| Overview |  |
Copyright © 2019, Fred Youhanaie
Authors: Fred Youhanaie (fyrlang@anydata.co.uk).
| eval_out/1 | Conditionally evaluate a tuple and out the result to the
unnamed instance. |
| eval_out/2 | Conditionally evaluate a tuple and out the result to a named
instance. |
| inst_to_name/2 | Convert an instance name to longer prefixed name. |
| wait4etsmgr/4 | wait for etsmgr to (re)start, then ask it to manage our table. |
eval_out(Tuple_in::tuple()) -> done
Conditionally evaluate a tuple and out the result to the
unnamed instance.
eval_out/2 for details.
eval_out(Inst_name::atom(), Tuple_in::tuple()) -> done
Conditionally evaluate a tuple and out the result to a named
instance.
The elements of the output tuple correspond to those of
Tuple_in. If any of the elements of Tuple_in are recognized as
function, then the corresponding output element will be the value
of the function.
Two types of patterns are recognized as functions and are
evaluated. A normal function expression of arity zero, fun () ->
expr end. And, a tuple with two elements, a function expresion of
arity N and a list of length N, N can be zero.
inst_to_name(Prefix::atom(), Inst_name::atom()) -> atom()
Convert an instance name to longer prefixed name.
This is used for obtaining the instance specific server/table
names. For example inst_to_name(espace_sup, aaa) will return
espace_sup_aaa.
If the instance name is espace, then the prefix is returned
without an instance name suffix. For example
inst_to_name(espace_sup, espace) will return espace_sup.
Instead of generating the full name each time this function is
called, we perform the conversion once and cache the result as an
entry in the persistent_term store. Each entry has the key
{espace, Inst_name, Prefix}, e.g. {espace, aaa, espace_sup},
and the full name as value, e.g. espace_sup_aaa.
persistent_term store will help speed up all named
instances, including the short lived espace:eval/2 processes.
wait4etsmgr(Inst_name::atom(), X2::init | recover, Table_name::atom(), Table_opts::term()) -> {ok, pid(), ets:tab()} | {error, term()}
wait for etsmgr to (re)start, then ask it to manage our table.
There are two occassions where this function is called:
init - start/restart of our gen_server that owns a table, in
this case we do not have, or know of, the ETS table. So we ask
etsmgr to create a new table using etsmgr:new_table/4. If
etsmgr is already managing such a table that does not already
belong to another process, then that table will be given to
us.recover - recovery of the etsmgr server, in this case we
ask etsmgr to start managing our ETS table.Generated by EDoc