(PYVMS LOGO) Python on OpenVMS

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RESERVE_EF - Reserve Event Flag


Allocates a specific event flag while vms_lib.get_ef() allocates an arbitrary event flag that is free.

Format:

    vms_lib.reserve_ef (event_flag_number)
Returns:

None

Arguments:

event_flag_number
Number of the event flag that is to be allocated.
Examples:
>>> import vms_lib

>>> # event flags 1 - 23 are initially reserved
>>> #  (compatibility to the RSX operating system)
>>> print vms_lib.reserve_ef (1)
Traceback (innermost last):
  File "<stdin>", line 1, in ?
vms_lib.error: (1409700, '%LIB-F-EF_ALRRES, event flag already reserved')

>>> # event flags 24 - 31 are reserved to OpenVMS
>>> print vms_lib.reserve_ef (24)
Traceback (innermost last):
  File "<stdin>", line 1, in ?
vms_lib.error: (1409708, '%LIB-F-EF_RESSYS, event flag reserved to system')

>>> # event flags 32 - 63 are initially free
>>> print vms_lib.reserve_ef (32)
None

>>> # an already allocated event flag cannot be allocate a second time
>>> print vms_lib.reserve_ef (32)
Traceback (innermost last):
  File "<stdin>", line 1, in ?
vms_lib.error: (1409700, '%LIB-F-EF_ALRRES, event flag already reserved')

>>> # an allocated event flag can be freed ...
>>> print vms_lib.free_ef (32)
None
>>> # ... and re-allocated again
>>> print vms_lib.reserve_ef (32)
None

>>> # event flags 1 - 23 are initially reserved ...
>>> print vms_lib.reserve_ef (1)
Traceback (innermost last):
  File "<stdin>", line 1, in ?
vms_lib.error: (1409700, '%LIB-F-EF_ALRRES, event flag already reserved')

>>> # ... but can be freed
>>> print vms_lib.free_ef (1)
None
>>> # ... and then re-allocated
>>> print vms_lib.reserve_ef (1)
None
>>>

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30-SEP-1998 ZE.