diff options
Diffstat (limited to 'erts/doc/src/erlang.xml')
| -rw-r--r-- | erts/doc/src/erlang.xml | 215 |
1 files changed, 180 insertions, 35 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index 2465f49581..b40aae5d28 100644 --- a/erts/doc/src/erlang.xml +++ b/erts/doc/src/erlang.xml @@ -189,6 +189,14 @@ </taglist> </desc> </datatype> + + <datatype> + <name name="dist_handle"></name> + <desc> + <p>An opaque handle identifing a distribution channel.</p> + </desc> + </datatype> + </datatypes> <funcs> @@ -1233,6 +1241,141 @@ end</code> </func> <func> + <name name="dist_ctrl_get_data" arity="1"/> + <fsummary>Get distribution channel data to pass to another node.</fsummary> + <desc> + <p> + Get distribution channel data from the local node that is + to be passed to the remote node. The distribution channel + is identified by <c><anno>DHandle</anno></c>. If no data + is available, the atom <c>none</c> is returned. One + can request to be informed by a message when more + 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> + <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_data_notification" arity="1"/> + <fsummary>Request notification about available outgoing distribution channel data.</fsummary> + <desc> + <p> + Request notification when more data is available to + fetch using + <seealso marker="erlang#dist_ctrl_get_data/1"><c>erlang:dist_ctrl_get_data(DHandle)</c></seealso> + for the distribution channel identified by + <c><anno>DHandle</anno></c>. When more data is present, + the caller will be sent the message <c>dist_data</c>. + Once a <c>dist_data</c> messages has been sent, no + more <c>dist_data</c> messages will be sent until + the <c>dist_ctrl_get_data_notification/1</c> function has been called + again. + </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_input_handler" arity="2"/> + <fsummary>Register distribution channel input handler process.</fsummary> + <desc> + <p> + Register an alternate input handler process for the + distribution channel identified by <c><anno>DHandle</anno></c>. + Once this function has been called, <c><anno>InputHandler</anno></c> + is the only process allowed to call + <seealso marker="erlang#dist_ctrl_put_data/2"><c>erlang:dist_ctrl_put_data(DHandle, Data)</c></seealso> + with the <c><anno>DHandle</anno></c> identifing this distribution + channel. + </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_put_data" arity="2"/> + <fsummary>Pass data into the VM from a distribution channel.</fsummary> + <desc> + <p> + Deliver distribution channel data from a remote node to the + local node. + </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 unless an alternate input handler process + has been registered using + <seealso marker="erlang#dist_ctrl_input_handler/2"><c>erlang:dist_ctrl_input_handler(DHandle, InputHandler)</c></seealso>. + If an alternate input handler has been registered, only + the registered input handler process 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"/> <fsummary>Return the Nth element of a tuple.</fsummary> <type_desc variable="N">1..tuple_size(<anno>Tuple</anno>)</type_desc> @@ -3683,6 +3826,12 @@ RealSystem = system + MissedSystem</code> </item> <tag><c>{env, <anno>Env</anno>}</c></tag> <item> + <p> + Types:<br/> + <c><anno>Name</anno> = </c><seealso marker="kernel:os#type-env_var_name"><c>os:env_var_name()</c></seealso><br/> + <c><anno>Val</anno> = </c><seealso marker="kernel:os#type-env_var_value"><c>os:env_var_value()</c></seealso><c> | false</c><br/> + <c>Env = [{<anno>Name</anno>, <anno>Val</anno>}]</c> + </p> <p>Only valid for <c>{spawn, <anno>Command</anno>}</c>, and <c>{spawn_executable, <anno>FileName</anno>}</c>. The environment of the started process is extended using @@ -3697,7 +3846,13 @@ RealSystem = system + MissedSystem</code> exception is <c><anno>Val</anno></c> being the atom <c>false</c> (in analogy with <seealso marker="kernel:os#getenv/1"><c>os:getenv/1</c></seealso>, - which removes the environment variable.</p> + which removes the environment variable. + </p> + <p> + For information about encoding requirements, see documentation + of the types for <c><anno>Name</anno></c> and + <c><anno>Val</anno></c>. + </p> </item> <tag><c>{args, [ string() | binary() ]}</c></tag> <item> @@ -4323,7 +4478,6 @@ RealSystem = system + MissedSystem</code> <desc> <p><c><anno>Locking</anno></c> is one of the following:</p> <list type="bulleted"> - <item><c>false</c> (emulator without SMP support)</item> <item><c>port_level</c> (port-specific locking)</item> <item><c>driver_level</c> (driver-specific locking)</item> </list> @@ -4727,8 +4881,8 @@ RealSystem = system + MissedSystem</code> selected for execution. Notice however that this does <em>not</em> mean that no processes on priority <c>low</c> or <c>normal</c> can run when processes - are running on priority <c>high</c>. On the runtime - system with SMP support, more processes can be running + are running on priority <c>high</c>. When using multiple + schedulers, more processes can be running in parallel than processes on priority <c>high</c>. That is, a <c>low</c> and a <c>high</c> priority process can execute at the same time.</p> @@ -4743,10 +4897,8 @@ RealSystem = system + MissedSystem</code> execution.</p> <note> <p>Do not depend on the scheduling - to remain exactly as it is today. Scheduling, at least on - the runtime system with SMP support, is likely to be - changed in a future release to use available - processor cores better.</p> + to remain exactly as it is today. Scheduling is likely to be + changed in a future release to use available processor cores better.</p> </note> <p>There is <em>no</em> automatic mechanism for avoiding priority inversion, such as priority inheritance @@ -6258,8 +6410,7 @@ true</pre> <p><c>statistics(exact_reductions)</c> is a more expensive operation than <seealso marker="#statistics_reductions"> - statistics(reductions)</seealso>, - especially on an Erlang machine with SMP support.</p> + statistics(reductions)</seealso>.</p> </note> </desc> </func> @@ -6336,17 +6487,24 @@ lists:map( <p><c><anno>MSAcc_Thread_Type</anno></c>s:</p> <taglist> <tag><c>scheduler</c></tag> - <item>The main execution threads that do most of the work.</item> + <item>The main execution threads that do most of the work. See + <seealso marker="erts:erl#+S">erl +S</seealso> for more details.</item> <tag><c>dirty_cpu_scheduler</c></tag> - <item>The threads for long running cpu intensive work.</item> + <item>The threads for long running cpu intensive work. See + <seealso marker="erts:erl#+SDcpu">erl +SDcpu</seealso> for more details.</item> <tag><c>dirty_io_scheduler</c></tag> - <item>The threads for long running I/O work.</item> + <item>The threads for long running I/O work. See + <seealso marker="erts:erl#+SDio">erl +SDio</seealso> for more details.</item> <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.</item> + file drivers) do offload non-CPU intensive work. See + <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> + <tag><c>poll</c></tag> + <item>Does the IO polling for the emulator. See + <seealso marker="erts:erl#+IOt">erl +IOt</seealso> for more details.</item> </taglist> <p>The following <c><anno>MSAcc_Thread_State</anno></c>s are available. All states are exclusive, meaning that a thread cannot be in two @@ -6643,8 +6801,8 @@ ok than available logical processors, this value may be greater than <c>1.0</c>.</p> <p>As of ERTS version 9.0, the Erlang runtime system - with SMP support will as default have more schedulers - than logical processors. This due to the dirty schedulers.</p> + will as default have more schedulers than logical processors. + This due to the dirty schedulers.</p> <note> <p><c>scheduler_wall_time</c> is by default disabled. To enable it, use @@ -7903,15 +8061,6 @@ ok The return value will always be <c>false</c>, as the <c>elib_malloc</c> allocator has been removed.</p> </item> - <tag><marker id="system_info_eager_check_io"/> - <c>eager_check_io</c></tag> - <item> - <p>Returns the value of command-line flag - <seealso marker="erl#+secio"><c>+secio</c></seealso> in - <c>erl(1)</c>, which is either <c>true</c> or <c>false</c>. - For information about the different values, see the - documentation of the command-line flag.</p> - </item> <tag><c>ets_limit</c></tag> <item> <p>Returns the maximum number of ETS tables allowed. This @@ -8014,9 +8163,7 @@ ok <taglist> <tag><c>disabled</c></tag> <item> - <p>The emulator has only one scheduler thread. The - emulator does not have SMP support, or have been - started with only one scheduler thread.</p> + <p>The emulator has been started with only one scheduler thread.</p> </item> <tag><c>blocked</c></tag> <item> @@ -8379,8 +8526,7 @@ ok </item> <tag><c>smp_support</c></tag> <item> - <p>Returns <c>true</c> if the emulator has been compiled - with SMP support, otherwise <c>false</c> is returned.</p> + <p>Returns <c>true</c>.</p> </item> <tag><marker id="system_info_start_time"/><c>start_time</c></tag> <item> @@ -8403,8 +8549,7 @@ ok </item> <tag><c>threads</c></tag> <item> - <p>Returns <c>true</c> if the emulator has been compiled - with thread support, otherwise <c>false</c> is returned.</p> + <p>Returns <c>true</c>.</p> </item> <tag><c>thread_pool_size</c></tag> <item> @@ -10523,9 +10668,9 @@ true</pre> <c>receive after 1 -> ok end</c>, except that <c>yield()</c> is faster.</p> <warning> - <p>There is seldom or never any need to use this BIF, - especially in the SMP emulator, as other processes have a - chance to run in another scheduler thread anyway. + <p>There is seldom or never any need to use this BIF + as other processes have a chance to run in another scheduler + thread anyway. Using this BIF without a thorough grasp of how the scheduler works can cause performance degradation.</p> </warning> |