A primitive meter keeper creator

MKEEPERC(0;PSB,M ==> 0;MKEEPER)
Produces a primitive meterkeeper suitable for slot 2 of a meter that you build. This meter keeper will save all restart exits from trapped domains and will restart them upon request. A small number of nodes are allocated from the PSB (on an as needed basis) to save the restart keys.

MKEEPERC(kt; ==> x'206')

A primitive meter keeper

MKEEPER(0; ==> 0)
All saved restart exits are forked.

MKEEPER(kt; ==> x'106')

MKEEPER(kt+4; ==> c)

Destroy the meter keeper

Return codes

c = 0 Meter keeper destroyed

c = 1 Meter keeper still holds restart keys and will not destroy itself.

The meter monitor keeps a collection of meters and records the time spent recently under each one.
Currently the elapsed time is halved about every minute.

In the following, "name" means a string of the form (1,lnm),(lnm,nm). lnm may be between 0 and 64 inclusive. By convention, nm consists of ASCII characters.

METMON(0,name; sb,m ==> c; m2,n) Create and monitor meter

Return code c:
0: A new meter has been created using space from sb and using m as the superior meter. m2 is a meter key to it and n is a node key to it. The meter is added to the collection of monitored meters. The counters are unlimited.

1: sb is not an official prompt space bank

2: sb can't provide a node.

3: name is already in use.

4: name is invalid - not all present or > 64 bytes in length

5: can't add name to record collection

METMON(1,name; ==> c;) Delete meter
Return code c:
0: The named monitored meter is no longer monitored. It is destroyed if METMON created it.

1: name not in use

4: name is invalid - not all present or > 64 bytes in length

METMON(2,name; m ==> c;) Monitor existing meter
m must be a fetch or node key to a meter.

Return code c:

0: The meter is added to the collection of monitored meters under the specified name.

1: Can't fetch from key m, or its slot 3 isn't a data key

3: name is already in use.

4: name is invalid - not all present or > 64 bytes in length

5: can't add name to record collection

METMON(3; ==> ;rc) Get record collection
Rc is a record collection that has a record for each monitored meter. The name of the record is the name specified with the meter. The key of the record is the node or fetch key to the meter. The string of the record has the following format:
(8, recent time), (8, last meter value), (1, flag)

where the first two are in long floating point format, and flag is 0 or 2, the order code by which the meter was added. Recent time is in units of seconds. It is the value of a variable which is updated once a minute as follows: it is halved, and then the CPU time used under the meter since the last updating is added.

METMON is not protected from abuses of rc.

METMON(kt; ==> X'2E')