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author | Raimo Niskanen <[email protected]> | 2016-04-15 10:09:54 +0200 |
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committer | Raimo Niskanen <[email protected]> | 2016-04-18 12:14:41 +0200 |
commit | a2f3c685b5aeac798e12302cf8fe7df13184b669 (patch) | |
tree | da557e71612c6eb1990d9a95b4c35327dad74acd | |
parent | 20b44db2843e280474a45665f2584f9130eb686b (diff) | |
download | otp-a2f3c685b5aeac798e12302cf8fe7df13184b669.tar.gz otp-a2f3c685b5aeac798e12302cf8fe7df13184b669.tar.bz2 otp-a2f3c685b5aeac798e12302cf8fe7df13184b669.zip |
Introduce corrections from Fred Hebert and Ingela
-rw-r--r-- | lib/stdlib/doc/src/gen_statem.xml | 2 | ||||
-rw-r--r-- | system/doc/design_principles/statem.xml | 21 |
2 files changed, 17 insertions, 6 deletions
diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml index bd70c4c37e..c21398d64d 100644 --- a/lib/stdlib/doc/src/gen_statem.xml +++ b/lib/stdlib/doc/src/gen_statem.xml @@ -45,7 +45,7 @@ using this module will have a standard set of interface functions and include functionality for tracing and error reporting. It will also fit into an OTP supervision tree. Refer to - <seealso marker="doc/design_principles:gen_server_concepts"> + <seealso marker="doc/design_principles:statem"> OTP Design Principles </seealso> for more information. diff --git a/system/doc/design_principles/statem.xml b/system/doc/design_principles/statem.xml index 65daeac782..02754bd23d 100644 --- a/system/doc/design_principles/statem.xml +++ b/system/doc/design_principles/statem.xml @@ -90,7 +90,7 @@ State(S) x Event(E) -> Actions(A), State(S')</pre> <pre> StateName(EventType, EventContent, Data) -> .. code for actions here ... - {next_state, StateName', Data'}.</pre> + {next_state, NewStateName, NewData}.</pre> <p> In the mode <c>handle_event_function</c> there is only one Erlang function that implements all state transition rules: @@ -612,7 +612,7 @@ stop() -> An example of event postponing comes in later in this chapter. See the <seealso marker="stdlib:gen_statem#type-action"> - documentation + reference manual </seealso> for details. You can for example actually reply to several callers and generate multiple next events to handle. @@ -735,7 +735,8 @@ open(cast, {button,_}, Data) -> <c>erlang:cancel_timer(Tref)</c>. </seealso> Note that a timeout message can not arrive after this, - unless you have postponed it before (why on earth one would do that). + unless you have postponed it (see the next section) before, + so make sure you do not accidentally postpone such messages. </p> <p> Another way to cancel a timer is to not cancel it, @@ -838,14 +839,24 @@ do_unlock() -> to implicitly postpone any events to the <c>locked</c> state. </p> <p> + A selective receive can not be used from a <c>gen_statem</c> + behaviour just as for any <c>gen_*</c> behavior + since the receive statement is within the <c>gen_*</c> engine itself. + It has to be there because all + <seealso marker="stdlib:sys"><c>sys</c></seealso> + compatible behaviours must respond to system messages and therefore + do that in their engine receive loop, + passing non-system messages to the callback module. + </p> + <p> The <seealso marker="stdlib:gen_statem#type-action"> state transition action </seealso> <c>postpone</c> is designed to be able to model - selective receive. Selective receive implicitly postpones + selective receives. A selective receive implicitly postpones any not received events, but the <c>postpone</c> - state transition action explicitly postpones a received event. + state transition action explicitly postpones one received event. </p> <p> Other than that both mechanisms have got the same theoretical |