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This module implements process groups. The groups in this
module differ from the groups in the module pg in several
ways. In pg, each message is sent to all members in the
group. In this module, each message may be sent to one, some, or
all members.
A group of processes can be accessed by a common name. For
example, if there is a group named foobar, there can be a
set of processes (which can be located on different nodes) which
are all members of the group foobar. There is no special
functions for sending a message to the group. Instead, client
functions should be written with the functions
get_members/1 and get_local_members/1 to find out
which process are members of the group. Then the message can be
sent to one or more members of the group.
If a member terminates, it is automatically removed from the group.
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This module is used by the |
Types:
Name = term()
Creates a new, empty process group. The group is globally visible on all nodes. If the group exists, nothing happens.
Types:
Name = term()
Deletes a process group.
get_closest_pid(Name) -> Pid | {error, Reason}
Types:
Name = term()
This is a useful dispatch function which can be used from client functions. It returns a process on the local node, if such a process exist. Otherwise, it chooses one randomly.
get_members(Name) -> [Pid] | {error, Reason}
Types:
Name = term()
Returns all processes in the group Name. This
function should be used from within a client function that
accesses the group. It is then optimized for speed.
get_local_members(Name) -> [Pid] | {error, Reason}
Types:
Name = term()
Returns all processes running on the local node in the
group Name. This function should to be used from
within a client function that accesses the group. It is then
optimized for speed.
join(Name, Pid) -> ok | {error, Reason}
Types:
Name = term()
Joins the process Pid to the group Name.
leave(Name, Pid) -> ok | {error, Reason}
Types:
Name = term()
Makes the process Pid leave the group Name.
Types:
Name = term()
Returns a list of all known groups.
start()
start_link() -> {ok, Pid} | {error, Reason}
Starts the pg2 server. Normally, the server does not need
to be started explicitly, as it is started dynamically if it
is needed. This is useful during development, but in a
target system the server should be started explicitly. Use
configuration parameters for kernel for this.
kernel(6), pg(3)