erl_global
(erl_interface)Note!
The support for VxWorks is deprecated as of OTP 22, and will be removed in OTP 23.
Note!
The old legacy erl_interface
library (functions
with prefix erl_
) is deprecated as of OTP 22, and will be
removed in OTP 23. This does not apply to the ei
library. Reasonably new gcc
compilers will issue deprecation
warnings. In order to disable these warnings, define the macro
EI_NO_DEPR_WARN
.
This module provides support for registering, looking
up, and unregistering names in the global
module.
For more information, see
kernel:global
.
Notice that the functions below perform an RPC using an open file descriptor provided by the caller. This file descriptor must not be used for other traffic during the global operation, as the function can then receive unexpected data and fail.
Functions
int fd;
int *count;
Retrieves a list of all known global names.
fd
is an open descriptor to an Erlang connection.count
is the address of an integer, orNULL
. Ifcount
is notNULL
, it is set by the function to the number of names found.
On success, the function returns an array of strings, each
containing a single registered name, and sets
count
to
the number of names found. The array is terminated
by a single NULL
pointer. On failure, the function returns
NULL
and count
is not modified.
Note!
It is the caller's responsibility to free the array
afterwards. It has been allocated by the function with a
single call to malloc()
, so a single
free()
is all that is necessary.
int fd;
const char *name;
ETERM *pid;
Registers a name in global
.
fd
is an open descriptor to an Erlang connection.name
is the name to register inglobal
.pid
is the pid that is to be associated withname
. This value is returned byglobal
when processes request the location ofname
.
Returns 0
on success, otherwise -1
.
int fd;
const char *name;
Unregisters a name from global
.
fd
is an open descriptor to an Erlang connection.name
is the name to unregister fromglobal
.
Returns 0
on success, otherwise -1
.
int fd;
const char *name;
char *node;
Looks up a name in global
.
fd
is an open descriptor to an Erlang connection.name
is the name that is to be looked up inglobal
.
If node
is not NULL
, it is a pointer to a
buffer where the function can fill in the name of the node where
name
is found. node
can be
passed directly to erl_connect()
if necessary.
On success, the function returns an Erlang pid containing the address
of the specified name, and the node is initialized to
the node name where name
is found. On failure,
NULL
is returned and node
is not
modified.