diff options
Diffstat (limited to 'system')
| -rw-r--r-- | system/doc/design_principles/statem.xml | 36 |
1 files changed, 20 insertions, 16 deletions
diff --git a/system/doc/design_principles/statem.xml b/system/doc/design_principles/statem.xml index 26e4840640..72aaafd780 100644 --- a/system/doc/design_principles/statem.xml +++ b/system/doc/design_principles/statem.xml @@ -216,6 +216,7 @@ handle_event(EventType, EventContent, State, Data) -> <code type="erl"><![CDATA[ -module(code_lock). -behaviour(gen_statem). +-define(NAME, code_lock). -export([start_link/1]). -export([button/1]). @@ -223,10 +224,10 @@ handle_event(EventType, EventContent, State, Data) -> -export([locked/3,open/3]). start_link(Code) -> - gen_statem:start_link({local,code_lock}, ?MODULE, Code, []). + gen_statem:start_link({local,?NAME}, ?MODULE, Code, []). button(Digit) -> - gen_statem:cast(code_lock, {button,Digit}). + gen_statem:cast(?NAME, {button,Digit}). init(Code) -> @@ -278,7 +279,7 @@ code_change(_Vsn, State, Data, _Extra) -> </p> <code type="erl"><![CDATA[ start_link(Code) -> - gen_statem:start_link({local,code_lock}, ?MODULE, Code, []). + gen_statem:start_link({local,?NAME}, ?MODULE, Code, []). ]]></code> <p> <c>start_link</c> calls the function @@ -290,9 +291,9 @@ start_link(Code) -> <list type="bulleted"> <item> <p> - The first argument, <c>{local,code_lock}</c>, specifies + The first argument, <c>{local,?NAME}</c>, specifies the name. In this case, the <c>gen_statem</c> is locally - registered as <c>code_lock</c>. + registered as <c>code_lock</c> through the macro <c>?NAME</c>. </p> <p> If the name is omitted, the <c>gen_statem</c> is not registered. @@ -394,11 +395,12 @@ init(Code) -> </p> <code type="erl"><![CDATA[ button(Digit) -> - gen_statem:cast(code_lock, {button,Digit}). + gen_statem:cast(?NAME, {button,Digit}). ]]></code> <p> - <c>code_lock</c> is the name of the <c>gen_statem</c> and must - agree with the name used to start it. + The first argument is the name of the <c>gen_statem</c> and must + agree with the name used to start it so therefore we use the + same macro <c>?NAME</c> as when starting. <c>{button,Digit}</c> is the actual event content. </p> <p> @@ -495,7 +497,7 @@ open(timeout, _, Data) -> ... code_length() -> - gen_statem:call(code_lock, code_length). + gen_statem:call(?NAME, code_length). ... locked(...) -> ... ; @@ -627,7 +629,7 @@ terminate(_Reason, State, _Data) -> ... stop() -> - gen_statem:stop(code_lock). + gen_statem:stop(?NAME). ]]></code> <p> This makes the <c>gen_statem</c> call the <c>terminate/3</c> @@ -882,18 +884,19 @@ open(cast, {button,_}, Data) -> </p> <code type="erl"><![CDATA[ -module(code_lock). +-define(NAME, code_lock_1). -export([start_link/1,button/1]). start_link(Code) -> spawn( fun () -> - true = register(code_lock, self()), + true = register(?NAME, self()), do_lock(), locked(Code, Code) end). button(Digit) -> - code_lock ! {button,Digit}. + ?NAME ! {button,Digit}. locked(Code, [Digit|Remaining]) -> receive @@ -1049,6 +1052,7 @@ enter(Tag, State, Data) -> <code type="erl"><![CDATA[ -module(code_lock). -behaviour(gen_statem). +-define(NAME, code_lock_2). -export([start_link/1,stop/0]). -export([button/1,code_length/0]). @@ -1056,14 +1060,14 @@ enter(Tag, State, Data) -> -export([locked/3,open/3]). start_link(Code) -> - gen_statem:start_link({local,code_lock}, ?MODULE, Code, []). + gen_statem:start_link({local,?NAME}, ?MODULE, Code, []). stop() -> - gen_statem:stop(code_lock). + gen_statem:stop(?NAME). button(Digit) -> - gen_statem:cast(code_lock, {button,Digit}). + gen_statem:cast(?NAME, {button,Digit}). code_length() -> - gen_statem:call(code_lock, code_length). + gen_statem:call(?NAME, code_length). init(Code) -> Data = #{code => Code}, |