join_watchgroup

JOIN_WATCHGROUP

adds a StopWatch watch to a watch group

SYNOPSIS
subroutine join_watchgroup (watch, handle, err)

type (watchtype), intent(IN) :: watch

OR

type (watchtype), intent(IN) :: watch(:)

type (watchgroup), intent(INOUT) :: handle

integer, optional, intent(OUT) :: err

DESCRIPTION
Adds the specified watch(es) to the specified watch group. The watch(es) and group must have been previously created with create_watch and create_watchgroup.

One or more watches must be specified. The argument watch can be a single variable of type watchtype (see stopwatch(3)) to add one watch, an array of type watchtype to add several watches.

The watch group is specified by handle, a variable of type watchgroup.

DIAGNOSTICS
If present, the optional intent OUT integer argument err returns a status code. The code is the sum of the values listed below.

An error message will be printed to a specified I/O unit (unit 6 by default) if print_errors is TRUE (default is TRUE). The error message contains more detail about the cause of the error than can be obtained from just the status code, so you should set print_errors to TRUE if you have trouble determining the cause of the error.

If abort_errors is TRUE (default is FALSE), the program will terminate on an error condition. Otherwise, the program will continue execution but the watch(es) will not be added to the group.

See option_stopwatch(3) for further information on print_errors, abort_errors and I/O units.

The relevant status codes and messages are:

0

No errors; execution successful.

1

Watch needs to be created. This error occurs if you attempt to add a watch that has been destroyed to a group. The watch must first be created again. See also the comment about watches that have never been created in the BUGS section.

512

Failed to allocate required memory. Memory is allocated in the group when a watch is added. Also, when join_watchgroup is called with an array or group of watches, temporary memory is allocated. This error occurs if the Fortran allocate statement returns a nonzero status indicating that memory could not be allocated. Avoid memory leaks by always destroying watches and groups before recreating them, and destroying local variable watches and groups before returning from a subroutine.

1024

Error occurred while deallocating memory. This error occurs if the Fortran deallocate statement returns a nonzero status while deallocating temporary memory used for an array or group of watches. The watches are added to the group, but be aware that other problems could develop as a result of the deallocate error.

EXAMPLES
type (watchtype) w1, w2(3)
type (watchgroup) g1
integer errcode

call join_watchgroup(w1, g1)
call join_watchgroup(w2, g1, errcode)

The first call adds the watch w1 to watch group g1.

The second call adds three watch to g1 and returns a status code.

BUGS
It cannot be determined whether or not a watch variable or watch group has been created (passed as an argument to create_watch or create_watchgroup). If a watch or watch group that has never been created is passed into join_watchgroup, it might generate a Fortran error due to passing a pointer with undefined association status to the Fortran intrinsic function associated. Some compilers will allow this as an extension to the Fortran 90 standard and recognize that the pointer is not associated, in which case the ``Watch needs to be created'' error message is generated.