ei_global
View SourceAccess globally registered names.
Description
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.
ei_global_names()
char **ei_global_names(ei_cnode *ec, int fd, int *count);Retrieves a list of all known global names.
ecis theei_cnoderepresenting the current cnode.fdis an open descriptor to an Erlang connection.countis the address of an integer, orNULL. Ifcountis 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.
Available since OTP 23.0
ei_global_register()
int ei_global_register(int fd, const char *name, erlang_pid *self);Registers a name in global.
fdis an open descriptor to an Erlang connection.nameis the name to register inglobal.pidis the pid that is to be associated withname. This value is returned byglobalwhen processes request the location ofname.
Returns 0 on success, otherwise -1.
Available since OTP 23.0
ei_global_unregister()
int ei_global_unregister(ei_cnode *ec, int fd, const char *name);Unregisters a name from global.
ecis theei_cnoderepresenting the current cnode.fdis an open descriptor to an Erlang connection.nameis the name to unregister fromglobal.
Returns 0 on success, otherwise -1.
Available since OTP 23.0
ei_global_whereis()
int ei_global_whereis(ei_cnode *ec, int fd, const char *name, erlang_pid* pid, char *node);Looks up a name in global.
ecis theei_cnoderepresenting the current cnode.fdis an open descriptor to an Erlang connection.nameis the name that is to be looked up inglobal.
The pid parameter is a pointer to a erlang_pid that the function will update
with the pid associated with the global name, if successful.
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
ei_connect() if necessary.
On success, the function returns 0, updates the erlang_pid pointed to by the
pid parameter, and the node parameter is initialized to the node name where
name is found. On failure, a negative number is returned.
Available since OTP 23.0