diff options
Diffstat (limited to 'erts/doc/src/erl_nif.xml')
| -rw-r--r-- | erts/doc/src/erl_nif.xml | 89 |
1 files changed, 82 insertions, 7 deletions
diff --git a/erts/doc/src/erl_nif.xml b/erts/doc/src/erl_nif.xml index 51ba70994a..5a69bed34c 100644 --- a/erts/doc/src/erl_nif.xml +++ b/erts/doc/src/erl_nif.xml @@ -714,6 +714,7 @@ typedef struct { typedef struct { ErlNifResourceDtor* dtor; ErlNifResourceStop* stop; + ErlNifResourceDown* down; } ErlNifResourceTypeInit;</code> <p>Initialization structure read by <seealso marker="#enif_open_resource_type_x"> enif_open_resource_type_x</seealso>.</p> @@ -1395,13 +1396,12 @@ typedef enum { <p>Returns <c>true</c> if a pending exception is associated with the environment <c>env</c>. If <c>reason</c> is a <c>NULL</c> pointer, ignore it. Otherwise, if a pending exception associated with - <c>env</c> exists, set <c>ERL_NIF_TERM</c> to which <c>reason</c> - points to the value of the exception's term. For example, if - <seealso marker="#enif_make_badarg"> + <c>env</c> exists, set <c>*reason</c> to the value of the exception + term. For example, if <seealso marker="#enif_make_badarg"> <c>enif_make_badarg</c></seealso> is called to set a pending <c>badarg</c> exception, a later call to <c>enif_has_pending_exception(env, &reason)</c> sets - <c>reason</c> to the atom <c>badarg</c>, then return <c>true</c>.</p> + <c>*reason</c> to the atom <c>badarg</c>, then return <c>true</c>.</p> <p>See also <seealso marker="#enif_make_badarg"> <c>enif_make_badarg</c></seealso> and <seealso marker="#enif_raise_exception"> @@ -2384,20 +2384,23 @@ enif_map_iterator_destroy(env, &iter);</code> called in the two callbacks <seealso marker="#load"><c>load</c></seealso> and <seealso marker="#upgrade"><c>upgrade</c></seealso>.</p> + <p>See also <seealso marker="#enif_open_resource_type_x"> + <c>enif_open_resource_type_x</c></seealso>.</p> </desc> </func> <func> <name><ret>ErlNifResourceType *</ret> <nametext>enif_open_resource_type_x(ErlNifEnv* env, const char* name, - ErlNifResourceTypeInit* init, + const ErlNifResourceTypeInit* init, ErlNifResourceFlags flags, ErlNifResourceFlags* tried)</nametext> </name> <fsummary>Create or takeover a resource type.</fsummary> <desc> <p>Same as <seealso marker="#enif_open_resource_type"><c>enif_open_resource_type</c></seealso> - except is also accept a <c>stop</c> callback for resource types that are - used together with <seealso marker="#enif_select"><c>enif_select</c></seealso>.</p> + except it accepts additional callback functions for resource types that are + used together with <seealso marker="#enif_select"><c>enif_select</c></seealso> + and <seealso marker="#enif_monitor_process"><c>enif_monitor_process</c></seealso>.</p> <p>Argument <c>init</c> is a pointer to an <seealso marker="#ErlNifResourceTypeInit"><c>ErlNifResourceTypeInit</c></seealso> structure that contains the function pointers for destructor, down and stop callbacks @@ -2695,6 +2698,21 @@ enif_map_iterator_destroy(env, &iter);</code> the event object. This safe way of closing event objects must be used even if all notifications have been received and no further calls to <c>enif_select</c> have been made.</p> + <p>The first call to <c>enif_select</c> for a specific OS <c>event</c> will establish + a relation between the event object and the containing resource. All subsequent calls + for an <c>event</c> must pass its containing resource as argument + <c>obj</c>. The relation is dissolved when <c>enif_select</c> has + been called with <c>mode</c> as <c>ERL_NIF_SELECT_STOP</c> and the + corresponding <c>stop</c> callback has returned. A resource can contain + several event objects but one event object can only be contained within + one resource. A resource will not be destructed until all its contained relations + have been dissolved.</p> + <note> + <p>Use <seealso marker="#enif_monitor_process"><c>enif_monitor_process</c></seealso> + together with <c>enif_select</c> to detect failing Erlang + processes and prevent them from causing permanent leakage of resources + and their contained OS event objects.</p> + </note> <p>Returns a non-negative value on success where the following bits can be set:</p> <taglist> <tag><c>ERL_NIF_SELECT_STOP_CALLED</c></tag> @@ -2984,6 +3002,63 @@ if (retval & ERL_NIF_SELECT_STOP_CALLED) { <c>erl_drv_tsd_set</c></seealso>.</p> </desc> </func> + + <func> + <name><ret>int</ret> + <nametext>enif_whereis_pid(ErlNifEnv *env, + ERL_NIF_TERM name, ErlNifPid *pid)</nametext></name> + <fsummary>Looks up a process by its registered name.</fsummary> + <desc> + <p>Looks up a process by its registered name.</p> + <taglist> + <tag><c>env</c></tag> + <item>The environment of the calling process. Must be <c>NULL</c> + only if calling from a created thread.</item> + <tag><c>name</c></tag> + <item>The name of a registered process, as an atom.</item> + <tag><c>*pid</c></tag> + <item>The <seealso marker="#ErlNifPid"><c>ErlNifPid</c></seealso> + in which the resolved process id is stored.</item> + </taglist> + <p>On success, sets <c>*pid</c> to the local process registered with + <c>name</c> and returns <c>true</c>. If <c>name</c> is not a + registered process, or is not an atom, <c>false</c> is returned and + <c>*pid</c> is unchanged.</p> + <p>Works as <seealso marker="erlang#whereis-1"> + <c>erlang:whereis/1</c></seealso>, but restricted to processes. See + <seealso marker="#enif_whereis_port"><c>enif_whereis_port</c></seealso> + to resolve registered ports.</p> + </desc> + </func> + + <func> + <name><ret>int</ret> + <nametext>enif_whereis_port(ErlNifEnv *env, + ERL_NIF_TERM name, ErlNifPort *port)</nametext></name> + <fsummary>Looks up a port by its registered name.</fsummary> + <desc> + <p>Looks up a port by its registered name.</p> + <taglist> + <tag><c>env</c></tag> + <item>The environment of the calling process. Must be <c>NULL</c> + only if calling from a created thread.</item> + <tag><c>name</c></tag> + <item>The name of a registered port, as an atom.</item> + <tag><c>*port</c></tag> + <item>The <seealso marker="#ErlNifPort"><c>ErlNifPort</c></seealso> + in which the resolved port id is stored.</item> + </taglist> + <p>On success, sets <c>*port</c> to the port registered with + <c>name</c> and returns <c>true</c>. If <c>name</c> is not a + registered port, or is not an atom, <c>false</c> is returned and + <c>*port</c> is unchanged.</p> + <p>Works as <seealso marker="erlang#whereis-1"> + <c>erlang:whereis/1</c></seealso>, but restricted to ports. See + <seealso marker="#enif_whereis_pid"><c>enif_whereis_pid</c></seealso> + to resolve registered processes.</p> + </desc> + </func> + </funcs> <section> |