorian_calendar) then
@@ -219,10 +226,12 @@ subroutine unittest_timemgr_teardown
 
     call timemgr_reset()
 
-    call ESMF_Finalize(rc=rc)
-    if (rc /= ESMF_SUCCESS) then
-       stop 'Error in ESMF_Finalize'
-    end if
+    ! If this is the end of the executable, we should call
+    ! ESMF_Finalize. But the timemgr setup and teardown routines can
+    ! be called multiple times within a single unit test executable,
+    ! and it's an error to re-call ESMF_Initialize after calling
+    ! ESMF_Finalize. So for now we just won't attempt to do an
+    ! ESMF_Finalize.
 
   end subroutine unittest_timemgr_teardown