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| author | Ingela Anderton Andin <[email protected]> | 2017-04-06 16:03:11 +0200 |
|---|---|---|
| committer | Ingela Anderton Andin <[email protected]> | 2017-04-27 11:07:38 +0200 |
| commit | c6bdd67b33b70d862e2a2d0f582106f2e930d970 (patch) | |
| tree | 6d8f9b0661466c4c36d88e8ee7666c4b8a0754c0 | |
| parent | a1100c46c2ca2121d723edc03cb7885e3014af7c (diff) | |
| download | otp-c6bdd67b33b70d862e2a2d0f582106f2e930d970.tar.gz otp-c6bdd67b33b70d862e2a2d0f582106f2e930d970.tar.bz2 otp-c6bdd67b33b70d862e2a2d0f582106f2e930d970.zip | |
stdlib: Deprecate gen_fsm
| -rw-r--r-- | lib/stdlib/doc/src/gen_fsm.xml | 1091 | ||||
| -rw-r--r-- | lib/stdlib/doc/src/gen_server.xml | 1 | ||||
| -rw-r--r-- | lib/stdlib/doc/src/gen_statem.xml | 11 | ||||
| -rw-r--r-- | lib/stdlib/doc/src/proc_lib.xml | 2 | ||||
| -rw-r--r-- | lib/stdlib/doc/src/supervisor.xml | 6 | ||||
| -rw-r--r-- | lib/stdlib/doc/src/sys.xml | 28 | ||||
| -rw-r--r-- | lib/stdlib/src/gen_fsm.erl | 20 | ||||
| -rw-r--r-- | lib/stdlib/src/otp_internal.erl | 49 | ||||
| -rw-r--r-- | system/doc/design_principles/fsm.xml | 338 | ||||
| -rw-r--r-- | system/doc/design_principles/part.xml | 1 | ||||
| -rw-r--r-- | system/doc/design_principles/spec_proc.xml | 86 | ||||
| -rw-r--r-- | system/doc/design_principles/sup_princ.xml | 3 | ||||
| -rw-r--r-- | system/doc/design_principles/xmlfiles.mk | 1 | ||||
| -rw-r--r-- | system/doc/reference_manual/modules.xml | 1 |
14 files changed, 298 insertions, 1340 deletions
diff --git a/lib/stdlib/doc/src/gen_fsm.xml b/lib/stdlib/doc/src/gen_fsm.xml index 719ab2b558..d74665060e 100644 --- a/lib/stdlib/doc/src/gen_fsm.xml +++ b/lib/stdlib/doc/src/gen_fsm.xml @@ -4,14 +4,14 @@ <erlref> <header> <copyright> - <year>1996</year><year>2016</year> + <year>1996-2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at - + http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software @@ -29,926 +29,177 @@ <rev></rev> </header> <module>gen_fsm</module> - <modulesummary>Generic finite state machine behavior.</modulesummary> - <description> - <note> - <p> - There is a new behaviour - <seealso marker="gen_statem"><c>gen_statem</c></seealso> - that is intended to replace <c>gen_fsm</c> for new code. - <c>gen_fsm</c> will not be removed for the foreseeable future - to keep old state machine implementations running. - </p> - </note> - <p>This behavior module provides a finite state machine. - A generic finite state machine process (<c>gen_fsm</c>) implemented - using this module has a standard set of interface functions - and includes functionality for tracing and error reporting. It - also fits into an OTP supervision tree. For more information, see - <seealso marker="doc/design_principles:fsm">OTP Design Principles</seealso>. - </p> - - <p>A <c>gen_fsm</c> process assumes all specific parts to be located in a - callback module exporting a predefined set of functions. The relationship - between the behavior functions and the callback functions is as - follows:</p> - - <pre> -gen_fsm module Callback module --------------- --------------- -gen_fsm:start -gen_fsm:start_link -----> Module:init/1 - -gen_fsm:stop -----> Module:terminate/3 - -gen_fsm:send_event -----> Module:StateName/2 - -gen_fsm:send_all_state_event -----> Module:handle_event/3 - -gen_fsm:sync_send_event -----> Module:StateName/3 - -gen_fsm:sync_send_all_state_event -----> Module:handle_sync_event/4 - -- -----> Module:handle_info/3 - -- -----> Module:terminate/3 + <modulesummary>Deprecated and replaced by <seealso marker="gen_statem"><c>gen_statem</c></seealso> </modulesummary> -- -----> Module:code_change/4</pre> - - <p>If a callback function fails or returns a bad value, the <c>gen_fsm</c> - process terminates.</p> - - <p>A <c>gen_fsm</c> process handles system messages as described in - <seealso marker="sys"><c>sys(3)</c></seealso>. The <c>sys</c> module - can be used for debugging a <c>gen_fsm</c> process.</p> - - <p>Notice that a <c>gen_fsm</c> process does not trap exit signals - automatically, this must be explicitly initiated in the callback - module.</p> - - <p>Unless otherwise stated, all functions in this module fail if - the specified <c>gen_fsm</c> process does not exist or if bad arguments - are specified.</p> - - <p>The <c>gen_fsm</c> process can go into hibernation - (see <seealso marker="erts:erlang#hibernate/3"> - <c>erlang:hibernate/3</c></seealso>) if a callback function - specifies <c>'hibernate'</c> instead of a time-out value. This - can be useful if the server is expected to be idle for a long - time. However, use this feature with care, as hibernation - implies at least two garbage collections (when hibernating and - shortly after waking up) and is not something you want to do - between each call to a busy state machine.</p> + <description> + <p> Deprecated and replaced by <seealso marker="gen_statem"><c>gen_statem</c></seealso> </p> </description> - - <funcs> - <func> - <name>cancel_timer(Ref) -> RemainingTime | false</name> - <fsummary>Cancel an internal timer in a generic FSM.</fsummary> - <type> - <v>Ref = reference()</v> - <v>RemainingTime = integer()</v> - </type> - <desc> - <p>Cancels an internal timer referred by <c>Ref</c> in the - <c>gen_fsm</c> process that calls this function.</p> - <p><c>Ref</c> is a reference returned from - <seealso marker="#send_event_after/2"> - <c>send_event_after/2</c></seealso> or - <seealso marker="#start_timer/2"><c>start_timer/2</c></seealso>.</p> - <p>If the timer has already timed out, but the event not yet - been delivered, it is cancelled as if it had <em>not</em> - timed out, so there is no false timer event after - returning from this function.</p> - <p>Returns the remaining time in milliseconds until the timer would - have expired if <c>Ref</c> referred to an active timer, otherwise - <c>false</c>.</p> - </desc> - </func> - - <func> - <name>enter_loop(Module, Options, StateName, StateData)</name> - <name>enter_loop(Module, Options, StateName, StateData, FsmName)</name> - <name>enter_loop(Module, Options, StateName, StateData, Timeout)</name> - <name>enter_loop(Module, Options, StateName, StateData, FsmName, Timeout)</name> - <fsummary>Enter the <c>gen_fsm</c> receive loop.</fsummary> - <type> - <v>Module = atom()</v> - <v>Options = [Option]</v> - <v> Option = {debug,Dbgs}</v> - <v> Dbgs = [Dbg]</v> - <v> Dbg = trace | log | statistics</v> - <v> | {log_to_file,FileName} | {install,{Func,FuncState}}</v> - <v>StateName = atom()</v> - <v>StateData = term()</v> - <v>FsmName = {local,Name} | {global,GlobalName}</v> - <v> | {via,Module,ViaName}</v> - <v> Name = atom()</v> - <v> GlobalName = ViaName = term()</v> - <v>Timeout = int() | infinity</v> - </type> - <desc> - <p>Makes an existing process into a <c>gen_fsm</c> process. - Does not return, - instead the calling process enters the <c>gen_fsm</c> receive - loop and becomes a <c>gen_fsm</c> process. The process <em>must</em> - have been started using one of the start functions in - <seealso marker="proc_lib"><c>proc_lib(3)</c></seealso>. The user is - responsible for any initialization of the process, including - registering a name for it.</p> - <p>This function is useful when a more complex initialization - procedure is needed than the <c>gen_fsm</c> behavior provides.</p> - <p><c>Module</c>, <c>Options</c>, and <c>FsmName</c> have - the same meanings as when calling - <seealso marker="#start_link/3"><c>start[_link]/3,4</c></seealso>. - However, if <c>FsmName</c> is specified, the process must have - been registered accordingly <em>before</em> this function is - called.</p> - <p><c>StateName</c>, <c>StateData</c>, and <c>Timeout</c> have - the same meanings as in the return value of - <seealso marker="#Moduleinit"><c>Module:init/1</c></seealso>. - The callback module <c>Module</c> does not need to - export an <c>init/1</c> function.</p> - <p>The function fails if the calling process was not started by a - <c>proc_lib</c> start function, or if it is not registered - according to <c>FsmName</c>.</p> - </desc> - </func> - - <func> - <name>reply(Caller, Reply) -> Result</name> - <fsummary>Send a reply to a caller.</fsummary> - <type> - <v>Caller - see below</v> - <v>Reply = term()</v> - <v>Result = term()</v> - </type> - <desc> - <p>This function can be used by a <c>gen_fsm</c> process to - explicitly send a reply to a client process that called - <seealso marker="#sync_send_event/2"> - <c>sync_send_event/2,3</c></seealso> or - <seealso marker="#sync_send_all_state_event/2"> - <c>sync_send_all_state_event/2,3</c></seealso> - when the reply cannot be defined in the return value of - <seealso marker="#Module:StateName/3"> - <c>Module:StateName/3</c></seealso> or - <seealso marker="#Module:handle_sync_event/4"> - <c>Module:handle_sync_event/4</c></seealso>.</p> - <p><c>Caller</c> must be the <c>From</c> argument provided to - the callback function. <c>Reply</c> is any term - given back to the client as the return value of - <c>sync_send_event/2,3</c> or - <c>sync_send_all_state_event/2,3</c>.</p> - <p>Return value <c>Result</c> is not further defined, and - is always to be ignored.</p> - </desc> - </func> - - <func> - <name>send_all_state_event(FsmRef, Event) -> ok</name> - <fsummary>Send an event asynchronously to a generic FSM.</fsummary> - <type> - <v>FsmRef = Name | {Name,Node} | {global,GlobalName}</v> - <v> | {via,Module,ViaName} | pid()</v> - <v> Name = Node = atom()</v> - <v> GlobalName = ViaName = term()</v> - <v>Event = term()</v> - </type> - <desc> - <p>Sends an event asynchronously to the <c>FsmRef</c> of the - <c>gen_fsm</c> process and returns <c>ok</c> immediately. - The <c>gen_fsm</c> process calls - <seealso marker="#Module:handle_event/3"> - <c>Module:handle_event/3</c></seealso> to handle the event.</p> - <p>For a description of the arguments, see - <seealso marker="#send_event/2"><c>send_event/2</c></seealso>.</p> - <p>The difference between <c>send_event/2</c> and - <c>send_all_state_event/2</c> is which callback function is - used to handle the event. This function is useful when - sending events that are handled the same way in every state, - as only one <c>handle_event</c> clause is needed to handle - the event instead of one clause in each state name function.</p> - </desc> - </func> - - <func> - <name>send_event(FsmRef, Event) -> ok</name> - <fsummary>Send an event asynchronously to a generic FSM.</fsummary> - <type> - <v>FsmRef = Name | {Name,Node} | {global,GlobalName}</v> - <v> | {via,Module,ViaName} | pid()</v> - <v> Name = Node = atom()</v> - <v> GlobalName = ViaName = term()</v> - <v>Event = term()</v> - </type> - <desc> - <p>Sends an event asynchronously to the <c>FsmRef</c> of the - <c>gen_fsm</c> process - and returns <c>ok</c> immediately. The <c>gen_fsm</c> process calls - <seealso marker="#Module:StateName/2"> - <c>Module:StateName/2</c></seealso> to handle the event, where - <c>StateName</c> is the name of the current state of - the <c>gen_fsm</c> process.</p> - <p><c>FsmRef</c> can be any of the following:</p> - <list type="bulleted"> - <item>The pid</item> - <item><c>Name</c>, if the <c>gen_fsm</c> process is locally - registered</item> - <item><c>{Name,Node}</c>, if the <c>gen_fsm</c> process is locally - registered at another node</item> - <item><c>{global,GlobalName}</c>, if the <c>gen_fsm</c> process is - globally registered</item> - <item><c>{via,Module,ViaName}</c>, if the <c>gen_fsm</c> process is - registered through an alternative process registry</item> - </list> - <p><c>Event</c> is any term that is passed as one of - the arguments to <c>Module:StateName/2</c>.</p> - </desc> - </func> - - <func> - <name>send_event_after(Time, Event) -> Ref</name> - <fsummary>Send a delayed event internally in a generic FSM.</fsummary> - <type> - <v>Time = integer()</v> - <v>Event = term()</v> - <v>Ref = reference()</v> - </type> - <desc> - <p>Sends a delayed event internally in the <c>gen_fsm</c> process - that calls this function after <c>Time</c> milliseconds. - Returns immediately a - reference that can be used to cancel the delayed send using - <seealso marker="#cancel_timer/1"><c>cancel_timer/1</c></seealso>.</p> - <p>The <c>gen_fsm</c> process calls - <seealso marker="#Module:StateName/2"> - <c>Module:StateName/2</c></seealso> to handle - the event, where <c>StateName</c> is the name of the current - state of the <c>gen_fsm</c> process at the time the delayed event is - delivered.</p> - <p><c>Event</c> is any term that is passed as one of - the arguments to <c>Module:StateName/2</c>.</p> - </desc> - </func> - - <func> - <name>start(Module, Args, Options) -> Result</name> - <name>start(FsmName, Module, Args, Options) -> Result</name> - <fsummary>Create a standalone <c>gen_fsm</c> process.</fsummary> - <type> - <v>FsmName = {local,Name} | {global,GlobalName}</v> - <v> | {via,Module,ViaName}</v> - <v> Name = atom()</v> - <v> GlobalName = ViaName = term()</v> - <v>Module = atom()</v> - <v>Args = term()</v> - <v>Options = [Option]</v> - <v> Option = {debug,Dbgs} | {timeout,Time} | {spawn_opt,SOpts}</v> - <v> Dbgs = [Dbg]</v> - <v> Dbg = trace | log | statistics</v> - <v> | {log_to_file,FileName} | {install,{Func,FuncState}}</v> - <v> SOpts = [term()]</v> - <v>Result = {ok,Pid} | ignore | {error,Error}</v> - <v> Pid = pid()</v> - <v> Error = {already_started,Pid} | term()</v> - </type> - <desc> - <p>Creates a standalone <c>gen_fsm</c> process, that is, a process that - is not part of a supervision tree and thus has no supervisor.</p> - <p>For a description of arguments and return values, see - <seealso marker="#start_link/3"><c>start_link/3,4</c></seealso>.</p> - </desc> - </func> - - <func> - <name>start_link(Module, Args, Options) -> Result</name> - <name>start_link(FsmName, Module, Args, Options) -> Result</name> - <fsummary>Create a <c>gen_fsm</c> process in a supervision tree. - </fsummary> - <type> - <v>FsmName = {local,Name} | {global,GlobalName}</v> - <v> | {via,Module,ViaName}</v> - <v> Name = atom()</v> - <v> GlobalName = ViaName = term()</v> - <v>Module = atom()</v> - <v>Args = term()</v> - <v>Options = [Option]</v> - <v> Option = {debug,Dbgs} | {timeout,Time} | {spawn_opt,SOpts}</v> - <v> Dbgs = [Dbg]</v> - <v> Dbg = trace | log | statistics</v> - <v> | {log_to_file,FileName} | {install,{Func,FuncState}}</v> - <v> SOpts = [SOpt]</v> - <v> SOpt - see erlang:spawn_opt/2,3,4,5</v> - <v>Result = {ok,Pid} | ignore | {error,Error}</v> - <v> Pid = pid()</v> - <v> Error = {already_started,Pid} | term()</v> - </type> - <desc> - <p>Creates a <c>gen_fsm</c> process as part of a supervision tree. - The function is to be called, directly or indirectly, by - the supervisor. For example, it ensures that - the <c>gen_fsm</c> process is linked to the supervisor.</p> - <p>The <c>gen_fsm</c> process calls - <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso> to - initialize. To ensure a synchronized startup procedure, - <c>start_link/3,4</c> does not return until - <c>Module:init/1</c> has returned.</p> - <list type="bulleted"> - <item> - <p>If <c>FsmName={local,Name}</c>, the <c>gen_fsm</c> process is - registered locally as <c>Name</c> using <c>register/2</c>.</p> - </item> - <item> - <p>If <c>FsmName={global,GlobalName}</c>, the <c>gen_fsm</c> process - is registered globally as <c>GlobalName</c> using - <seealso marker="kernel:global#register_name/2"> - <c>global:register_name/2</c></seealso>.</p> - </item> - <item> - <p>If <c>FsmName={via,Module,ViaName}</c>, the <c>gen_fsm</c> - process registers with the registry represented by <c>Module</c>. - The <c>Module</c> callback is to export the functions - <c>register_name/2</c>, <c>unregister_name/1</c>, - <c>whereis_name/1</c>, and <c>send/2</c>, which are to behave - like the corresponding functions in - <seealso marker="kernel:global"><c>global</c></seealso>. - Thus, <c>{via,global,GlobalName}</c> is a valid reference.</p> - </item> - </list> - <p>If no name is provided, the <c>gen_fsm</c> process is not - registered.</p> - <p><c>Module</c> is the name of the callback module.</p> - <p><c>Args</c> is any term that is passed as - the argument to <c>Module:init/1</c>.</p> - <p>If option <c>{timeout,Time}</c> is present, the <c>gen_fsm</c> - process is allowed to spend <c>Time</c> milliseconds initializing - or it terminates and the start function returns - <c>{error,timeout}</c>.</p> - <p>If option <c>{debug,Dbgs}</c> is present, the corresponding - <c>sys</c> function is called for each item in <c>Dbgs</c>; see - <seealso marker="sys"><c>sys(3)</c></seealso>.</p> - <p>If option <c>{spawn_opt,SOpts}</c> is present, <c>SOpts</c> is - passed as option list to the <c>spawn_opt</c> BIF that is used to - spawn the <c>gen_fsm</c> process; see - <seealso marker="erts:erlang#spawn_opt/2"> - <c>spawn_opt/2</c></seealso>.</p> - <note> - <p>Using spawn option <c>monitor</c> is not - allowed, it causes the function to fail with reason - <c>badarg</c>.</p> - </note> - <p>If the <c>gen_fsm</c> process is successfully created and - initialized, the function returns <c>{ok,Pid}</c>, where <c>Pid</c> - is the pid of the <c>gen_fsm</c> process. If a process with the - specified <c>FsmName</c> exists already, the function returns - <c>{error,{already_started,Pid}}</c>, where <c>Pid</c> is - the pid of that process.</p> - <p>If <c>Module:init/1</c> fails with <c>Reason</c>, - the function returns <c>{error,Reason}</c>. If - <c>Module:init/1</c> returns <c>{stop,Reason}</c> or - <c>ignore</c>, the process is terminated and the function - returns <c>{error,Reason}</c> or <c>ignore</c>, respectively.</p> - </desc> - </func> - - <func> - <name>start_timer(Time, Msg) -> Ref</name> - <fsummary>Send a time-out event internally in a generic FSM.</fsummary> - <type> - <v>Time = integer()</v> - <v>Msg = term()</v> - <v>Ref = reference()</v> - </type> - <desc> - <p>Sends a time-out event internally in the <c>gen_fsm</c> - process that calls this function after <c>Time</c> milliseconds. - Returns immediately a - reference that can be used to cancel the timer using - <seealso marker="#cancel_timer/1"><c>cancel_timer/1</c></seealso>.</p> - <p>The <c>gen_fsm</c> process calls - <seealso marker="#Module:StateName/2"> - <c>Module:StateName/2</c></seealso> to handle - the event, where <c>StateName</c> is the name of the current - state of the <c>gen_fsm</c> process at the time the time-out - message is delivered.</p> - <p><c>Msg</c> is any term that is passed in the - time-out message, <c>{timeout, Ref, Msg}</c>, as one of - the arguments to <c>Module:StateName/2</c>.</p> - </desc> - </func> - - <func> - <name>stop(FsmRef) -> ok</name> - <name>stop(FsmRef, Reason, Timeout) -> ok</name> - <fsummary>Synchronously stop a generic FSM.</fsummary> - <type> - <v>FsmRef = Name | {Name,Node} | {global,GlobalName}</v> - <v> | {via,Module,ViaName} | pid()</v> - <v> Node = atom()</v> - <v> GlobalName = ViaName = term()</v> - <v>Reason = term()</v> - <v>Timeout = int()>0 | infinity</v> - </type> - <desc> - <p>Orders a generic finite state machine to exit with the specified - <c>Reason</c> and waits for it to terminate. The <c>gen_fsm</c> - process calls <seealso marker="#Module:terminate/3"> - <c>Module:terminate/3</c></seealso> before exiting.</p> - <p>The function returns <c>ok</c> if the generic finite state machine - terminates with the expected reason. Any other reason than - <c>normal</c>, <c>shutdown</c>, or <c>{shutdown,Term}</c> causes an - error report to be issued using - <seealso marker="kernel:error_logger#format/2"> - <c>error_logger:format/2</c></seealso>. - The default <c>Reason</c> is <c>normal</c>.</p> - <p><c>Timeout</c> is an integer greater than zero that - specifies how many milliseconds to wait for the generic FSM - to terminate, or the atom <c>infinity</c> to wait - indefinitely. The default value is <c>infinity</c>. If the - generic finite state machine has not terminated within the specified - time, a <c>timeout</c> exception is raised.</p> - <p>If the process does not exist, a <c>noproc</c> exception - is raised.</p> - </desc> - </func> - - <func> - <name>sync_send_all_state_event(FsmRef, Event) -> Reply</name> - <name>sync_send_all_state_event(FsmRef, Event, Timeout) -> Reply</name> - <fsummary>Send an event synchronously to a generic FSM.</fsummary> - <type> - <v>FsmRef = Name | {Name,Node} | {global,GlobalName}</v> - <v> | {via,Module,ViaName} | pid()</v> - <v> Name = Node = atom()</v> - <v> GlobalName = ViaName = term()</v> - <v>Event = term()</v> - <v>Timeout = int()>0 | infinity</v> - <v>Reply = term()</v> - </type> - <desc> - <p>Sends an event to the <c>FsmRef</c> of the <c>gen_fsm</c> - process and waits until a reply arrives or a time-out occurs. - The <c>gen_fsm</c> process calls - <seealso marker="#Module:handle_sync_event/4"> - <c>Module:handle_sync_event/4</c></seealso> to handle the event.</p> - <p>For a description of <c>FsmRef</c> and <c>Event</c>, see - <seealso marker="#send_event/2">send_event/2</seealso>. - For a description of <c>Timeout</c> and <c>Reply</c>, see - <seealso marker="#sync_send_event/3"> - <c>sync_send_event/3</c></seealso>.</p> - <p>For a discussion about the difference between - <c>sync_send_event</c> and <c>sync_send_all_state_event</c>, see - <seealso marker="#send_all_state_event/2"> - <c>send_all_state_event/2</c></seealso>.</p> - </desc> - </func> - - <func> - <name>sync_send_event(FsmRef, Event) -> Reply</name> - <name>sync_send_event(FsmRef, Event, Timeout) -> Reply</name> - <fsummary>Send an event synchronously to a generic FSM.</fsummary> - <type> - <v>FsmRef = Name | {Name,Node} | {global,GlobalName}</v> - <v> | {via,Module,ViaName} | pid()</v> - <v> Name = Node = atom()</v> - <v> GlobalName = ViaName = term()</v> - <v>Event = term()</v> - <v>Timeout = int()>0 | infinity</v> - <v>Reply = term()</v> - </type> - <desc> - <p>Sends an event to the <c>FsmRef</c> of the <c>gen_fsm</c> - process and waits until a reply arrives or a time-out occurs. - <c>The gen_fsm</c> process calls - <seealso marker="#Module:StateName/3"> - <c>Module:StateName/3</c></seealso> to handle the event, where - <c>StateName</c> is the name of the current state of - the <c>gen_fsm</c> process.</p> - <p>For a description of <c>FsmRef</c> and <c>Event</c>, see - <seealso marker="#send_event/2"><c>send_event/2</c></seealso>.</p> - <p><c>Timeout</c> is an integer greater than zero that - specifies how many milliseconds to wait for a reply, or - the atom <c>infinity</c> to wait indefinitely. Defaults - to 5000. If no reply is received within the specified time, - the function call fails.</p> - <p>Return value <c>Reply</c> is defined in the return value - of <c>Module:StateName/3</c>.</p> - </desc> - </func> - </funcs> - - <section> - <title>Callback Functions</title> - <p>The following functions are to be exported from a <c>gen_fsm</c> - callback module.</p> - - <p><em>state name</em> denotes a state of the state machine.</p> - - <p><em>state data</em> denotes the internal state of the Erlang process - that implements the state machine.</p> - </section> - - <funcs> - <func> - <name>Module:code_change(OldVsn, StateName, StateData, Extra) -> {ok, NextStateName, NewStateData}</name> - <fsummary>Update the internal state data during upgrade/downgrade. - </fsummary> - <type> - <v>OldVsn = Vsn | {down, Vsn}</v> - <v> Vsn = term()</v> - <v>StateName = NextStateName = atom()</v> - <v>StateData = NewStateData = term()</v> - <v>Extra = term()</v> - </type> - <desc> - <p>This function is called by a <c>gen_fsm</c> process when it is to - update its internal state data during a release upgrade/downgrade, - that is, when instruction <c>{update,Module,Change,...}</c>, - where <c>Change={advanced,Extra}</c>, is given in - the <c>appup</c> file; see section - <seealso marker="doc/design_principles:release_handling#instr"> - Release Handling Instructions</seealso> in OTP Design Principles.</p> - <p>For an upgrade, <c>OldVsn</c> is <c>Vsn</c>, and for a downgrade, - <c>OldVsn</c> is <c>{down,Vsn}</c>. <c>Vsn</c> is defined by the - <c>vsn</c> attribute(s) of the old version of the callback module - <c>Module</c>. If no such attribute is defined, the version is - the checksum of the Beam file.</p> - <p><c>StateName</c> is the current state name and <c>StateData</c> the - internal state data of the <c>gen_fsm</c> process.</p> - <p><c>Extra</c> is passed "as is" from the <c>{advanced,Extra}</c> - part of the update instruction.</p> - <p>The function is to return the new current state name and - updated internal data.</p> - </desc> - </func> - - <func> - <name>Module:format_status(Opt, [PDict, StateData]) -> Status</name> - <fsummary>Optional function for providing a term describing the - current <c>gen_fsm</c> process status.</fsummary> - <type> - <v>Opt = normal | terminate</v> - <v>PDict = [{Key, Value}]</v> - <v>StateData = term()</v> - <v>Status = term()</v> - </type> - <desc> - <note> - <p>This callback is optional, so callback modules need not - export it. The <c>gen_fsm</c> module provides a default - implementation of this function that returns the callback - module state data.</p> - </note> - <p>This function is called by a <c>gen_fsm</c> process in the - following situations:</p> - <list type="bulleted"> - <item>One of <seealso marker="sys#get_status/1"> - <c>sys:get_status/1,2</c></seealso> - is invoked to get the <c>gen_fsm</c> status. <c>Opt</c> is set to - the atom <c>normal</c> for this case.</item> - <item>The <c>gen_fsm</c> process terminates abnormally and logs an - error. <c>Opt</c> is set to the atom <c>terminate</c> for - this case.</item> - </list> - <p>This function is useful for changing the form and - appearance of the <c>gen_fsm</c> status for these cases. A callback - module wishing to change the <c>sys:get_status/1,2</c> - return value as well as how its status appears in - termination error logs, exports an instance - of <c>format_status/2</c> that returns a term describing the - current status of the <c>gen_fsm</c> process.</p> - <p><c>PDict</c> is the current value of the process dictionary of the - <c>gen_fsm</c> process.</p> - <p><c>StateData</c> is the internal state data of the - <c>gen_fsm</c> process.</p> - <p>The function is to return <c>Status</c>, a term that - change the details of the current state and status of - the <c>gen_fsm</c> process. There are no restrictions on the - form <c>Status</c> can take, but for - the <c>sys:get_status/1,2</c> case (when <c>Opt</c> - is <c>normal</c>), the recommended form for - the <c>Status</c> value is <c>[{data, [{"StateData", - Term}]}]</c>, where <c>Term</c> provides relevant details of - the <c>gen_fsm</c> state data. Following this recommendation is not - required, but it makes the callback module status - consistent with the rest of the <c>sys:get_status/1,2</c> - return value.</p> - <p>One use for this function is to return compact alternative - state data representations to avoid that large state terms - are printed in log files.</p> - </desc> - </func> - - <func> - <name>Module:handle_event(Event, StateName, StateData) -> Result</name> - <fsummary>Handle an asynchronous event.</fsummary> - <type> - <v>Event = term()</v> - <v>StateName = atom()</v> - <v>StateData = term()</v> - <v>Result = {next_state,NextStateName,NewStateData}</v> - <v> | {next_state,NextStateName,NewStateData,Timeout}</v> - <v> | {next_state,NextStateName,NewStateData,hibernate}</v> - <v> | {stop,Reason,NewStateData}</v> - <v> NextStateName = atom()</v> - <v> NewStateData = term()</v> - <v> Timeout = int()>0 | infinity</v> - <v> Reason = term()</v> - </type> - <desc> - <p>Whenever a <c>gen_fsm</c> process receives an event sent using - <seealso marker="#send_all_state_event/2"> - <c>send_all_state_event/2</c></seealso>, - this function is called to handle the event.</p> - <p><c>StateName</c> is the current state name of the <c>gen_fsm</c> - process.</p> - <p>For a description of the other arguments and possible return values, - see <seealso marker="#Module:StateName/2"> - <c>Module:StateName/2</c></seealso>.</p> - </desc> - </func> - - <func> - <name>Module:handle_info(Info, StateName, StateData) -> Result</name> - <fsummary>Handle an incoming message.</fsummary> - <type> - <v>Info = term()</v> - <v>StateName = atom()</v> - <v>StateData = term()</v> - <v>Result = {next_state,NextStateName,NewStateData}</v> - <v> | {next_state,NextStateName,NewStateData,Timeout}</v> - <v> | {next_state,NextStateName,NewStateData,hibernate}</v> - <v> | {stop,Reason,NewStateData}</v> - <v> NextStateName = atom()</v> - <v> NewStateData = term()</v> - <v> Timeout = int()>0 | infinity</v> - <v> Reason = normal | term()</v> - </type> - <desc> - <p>This function is called by a <c>gen_fsm</c> process when it receives - any other message than a synchronous or asynchronous event (or a - system message).</p> - <p><c>Info</c> is the received message.</p> - <p>For a description of the other arguments and possible return values, - see <seealso marker="#Module:StateName/2"> - <c>Module:StateName/2</c></seealso>.</p> - </desc> - </func> - - <func> - <name>Module:handle_sync_event(Event, From, StateName, StateData) -> Result</name> - <fsummary>Handle a synchronous event.</fsummary> - <type> - <v>Event = term()</v> - <v>From = {pid(),Tag}</v> - <v>StateName = atom()</v> - <v>StateData = term()</v> - <v>Result = {reply,Reply,NextStateName,NewStateData}</v> - <v> | {reply,Reply,NextStateName,NewStateData,Timeout}</v> - <v> | {reply,Reply,NextStateName,NewStateData,hibernate}</v> - <v> | {next_state,NextStateName,NewStateData}</v> - <v> | {next_state,NextStateName,NewStateData,Timeout}</v> - <v> | {next_state,NextStateName,NewStateData,hibernate}</v> - <v> | {stop,Reason,Reply,NewStateData} | {stop,Reason,NewStateData}</v> - <v> Reply = term()</v> - <v> NextStateName = atom()</v> - <v> NewStateData = term()</v> - <v> Timeout = int()>0 | infinity</v> - <v> Reason = term()</v> - </type> - <desc> - <p>Whenever a <c>gen_fsm</c> process receives an event sent using - <seealso marker="#sync_send_all_state_event/2"> - <c>sync_send_all_state_event/2,3</c></seealso>, - this function is called to handle the event.</p> - <p><c>StateName</c> is the current state name of the <c>gen_fsm</c> - process.</p> - <p>For a description of the other arguments and possible return values, - see <seealso marker="#Module:StateName/3"> - <c>Module:StateName/3</c></seealso>.</p> - </desc> - </func> - - <func> - <name>Module:init(Args) -> Result</name> - <fsummary>Initialize process and internal state name and state data. - </fsummary> - <type> - <v>Args = term()</v> - <v>Result = {ok,StateName,StateData} | {ok,StateName,StateData,Timeout}</v> - <v> | {ok,StateName,StateData,hibernate}</v> - <v> | {stop,Reason} | ignore</v> - <v> StateName = atom()</v> - <v> StateData = term()</v> - <v> Timeout = int()>0 | infinity</v> - <v> Reason = term()</v> - </type> - <desc> - <marker id="Moduleinit"></marker> - <p>Whenever a <c>gen_fsm</c> process is started using - <seealso marker="#start/3"><c>start/3,4</c></seealso> or - <seealso marker="#start_link/3"><c>start_link/3,4</c></seealso>, - this function is called by the new process to initialize.</p> - <p><c>Args</c> is the <c>Args</c> argument provided to the start - function.</p> - <p>If initialization is successful, the function is to return - <c>{ok,StateName,StateData}</c>, - <c>{ok,StateName,StateData,Timeout}</c>, or - <c>{ok,StateName,StateData,hibernate}</c>, where <c>StateName</c> - is the initial state name and <c>StateData</c> the initial - state data of the <c>gen_fsm</c> process.</p> - <p>If an integer time-out value is provided, a time-out occurs - unless an event or a message is received within <c>Timeout</c> - milliseconds. A time-out is represented by the atom - <c>timeout</c> and is to be handled by the - <seealso marker="#Module:StateName/2"> - <c>Module:StateName/2</c></seealso> callback functions. The atom - <c>infinity</c> can be used to wait indefinitely, this is - the default value.</p> - <p>If <c>hibernate</c> is specified instead of a time-out value, the - process goes into hibernation when waiting for the next message - to arrive (by calling <seealso marker="proc_lib#hibernate/3"> - <c>proc_lib:hibernate/3</c></seealso>).</p> - <p>If the initialization fails, the function returns - <c>{stop,Reason}</c>, where <c>Reason</c> is any term, - or <c>ignore</c>.</p> - </desc> - </func> - - <func> - <name>Module:StateName(Event, StateData) -> Result</name> - <fsummary>Handle an asynchronous event.</fsummary> - <type> - <v>Event = timeout | term()</v> - <v>StateData = term()</v> - <v>Result = {next_state,NextStateName,NewStateData} </v> - <v> | {next_state,NextStateName,NewStateData,Timeout}</v> - <v> | {next_state,NextStateName,NewStateData,hibernate}</v> - <v> | {stop,Reason,NewStateData}</v> - <v> NextStateName = atom()</v> - <v> NewStateData = term()</v> - <v> Timeout = int()>0 | infinity</v> - <v> Reason = term()</v> - </type> - <desc> - <p>There is to be one instance of this function for each - possible state name. Whenever a <c>gen_fsm</c> process receives - an event sent using - <seealso marker="#send_event/2"><c>send_event/2</c></seealso>, - the instance of this function with the same name as - the current state name <c>StateName</c> is called to handle - the event. It is also called if a time-out occurs.</p> - <p><c>Event</c> is either the atom <c>timeout</c>, if a time-out - has occurred, or the <c>Event</c> argument provided to - <c>send_event/2</c>.</p> - <p><c>StateData</c> is the state data of the <c>gen_fsm</c> process.</p> - <p>If the function returns - <c>{next_state,NextStateName,NewStateData}</c>, - <c>{next_state,NextStateName,NewStateData,Timeout}</c>, or - <c>{next_state,NextStateName,NewStateData,hibernate}</c>, the - <c>gen_fsm</c> process continues executing with the current state - name set to <c>NextStateName</c> and with the possibly - updated state data <c>NewStateData</c>. For a description of - <c>Timeout</c> and <c>hibernate</c>, see - <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso>.</p> - <p>If the function returns <c>{stop,Reason,NewStateData}</c>, - the <c>gen_fsm</c> process calls - <c>Module:terminate(Reason,StateName,NewStateData)</c> and - terminates.</p> - </desc> - </func> - - <func> - <name>Module:StateName(Event, From, StateData) -> Result</name> - <fsummary>Handle a synchronous event.</fsummary> - <type> - <v>Event = term()</v> - <v>From = {pid(),Tag}</v> - <v>StateData = term()</v> - <v>Result = {reply,Reply,NextStateName,NewStateData}</v> - <v> | {reply,Reply,NextStateName,NewStateData,Timeout}</v> - <v> | {reply,Reply,NextStateName,NewStateData,hibernate}</v> - <v> | {next_state,NextStateName,NewStateData}</v> - <v> | {next_state,NextStateName,NewStateData,Timeout}</v> - <v> | {next_state,NextStateName,NewStateData,hibernate}</v> - <v> | {stop,Reason,Reply,NewStateData} | {stop,Reason,NewStateData}</v> - <v> Reply = term()</v> - <v> NextStateName = atom()</v> - <v> NewStateData = term()</v> - <v> Timeout = int()>0 | infinity</v> - <v> Reason = normal | term()</v> - </type> - <desc> - <p>There is to be one instance of this function for each - possible state name. Whenever a <c>gen_fsm</c> process receives an - event sent using <seealso marker="#sync_send_event/2"> - <c>sync_send_event/2,3</c></seealso>, - the instance of this function with the same name as - the current state name <c>StateName</c> is called to handle - the event.</p> - <p><c>Event</c> is the <c>Event</c> argument provided to - <c>sync_send_event/2,3</c>.</p> - <p><c>From</c> is a tuple <c>{Pid,Tag}</c> where <c>Pid</c> is - the pid of the process that called <c>sync_send_event/2,3</c> - and <c>Tag</c> is a unique tag.</p> - <p><c>StateData</c> is the state data of the <c>gen_fsm</c> process.</p> - <list type="bulleted"> - <item> - <p>If <c>{reply,Reply,NextStateName,NewStateData}</c>, - <c>{reply,Reply,NextStateName,NewStateData,Timeout}</c>, or - <c>{reply,Reply,NextStateName,NewStateData,hibernate}</c> is - returned, <c>Reply</c> is given back to <c>From</c> as the return - value of <c>sync_send_event/2,3</c>. The <c>gen_fsm</c> process - then continues executing with the current state name set to - <c>NextStateName</c> and with the possibly updated state data - <c>NewStateData</c>. For a description of <c>Timeout</c> and - <c>hibernate</c>, see - <seealso marker="#Module:init/1"> - <c>Module:init/1</c></seealso>.</p> - </item> - <item> - <p>If <c>{next_state,NextStateName,NewStateData}</c>, - <c>{next_state,NextStateName,NewStateData,Timeout}</c>, or - <c>{next_state,NextStateName,NewStateData,hibernate}</c> is - returned, the <c>gen_fsm</c> process continues executing in - <c>NextStateName</c> with <c>NewStateData</c>. - Any reply to <c>From</c> must be specified explicitly using - <seealso marker="#reply/2"><c>reply/2</c></seealso>.</p> - </item> - <item> - <p>If the function returns - <c>{stop,Reason,Reply,NewStateData}</c>, <c>Reply</c> is - given back to <c>From</c>. If the function returns - <c>{stop,Reason,NewStateData}</c>, any reply to <c>From</c> - must be specified explicitly using <c>reply/2</c>. - The <c>gen_fsm</c> process then calls - <c>Module:terminate(Reason,StateName,NewStateData)</c> and - terminates.</p> - </item> - </list> - </desc> - </func> - - <func> - <name>Module:terminate(Reason, StateName, StateData)</name> - <fsummary>Clean up before termination.</fsummary> - <type> - <v>Reason = normal | shutdown | {shutdown,term()} | term()</v> - <v>StateName = atom()</v> - <v>StateData = term()</v> - </type> - <desc> - <p>This function is called by a <c>gen_fsm</c> process when it is about - to terminate. It is to be the opposite of - <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso> - and do any necessary cleaning up. When it returns, the <c>gen_fsm</c> - process terminates with <c>Reason</c>. The return value is ignored. - </p> - <p><c>Reason</c> is a term denoting the stop reason, - <c>StateName</c> is the current state name, and - <c>StateData</c> is the state data of the <c>gen_fsm</c> process.</p> - <p><c>Reason</c> depends on why the <c>gen_fsm</c> process is - terminating. If - it is because another callback function has returned a stop - tuple <c>{stop,..}</c>, <c>Reason</c> has the value - specified in that tuple. If it is because of a failure, - <c>Reason</c> is the error reason.</p> - <p>If the <c>gen_fsm</c> process is part of a supervision tree and is - ordered by its supervisor to terminate, this function is called - with <c>Reason=shutdown</c> if the following conditions apply:</p> - <list type="bulleted"> - <item> - <p>The <c>gen_fsm</c> process has been set to trap exit signals.</p> - </item> - <item> - <p>The shutdown strategy as defined in the child specification of - the supervisor is an integer time-out value, not - <c>brutal_kill</c>.</p> - </item> - </list> - <p>Even if the <c>gen_fsm</c> process is <em>not</em> part of a - supervision tree, - this function is called if it receives an <c>'EXIT'</c> - message from its parent. <c>Reason</c> is the same as in - the <c>'EXIT'</c> message.</p> - <p>Otherwise, the <c>gen_fsm</c> process terminates immediately.</p> - <p>Notice that for any other reason than <c>normal</c>, - <c>shutdown</c>, or <c>{shutdown,Term}</c> the <c>gen_fsm</c> process - is assumed to terminate because of an error and an error report is - issued using <seealso marker="kernel:error_logger#format/2"> - <c>error_logger:format/2</c></seealso>.</p> - </desc> - </func> - </funcs> - + <section> - <title>See Also</title> - <p><seealso marker="gen_event"><c>gen_event(3)</c></seealso>, - <seealso marker="gen_server"><c>gen_server(3)</c></seealso>, - <seealso marker="gen_statem"><c>gen_statem(3)</c></seealso>, - <seealso marker="proc_lib"><c>proc_lib(3)</c></seealso>, - <seealso marker="supervisor"><c>supervisor(3)</c></seealso>, - <seealso marker="sys"><c>sys(3)</c></seealso></p> + <marker id="Migration to gen_statem"/> + <title>Migration to gen_statem</title> + + <p>Here follows a simple example of turning a gen_fsm into + a <seealso marker="gen_statem"><c>gen_statem</c></seealso>. The example comes + from the previous Users Guide for <c>gen_fsm</c> </p> + + <code type="erl"> +-module(code_lock). +-define(NAME, code_lock). +%-define(BEFORE_REWRITE, true). + +-ifdef(BEFORE_REWRITE). +-behaviour(gen_fsm). +-else. +-behaviour(gen_statem). +-endif. + +-export([start_link/1, button/1, stop/0]). + +-ifdef(BEFORE_REWRITE). +-export([init/1, locked/2, open/2, handle_sync_event/4, handle_event/3, + handle_info/3, terminate/3, code_change/4]). +-else. +-export([init/1, callback_mode/0, locked/3, open/3, terminate/3, code_change/4]). +%% Add callback__mode/0 +%% Change arity of the state functions +%% Remove handle_info/3 +-endif. + +-ifdef(BEFORE_REWRITE). +start_link(Code) -> + gen_fsm:start_link({local, ?NAME}, ?MODULE, Code, []). +-else. +start_link(Code) -> + gen_statem:start_link({local,?NAME}, ?MODULE, Code, []). +-endif. + +-ifdef(BEFORE_REWRITE). +button(Digit) -> + gen_fsm:send_event(?NAME, {button, Digit}). +-else. +button(Digit) -> + gen_statem:cast(?NAME, {button,Digit}). + %% send_event is asynchronous and becomes a cast +-endif. + +-ifdef(BEFORE_REWRITE). +stop() -> + gen_fsm:sync_send_all_state_event(?NAME, stop). +-else. +stop() -> + gen_statem:call(?NAME, stop). + %% sync_send is synchronous and becomes call + %% all_state is handled by callback code in gen_statem +-endif. + +init(Code) -> + do_lock(), + Data = #{code => Code, remaining => Code}, + {ok, locked, Data}. + +-ifdef(BEFORE_REWRITE). +-else. +callback_mode() -> + state_functions. +%% state_functions mode is the mode most similar to +%% gen_fsm. There is also handle_event mode which is +%% a fairly different concept. +-endif. + +-ifdef(BEFORE_REWRITE). +locked({button, Digit}, Data0) -> + case analyze_lock(Digit, Data0) of + {open = StateName, Data} -> + {next_state, StateName, Data, 10000}; + {StateName, Data} -> + {next_state, StateName, Data} + end. +-else. +locked(cast, {button,Digit}, Data0) -> + case analyze_lock(Digit, Data0) of + {open = StateName, Data} -> + {next_state, StateName, Data, 10000}; + {StateName, Data} -> + {next_state, StateName, Data} + end; +locked({call, From}, Msg, Data) -> + handle_call(From, Msg, Data); +locked({info, Msg}, StateName, Data) -> + handle_info(Msg, StateName, Data). +%% Arity differs +%% All state events are dispatched to handle_call and handle_info help +%% functions. If you want to handle a call or cast event specifically +%% for this state you would add a special clause for it above. +-endif. + +-ifdef(BEFORE_REWRITE). +open(timeout, State) -> + do_lock(), + {next_state, locked, State}; +open({button,_}, Data) -> + {next_state, locked, Data}. +-else. +open(timeout, _, Data) -> + do_lock(), + {next_state, locked, Data}; +open(cast, {button,_}, Data) -> + {next_state, locked, Data}; +open({call, From}, Msg, Data) -> + handle_call(From, Msg, Data); +open(info, Msg, Data) -> + handle_info(Msg, open, Data). +%% Arity differs +%% All state events are dispatched to handle_call and handle_info help +%% functions. If you want to handle a call or cast event specifically +%% for this state you would add a special clause for it above. +-endif. + +-ifdef(BEFORE_REWRITE). +handle_sync_event(stop, _From, _StateName, Data) -> + {stop, normal, ok, Data}. + +handle_event(Event, StateName, Data) -> + {stop, {shutdown, {unexpected, Event, StateName}}, Data}. + +handle_info(Info, StateName, Data) -> + {stop, {shutdown, {unexpected, Info, StateName}}, StateName, Data}. +-else. +-endif. + +terminate(_Reason, State, _Data) -> + State =/= locked andalso do_lock(), + ok. +code_change(_Vsn, State, Data, _Extra) -> + {ok, State, Data}. + +%% Internal functions +-ifdef(BEFORE_REWRITE). +-else. +handle_call(From, stop, Data) -> + {stop_and_reply, normal, {reply, From, ok}, Data}. + +handle_info(Info, StateName, Data) -> + {stop, {shutdown, {unexpected, Info, StateName}}, StateName, Data}. +%% These are internal functions for handling all state events +%% and not behaviour callbacks as in gen_fsm +-endif. + +analyze_lock(Digit, #{code := Code, remaining := Remaining} = Data) -> + case Remaining of + [Digit] -> + do_unlock(), + {open, Data#{remaining := Code}}; + [Digit|Rest] -> % Incomplete + {locked, Data#{remaining := Rest}}; + _Wrong -> + {locked, Data#{remaining := Code}} + end. + +do_lock() -> + io:format("Lock~n", []). +do_unlock() -> + io:format("Unlock~n", []). + </code> </section> </erlref> diff --git a/lib/stdlib/doc/src/gen_server.xml b/lib/stdlib/doc/src/gen_server.xml index 662076b5f0..74fbfcc1bb 100644 --- a/lib/stdlib/doc/src/gen_server.xml +++ b/lib/stdlib/doc/src/gen_server.xml @@ -796,7 +796,6 @@ gen_server:abcast -----> Module:handle_cast/2 <section> <title>See Also</title> <p><seealso marker="gen_event"><c>gen_event(3)</c></seealso>, - <seealso marker="gen_fsm"><c>gen_fsm(3)</c></seealso>, <seealso marker="gen_statem"><c>gen_statem(3)</c></seealso>, <seealso marker="proc_lib"><c>proc_lib(3)</c></seealso>, <seealso marker="supervisor"><c>supervisor(3)</c></seealso>, diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml index 5eb13db1aa..18089a8191 100644 --- a/lib/stdlib/doc/src/gen_statem.xml +++ b/lib/stdlib/doc/src/gen_statem.xml @@ -62,8 +62,8 @@ </p> </note> <p> - The <c>gen_statem</c> behavior is intended to replace - <seealso marker="gen_fsm"><c>gen_fsm</c></seealso> for new code. + The <c>gen_statem</c> behavior replaces + <seealso marker="gen_fsm"><c>gen_fsm</c> </seealso> in Erlang/OTP 20.0. It has the same features and adds some really useful: </p> <list type="bulleted"> @@ -78,8 +78,10 @@ <p> The callback model(s) for <c>gen_statem</c> differs from the one for <seealso marker="gen_fsm"><c>gen_fsm</c></seealso>, - but it is still fairly easy to rewrite - from <c>gen_fsm</c> to <c>gen_statem</c>. + but it is still fairly easy to + <seealso marker="gen_fsm#Migration to gen_statem"> + rewrite from + </seealso> <c>gen_fsm</c> to <c>gen_statem</c>. </p> <p> A generic state machine process (<c>gen_statem</c>) implemented @@ -945,7 +947,6 @@ handle_event(_, _, State, Data) -> <seealso marker="#state callback">state callback</seealso> return value <c>{next_state,NextState,NewData,Timeout}</c> allowed like for <c>gen_fsm</c>'s - <seealso marker="gen_fsm#Module:StateName/2"><c>Module:StateName/2</c></seealso>. </p> </item> <tag><c>timeout</c></tag> diff --git a/lib/stdlib/doc/src/proc_lib.xml b/lib/stdlib/doc/src/proc_lib.xml index e64b2ce18a..7939a0ef61 100644 --- a/lib/stdlib/doc/src/proc_lib.xml +++ b/lib/stdlib/doc/src/proc_lib.xml @@ -36,7 +36,7 @@ the <seealso marker="doc/design_principles:des_princ"> OTP Design Principles</seealso>. Specifically, the functions in this module are used by the OTP standard behaviors (for example, - <c>gen_server</c>, <c>gen_fsm</c>, and <c>gen_statem</c>) + <c>gen_server</c> and <c>gen_statem</c>) when starting new processes. The functions can also be used to start <em>special processes</em>, user-defined processes that comply to the OTP design principles. For an example, diff --git a/lib/stdlib/doc/src/supervisor.xml b/lib/stdlib/doc/src/supervisor.xml index bb06d3645e..a42cfdd567 100644 --- a/lib/stdlib/doc/src/supervisor.xml +++ b/lib/stdlib/doc/src/supervisor.xml @@ -36,7 +36,6 @@ process can either be another supervisor or a worker process. Worker processes are normally implemented using one of the <seealso marker="gen_event"><c>gen_event</c></seealso>, - <seealso marker="gen_fsm"><c>gen_fsm</c></seealso>, <seealso marker="gen_server"><c>gen_server</c></seealso>, or <seealso marker="gen_statem"><c>gen_statem</c></seealso> behaviors. A supervisor implemented using this module has @@ -237,8 +236,8 @@ child_spec() = #{id => child_id(), % mandatory <p><c>modules</c> is used by the release handler during code replacement to determine which processes are using a certain module. As a rule of thumb, if the child process is a - <c>supervisor</c>, <c>gen_server</c>, - <c>gen_statem</c>, or <c>gen_fsm</c>, + <c>supervisor</c>, <c>gen_server</c> or, + <c>gen_statem</c>, this is to be a list with one element <c>[Module]</c>, where <c>Module</c> is the callback module. If the child process is an event manager (<c>gen_event</c>) with a @@ -706,7 +705,6 @@ child_spec() = #{id => child_id(), % mandatory <section> <title>See Also</title> <p><seealso marker="gen_event"><c>gen_event(3)</c></seealso>, - <seealso marker="gen_fsm"><c>gen_fsm(3)</c></seealso>, <seealso marker="gen_statem"><c>gen_statem(3)</c></seealso>, <seealso marker="gen_server"><c>gen_server(3)</c></seealso>, <seealso marker="sys"><c>sys(3)</c></seealso></p> diff --git a/lib/stdlib/doc/src/sys.xml b/lib/stdlib/doc/src/sys.xml index 45171f814d..78840aaaf3 100644 --- a/lib/stdlib/doc/src/sys.xml +++ b/lib/stdlib/doc/src/sys.xml @@ -168,12 +168,6 @@ </item> <item> <p>For a - <seealso marker="gen_fsm"><c>gen_fsm</c></seealso> - process, <c><anno>State</anno></c> is the tuple - <c>{CurrentStateName, CurrentStateData}</c>.</p> - </item> - <item> - <p>For a <seealso marker="gen_statem"><c>gen_statem</c></seealso> process, <c><anno>State</anno></c> is the tuple <c>{CurrentState,CurrentData}</c>.</p> @@ -222,7 +216,7 @@ <p>Function <c>system_get_state/1</c> is primarily useful for user-defined behaviors and modules that implement OTP <seealso marker="#special_process">special processes</seealso>. - The <c>gen_server</c>, <c>gen_fsm</c>, + The <c>gen_server</c>, <c>gen_statem</c>, and <c>gen_event</c> OTP behavior modules export this function, so callback modules for those behaviors need not to supply their own.</p> @@ -246,11 +240,6 @@ process returns the state of the callback module.</p> </item> <item> - <p>A <seealso marker="gen_fsm"><c>gen_fsm</c></seealso> - process returns information, such as its current - state name and state data.</p> - </item> - <item> <p>A <seealso marker="gen_statem"><c>gen_statem</c></seealso> process returns information, such as its current state name and state data.</p> @@ -262,14 +251,12 @@ </item> </list> <p>Callback modules for <c>gen_server</c>, - <c>gen_fsm</c>, <c>gen_statem</c>, and <c>gen_event</c> + <c>gen_statem</c>, and <c>gen_event</c> can also change the value of <c><anno>Misc</anno></c> by exporting a function <c>format_status/2</c>, which contributes module-specific information. For details, see <seealso marker="gen_server#Module:format_status/2"> <c>gen_server:format_status/2</c></seealso>, - <seealso marker="gen_fsm#Module:format_status/2"> - <c>gen_fsm:format_status/2</c></seealso>, <seealso marker="gen_statem#Module:format_status/2"> <c>gen_statem:format_status/2</c></seealso>, and <seealso marker="gen_event#Module:format_status/2"> @@ -373,13 +360,6 @@ is a new instance of that state.</p> </item> <item> - <p>For a <seealso marker="gen_fsm"><c>gen_fsm</c></seealso> process, - <c><anno>State</anno></c> is the tuple <c>{CurrentStateName, - CurrentStateData}</c>, and <c><anno>NewState</anno></c> is a - similar tuple, which can contain - a new state name, new state data, or both.</p> - </item> - <item> <p>For a <seealso marker="gen_statem"><c>gen_statem</c></seealso> process, <c><anno>State</anno></c> is the tuple <c>{CurrentState,CurrentData}</c>, @@ -422,7 +402,7 @@ return its <c><anno>State</anno></c> argument.</p> <p>If a <c><anno>StateFun</anno></c> function crashes or throws an exception, the original state of the process is unchanged for - <c>gen_server</c>, <c>gen_fsm</c>, and <c>gen_statem</c> processes. + <c>gen_server</c>, and <c>gen_statem</c> processes. For <c>gen_event</c> processes, a crashing or failing <c><anno>StateFun</anno></c> function means that only the state of the particular event handler it was @@ -462,7 +442,7 @@ user-defined behaviors and modules that implement OTP <seealso marker="#special_process">special processes</seealso>. The OTP behavior modules <c>gen_server</c>, - <c>gen_fsm</c>, <c>gen_statem</c>, and <c>gen_event</c> + <c>gen_statem</c>, and <c>gen_event</c> export this function, so callback modules for those behaviors need not to supply their own.</p> </desc> diff --git a/lib/stdlib/src/gen_fsm.erl b/lib/stdlib/src/gen_fsm.erl index e925a75fe8..0c76e97741 100644 --- a/lib/stdlib/src/gen_fsm.erl +++ b/lib/stdlib/src/gen_fsm.erl @@ -124,6 +124,26 @@ system_replace_state/2, format_status/2]). +-deprecated({start, 3, next_major_release}). +-deprecated({start, 4, next_major_release}). +-deprecated({start_link, 3, next_major_release}). +-deprecated({start_link, 4, next_major_release}). +-deprecated({stop, 1, next_major_release}). +-deprecated({stop, 3, next_major_release}). +-deprecated({send_event, 2, next_major_release}). +-deprecated({sync_send_event, 2, next_major_release}). +-deprecated({sync_send_event, 3, next_major_release}). +-deprecated({send_all_state_event, 2, next_major_release}). +-deprecated({sync_send_all_state_event, 2, next_major_release}). +-deprecated({sync_send_all_state_event, 3, next_major_release}). +-deprecated({reply, 2, next_major_release}). +-deprecated({start_timer, 2, next_major_release}). +-deprecated({send_event_after, 2, next_major_release}). +-deprecated({cancel_timer, 1, next_major_release}). +-deprecated({enter_loop, 4, next_major_release}). +-deprecated({enter_loop, 5, next_major_release}). +-deprecated({enter_loop, 6, next_major_release}). + -import(error_logger, [format/2]). %%% --------------------------------------------------- diff --git a/lib/stdlib/src/otp_internal.erl b/lib/stdlib/src/otp_internal.erl index d89ff4a624..42094e3088 100644 --- a/lib/stdlib/src/otp_internal.erl +++ b/lib/stdlib/src/otp_internal.erl @@ -55,6 +55,55 @@ obsolete_1(erlang, now, 0) -> obsolete_1(calendar, local_time_to_universal_time, 1) -> {deprecated, {calendar, local_time_to_universal_time_dst, 1}}; +%% *** STDLIB added in OTP 20 *** + +obsolete_1(gen_fsm, start, 3) -> + {deprecated, {gen_statem, start, 3}}; +obsolete_1(gen_fsm, start, 4) -> + {deprecated, {gen_statem, start, 4}}; + +obsolete_1(gen_fsm, start_link, 3) -> + {deprecated, {gen_statem, start, 3}}; +obsolete_1(gen_fsm, start_link, 4) -> + {deprecated, {gen_statem, start, 4}}; + +obsolete_1(gen_fsm, stop, 1) -> + {deprecated, {gen_statem, stop, 1}}; +obsolete_1(gen_fsm, stop, 3) -> + {deprecated, {gen_statem, stop, 3}}; + +obsolete_1(gen_fsm, enter_loop, 4) -> + {deprecated, {gen_statem, enter_loop, 4}}; +obsolete_1(gen_fsm, enter_loop, 5) -> + {deprecated, {gen_statem, enter_loop, 5}}; +obsolete_1(gen_fsm, enter_loop, 6) -> + {deprecated, {gen_statem, enter_loop, 6}}; + +obsolete_1(gen_fsm, reply, 2) -> + {deprecated, {gen_statem, reply, 2}}; + +obsolete_1(gen_fsm, send_event, 2) -> + {deprecated, {gen_statem, cast, 1}}; +obsolete_1(gen_fsm, send_all_state_event, 2) -> + {deprecated, {gen_statem, cast, 1}}; + +obsolete_1(gen_fsm, sync_send_event, 2) -> + {deprecated, {gen_statem, call, 2}}; +obsolete_1(gen_fsm, sync_send_event, 3) -> + {deprecated, {gen_statem, call, 3}}; + +obsolete_1(gen_fsm, sync_send_all_state_event, 2) -> + {deprecated, {gen_statem, call, 2}}; +obsolete_1(gen_fsm, sync_send_all_state_event, 3) -> + {deprecated, {gen_statem, call, 3}}; + +obsolete_1(gen_fsm, start_timer, 2) -> + {deprecated, {erlang, start_timer, 2}}; +obsolete_1(gen_fsm, cancel_timer, 1) -> + {deprecated, {erlang, cancel_timer, 1}}; +obsolete_1(gen_fsm, send_event_after, 2) -> + {deprecated, {erlang, send_after, 2}}; + %% *** CRYPTO added in OTP 20 *** obsolete_1(crypto, rand_uniform, 2) -> diff --git a/system/doc/design_principles/fsm.xml b/system/doc/design_principles/fsm.xml deleted file mode 100644 index 4f2b75e6e8..0000000000 --- a/system/doc/design_principles/fsm.xml +++ /dev/null @@ -1,338 +0,0 @@ -<?xml version="1.0" encoding="utf-8" ?> -<!DOCTYPE chapter SYSTEM "chapter.dtd"> - -<chapter> - <header> - <copyright> - <year>1997</year><year>2016</year> - <holder>Ericsson AB. All Rights Reserved.</holder> - </copyright> - <legalnotice> - Licensed under the Apache License, Version 2.0 (the "License"); - you may not use this file except in compliance with the License. - You may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 - - Unless required by applicable law or agreed to in writing, software - distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the License for the specific language governing permissions and - limitations under the License. - - </legalnotice> - - <title>gen_fsm Behaviour</title> - <prepared></prepared> - <docno></docno> - <date></date> - <rev></rev> - <file>fsm.xml</file> - </header> - <marker id="gen_fsm behaviour"></marker> - <note> - <p> - There is a new behaviour - <seealso marker="statem"><c>gen_statem</c></seealso> - that is intended to replace <c>gen_fsm</c> for new code. - It has the same features and add some really useful. - This module will not be removed for the foreseeable future - to keep old state machine implementations running. - </p> - </note> - <p>This section is to be read with the <c>gen_fsm(3)</c> manual page - in STDLIB, where all interface functions and callback - functions are described in detail.</p> - - <section> - <title>Finite-State Machines</title> - <p>A Finite-State Machine (FSM) can be described as a set of - relations of the form:</p> - <pre> -State(S) x Event(E) -> Actions(A), State(S')</pre> - <p>These relations are interpreted as meaning:</p> - <quote> - <p>If we are in state <c>S</c> and event <c>E</c> occurs, we - are to perform actions <c>A</c> and make a transition to - state <c>S'</c>.</p> - </quote> - <p>For an FSM implemented using the <c>gen_fsm</c> behaviour, - the state transition rules are written as a number of Erlang - functions, which conform to the following convention:</p> - <pre> -StateName(Event, StateData) -> - .. code for actions here ... - {next_state, StateName', StateData'}</pre> - </section> - - <section> - <title>Example</title> - <p>A door with a code lock can be viewed as an FSM. Initially, - the door is locked. Anytime someone presses a button, this - generates an event. Depending on what buttons have been pressed - before, the sequence so far can be correct, incomplete, or wrong.</p> - <p>If it is correct, the door is unlocked for 30 seconds (30,000 ms). - If it is incomplete, we wait for another button to be pressed. If - it is is wrong, we start all over, waiting for a new button - sequence.</p> - <p>Implementing the code lock FSM using <c>gen_fsm</c> results in - the following callback module:</p> - <marker id="ex"></marker> - <code type="none"><![CDATA[ --module(code_lock). --behaviour(gen_fsm). - --export([start_link/1]). --export([button/1]). --export([init/1, locked/2, open/2]). - -start_link(Code) -> - gen_fsm:start_link({local, code_lock}, code_lock, lists:reverse(Code), []). - -button(Digit) -> - gen_fsm:send_event(code_lock, {button, Digit}). - -init(Code) -> - {ok, locked, {[], Code}}. - -locked({button, Digit}, {SoFar, Code}) -> - case [Digit|SoFar] of - Code -> - do_unlock(), - {next_state, open, {[], Code}, 30000}; - Incomplete when length(Incomplete)<length(Code) -> - {next_state, locked, {Incomplete, Code}}; - _Wrong -> - {next_state, locked, {[], Code}} - end. - -open(timeout, State) -> - do_lock(), - {next_state, locked, State}.]]></code> - <p>The code is explained in the next sections.</p> - </section> - - <section> - <title>Starting gen_fsm</title> - <p>In the example in the previous section, the <c>gen_fsm</c> is - started by calling <c>code_lock:start_link(Code)</c>:</p> - <code type="none"> -start_link(Code) -> - gen_fsm:start_link({local, code_lock}, code_lock, lists:reverse(Code), []). - </code> - <p><c>start_link</c> calls the function <c>gen_fsm:start_link/4</c>, - which spawns and links to a new process, a <c>gen_fsm</c>.</p> - <list type="bulleted"> - <item> - <p>The first argument, <c>{local, code_lock}</c>, specifies - the name. In this case, the <c>gen_fsm</c> is locally - registered as <c>code_lock</c>.</p> - <p>If the name is omitted, the <c>gen_fsm</c> is not registered. - Instead its pid must be used. The name can also be given - as <c>{global, Name}</c>, in which case the <c>gen_fsm</c> is - registered using <c>global:register_name/2</c>.</p> - </item> - <item> - <p>The second argument, <c>code_lock</c>, is the name of - the callback module, that is, the module where the callback - functions are located.</p> - <p>The interface functions (<c>start_link</c> and <c>button</c>) - are then located in the same module as the callback - functions (<c>init</c>, <c>locked</c>, and <c>open</c>). This - is normally good programming practice, to have the code - corresponding to one process contained in one module.</p> - </item> - <item> - <p>The third argument, <c>Code</c>, is a list of digits that - which is passed reversed to the callback function <c>init</c>. - Here, <c>init</c> - gets the correct code for the lock as indata.</p> - </item> - <item> - <p>The fourth argument, <c>[]</c>, is a list of options. See - the <c>gen_fsm(3)</c> manual page for available options.</p> - </item> - </list> - <p>If name registration succeeds, the new <c>gen_fsm</c> process calls - the callback function <c>code_lock:init(Code)</c>. This function - is expected to return <c>{ok, StateName, StateData}</c>, where - <c>StateName</c> is the name of the initial state of the - <c>gen_fsm</c>. In this case <c>locked</c>, assuming the door is - locked to begin with. <c>StateData</c> is the internal state of - the <c>gen_fsm</c>. (For <c>gen_fsm</c>, the internal state is - often referred to 'state data' to - distinguish it from the state as in states of a state machine.) - In this case, the state data is the button sequence so far (empty - to begin with) and the correct code of the lock.</p> - <code type="none"> -init(Code) -> - {ok, locked, {[], Code}}.</code> - <p><c>gen_fsm:start_link</c> is synchronous. It does not return until - the <c>gen_fsm</c> has been initialized and is ready to - receive notifications.</p> - <p><c>gen_fsm:start_link</c> must be used if the <c>gen_fsm</c> is - part of a supervision tree, that is, started by a supervisor. There - is another function, <c>gen_fsm:start</c>, to start a standalone - <c>gen_fsm</c>, that is, a <c>gen_fsm</c> that is not part of a - supervision tree.</p> - </section> - - <section> - <title>Notifying about Events</title> - <p>The function notifying the code lock about a button event is - implemented using <c>gen_fsm:send_event/2</c>:</p> - <code type="none"> -button(Digit) -> - gen_fsm:send_event(code_lock, {button, Digit}).</code> - <p><c>code_lock</c> is the name of the <c>gen_fsm</c> and must - agree with the name used to start it. - <c>{button, Digit}</c> is the actual event.</p> - <p>The event is made into a message and sent to the <c>gen_fsm</c>. - When the event is received, the <c>gen_fsm</c> calls - <c>StateName(Event, StateData)</c>, which is expected to return a - tuple <c>{next_state,StateName1,StateData1}</c>. - <c>StateName</c> is the name of the current state and - <c>StateName1</c> is the name of the next state to go to. - <c>StateData1</c> is a new value for the state data of - the <c>gen_fsm</c>.</p> - <code type="none"><![CDATA[ -locked({button, Digit}, {SoFar, Code}) -> - case [Digit|SoFar] of - Code -> - do_unlock(), - {next_state, open, {[], Code}, 30000}; - Incomplete when length(Incomplete)<length(Code) -> - {next_state, locked, {Incomplete, Code}}; - _Wrong -> - {next_state, locked, {[], Code}}; - end. - -open(timeout, State) -> - do_lock(), - {next_state, locked, State}.]]></code> - <p>If the door is locked and a button is pressed, the complete - button sequence so far is compared with the correct code for - the lock and, depending on the result, the door is either unlocked - and the <c>gen_fsm</c> goes to state <c>open</c>, or the door - remains in state <c>locked</c>.</p> - </section> - - <section> - <title>Time-Outs</title> - <p>When a correct code has been given, the door is unlocked and - the following tuple is returned from <c>locked/2</c>:</p> - <code type="none"> -{next_state, open, {[], Code}, 30000};</code> - <p>30,000 is a time-out value in milliseconds. After this time, - that is, 30 seconds, a time-out occurs. Then, - <c>StateName(timeout, StateData)</c> is called. The time-out - then occurs when the door has been in state <c>open</c> for 30 - seconds. After that the door is locked again:</p> - <code type="none"> -open(timeout, State) -> - do_lock(), - {next_state, locked, State}.</code> - </section> - - <section> - <title>All State Events</title> - <p>Sometimes an event can arrive at any state of the <c>gen_fsm</c>. - Instead of sending the message with <c>gen_fsm:send_event/2</c> - and writing one clause handling the event for each state function, - the message can be sent with <c>gen_fsm:send_all_state_event/2</c> - and handled with <c>Module:handle_event/3</c>:</p> - <code type="none"> --module(code_lock). -... --export([stop/0]). -... - -stop() -> - gen_fsm:send_all_state_event(code_lock, stop). - -... - -handle_event(stop, _StateName, StateData) -> - {stop, normal, StateData}.</code> - </section> - - <section> - <title>Stopping</title> - - <section> - <title>In a Supervision Tree</title> - <p>If the <c>gen_fsm</c> is part of a supervision tree, no stop - function is needed. The <c>gen_fsm</c> is automatically - terminated by its supervisor. Exactly how this is done is - defined by a - <seealso marker="sup_princ#shutdown">shutdown strategy</seealso> - set in the supervisor.</p> - <p>If it is necessary to clean up before termination, the shutdown - strategy must be a time-out value and the <c>gen_fsm</c> must be - set to trap exit signals in the <c>init</c> function. When ordered - to shutdown, the <c>gen_fsm</c> then calls the callback function - <c>terminate(shutdown, StateName, StateData)</c>:</p> - <code type="none"> -init(Args) -> - ..., - process_flag(trap_exit, true), - ..., - {ok, StateName, StateData}. - -... - -terminate(shutdown, StateName, StateData) -> - ..code for cleaning up here.. - ok.</code> - </section> - - <section> - <title>Standalone gen_fsm</title> - <p>If the <c>gen_fsm</c> is not part of a supervision tree, a stop - function can be useful, for example:</p> - <code type="none"> -... --export([stop/0]). -... - -stop() -> - gen_fsm:send_all_state_event(code_lock, stop). -... - -handle_event(stop, _StateName, StateData) -> - {stop, normal, StateData}. - -... - -terminate(normal, _StateName, _StateData) -> - ok.</code> - <p>The callback function handling the <c>stop</c> event returns a - tuple, <c>{stop,normal,StateData1}</c>, where <c>normal</c> - specifies that it is a normal termination and <c>StateData1</c> - is a new value for the state data of the <c>gen_fsm</c>. This - causes the <c>gen_fsm</c> to call - <c>terminate(normal,StateName,StateData1)</c> and then - it terminates gracefully:</p> - </section> - </section> - - <section> - <title>Handling Other Messages</title> - <p>If the <c>gen_fsm</c> is to be able to receive other messages - than events, the callback function - <c>handle_info(Info, StateName, StateData)</c> must be implemented - to handle them. Examples of - other messages are exit messages, if the <c>gen_fsm</c> is linked to - other processes (than the supervisor) and trapping exit signals.</p> - <code type="none"> -handle_info({'EXIT', Pid, Reason}, StateName, StateData) -> - ..code to handle exits here.. - {next_state, StateName1, StateData1}.</code> - <p>The code_change method must also be implemented.</p> - <code type="none"> -code_change(OldVsn, StateName, StateData, Extra) -> - ..code to convert state (and more) during code change - {ok, NextStateName, NewStateData}</code> - </section> -</chapter> - diff --git a/system/doc/design_principles/part.xml b/system/doc/design_principles/part.xml index 6495211e04..d52070a674 100644 --- a/system/doc/design_principles/part.xml +++ b/system/doc/design_principles/part.xml @@ -30,7 +30,6 @@ </header> <xi:include href="des_princ.xml"/> <xi:include href="gen_server_concepts.xml"/> - <xi:include href="fsm.xml"/> <xi:include href="statem.xml"/> <xi:include href="events.xml"/> <xi:include href="sup_princ.xml"/> diff --git a/system/doc/design_principles/spec_proc.xml b/system/doc/design_principles/spec_proc.xml index 5b156ac263..d663c5df79 100644 --- a/system/doc/design_principles/spec_proc.xml +++ b/system/doc/design_principles/spec_proc.xml @@ -45,61 +45,63 @@ <p>The <c>sys</c> module has functions for simple debugging of processes implemented using behaviours. The <c>code_lock</c> example from - <seealso marker="fsm#ex">gen_fsm Behaviour</seealso> + <seealso marker="statem#Example">gen_statem Behaviour</seealso> is used to illustrate this:</p> <pre> -% <input>erl</input> -Erlang (BEAM) emulator version 5.2.3.6 [hipe] [threads:0] +Erlang/OTP 20 [DEVELOPMENT] [erts-9.0] [source-5ace45e] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:10] [hipe] [kernel-poll:false] -Eshell V5.2.3.6 (abort with ^G) -1> <input>code_lock:start_link([1,2,3,4]).</input> -{ok,<0.32.0>} -2> <input>sys:statistics(code_lock, true).</input> +Eshell V9.0 (abort with ^G) +1> code_lock:start_link([1,2,3,4]). +Lock +{ok,<0.63.0>} +2> sys:statistics(code_lock, true). ok -3> <input>sys:trace(code_lock, true).</input> +3> sys:trace(code_lock, true). ok -4> <input>code_lock:button(4).</input> -*DBG* code_lock got event {button,4} in state closed +4> code_lock:button(1). +*DBG* code_lock receive cast {button,1} in state locked ok -*DBG* code_lock switched to state closed -5> <input>code_lock:button(3).</input> -*DBG* code_lock got event {button,3} in state closed +*DBG* code_lock consume cast {button,1} in state locked +5> code_lock:button(2). +*DBG* code_lock receive cast {button,2} in state locked ok -*DBG* code_lock switched to state closed -6> <input>code_lock:button(2).</input> -*DBG* code_lock got event {button,2} in state closed +*DBG* code_lock consume cast {button,2} in state locked +6> code_lock:button(3). +*DBG* code_lock receive cast {button,3} in state locked ok -*DBG* code_lock switched to state closed -7> <input>code_lock:button(1).</input> -*DBG* code_lock got event {button,1} in state closed +*DBG* code_lock consume cast {button,3} in state locked +7> code_lock:button(4). +*DBG* code_lock receive cast {button,4} in state locked ok -OPEN DOOR -*DBG* code_lock switched to state open -*DBG* code_lock got event timeout in state open -CLOSE DOOR -*DBG* code_lock switched to state closed -8> <input>sys:statistics(code_lock, get).</input> -{ok,[{start_time,{{2003,6,12},{14,11,40}}}, - {current_time,{{2003,6,12},{14,12,14}}}, - {reductions,333}, +Unlock +*DBG* code_lock consume cast {button,4} in state locked +*DBG* code_lock receive state_timeout lock in state open +Lock +*DBG* code_lock consume state_timeout lock in state open +8> sys:statistics(code_lock, get). +{ok,[{start_time,{{2017,4,21},{16,8,7}}}, + {current_time,{{2017,4,21},{16,9,42}}}, + {reductions,2973}, {messages_in,5}, {messages_out,0}]} -9> <input>sys:statistics(code_lock, false).</input> +9> sys:statistics(code_lock, false). ok -10> <input>sys:trace(code_lock, false).</input> +10> sys:trace(code_lock, false). ok -11> <input>sys:get_status(code_lock).</input> -{status,<0.32.0>, - {module,gen_fsm}, - [[{'$ancestors',[<0.30.0>]}, - {'$initial_call',{gen,init_it, - [gen_fsm,<0.30.0>,<0.30.0>, - {local,code_lock}, - code_lock, - [1,2,3,4], - []]}}], - running,<0.30.0>,[], - [code_lock,closed,{[],[1,2,3,4]},code_lock,infinity]]}</pre> +11> sys:get_status(code_lock). +{status,<0.63.0>, + {module,gen_statem}, + [[{'$initial_call',{code_lock,init,1}}, + {'$ancestors',[<0.61.0>]}], + running,<0.61.0>,[], + [{header,"Status for state machine code_lock"}, + {data,[{"Status",running}, + {"Parent",<0.61.0>}, + {"Logged Events",[]}, + {"Postponed",[]}]}, + {data,[{"State", + {locked,#{code => [1,2,3,4],remaining => [1,2,3,4]}}}]}]]} + </pre> </section> <section> diff --git a/system/doc/design_principles/sup_princ.xml b/system/doc/design_principles/sup_princ.xml index 478d1bf714..4fd210aa48 100644 --- a/system/doc/design_principles/sup_princ.xml +++ b/system/doc/design_principles/sup_princ.xml @@ -276,7 +276,6 @@ child_spec() = #{id => child_id(), % mandatory <list type="bulleted"> <item><c>supervisor:start_link</c></item> <item><c>gen_server:start_link</c></item> - <item><c>gen_fsm:start_link</c></item> <item><c>gen_statem:start_link</c></item> <item><c>gen_event:start_link</c></item> <item>A function compliant with these functions. For details, @@ -341,7 +340,7 @@ child_spec() = #{id => child_id(), % mandatory <p><c>modules</c> are to be a list with one element <c>[Module]</c>, where <c>Module</c> is the name of the callback module, if the child process is a supervisor, - gen_server, gen_fsm or gen_statem. + gen_server, gen_statem. If the child process is a gen_event, the value shall be <c>dynamic</c>.</p> <p>This information is used by the release handler during diff --git a/system/doc/design_principles/xmlfiles.mk b/system/doc/design_principles/xmlfiles.mk index e476255d62..8877e94f39 100644 --- a/system/doc/design_principles/xmlfiles.mk +++ b/system/doc/design_principles/xmlfiles.mk @@ -24,7 +24,6 @@ DESIGN_PRINCIPLES_CHAPTER_FILES = \ des_princ.xml \ distributed_applications.xml \ events.xml \ - fsm.xml \ statem.xml \ gen_server_concepts.xml \ included_applications.xml \ diff --git a/system/doc/reference_manual/modules.xml b/system/doc/reference_manual/modules.xml index 96968b547e..6fe6680c84 100644 --- a/system/doc/reference_manual/modules.xml +++ b/system/doc/reference_manual/modules.xml @@ -143,7 +143,6 @@ fact(0) -> % | standard behaviours:</p> <list type="bulleted"> <item><c>gen_server</c></item> - <item><c>gen_fsm</c></item> <item><c>gen_statem</c></item> <item><c>gen_event</c></item> <item><c>supervisor</c></item> |