diff options
Diffstat (limited to 'lib/stdlib/doc/src')
| -rw-r--r-- | lib/stdlib/doc/src/beam_lib.xml | 46 | ||||
| -rw-r--r-- | lib/stdlib/doc/src/gen_fsm.xml | 1109 | ||||
| -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/sets.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/doc/src/unicode_usage.xml | 17 |
9 files changed, 227 insertions, 995 deletions
diff --git a/lib/stdlib/doc/src/beam_lib.xml b/lib/stdlib/doc/src/beam_lib.xml index d5ec90b060..031d79d0e2 100644 --- a/lib/stdlib/doc/src/beam_lib.xml +++ b/lib/stdlib/doc/src/beam_lib.xml @@ -42,10 +42,10 @@ and the corresponding identifiers are as follows:</p> <list type="bulleted"> - <item><c>abstract_code ("Abst")</c></item> <item><c>atoms ("Atom")</c></item> <item><c>attributes ("Attr")</c></item> <item><c>compile_info ("CInf")</c></item> + <item><c>debug_info ("Dbgi")</c></item> <item><c>exports ("ExpT")</c></item> <item><c>imports ("ImpT")</c></item> <item><c>indexed_imports ("ImpT")</c></item> @@ -60,9 +60,8 @@ <title>Debug Information/Abstract Code</title> <p>Option <c>debug_info</c> can be specified to the Compiler (see <seealso marker="compiler:compile#debug_info"><c>compile(3)</c></seealso>) - to have debug information in the form of abstract code (see section - <seealso marker="erts:absform">The Abstract Format</seealso> in the - ERTS User's Guide) stored in the <c>abstract_code</c> chunk. + to have debug information, such as <seealso marker="erts:absform">Erlang + Abstract Format</seealso>, stored in the <c>debug_info</c> chunk. Tools such as Debugger and Xref require the debug information to be included.</p> @@ -79,7 +78,7 @@ <section> <title>Reconstruct Source Code</title> - <p>The following example shows how to reconstruct source code from + <p>The following example shows how to reconstruct Erlang source code from the debug information in a BEAM file <c>Beam</c>:</p> <code type="none"> @@ -117,7 +116,7 @@ io:fwrite("~s~n", [erl_prettypr:format(erl_syntax:form_list(AC))]).</code> <list type="ordered"> <item> - <p>Use Compiler option <c>{debug_info,Key}</c>, see + <p>Use Compiler option <c>{debug_info_key,Key}</c>, see <seealso marker="compiler:compile#debug_info_key"><c>compile(3)</c></seealso> and function <seealso marker="#crypto_key_fun/1"><c>crypto_key_fun/1</c></seealso> @@ -198,18 +197,40 @@ io:fwrite("~s~n", [erl_prettypr:format(erl_syntax:form_list(AC))]).</code> <datatype> <name name="chunkid"/> <desc> - <p>"Abst" | "Attr" | "CInf" | "ExpT" | "ImpT" | "LocT" | "Atom"</p> + <p>"Attr" | "CInf" | "Dbgi" | "ExpT" | "ImpT" | "LocT" | "AtU8"</p> </desc> </datatype> <datatype> <name name="dataB"/> </datatype> <datatype> + <name name="debug_info"/> + <desc> + <p>The format stored in the <c>debug_info</c> chunk. + To retrieve particular code representation from the backend, + <c>Backend:debug_info(Format, Module, Data, Opts)</c> must be + invoked. <c>Format</c> is an atom, such as <c>erlang_v1</c> for + the Erlang Abstract Format or <c>core_v1</c> for Core Erlang. + <c>Module</c> is the module represented by the beam file and + <c>Data</c> is the value stored in the debug info chunk. + <c>Opts</c> is any list of values supported by the <c>Backend</c>. + <c>Backend:debug_info/4</c> must return <c>{ok, Code}</c> or + <c>{error, Term}</c>.</p> + + <p>Developers must always invoke the <c>debug_info/4</c> function + and never rely on the <c>Data</c> stored in the <c>debug_info</c> + chunk, as it is opaque and may change at any moment. <c>no_debug_info</c> + means that chunk <c>"Dbgi"</c> is present, but empty.</p> + </desc> + </datatype> + <datatype> <name name="abst_code"/> <desc> <p>It is not checked that the forms conform to the abstract format indicated by <c><anno>AbstVersion</anno></c>. <c>no_abstract_code</c> means that chunk <c>"Abst"</c> is present, but empty.</p> + <p>For modules compiled with OTP 20 onwards, the <c>abst_code</c> chunk + is automatically computed from the <c>debug_info</c> chunk.</p> </desc> </datatype> <datatype> @@ -346,7 +367,7 @@ io:fwrite("~s~n", [erl_prettypr:format(erl_syntax:form_list(AC))]).</code> <desc> <p>Registers an unary fun that is called if <c>beam_lib</c> must read an - <c>abstract_code</c> chunk that has been encrypted. The fun + <c>debug_info</c> chunk that has been encrypted. The fun is held in a process that is started by the function.</p> <p>If a fun is already registered when attempting to register a fun, <c>{error, exists}</c> is returned.</p> @@ -443,7 +464,8 @@ CryptoKeyFun(clear) -> term()</code> <desc> <p>Removes all chunks from a BEAM file except those needed by the loader. In particular, - the debug information (chunk <c>abstract_code</c>) is removed.</p> + the debug information (chunk <c>debug_info</c> and <c>abstract_code</c>) + is removed.</p> </desc> </func> @@ -454,9 +476,9 @@ CryptoKeyFun(clear) -> term()</code> <desc> <p>Removes all chunks except those needed by the loader from BEAM files. In particular, - the debug information (chunk <c>abstract_code</c>) is removed. - The returned list contains one element for each specified filename, - in the same order as in <c>Files</c>.</p> + the debug information (chunk <c>debug_info</c> and <c>abstract_code</c>) + is removed. The returned list contains one element for each + specified filename, in the same order as in <c>Files</c>.</p> </desc> </func> diff --git a/lib/stdlib/doc/src/gen_fsm.xml b/lib/stdlib/doc/src/gen_fsm.xml index 691a039e34..e70f347479 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 @@ -29,945 +29,176 @@ <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> - <note> - <p>This callback is optional, so callback modules need not export it. - If a release upgrade/downgrade with <c>Change={advanced,Extra}</c> - specified in the <c>appup</c> file is made when <c>code_change/4</c> - isn't implemented the process will crash with an <c>undef</c> exit - reason.</p> - </note> - <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> - <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 logs about the unexpected - <c>Info</c> message, drops it and returns - <c>{next_state, StateName, StateData}</c>.</p> - </note> - <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> - <note> - <p>This callback is optional, so callback modules need not - export it. The <c>gen_fsm</c> module provides a default - implementation without cleanup.</p> - </note> - <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 4540449792..0bcbbc2805 100644 --- a/lib/stdlib/doc/src/gen_server.xml +++ b/lib/stdlib/doc/src/gen_server.xml @@ -814,7 +814,6 @@ 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/sets.xml b/lib/stdlib/doc/src/sets.xml index 44dc104645..4dc5d68151 100644 --- a/lib/stdlib/doc/src/sets.xml +++ b/lib/stdlib/doc/src/sets.xml @@ -40,7 +40,7 @@ <p>This module provides the same interface as the <seealso marker="ordsets"><c>ordsets(3)</c></seealso> module - but with a defined representation. One difference is + but with an undefined representation. One difference is that while this module considers two elements as different if they do not match (<c>=:=</c>), <c>ordsets</c> considers two elements as different if and only if they do not compare equal (<c>==</c>).</p> 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/doc/src/unicode_usage.xml b/lib/stdlib/doc/src/unicode_usage.xml index 11b84f552a..6af2fa9fa3 100644 --- a/lib/stdlib/doc/src/unicode_usage.xml +++ b/lib/stdlib/doc/src/unicode_usage.xml @@ -64,8 +64,8 @@ source files was switched to UTF-8.</p></item> <item><p>In Erlang/OTP 20.0, atoms and function can contain - Unicode characters. Module names are still restricted to - the ISO-Latin-1 range.</p> + Unicode characters. Module names, application names, and node + names are still restricted to the ISO Latin-1 range.</p> <p>Support was added for normalizations forms in <c>unicode</c> and the <c>string</c> module now handles utf8-encoded binaries.</p></item> @@ -352,10 +352,11 @@ <p>Having the source code in UTF-8 also allows you to write string literals, function names, and atoms containing Unicode characters with code points > 255. - Module names are still restricted to the ISO Latin-1 range. - Binary literals, where you use type + Module names, application names, and node names are still restricted + to the ISO Latin-1 range. Binary literals, where you use type <c>/utf8</c>, can also be expressed using Unicode characters > 255. - Having module names using characters other than 7-bit ASCII can cause + Having module names or application names using characters other than + 7-bit ASCII can cause trouble on operating systems with inconsistent file naming schemes, and can hurt portability, so it is not recommended.</p> <p>EEP 40 suggests that the language is also to allow for Unicode @@ -451,8 +452,8 @@ external_charlist() = maybe_improper_list(char() | external_unicode_binary() | marker="stdlib:epp#encoding"><c>epp(3)</c></seealso> module. As from Erlang/OTP R16, strings and comments can be written using Unicode. As from Erlang/OTP 20, also atoms and functions can be - written using Unicode. Modules names must still be named using - characters from the ISO Latin-1 character set. (These + written using Unicode. Modules, applications, and nodes must still be + named using characters from the ISO Latin-1 character set. (These restrictions in the language are independent of the encoding of the source file.)</p> @@ -780,7 +781,7 @@ Eshell V5.10.1 (abort with ^G) filenames or directory names. If the file system content is listed, you also get Unicode lists as return value. The support lies in the Kernel and STDLIB modules, which is why - most applications (that does not explicitly require the filenames + most applications (that do not explicitly require the filenames to be in the ISO Latin-1 range) benefit from the Unicode support without change.</p> |