diff options
| -rw-r--r-- | lib/stdlib/doc/src/gen_statem.xml | 13 | ||||
| -rw-r--r-- | lib/stdlib/src/gen_statem.erl | 4 |
2 files changed, 11 insertions, 6 deletions
diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml index 15e9584360..8462f5ff5f 100644 --- a/lib/stdlib/doc/src/gen_statem.xml +++ b/lib/stdlib/doc/src/gen_statem.xml @@ -1212,11 +1212,13 @@ erlang:'!' -----> Module:StateName/5 </type> <desc> <note> - <p>This callback is optional, so callback modules need not + <p>This callback is optional, so a callback module need not export it. The <c>gen_statem</c> module provides a default - implementation of this function that returns the callback - module state and data. The default function will also - be used if this callback fails. + implementation of this function that returns + <c>{State,Data}</c>. If this callback fails the default + function will return <c>{State,Info}</c> + where <c>Info</c> informs of the crash but no details, + to hide possibly sensitive data. </p> </note> <p>This function is called by a <c>gen_statem</c> process when:</p> @@ -1270,7 +1272,8 @@ erlang:'!' -----> Module:StateName/5 </p> <p>One use for this function is to return compact alternative state representations to avoid having large state terms - printed in logfiles. + printed in logfiles. Another is to hide sensitive data from + being written to the error log. </p> <p>This function may use <seealso marker="erts:erlang#throw/1"><c>throw</c></seealso>, diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl index 1ca2e1009c..b580eaab97 100644 --- a/lib/stdlib/src/gen_statem.erl +++ b/lib/stdlib/src/gen_statem.erl @@ -1214,7 +1214,9 @@ format_status( catch Result -> Result; _:_ -> - format_status_default(Opt, State, Data) + format_status_default( + Opt, State, + "Module:format_status/2 crashed") end; false -> format_status_default(Opt, State, Data) |