diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/stdlib/doc/src/gen_statem.xml | 17 | ||||
| -rw-r--r-- | lib/stdlib/src/gen_statem.erl | 3 |
2 files changed, 11 insertions, 9 deletions
diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml index 5eb13db1aa..f7baaad5d1 100644 --- a/lib/stdlib/doc/src/gen_statem.xml +++ b/lib/stdlib/doc/src/gen_statem.xml @@ -146,7 +146,7 @@ erlang:'!' -----> Module:StateName/3 This gathers all code for a specific state in one function as the <c>gen_statem</c> engine branches depending on state name. - Notice the fact that there is a mandatory callback function + Note the fact that the callback function <seealso marker="#Module:terminate/3"><c>Module:terminate/3</c></seealso> makes the state name <c>terminate</c> unusable in this mode. </p> @@ -1704,7 +1704,7 @@ handle_event(_, _, State, Data) -> <func> <name>Module:init(Args) -> Result(StateType)</name> <fsummary> - Optional function for initializing process and internal state. + Initializing process and internal state. </fsummary> <type> <v>Args = term()</v> @@ -1720,7 +1720,7 @@ handle_event(_, _, State, Data) -> <seealso marker="#start_link/3"><c>start_link/3,4</c></seealso> or <seealso marker="#start/3"><c>start/3,4</c></seealso>, - this optional function is called by the new process to initialize + this function is called by the new process to initialize the implementation state and server data. </p> <p> @@ -1729,13 +1729,16 @@ handle_event(_, _, State, Data) -> </p> <note> <p> - This callback is optional, so a callback module does not need - to export it, but most do. If this function is not exported, - the <c>gen_statem</c> should be started through + Note that if the <c>gen_statem</c> is started trough <seealso marker="proc_lib"><c>proc_lib</c></seealso> and - <seealso marker="#enter_loop/4"><c>enter_loop/4-6</c></seealso>. + <seealso marker="#enter_loop/4"><c>enter_loop/4-6</c></seealso>, + this callback will never be called. + Since this callback is not optional it can + in that case be implemented as: </p> + <pre> +init(Args) -> erlang:error(not_implemented, [Args]).</pre> </note> </desc> </func> diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl index cacc932ec4..242ff87be7 100644 --- a/lib/stdlib/src/gen_statem.erl +++ b/lib/stdlib/src/gen_statem.erl @@ -287,8 +287,7 @@ StatusOption :: 'normal' | 'terminate'. -optional_callbacks( - [init/1, % One may use enter_loop/5,6,7 instead - format_status/2, % Has got a default implementation + [format_status/2, % Has got a default implementation terminate/3, % Has got a default implementation code_change/4, % Only needed by advanced soft upgrade %% |