diff options
Diffstat (limited to 'erts/doc/src/erlang.xml')
| -rw-r--r-- | erts/doc/src/erlang.xml | 114 |
1 files changed, 110 insertions, 4 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index 6932b18571..f41ed87048 100644 --- a/erts/doc/src/erlang.xml +++ b/erts/doc/src/erlang.xml @@ -126,7 +126,7 @@ instance.</p> <p>One can get an approximation of the <c>native</c> time unit by calling - <seealso marker="erlang:convert_time_unit/3"> + <seealso marker="#convert_time_unit/3"> <c>erlang:convert_time_unit(1, second, native)</c></seealso>. The result equals the number of whole <c>native</c> time units per second. If @@ -1269,6 +1269,42 @@ end</code> data is available by calling <seealso marker="erlang#dist_ctrl_get_data_notification/1"><c>erlang:dist_ctrl_get_data_notification(DHandle)</c></seealso>. </p> + <p>The returned value when there are data available depends + on the value of the <c>get_size</c> option configured on the + distribution channel identified by <c><anno>DHandle</anno></c>. + For more information see the documentation of the <c>get_size</c> + option for the + <seealso marker="#dist_ctrl_set_opt/3"><c>erlang:dist_ctrl_set_opt/3</c></seealso> + function.</p> + <note><p> + Only the process registered as distribution + controller for the distribution channel identified by + <c><anno>DHandle</anno></c> is allowed to call this + function. + </p></note> + <p> + This function is used when implementing an alternative + distribution carrier using processes as distribution + controllers. <c><anno>DHandle</anno></c> is retrived + via the callback + <seealso marker="erts:alt_dist#hs_data_f_handshake_complete"><c>f_handshake_complete</c></seealso>. + More information can be found in the documentation of + <seealso marker="erts:alt_dist#distribution_module">ERTS + User's Guide ➜ How to implement an Alternative Carrier + for the Erlang Distribution ➜ Distribution Module</seealso>. + </p> + </desc> + </func> + + <func> + <name name="dist_ctrl_get_opt" arity="2" clause_i="1" since="OTP 22.0"/> + <fsummary>Get value of the get_size option on a distribution channel</fsummary> + <desc> + <p>Returns the value of the <c>get_size</c> option on the distribution channel + identified by <c><anno>DHandle</anno></c>. For more information see the + documentation of the <c>get_size</c> option for the + <seealso marker="#dist_ctrl_set_opt/3"><c>erlang:dist_ctrl_set_opt/3</c></seealso> + function.</p> <note><p> Only the process registered as distribution controller for the distribution channel identified by @@ -1392,6 +1428,55 @@ end</code> </func> <func> + <name name="dist_ctrl_set_opt" arity="3" clause_i="1" since="OTP 22.0"/> + <fsummary>Set value of the get_size option on a distribution channel</fsummary> + <desc> + <p>Sets the value of the <c>get_size</c> option on the distribution channel + identified by <c><anno>DHandle</anno></c>. This option controls the return + value of calls to + <seealso marker="#dist_ctrl_get_data/1">erlang:dist_ctrl_get_data(<anno>DHandle</anno>)</seealso> + where <c><anno>DHandle</anno></c> equals <c><anno>DHandle</anno></c> used + when setting this option. + When the <c>get_size</c> option is:</p> + <taglist> + <tag><c>false</c></tag> + <item> + and there are distribution data available, a call to + <c>erlang:dist_ctrl_get_data(<anno>DHandle</anno>)</c> + will just return <c>Data</c> to pass over the channel. + This is the default value of the <c>get_size</c> option. + </item> + <tag><c>true</c></tag> + <item> + and there are distribution data available, a call to + <c>erlang:dist_ctrl_get_data(<anno>DHandle</anno>)</c> + will return <c>Data</c> to pass over the channel as well as + the <c>Size</c> of <c>Data</c> in bytes. This is returned as + a tuple on the form <c>{Size, Data}</c>. + </item> + </taglist> + <p>All options are set to default when a channel is closed.</p> + <note><p> + Only the process registered as distribution + controller for the distribution channel identified by + <c><anno>DHandle</anno></c> is allowed to call this + function. + </p></note> + <p> + This function is used when implementing an alternative + distribution carrier using processes as distribution + controllers. <c><anno>DHandle</anno></c> is retrived + via the callback + <seealso marker="erts:alt_dist#hs_data_f_handshake_complete"><c>f_handshake_complete</c></seealso>. + More information can be found in the documentation of + <seealso marker="erts:alt_dist#distribution_module">ERTS + User's Guide ➜ How to implement an Alternative Carrier + for the Erlang Distribution ➜ Distribution Module</seealso>. + </p> + </desc> + </func> + + <func> <name name="element" arity="2" since=""/> <fsummary>Return the Nth element of a tuple.</fsummary> <type_desc variable="N">1..tuple_size(<anno>Tuple</anno>)</type_desc> @@ -1751,6 +1836,10 @@ true</pre> <item> <p><c>Pid</c> is the process identifier of the process that originally created the fun.</p> + <p>It might point to the <c>init</c> process if the + <c>Fun</c> was statically allocated when module was + loaded (this optimisation is performed for local + functions that do not capture the enviornment).</p> </item> <tag><c>{index, Index}</c></tag> <item> @@ -3016,6 +3105,7 @@ false</code> Map = #{42 => value_two,1337 => "value one","a" => 1}, map_get(Key,Map). "value one"</code> + <p>Allowed in guard tests.</p> </desc> </func> @@ -4574,6 +4664,7 @@ RealSystem = system + MissedSystem</code> <name name="port_info" arity="2" clause_i="6" since="OTP R16B"/> <fsummary>Information about the memory size of a port.</fsummary> <desc> + <marker id="port_info_memory"/> <p><c><anno>Bytes</anno></c> is the total number of bytes allocated for this port by the runtime system. The port itself can have allocated memory that is not @@ -5206,11 +5297,13 @@ RealSystem = system + MissedSystem</code> changed or removed without prior notice.</p> </item> <tag><c>{current_function, {<anno>Module</anno>, - <anno>Function</anno>, Arity}}</c></tag> + <anno>Function</anno>, Arity} | undefined}</c></tag> <item> <p><c><anno>Module</anno></c>, <c><anno>Function</anno></c>, <c><anno>Arity</anno></c> is - the current function call of the process.</p> + the current function call of the process. The value + <c>undefined</c> can be returned if the process is + currently executing native compiled code.</p> </item> <tag><c>{current_location, {<anno>Module</anno>, <anno>Function</anno>, <anno>Arity</anno>, @@ -5296,6 +5389,7 @@ RealSystem = system + MissedSystem</code> </item> <tag><c>{memory, <anno>Size</anno>}</c></tag> <item> + <marker id="process_info_memory"/> <p><c><anno>Size</anno></c> is the size in bytes of the process. This includes call stack, heap, and internal structures.</p> </item> @@ -6585,7 +6679,7 @@ lists:map( <tag><c>async</c></tag> <item>Async threads are used by various linked-in drivers (mainly the file drivers) do offload non-CPU intensive work. See - <seealso marker="erts:erl#+async_thread_pool_size">erl +A</seealso> for more details.</item> + <seealso marker="erts:erl#async_thread_pool_size">erl +A</seealso> for more details.</item> <tag><c>aux</c></tag> <item>Takes care of any work that is not specifically assigned to a scheduler.</item> @@ -9319,6 +9413,18 @@ Metadata = #{ pid => pid(), <p>Returns the previous system monitor settings just like <seealso marker="#system_monitor/0"> <c>erlang:system_monitor/0</c></seealso>.</p> + <p>The arguments to <c>system_monitor/2</c> specifies how all + system monitoring on the node should be done, not how it should be + changed. This means only one process at a time + (<c><anno>MonitorPid</anno></c>) can be the receiver of system monitor + messages. Also, the way to clear a specific monitor option + is to not include it in the list <c><anno>Options</anno></c>. All + system monitoring will, however, be cleared if the process identified by + <c><anno>MonitorPid</anno></c> terminates.</p> + <p>There are no special option values (like zero) to clear an option. + Some of the options have a unspecified minimum value. Lower values + will be adjusted to the minimum value. For example, it is currently not + possible to monitor all garbage collections with <c>{long_gc, 0}</c>.</p> <note> <p>If a monitoring process gets so large that it itself starts to cause system monitor messages when garbage |