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-rw-r--r--lib/stdlib/doc/src/epp.xml1
-rw-r--r--lib/stdlib/doc/src/gen_statem.xml1779
-rw-r--r--lib/stdlib/doc/src/proc_lib.xml7
-rw-r--r--lib/stdlib/src/epp.erl65
-rw-r--r--lib/stdlib/src/gen_statem.erl493
-rw-r--r--lib/stdlib/src/otp_internal.erl2
-rw-r--r--lib/stdlib/src/proc_lib.erl5
-rw-r--r--lib/stdlib/test/epp_SUITE.erl63
-rw-r--r--lib/stdlib/test/erl_lint_SUITE.erl6
-rw-r--r--lib/stdlib/test/gen_statem_SUITE.erl10
10 files changed, 1268 insertions, 1163 deletions
diff --git a/lib/stdlib/doc/src/epp.xml b/lib/stdlib/doc/src/epp.xml
index 0802f0e47c..ac87f9c2b6 100644
--- a/lib/stdlib/doc/src/epp.xml
+++ b/lib/stdlib/doc/src/epp.xml
@@ -102,6 +102,7 @@
<func>
<name name="parse_erl_form" arity="1"/>
<fsummary>Return the next Erlang form from the opened Erlang source file</fsummary>
+ <type name="warning_info"/>
<desc>
<p>Returns the next Erlang form from the opened Erlang source file.
The tuple <c>{eof, <anno>Line</anno>}</c> is returned at end-of-file. The first
diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml
index ec7f267c64..0e7d6e53e9 100644
--- a/lib/stdlib/doc/src/gen_statem.xml
+++ b/lib/stdlib/doc/src/gen_statem.xml
@@ -29,39 +29,49 @@
<rev></rev>
</header>
<module>gen_statem</module>
- <modulesummary>Generic State Machine Behaviour</modulesummary>
+ <modulesummary>Generic state machine behavior.</modulesummary>
<description>
<p>
- A behaviour module for implementing a state machine. Two
+ This behavior module provides a state machine. Two
<seealso marker="#type-callback_mode"><em>callback modes</em></seealso>
- are supported. One for finite state machines
- (<seealso marker="gen_fsm"><c>gen_fsm</c></seealso> like)
- that requires the state to be an atom and uses that state as
- the name of the current callback function,
- and one without restriction on the state data type
- that uses one callback function for all states.
- </p>
- <p>
- This is a new behaviour in OTP-19.0.
- It has been thoroughly reviewed, is stable enough
- to be used by at least two heavy OTP applications, and is here to stay.
- But depending on user feedback, we do not expect
- but might find it necessary to make minor
- not backwards compatible changes into OTP-20.0,
- so its state can be designated as "not quite experimental"...
+ are supported:
</p>
+ <list type="bulleted">
+ <item>
+ <p>One for finite-state machines
+ (<seealso marker="gen_fsm"><c>gen_fsm</c></seealso> like),
+ which requires the state to be an atom and uses that state as
+ the name of the current callback function
+ </p>
+ </item>
+ <item>
+ <p>One without restriction on the state data type
+ that uses one callback function for all states
+ </p>
+ </item>
+ </list>
+ <note>
+ <p>
+ This is a new behavior in Erlang/OTP 19.0.
+ It has been thoroughly reviewed, is stable enough
+ to be used by at least two heavy OTP applications, and is here to stay.
+ Depending on user feedback, we do not expect
+ but can find it necessary to make minor
+ not backward compatible changes into Erlang/OTP 20.0.
+ </p>
+ </note>
<p>
- The <c>gen_statem</c> behaviour is intended to replace
+ The <c>gen_statem</c> behavior is intended to replace
<seealso marker="gen_fsm"><c>gen_fsm</c></seealso> for new code.
- It has the same features and add some really useful:
+ It has the same features and adds some really useful:
</p>
<list type="bulleted">
- <item>State code is gathered</item>
- <item>The state can be any term</item>
- <item>Events can be postponed</item>
- <item>Events can be self generated</item>
- <item>A reply can be sent from a later state</item>
- <item>There can be multiple sys traceable replies</item>
+ <item>State code is gathered.</item>
+ <item>The state can be any term.</item>
+ <item>Events can be postponed.</item>
+ <item>Events can be self-generated.</item>
+ <item>A reply can be sent from a later state.</item>
+ <item>There can be multiple <c>sys</c> traceable replies.</item>
</list>
<p>
The callback model(s) for <c>gen_statem</c> differs from
@@ -71,19 +81,16 @@
</p>
<p>
A generic state machine process (<c>gen_statem</c>) implemented
- 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:statem">
- OTP Design Principles
- </seealso>
- for more information.
+ 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:statem">OTP Design Principles</seealso>.
</p>
<p>
A <c>gen_statem</c> assumes all specific parts to be located in a
- callback module exporting a pre-defined set of functions.
- The relationship between the behaviour functions and the callback
- functions can be illustrated as follows:</p>
+ callback module exporting a predefined set of functions.
+ The relationship between the behavior functions and the callback
+ functions is as follows:</p>
<pre>
gen_statem module Callback module
----------------- ---------------
@@ -103,59 +110,54 @@ erlang:'!' -----> Module:StateName/3
- -----> Module:code_change/4</pre>
<p>
Events are of different
- <seealso marker="#type-event_type">types</seealso>
+ <seealso marker="#type-event_type">types</seealso>,
so the callback functions can know the origin of an event
and how to respond.
</p>
<p>
If a callback function fails or returns a bad value,
- the <c>gen_statem</c> will terminate. An exception of class
- <seealso marker="erts:erlang#throw/1"><c>throw</c></seealso>,
- however, is not regarded as an error but as a valid return.
+ the <c>gen_statem</c> terminates. However, an exception of class
+ <seealso marker="erts:erlang#throw/1"><c>throw</c></seealso>
+ is not regarded as an error but as a valid return.
</p>
- <marker id="state_function" />
+ <marker id="state_function"/>
<p>
The "<em>state function</em>" for a specific
<seealso marker="#type-state">state</seealso>
in a <c>gen_statem</c> is the callback function that is called
- for all events in this state, and is selected depending on which
+ for all events in this state. It is selected depending on which
<seealso marker="#type-callback_mode"><em>callback mode</em></seealso>
- that the implementation specifies when the the server starts.
+ that the implementation specifies when the server starts.
</p>
<p>
When the
<seealso marker="#type-callback_mode"><em>callback mode</em></seealso>
- is <c>state_functions</c>, the state has to be an atom and
- is used as the state function name. See
- <seealso marker="#Module:StateName/3">
- <c>Module:StateName/3</c>
- </seealso>.
+ is <c>state_functions</c>, the state must be an atom and
+ is used as the state function name; see
+ <seealso marker="#Module:StateName/3"><c>Module:StateName/3</c></seealso>.
This gathers all code for a specific state
- in one function and hence dispatches on state first.
- Note that in this mode the fact that there is
- a mandatory callback function
- <seealso marker="#Module:terminate/3">
- <c>Module:terminate/3</c>
- </seealso> makes the state name <c>terminate</c> unusable.
+ in one function as the <c>gen_statem</c> engine
+ branches depending on state name.
+ Notice that in this mode the mandatory callback function
+ <seealso marker="#Module:terminate/3"><c>Module:terminate/3</c></seealso>
+ makes the state name <c>terminate</c> unusable.
</p>
<p>
When the
<seealso marker="#type-callback_mode"><em>callback mode</em></seealso>
- is <c>handle_event_function</c> the state can be any term
+ is <c>handle_event_function</c>, the state can be any term
and the state function name is
- <seealso marker="#Module:handle_event/4">
- <c>Module:handle_event/4</c>
- </seealso>.
- This makes it easy to dispatch on state or on event as you desire.
+ <seealso marker="#Module:handle_event/4"><c>Module:handle_event/4</c></seealso>.
+ This makes it easy to branch depending on state or event as you desire.
Be careful about which events you handle in which
- states so you do not accidentally postpone one event
+ states so that you do not accidentally postpone an event
forever creating an infinite busy loop.
</p>
<p>
The <c>gen_statem</c> enqueues incoming events in order of arrival
and presents these to the
<seealso marker="#state_function">state function</seealso>
- in that order. The state function can postpone an event
+ in that order. The state function can postpone an event
so it is not retried in the current state.
After a state change the queue restarts with the postponed events.
</p>
@@ -163,91 +165,85 @@ erlang:'!' -----> Module:StateName/3
The <c>gen_statem</c> event queue model is sufficient
to emulate the normal process message queue with selective receive.
Postponing an event corresponds to not matching it
- in a receive statement and changing states corresponds
+ in a receive statement, and changing states corresponds
to entering a new receive statement.
</p>
<p>
The <seealso marker="#state_function">state function</seealso>
can insert events using the
- <seealso marker="#type-action">
- <c>action()</c> <c>next_event</c>
- </seealso>
+ <seealso marker="#type-action"><c>action()</c></seealso>
+ <c>next_event</c>
and such an event is inserted as the next to present
- to the state function. That is: as if it is
- the oldest incoming event. There is a dedicated
- <seealso marker="#type-event_type">
- <c>event_type()</c>
- </seealso>
- <c>internal</c> that can be used for such events making them impossible
+ to the state function. That is, as if it is
+ the oldest incoming event. A dedicated
+ <seealso marker="#type-event_type"><c>event_type()</c></seealso>
+ <c>internal</c> can be used for such events making them impossible
to mistake for external events.
</p>
<p>
Inserting an event replaces the trick of calling your own
state handling functions that you often would have to
- resort to in for example <seealso marker="gen_fsm"><c>gen_fsm</c></seealso>
+ resort to in, for example,
+ <seealso marker="gen_fsm"><c>gen_fsm</c></seealso>
to force processing an inserted event before others.
- A warning, though: if you in <c>gen_statem</c> for example
- postpone an event in one state and then call some other state function of yours,
- you have not changed states and hence the postponed event will not be retried,
- which is logical but might be confusing.
</p>
+ <note>
+ <p>If you in <c>gen_statem</c>, for example, postpone
+ an event in one state and then call another state function
+ of yours, you have not changed states and hence the postponed event
+ is not retried, which is logical but can be confusing.
+ </p>
+ </note>
<p>
- See the type
- <seealso marker="#type-transition_option">
- <c>transition_option()</c>
- </seealso>
- for the details of a state transition.
+ For the details of a state transition, see type
+ <seealso marker="#type-transition_option"><c>transition_option()</c></seealso>.
</p>
<p>
- A <c>gen_statem</c> handles system messages as documented in
+ A <c>gen_statem</c> handles system messages as described in
<seealso marker="sys"><c>sys</c></seealso>.
- The <c>sys</c>module can be used for debugging a <c>gen_statem</c>.
+ The <c>sys</c> module can be used for debugging a <c>gen_statem</c>.
</p>
<p>
- Note that a <c>gen_statem</c> does not trap exit signals
+ Notice that a <c>gen_statem</c> does not trap exit signals
automatically, this must be explicitly initiated in
the callback module (by calling
- <seealso marker="erts:erlang#process_flag/2">
- <c>process_flag(trap_exit, true)</c></seealso>.
+ <seealso marker="erts:erlang#process_flag/2"><c>process_flag(trap_exit, true)</c></seealso>.
</p>
<p>
Unless otherwise stated, all functions in this module fail if
the specified <c>gen_statem</c> does not exist or
- if bad arguments are given.
+ if bad arguments are specified.
</p>
<p>
The <c>gen_statem</c> process can go into hibernation; see
- <seealso marker="proc_lib#hibernate/3">
- <c>proc_lib:hibernate/3</c>.
- </seealso>
+ <seealso marker="proc_lib#hibernate/3"><c>proc_lib:hibernate/3</c></seealso>.
It is done when a
<seealso marker="#state_function">state function</seealso> or
<seealso marker="#Module:init/1"><c>Module:init/1</c></seealso>
specifies <c>hibernate</c> in the returned
<seealso marker="#type-action"><c>Actions</c></seealso>
- list. This feature might be useful to reclaim process heap memory
+ list. This feature can be useful to reclaim process heap memory
while the server is expected to be idle for a long time.
- However, use this feature with care
- since hibernation can be too costly
+ However, use this feature with care,
+ as hibernation can be too costly
to use after every event; see
- <seealso marker="erts:erlang#hibernate/3">
- <c>erlang:hibernate/3</c>.
- </seealso>
+ <seealso marker="erts:erlang#hibernate/3"><c>erlang:hibernate/3</c></seealso>.
</p>
</description>
<section>
- <title>EXAMPLE</title>
+ <title>Example</title>
<p>
- This example shows a simple pushbutton model
+ The following example shows a simple pushbutton model
for a toggling pushbutton implemented with
<seealso marker="#type-callback_mode"><em>callback mode</em></seealso>
<c>state_functions</c>.
You can push the button and it replies if it went on or off,
and you can ask for a count of how many times it has been
- pushed to on.
+ pushed to switch on.
</p>
- <p>This is the complete callback module file <c>pushbutton.erl</c>:</p>
+ <p>The following is the complete callback module file
+ <c>pushbutton.erl</c>:</p>
<code type="erl">
-module(pushbutton).
-behaviour(gen_statem).
@@ -305,7 +301,7 @@ handle_event(_, _, Data) ->
%% Ignore all other events
{keep_state,Data}.
</code>
- <p>And this is a shell session when running it:</p>
+ <p>The following is a shell session when running it:</p>
<pre>
1> pushbutton:start().
{ok,&lt;0.36.0>}
@@ -326,12 +322,11 @@ ok
in function gen:do_for_proc/2 (gen.erl, line 261)
in call from gen_statem:call/3 (gen_statem.erl, line 386)
</pre>
-
<p>
- And just to compare styles here is the same example using
+ To compare styles, here follows the same example using
<seealso marker="#type-callback_mode"><em>callback mode</em></seealso>
- <c>state_functions</c>, or rather here is code to replace
- from the <c>init/1</c> function of the <c>pushbutton.erl</c>
+ <c>state_functions</c>, or rather the code to replace
+ from function <c>init/1</c> of the <c>pushbutton.erl</c>
example file above:
</p>
<code type="erl">
@@ -364,107 +359,108 @@ handle_event(_, _, State, Data) ->
<datatypes>
<datatype>
- <name name="server_name" />
+ <name name="server_name"/>
<desc>
<p>
Name specification to use when starting
- a <c>gen_statem</c> server. See
- <seealso marker="#start_link/3">
- <c>start_link/3</c>
- </seealso>
+ a <c>gen_statem</c> server. See
+ <seealso marker="#start_link/3"><c>start_link/3</c></seealso>
and
- <seealso marker="#type-server_ref">
- <c>server_ref()</c>
- </seealso> below.
+ <seealso marker="#type-server_ref"><c>server_ref()</c></seealso>
+ below.
</p>
</desc>
</datatype>
<datatype>
- <name name="server_ref" />
+ <name name="server_ref"/>
<desc>
<p>
Server specification to use when addressing
a <c>gen_statem</c> server.
See <seealso marker="#call/2"><c>call/2</c></seealso> and
- <seealso marker="#type-server_name">
- <c>server_name()</c>
- </seealso>
+ <seealso marker="#type-server_name"><c>server_name()</c></seealso>
above.
</p>
<p>It can be:</p>
<taglist>
- <tag><c>pid()</c><br />
- <c>LocalName</c></tag>
- <item>The <c>gen_statem</c> is locally registered.</item>
- <tag><c>Name, Node</c></tag>
+ <tag><c>pid() | LocalName</c></tag>
<item>
- The <c>gen_statem</c> is locally registered
- on another node.
+ <p>
+ The <c>gen_statem</c> is locally registered.
+ </p>
+ </item>
+ <tag><c>{Name,Node}</c></tag>
+ <item>
+ <p>
+ The <c>gen_statem</c> is locally registered
+ on another node.
+ </p>
</item>
- <tag><c>GlobalName</c></tag>
+ <tag><c>{global,GlobalName}</c></tag>
<item>
- The <c>gen_statem</c> is globally registered
- in <seealso marker="kernel:global"><c>global</c></seealso>.
+ <p>
+ The <c>gen_statem</c> is globally registered in
+ <seealso marker="kernel:global"><c>kernel:global</c></seealso>.
+ </p>
</item>
- <tag><c>RegMod, ViaName</c></tag>
+ <tag><c>{via,RegMod,ViaName}</c></tag>
<item>
- The <c>gen_statem</c> is registered through
- an alternative process registry.
- The registry callback module <c>RegMod</c>
- should export the functions
- <c>register_name/2</c>, <c>unregister_name/1</c>,
- <c>whereis_name/1</c> and <c>send/2</c>,
- which should behave like the corresponding functions
- in <seealso marker="kernel:global"><c>global</c></seealso>.
- Thus, <c>{via,global,GlobalName}</c> is the same as
- <c>{global,GlobalName}</c>.
+ <p>
+ The <c>gen_statem</c> is registered in
+ an alternative process registry.
+ The registry callback module <c>RegMod</c>
+ is to export 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>kernel:global</c></seealso>.
+ Thus, <c>{via,global,GlobalName}</c> is the same as
+ <c>{global,GlobalName}</c>.
+ </p>
</item>
</taglist>
</desc>
</datatype>
<datatype>
- <name name="debug_opt" />
+ <name name="debug_opt"/>
<desc>
<p>
Debug option that can be used when starting
- a <c>gen_statem</c> server through for example
+ a <c>gen_statem</c> server through, for example,
<seealso marker="#enter_loop/5"><c>enter_loop/5</c></seealso>.
</p>
<p>
- For every entry in <c><anno>Dbgs</anno></c>
+ For every entry in <c><anno>Dbgs</anno></c>,
the corresponding function in
- <seealso marker="sys"><c>sys</c></seealso> will be called.
+ <seealso marker="sys"><c>sys</c></seealso> is called.
</p>
</desc>
</datatype>
<datatype>
- <name name="start_opt" />
+ <name name="start_opt"/>
<desc>
<p>
Options that can be used when starting
- a <c>gen_statem</c> server through for example
+ a <c>gen_statem</c> server through, for example,
<seealso marker="#start_link/3"><c>start_link/3</c></seealso>.
</p>
</desc>
</datatype>
<datatype>
- <name name="start_ret" />
+ <name name="start_ret"/>
<desc>
<p>
- Return value from the start functions for_example
+ Return value from the start functions, for example,
<seealso marker="#start_link/3"><c>start_link/3</c></seealso>.
</p>
</desc>
</datatype>
-
<datatype>
- <name name="from" />
+ <name name="from"/>
<desc>
<p>
- Destination to use when replying through for example the
- <seealso marker="#type-action">
- <c>action()</c>
- </seealso>
+ Destination to use when replying through, for example, the
+ <seealso marker="#type-action"><c>action()</c></seealso>
<c>{reply,From,Reply}</c>
to a process that has called the <c>gen_statem</c> server using
<seealso marker="#call/2"><c>call/2</c></seealso>.
@@ -472,231 +468,228 @@ handle_event(_, _, State, Data) ->
</desc>
</datatype>
<datatype>
- <name name="state" />
+ <name name="state"/>
<desc>
<p>
- After a state change (<c>NextState =/= State</c>)
+ After a state change (<c>NextState =/= State</c>),
all postponed events are retried.
</p>
</desc>
</datatype>
<datatype>
- <name name="state_name" />
+ <name name="state_name"/>
<desc>
<p>
If the
<seealso marker="#type-callback_mode"><em>callback mode</em></seealso>
is <c>state_functions</c>,
- the state has to be of this type.
+ the state must be of this type.
</p>
</desc>
</datatype>
<datatype>
- <name name="data" />
+ <name name="data"/>
<desc>
<p>
A term in which the state machine implementation
- should store any server data it needs. The difference between
+ is to store any server data it needs. The difference between
this and the <seealso marker="#type-state"><c>state()</c></seealso>
itself is that a change in this data does not cause
- postponed events to be retried. Hence if a change
+ postponed events to be retried. Hence, if a change
in this data would change the set of events that
- are handled than that data item should be made
+ are handled, then that data item is to be made
a part of the state.
</p>
</desc>
</datatype>
<datatype>
- <name name="event_type" />
+ <name name="event_type"/>
<desc>
<p>
- External events are of 3 different type:
- <c>{call,<anno>From</anno>}</c>, <c>cast</c> or <c>info</c>.
+ External events are of three types:
+ <c>{call,<anno>From</anno>}</c>, <c>cast</c>, or <c>info</c>.
<seealso marker="#call/2">Calls</seealso>
(synchronous) and
<seealso marker="#cast/2">casts</seealso>
originate from the corresponding API functions.
- For calls the event contain whom to reply to.
+ For calls, the event contains whom to reply to.
Type <c>info</c> originates from regular process messages sent
- to the <c>gen_statem</c>. It is also possible for the state machine
- implementation to generate events of types
+ to the <c>gen_statem</c>. Also, the state machine
+ implementation can generate events of types
<c>timeout</c> and <c>internal</c> to itself.
</p>
</desc>
</datatype>
<datatype>
- <name name="callback_mode" />
+ <name name="callback_mode"/>
<desc>
<p>
The <em>callback mode</em> is selected when starting the
<c>gen_statem</c> using the return value from
<seealso marker="#Module:init/1"><c>Module:init/1</c></seealso>
or when calling
- <seealso marker="#enter_loop/5"><c>enter_loop/5-7</c></seealso>,
+ <seealso marker="#enter_loop/5"><c>enter_loop/5,6,7</c></seealso>,
and with the return value from
- <seealso marker="#Module:code_change/4">
- <c>Module:code_change/4</c>.
- </seealso>
+ <seealso marker="#Module:code_change/4"><c>Module:code_change/4</c></seealso>.
</p>
<taglist>
<tag><c>state_functions</c></tag>
<item>
- The state has to be of type
- <seealso marker="#type-state_name"><c>state_name()</c></seealso>
- and one callback function per state that is
- <seealso marker="#Module:StateName/3">
- <c>Module:StateName/3</c>
- </seealso>
- is used.
+ <p>
+ The state must be of type
+ <seealso marker="#type-state_name"><c>state_name()</c></seealso>
+ and one callback function per state, that is,
+ <seealso marker="#Module:StateName/3"><c>Module:StateName/3</c></seealso>,
+ is used.
+ </p>
</item>
<tag><c>handle_event_function</c></tag>
<item>
- The state can be any term and the callback function
- <seealso marker="#Module:handle_event/4">
- <c>Module:handle_event/4</c>
- </seealso>
- is used for all states.
+ <p>
+ The state can be any term and the callback function
+ <seealso marker="#Module:handle_event/4"><c>Module:handle_event/4</c></seealso>
+ is used for all states.
+ </p>
</item>
</taglist>
</desc>
</datatype>
<datatype>
- <name name="transition_option" />
+ <name name="transition_option"/>
<desc>
<p>
- Transition options may be set by
+ Transition options can be set by
<seealso marker="#type-action">actions</seealso>
- and they modify some details below in how
+ and they modify the following in how
the state transition is done:
</p>
<list type="ordered">
<item>
- All
- <seealso marker="#type-action">actions</seealso>
- are processed in order of appearance.
+ <p>
+ All
+ <seealso marker="#type-action">actions</seealso>
+ are processed in order of appearance.
+ </p>
</item>
<item>
- If
- <seealso marker="#type-postpone">
- <c>postpone()</c>
- </seealso>
- is <c>true</c>
- the current event is postponed.
+ <p>
+ If
+ <seealso marker="#type-postpone"><c>postpone()</c></seealso>
+ is <c>true</c>,
+ the current event is postponed.
+ </p>
</item>
<item>
- If the state changes the queue of incoming events
- is reset to start with the oldest postponed.
+ <p>
+ If the state changes, the queue of incoming events
+ is reset to start with the oldest postponed.
+ </p>
</item>
<item>
- All events stored with
- <seealso marker="#type-action">
- <c>action()</c>
- </seealso>
- <c>next_event</c>
- are inserted in the queue to be processed before
- all other events.
+ <p>
+ All events stored with
+ <seealso marker="#type-action"><c>action()</c></seealso>
+ <c>next_event</c>
+ are inserted in the queue to be processed before
+ all other events.
+ </p>
</item>
<item>
- If an
- <seealso marker="#type-event_timeout">
- <c>event_timeout()</c>
- </seealso>
- is set through
- <seealso marker="#type-action">
- <c>action()</c>
- </seealso>
- <c>timeout</c>
- an event timer may be started or a timeout zero event
- may be enqueued.
+ <p>
+ If an
+ <seealso marker="#type-event_timeout"><c>event_timeout()</c></seealso>
+ is set through
+ <seealso marker="#type-action"><c>action()</c></seealso>
+ <c>timeout</c>,
+ an event timer can be started or a time-out zero event
+ can be enqueued.
+ </p>
</item>
<item>
- The (possibly new)
- <seealso marker="#state_function">state function</seealso>
- is called with the oldest enqueued event if there is any,
- otherwise the <c>gen_statem</c> goes into <c>receive</c>
- or hibernation
- (if
- <seealso marker="#type-hibernate">
- <c>hibernate()</c>
- </seealso>
- is <c>true</c>)
- to wait for the next message. In hibernation the next
- non-system event awakens the <c>gen_statem</c>, or rather
- the next incoming message awakens the <c>gen_statem</c>
- but if it is a system event
- it goes right back into hibernation.
+ <p>
+ The (possibly new)
+ <seealso marker="#state_function">state function</seealso>
+ is called with the oldest enqueued event if there is any,
+ otherwise the <c>gen_statem</c> goes into <c>receive</c>
+ or hibernation
+ (if
+ <seealso marker="#type-hibernate"><c>hibernate()</c></seealso>
+ is <c>true</c>)
+ to wait for the next message. In hibernation the next
+ non-system event awakens the <c>gen_statem</c>, or rather
+ the next incoming message awakens the <c>gen_statem</c>,
+ but if it is a system event
+ it goes right back into hibernation.
+ </p>
</item>
</list>
</desc>
</datatype>
<datatype>
- <name name="postpone" />
+ <name name="postpone"/>
<desc>
<p>
- If <c>true</c> postpone the current event and retry
+ If <c>true</c>, postpones the current event and retries
it when the state changes
(<c>NextState =/= State</c>).
</p>
</desc>
</datatype>
<datatype>
- <name name="hibernate" />
+ <name name="hibernate"/>
<desc>
<p>
- If <c>true</c> hibernate the <c>gen_statem</c>
+ If <c>true</c>, hibernates the <c>gen_statem</c>
by calling
- <seealso marker="proc_lib#hibernate/3">
- <c>proc_lib:hibernate/3</c>
- </seealso>
+ <seealso marker="proc_lib#hibernate/3"><c>proc_lib:hibernate/3</c></seealso>
before going into <c>receive</c>
to wait for a new external event.
If there are enqueued events,
- to prevent receiving any new event; a
- <seealso marker="erts:erlang#garbage_collect/0">
- <c>garbage_collect/0</c>
- </seealso> is done instead to simulate
+ to prevent receiving any new event, an
+ <seealso marker="erts:erlang#garbage_collect/0"><c>erlang:garbage_collect/0</c></seealso>
+ is done instead to simulate
that the <c>gen_statem</c> entered hibernation
and immediately got awakened by the oldest enqueued event.
</p>
</desc>
</datatype>
<datatype>
- <name name="event_timeout" />
+ <name name="event_timeout"/>
<desc>
<p>
- Generate an event of
+ Generates an event of
<seealso marker="#type-event_type"><c>event_type()</c></seealso>
<c>timeout</c>
- after this time (in milliseconds) unless some other
- event arrives in which case this timeout is cancelled.
- Note that a retried or inserted event
- counts just like a new in this respect.
+ after this time (in milliseconds) unless another
+ event arrives in which case this time-out is cancelled.
+ Notice that a retried or inserted event
+ counts like a new in this respect.
</p>
<p>
- If the value is <c>infinity</c> no timer is started since
- it will never trigger anyway.
+ If the value is <c>infinity</c>, no timer is started, as
+ it never triggers anyway.
</p>
<p>
- If the value is <c>0</c> the timeout event is immediately enqueued
- unless there already are enqueued events since then the
- timeout is immediately cancelled.
- This is a feature ensuring that a timeout <c>0</c> event
- will be processed before any not yet received external event.
+ If the value is <c>0</c>, the time-out event is immediately enqueued
+ unless there already are enqueued events, as the
+ time-out is then immediately cancelled.
+ This is a feature ensuring that a time-out <c>0</c> event
+ is processed before any not yet received external event.
</p>
<p>
- Note that it is not possible nor needed to cancel this timeout
- since it is cancelled automatically by any other event.
+ Notice that it is not possible or needed to cancel this time-out,
+ as it is cancelled automatically by any other event.
</p>
</desc>
</datatype>
<datatype>
- <name name="action" />
+ <name name="action"/>
<desc>
<p>
- These state transition actions may be invoked by
+ These state transition actions can be invoked by
returning them from the
- <seealso marker="#state_function">state function</seealso>,
- from <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso>
+ <seealso marker="#state_function">state function</seealso>, from
+ <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso>
or by giving them to
<seealso marker="#enter_loop/6"><c>enter_loop/6,7</c></seealso>.
</p>
@@ -705,91 +698,81 @@ handle_event(_, _, State, Data) ->
</p>
<p>
Actions that set
- <seealso marker="#type-transition_option">
- transition options
- </seealso>
- overrides any previous of the same type,
+ <seealso marker="#type-transition_option">transition options</seealso>
+ override any previous of the same type,
so the last in the containing list wins.
- For example the last
- <seealso marker="#type-event_timeout">
- <c>event_timeout()</c>
- </seealso>
+ For example, the last
+ <seealso marker="#type-event_timeout"><c>event_timeout()</c></seealso>
overrides any other <c>event_timeout()</c> in the list.
</p>
<taglist>
<tag><c>postpone</c></tag>
<item>
- Set the
- <seealso marker="#type-transition_option">
- <c>transition_option()</c>
- </seealso>
- <seealso marker="#type-postpone">
- <c>postpone()</c>
- </seealso>
- for this state transition.
- This action is ignored when returned from
- <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso>
- or given to
- <seealso marker="#enter_loop/5"><c>enter_loop/5,6</c></seealso>
- since there is no event to postpone in those cases.
+ <p>
+ Sets the
+ <seealso marker="#type-transition_option"><c>transition_option()</c></seealso>
+ <seealso marker="#type-postpone"><c>postpone()</c></seealso>
+ for this state transition.
+ This action is ignored when returned from
+ <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso>
+ or given to
+ <seealso marker="#enter_loop/5"><c>enter_loop/5,6</c></seealso>,
+ as there is no event to postpone in those cases.
+ </p>
</item>
<tag><c>hibernate</c></tag>
<item>
- Set the
- <seealso marker="#type-transition_option">
- <c>transition_option()</c>
- </seealso>
- <seealso marker="#type-hibernate">
- <c>hibernate()</c>
- </seealso>
- for this state transition.
+ <p>
+ Sets the
+ <seealso marker="#type-transition_option"><c>transition_option()</c></seealso>
+ <seealso marker="#type-hibernate"><c>hibernate()</c></seealso>
+ for this state transition.
+ </p>
</item>
<tag><c>Timeout</c></tag>
<item>
- Short for <c>{timeout,Timeout,Timeout}</c> that is
- the timeout message is the timeout time.
- This form exists to make the
- <seealso marker="#state_function">state function</seealso>
- return value <c>{next_state,NextState,NewData,Timeout}</c>
- allowed like for
- <seealso marker="gen_fsm#Module:StateName/2">
- <c>gen_fsm Module:StateName/2</c>.
- </seealso>
+ <p>
+ Short for <c>{timeout,Timeout,Timeout}</c>, that is,
+ the time-out message is the time-out time.
+ This form exists to make the
+ <seealso marker="#state_function">state function</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>
<item>
- Set the
- <seealso marker="#type-transition_option">
- <c>transition_option()</c>
- </seealso>
- <seealso marker="#type-event_timeout">
- <c>event_timeout()</c>
- </seealso>
- to <c><anno>Time</anno></c> with <c><anno>EventContent</anno></c>.
+ <p>
+ Sets the
+ <seealso marker="#type-transition_option"><c>transition_option()</c></seealso>
+ <seealso marker="#type-event_timeout"><c>event_timeout()</c></seealso>
+ to <c><anno>Time</anno></c> with <c><anno>EventContent</anno></c>.
+ </p>
</item>
<tag><c>reply_action()</c></tag>
- <item>Reply to a caller.</item>
+ <item>
+ <p>
+ Replies to a caller.
+ </p>
+ </item>
<tag><c>next_event</c></tag>
<item>
- Store the given <c><anno>EventType</anno></c>
+ <p>
+ Stores the specified <c><anno>EventType</anno></c>
and <c><anno>EventContent</anno></c> for insertion after all
actions have been executed.
- </item>
- <item>
+ </p>
<p>
The stored events are inserted in the queue as the next to process
- before any already queued events. The order of these stored events
- is preserved so the first <c>next_event</c> in the containing list
- will become the first to process.
+ before any already queued events. The order of these stored events
+ is preserved, so the first <c>next_event</c> in the containing
+ list becomes the first to process.
</p>
- </item>
- <item>
<p>
An event of type
- <seealso marker="#type-event_type">
- <c>internal</c>
- </seealso>
- should be used when you want to reliably distinguish
+ <seealso marker="#type-event_type"><c>internal</c></seealso>
+ is to be used when you want to reliably distinguish
an event inserted this way from any external event.
</p>
</item>
@@ -797,303 +780,126 @@ handle_event(_, _, State, Data) ->
</desc>
</datatype>
<datatype>
- <name name="reply_action" />
+ <name name="reply_action"/>
<desc>
<p>
- Reply to a caller waiting for a reply in
+ Replies to a caller waiting for a reply in
<seealso marker="#call/2"><c>call/2</c></seealso>.
- <c><anno>From</anno></c> must be the term from the
- <seealso marker="#type-event_type">
- <c>{call,<anno>From</anno>}</c>
- </seealso>
- argument to the
+ <c><anno>From</anno></c> must be the term from argument
+ <seealso marker="#type-event_type"><c>{call,<anno>From</anno>}</c></seealso>
+ to the
<seealso marker="#state_function">state function</seealso>.
</p>
</desc>
</datatype>
<datatype>
- <name name="state_function_result" />
+ <name name="state_function_result"/>
<desc>
<taglist>
<tag><c>next_state</c></tag>
<item>
- The <c>gen_statem</c> will do a state transition to
- <c><anno>NextStateName</anno></c>
- (which may be the same as the current state),
- set <c><anno>NewData</anno></c>
- and execute all <c><anno>Actions</anno></c>
+ <p>
+ The <c>gen_statem</c> does a state transition to
+ <c><anno>NextStateName</anno></c>
+ (which can be the same as the current state),
+ sets <c><anno>NewData</anno></c>,
+ and executes all <c><anno>Actions</anno></c>.
+ </p>
</item>
</taglist>
<p>
All these terms are tuples or atoms and this property
- will hold in any future version of <c>gen_statem</c>,
- just in case you need such a promise.
+ will hold in any future version of <c>gen_statem</c>.
</p>
</desc>
</datatype>
<datatype>
- <name name="handle_event_result" />
+ <name name="handle_event_result"/>
<desc>
<taglist>
<tag><c>next_state</c></tag>
<item>
- The <c>gen_statem</c> will do a state transition to
- <c><anno>NextState</anno></c>
- (which may be the same as the current state),
- set <c><anno>NewData</anno></c>
- and execute all <c><anno>Actions</anno></c>
+ <p>
+ The <c>gen_statem</c> does a state transition to
+ <c><anno>NextState</anno></c>
+ (which can be the same as the current state),
+ sets <c><anno>NewData</anno></c>,
+ and executes all <c><anno>Actions</anno></c>.
+ </p>
</item>
</taglist>
<p>
All these terms are tuples or atoms and this property
- will hold in any future version of <c>gen_statem</c>,
- just in case you need such a promise.
+ will hold in any future version of <c>gen_statem</c>.
</p>
</desc>
</datatype>
<datatype>
- <name name="common_state_callback_result" />
+ <name name="common_state_callback_result"/>
<desc>
<taglist>
<tag><c>stop</c></tag>
<item>
- Terminate the <c>gen_statem</c> by calling
- <seealso marker="#Module:terminate/3">
- <c>Module:terminate/3</c>
- </seealso>
- with <c>Reason</c> and
- <c><anno>NewData</anno></c>, if given.
+ <p>
+ Terminates the <c>gen_statem</c> by calling
+ <seealso marker="#Module:terminate/3"><c>Module:terminate/3</c></seealso>
+ with <c>Reason</c> and
+ <c><anno>NewData</anno></c>, if specified.
+ </p>
</item>
<tag><c>stop_and_reply</c></tag>
<item>
- Send all <c><anno>Replies</anno></c>
- then terminate the <c>gen_statem</c> by calling
- <seealso marker="#Module:terminate/3">
- <c>Module:terminate/3</c>
- </seealso>
- with <c>Reason</c> and
- <c><anno>NewData</anno></c>, if given.
+ <p>
+ Sends all <c><anno>Replies</anno></c>,
+ then terminates the <c>gen_statem</c> by calling
+ <seealso marker="#Module:terminate/3"><c>Module:terminate/3</c></seealso>
+ with <c>Reason</c> and
+ <c><anno>NewData</anno></c>, if specified.
+ </p>
</item>
<tag><c>keep_state</c></tag>
<item>
- The <c>gen_statem</c> will keep the current state, or
- do a state transition to the current state if you like,
- set <c><anno>NewData</anno></c>
- and execute all <c><anno>Actions</anno></c>.
- This is the same as
- <c>{next_state,CurrentState,<anno>NewData</anno>,<anno>Actions</anno>}</c>.
+ <p>
+ The <c>gen_statem</c> keeps the current state, or
+ does a state transition to the current state if you like,
+ sets <c><anno>NewData</anno></c>,
+ and executes all <c><anno>Actions</anno></c>.
+ This is the same as
+ <c>{next_state,CurrentState,<anno>NewData</anno>,<anno>Actions</anno>}</c>.
+ </p>
</item>
<tag><c>keep_state_and_data</c></tag>
<item>
- The <c>gen_statem</c> will keep the current state or
- do a state transition to the current state if you like,
- keep the current server data,
- and execute all <c><anno>Actions</anno></c>.
- This is the same as
- <c>{next_state,CurrentState,CurrentData,<anno>Actions</anno>}</c>.
+ <p>
+ The <c>gen_statem</c> keeps the current state or
+ does a state transition to the current state if you like,
+ keeps the current server data,
+ and executes all <c><anno>Actions</anno></c>.
+ This is the same as
+ <c>{next_state,CurrentState,CurrentData,<anno>Actions</anno>}</c>.
+ </p>
</item>
</taglist>
<p>
All these terms are tuples or atoms and this property
- will hold in any future version of <c>gen_statem</c>,
- just in case you need such a promise.
+ will hold in any future version of <c>gen_statem</c>.
</p>
</desc>
</datatype>
</datatypes>
<funcs>
-
- <func>
- <name name="start_link" arity="3" />
- <name name="start_link" arity="4" />
- <fsummary>Create a linked <c>gen_statem</c> process</fsummary>
- <desc>
- <p>
- Creates a <c>gen_statem</c> process according
- to OTP design principles
- (using
- <seealso marker="proc_lib"><c>proc_lib</c></seealso>
- primitives)
- that is linked to the calling process.
- This is essential when the <c>gen_statem</c> shall be part of
- a supervision tree so it gets linked to its supervisor.
- </p>
- <p>
- The <c>gen_statem</c> process calls
- <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso>
- to initialize the server. To ensure a synchronized start-up
- procedure, <c>start_link/3,4</c> does not return until
- <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso>
- has returned.
- </p>
- <p>
- <c><anno>ServerName</anno></c> specifies the
- <seealso marker="#type-server_name">
- <c>server_name()</c>
- </seealso>
- to register for the <c>gen_statem</c>.
- If the <c>gen_statem</c> is started with <c>start_link/3</c>
- no <c><anno>ServerName</anno></c> is provided and
- the <c>gen_statem</c> is not registered.
- </p>
- <p><c><anno>Module</anno></c> is the name of the callback module.</p>
- <p>
- <c><anno>Args</anno></c> is an arbitrary term which is passed as
- the argument to
- <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso>.
- </p>
- <p>
- If the option <c>{timeout,Time}</c> is present in
- <c><anno>Opts</anno></c>, the <c>gen_statem</c>
- is allowed to spend <c>Time</c> milliseconds initializing
- or it will be terminated and the start function will return
- <seealso marker="#type-start_ret"><c>{error,timeout}</c></seealso>.
- </p>
- <p>
- If the option
- <seealso marker="#type-debug_opt"><c>{debug,Dbgs}</c></seealso>
- is present in <c><anno>Opts</anno></c>, debugging through
- <seealso marker="sys"><c>sys</c></seealso> is activated.
- </p>
- <p>
- If the option <c>{spawn_opt,SpawnOpts}</c> is present in
- <c><anno>Opts</anno></c>, <c>SpawnOpts</c> will be passed
- as option list to
- <seealso marker="erts:erlang#spawn_opt/2"><c>spawn_opt/2</c></seealso>
- which is used to spawn the <c>gen_statem</c> process.
- </p>
- <note>
- <p>
- Using the spawn option <c>monitor</c> is currently not
- allowed, but will cause this function to fail with reason
- <c>badarg</c>.
- </p>
- </note>
- <p>
- If the <c>gen_statem</c> is successfully created
- and initialized this function returns
- <seealso marker="#type-start_ret">
- <c>{ok,Pid}</c>,
- </seealso>
- where <c>Pid</c> is the <c>pid()</c>
- of the <c>gen_statem</c>.
- If there already exists a process with the specified
- <c><anno>ServerName</anno></c> this function returns
- <seealso marker="#type-start_ret"><c>{error,{already_started,Pid}}</c></seealso>,
- where <c>Pid</c> is the <c>pid()</c> of that process.
- </p>
- <p>
- If <c>Module:init/1</c> fails with <c>Reason</c>,
- this function returns
- <seealso marker="#type-start_ret"><c>{error,Reason}</c></seealso>.
- If <c>Module:init/1</c> returns
- <seealso marker="#type-start_ret">
- <c>{stop,Reason}</c>
- </seealso>
- or
- <seealso marker="#type-start_ret"><c>ignore</c></seealso>,
- the process is terminated and this function
- returns
- <seealso marker="#type-start_ret">
- <c>{error,Reason}</c>
- </seealso>
- or
- <seealso marker="#type-start_ret"><c>ignore</c></seealso>,
- respectively.
- </p>
- </desc>
- </func>
-
-
- <func>
- <name name="start" arity="3" />
- <name name="start" arity="4" />
- <fsummary>Create a stand-alone <c>gen_statem</c> process</fsummary>
- <desc>
- <p>
- Creates a stand-alone <c>gen_statem</c> process according to
- OTP design principles (using
- <seealso marker="proc_lib"><c>proc_lib</c></seealso>
- primitives).
- Since it does not get linked to the calling process
- this start function can not be used by a supervisor
- to start a child.
- </p>
- <p>
- See <seealso marker="#start_link/3"><c>start_link/3,4</c></seealso>
- for a description of arguments and return values.
- </p>
- </desc>
- </func>
-
- <func>
- <name name="stop" arity="1" />
- <fsummary>Synchronously stop a generic server</fsummary>
- <desc>
- <p>
- The same as
- <seealso marker="#stop/3">
- <c>stop(<anno>ServerRef</anno>, normal, infinity)</c>.
- </seealso>
- </p>
- </desc>
- </func>
- <func>
- <name name="stop" arity="3" />
- <fsummary>Synchronously stop a generic server</fsummary>
- <desc>
- <p>
- Orders the <c>gen_statem</c>
- <seealso marker="#type-server_ref">
- <c><anno>ServerRef</anno></c>
- </seealso>
- to exit with the given <c><anno>Reason</anno></c>
- and waits for it to terminate.
- The <c>gen_statem</c> will call
- <seealso marker="#Module:terminate/3">
- <c>Module:terminate/3</c>
- </seealso>
- before exiting.
- </p>
- <p>
- This function returns <c>ok</c> if the server terminates
- with the expected reason. Any other reason than <c>normal</c>,
- <c>shutdown</c>, or <c>{shutdown,Term}</c> will cause an
- error report to be issued through
- <seealso marker="kernel:error_logger#format/2">
- <c>error_logger:format/2</c>.
- </seealso>
- The default <c><anno>Reason</anno></c> is <c>normal</c>.
- </p>
- <p>
- <c><anno>Timeout</anno></c> is an integer greater than zero
- which specifies how many milliseconds to wait for the server to
- terminate, or the atom <c>infinity</c> to wait indefinitely.
- The default value is <c>infinity</c>.
- If the server 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 name="call" arity="2" />
- <name name="call" arity="3" />
- <fsummary>Make a synchronous call to a <c>gen_statem</c></fsummary>
+ <name name="call" arity="2"/>
+ <name name="call" arity="3"/>
+ <fsummary>Make a synchronous call to a <c>gen_statem</c>.</fsummary>
<desc>
<p>
Makes a synchronous call to the <c>gen_statem</c>
- <seealso marker="#type-server_ref">
- <c><anno>ServerRef</anno></c>
- </seealso>
+ <seealso marker="#type-server_ref"><c><anno>ServerRef</anno></c></seealso>
by sending a request
and waiting until its reply arrives.
- The <c>gen_statem</c> will call the
+ The <c>gen_statem</c> calls the
<seealso marker="#state_function">state function</seealso> with
<seealso marker="#type-event_type"><c>event_type()</c></seealso>
<c>{call,From}</c> and event content
@@ -1108,43 +914,41 @@ handle_event(_, _, State, Data) ->
and that <c><anno>Reply</anno></c> becomes the return value
of this function.
</p>
- <p>
- <c><anno>Timeout</anno></c> is an integer greater than zero
+ <p>
+ <c><anno>Timeout</anno></c> is an integer &gt; 0,
which specifies how many milliseconds to wait for a reply,
or the atom <c>infinity</c> to wait indefinitely,
- which is the default. If no reply is received within
+ which is the default. If no reply is received within
the specified time, the function call fails.
</p>
<note>
<p>
To avoid getting a late reply in the caller's
- inbox this function spawns a proxy process that
- does the call. A late reply gets delivered to the
- dead proxy process hence gets discarded. This is
+ inbox, this function spawns a proxy process that
+ does the call. A late reply gets delivered to the
+ dead proxy process, hence gets discarded. This is
less efficient than using
<c><anno>Timeout</anno> =:= infinity</c>.
</p>
</note>
- <p>
- The call may fail for example if the <c>gen_statem</c> dies
+ <p>
+ The call can fail, for example, if the <c>gen_statem</c> dies
before or during this function call.
</p>
</desc>
</func>
<func>
- <name name="cast" arity="2" />
- <fsummary>Send an asynchronous event to a <c>gen_statem</c></fsummary>
+ <name name="cast" arity="2"/>
+ <fsummary>Send an asynchronous event to a <c>gen_statem</c>.</fsummary>
<desc>
<p>
Sends an asynchronous event to the <c>gen_statem</c>
- <seealso marker="#type-server_ref">
- <c><anno>ServerRef</anno></c>
- </seealso>
+ <seealso marker="#type-server_ref"><c><anno>ServerRef</anno></c></seealso>
and returns <c>ok</c> immediately,
ignoring if the destination node or <c>gen_statem</c>
does not exist.
- The <c>gen_statem</c> will call the
+ The <c>gen_statem</c> calls the
<seealso marker="#state_function">state function</seealso> with
<seealso marker="#type-event_type"><c>event_type()</c></seealso>
<c>cast</c> and event content
@@ -1154,68 +958,29 @@ handle_event(_, _, State, Data) ->
</func>
<func>
- <name name="reply" arity="1" />
- <name name="reply" arity="2" />
- <fsummary>Reply to a caller</fsummary>
- <desc>
- <p>
- This function can be used by a <c>gen_statem</c>
- to explicitly send a reply to a process that waits in
- <seealso marker="#call/2"><c>call/2</c></seealso>
- when the reply cannot be defined in
- the return value of a
- <seealso marker="#state_function">state function</seealso>.
- </p>
- <p>
- <c><anno>From</anno></c> must be the term from the
- <seealso marker="#type-event_type">
- <c>{call,<anno>From</anno>}</c>
- </seealso>
- argument to the
- <seealso marker="#state_function">state function</seealso>.
- <c><anno>From</anno></c> and <c><anno>Reply</anno></c>
- can also be specified using a
- <seealso marker="#type-reply_action">
- <c>reply_action()</c>
- </seealso>
- and multiple replies with a list of them.
- </p>
- <note>
- <p>
- A reply sent with this function will not be visible
- in <seealso marker="sys"><c>sys</c></seealso> debug output.
- </p>
- </note>
- </desc>
- </func>
-
- <func>
- <name name="enter_loop" arity="5" />
- <fsummary>Enter the <c>gen_statem</c> receive loop</fsummary>
+ <name name="enter_loop" arity="5"/>
+ <fsummary>Enter the <c>gen_statem</c> receive loop.</fsummary>
<desc>
<p>
The same as
<seealso marker="#enter_loop/7"><c>enter_loop/7</c></seealso>
except that no
- <seealso marker="#type-server_name">
- <c>server_name()</c>
- </seealso>
+ <seealso marker="#type-server_name"><c>server_name()</c></seealso>
must have been registered.
</p>
</desc>
</func>
+
<func>
- <name name="enter_loop" arity="6" />
- <fsummary>Enter the <c>gen_statem</c> receive loop</fsummary>
+ <name name="enter_loop" arity="6"/>
+ <fsummary>Enter the <c>gen_statem</c> receive loop.</fsummary>
<desc>
<p>
- If <c><anno>Server_or_Actions</anno></c> is a <c>list()</c>
+ If <c><anno>Server_or_Actions</anno></c> is a <c>list()</c>,
the same as
<seealso marker="#enter_loop/7"><c>enter_loop/7</c></seealso>
except that no
- <seealso marker="#type-server_name">
- <c>server_name()</c>
- </seealso>
+ <seealso marker="#type-server_name"><c>server_name()</c></seealso>
must have been registered and
<c>Actions = <anno>Server_or_Actions</anno></c>.
</p>
@@ -1228,73 +993,350 @@ handle_event(_, _, State, Data) ->
</p>
</desc>
</func>
+
<func>
- <name name="enter_loop" arity="7" />
- <fsummary>Enter the <c>gen_statem</c> receive loop</fsummary>
+ <name name="enter_loop" arity="7"/>
+ <fsummary>Enter the <c>gen_statem</c> receive loop.</fsummary>
<desc>
- <p>
- Makes an the calling process become a <c>gen_statem</c>.
- Does not return, instead the calling process will enter
- the <c>gen_statem</c> receive loop and become
+ <p>
+ Makes the calling process become a <c>gen_statem</c>.
+ Does not return, instead the calling process enters
+ the <c>gen_statem</c> receive loop and becomes
a <c>gen_statem</c> server.
The process <em>must</em> have been started
using one of the start functions in
- <seealso marker="proc_lib"><c>proc_lib</c></seealso>.
+ <seealso marker="proc_lib"><c>proc_lib</c></seealso>.
The user is responsible for any initialization of the process,
including registering a name for it.
</p>
- <p>
+ <p>
This function is useful when a more complex initialization
- procedure is needed than
- the <c>gen_statem</c> behaviour provides.
+ procedure is needed than
+ the <c>gen_statem</c> behavior provides.
</p>
- <p>
- <c><anno>Module</anno></c>, <c><anno>Opts</anno></c> and
+ <p>
+ <c><anno>Module</anno></c>, <c><anno>Opts</anno></c>, and
<c><anno>Server</anno></c> have the same meanings
as when calling
- <seealso marker="#start_link/3">
- <c>gen_statem:start[_link]/3,4</c>.
- </seealso>
- However, the
- <seealso marker="#type-server_name">
- <c>server_name()</c>
- </seealso>
+ <seealso marker="#start_link/3"><c>start[_link]/3,4</c></seealso>.
+ However, the
+ <seealso marker="#type-server_name"><c>server_name()</c></seealso>
name must have been registered accordingly
<em>before</em> this function is called.</p>
<p>
<c><anno>CallbackMode</anno></c>, <c><anno>State</anno></c>,
- <c><anno>Data</anno></c> and <c><anno>Actions</anno></c>
+ <c><anno>Data</anno></c>, and <c><anno>Actions</anno></c>
have the same meanings as in the return value of
- <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso>.
- Also, the callback module <c><anno>Module</anno></c>
+ <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso>.
+ Also, the callback module <c><anno>Module</anno></c>
does not need to export an <c>init/1</c> function.
</p>
<p>
- Failure: If the calling process was not started by a
- <seealso marker="proc_lib"><c>proc_lib</c></seealso>
+ The function fails if the calling process was not started by a
+ <seealso marker="proc_lib"><c>proc_lib</c></seealso>
start function, or if it is not registered
- according to
+ according to
<seealso marker="#type-server_name"><c>server_name()</c></seealso>.
</p>
</desc>
</func>
- </funcs>
+ <func>
+ <name name="reply" arity="1"/>
+ <name name="reply" arity="2"/>
+ <fsummary>Reply to a caller.</fsummary>
+ <desc>
+ <p>
+ This function can be used by a <c>gen_statem</c>
+ to explicitly send a reply to a process that waits in
+ <seealso marker="#call/2"><c>call/2</c></seealso>
+ when the reply cannot be defined in
+ the return value of a
+ <seealso marker="#state_function">state function</seealso>.
+ </p>
+ <p>
+ <c><anno>From</anno></c> must be the term from argument
+ <seealso marker="#type-event_type"><c>{call,<anno>From</anno>}</c></seealso>
+ to the
+ <seealso marker="#state_function">state function</seealso>.
+ <c><anno>From</anno></c> and <c><anno>Reply</anno></c>
+ can also be specified using a
+ <seealso marker="#type-reply_action"><c>reply_action()</c></seealso>
+ and multiple replies with a list of them.
+ </p>
+ <note>
+ <p>
+ A reply sent with this function is not visible
+ in <seealso marker="sys"><c>sys</c></seealso> debug output.
+ </p>
+ </note>
+ </desc>
+ </func>
+ <func>
+ <name name="start" arity="3"/>
+ <name name="start" arity="4"/>
+ <fsummary>Create a standalone <c>gen_statem</c> process.</fsummary>
+ <desc>
+ <p>
+ Creates a standalone <c>gen_statem</c> process according to
+ OTP design principles (using
+ <seealso marker="proc_lib"><c>proc_lib</c></seealso>
+ primitives).
+ As it does not get linked to the calling process,
+ this start function cannot be used by a supervisor
+ to start a child.
+ </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 name="start_link" arity="3"/>
+ <name name="start_link" arity="4"/>
+ <fsummary>Create a linked <c>gen_statem</c> process.</fsummary>
+ <desc>
+ <p>
+ Creates a <c>gen_statem</c> process according
+ to OTP design principles
+ (using
+ <seealso marker="proc_lib"><c>proc_lib</c></seealso>
+ primitives)
+ that is linked to the calling process.
+ This is essential when the <c>gen_statem</c> must be part of
+ a supervision tree so it gets linked to its supervisor.
+ </p>
+ <p>
+ The <c>gen_statem</c> process calls
+ <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso>
+ to initialize the server. To ensure a synchronized startup
+ procedure, <c>start_link/3,4</c> does not return until
+ <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso>
+ has returned.
+ </p>
+ <p>
+ <c><anno>ServerName</anno></c> specifies the
+ <seealso marker="#type-server_name"><c>server_name()</c></seealso>
+ to register for the <c>gen_statem</c>.
+ If the <c>gen_statem</c> is started with <c>start_link/3</c>,
+ no <c><anno>ServerName</anno></c> is provided and
+ the <c>gen_statem</c> is not registered.
+ </p>
+ <p><c><anno>Module</anno></c> is the name of the callback module.</p>
+ <p>
+ <c><anno>Args</anno></c> is an arbitrary term that is passed as
+ the argument to
+ <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso>.
+ </p>
+ <list type="bulleted">
+ <item>
+ <p>
+ If option <c>{timeout,Time}</c> is present in
+ <c><anno>Opts</anno></c>, the <c>gen_statem</c>
+ is allowed to spend <c>Time</c> milliseconds initializing
+ or it terminates and the start function returns
+ <seealso marker="#type-start_ret"><c>{error,timeout}</c></seealso>.
+ </p>
+ </item>
+ <item>
+ <p>
+ If option
+ <seealso marker="#type-debug_opt"><c>{debug,Dbgs}</c></seealso>
+ is present in <c><anno>Opts</anno></c>, debugging through
+ <seealso marker="sys"><c>sys</c></seealso> is activated.
+ </p>
+ </item>
+ <item>
+ <p>
+ If option <c>{spawn_opt,SpawnOpts}</c> is present in
+ <c><anno>Opts</anno></c>, <c>SpawnOpts</c> is passed
+ as option list to
+ <seealso marker="erts:erlang#spawn_opt/2"><c>erlang:spawn_opt/2</c></seealso>,
+ which is used to spawn the <c>gen_statem</c> process.
+ </p>
+ </item>
+ </list>
+ <note>
+ <p>
+ Using spawn option <c>monitor</c> is not
+ allowed, it causes this function to fail with reason
+ <c>badarg</c>.
+ </p>
+ </note>
+ <p>
+ If the <c>gen_statem</c> is successfully created
+ and initialized, this function returns
+ <seealso marker="#type-start_ret"><c>{ok,Pid}</c></seealso>,
+ where <c>Pid</c> is the <c>pid()</c>
+ of the <c>gen_statem</c>.
+ If a process with the specified <c><anno>ServerName</anno></c>
+ exists already, this function returns
+ <seealso marker="#type-start_ret"><c>{error,{already_started,Pid}}</c></seealso>,
+ where <c>Pid</c> is the <c>pid()</c> of that process.
+ </p>
+ <p>
+ If <c>Module:init/1</c> fails with <c>Reason</c>,
+ this function returns
+ <seealso marker="#type-start_ret"><c>{error,Reason}</c></seealso>.
+ If <c>Module:init/1</c> returns
+ <seealso marker="#type-start_ret"><c>{stop,Reason}</c></seealso>
+ or
+ <seealso marker="#type-start_ret"><c>ignore</c></seealso>,
+ the process is terminated and this function
+ returns
+ <seealso marker="#type-start_ret"><c>{error,Reason}</c></seealso>
+ or
+ <seealso marker="#type-start_ret"><c>ignore</c></seealso>,
+ respectively.
+ </p>
+ </desc>
+ </func>
+
+ <func>
+ <name name="stop" arity="1"/>
+ <fsummary>Synchronously stop a generic server.</fsummary>
+ <desc>
+ <p>
+ The same as
+ <seealso marker="#stop/3"><c>stop(<anno>ServerRef</anno>, normal, infinity)</c></seealso>.
+ </p>
+ </desc>
+ </func>
+
+ <func>
+ <name name="stop" arity="3"/>
+ <fsummary>Synchronously stop a generic server.</fsummary>
+ <desc>
+ <p>
+ Orders the <c>gen_statem</c>
+ <seealso marker="#type-server_ref"><c><anno>ServerRef</anno></c></seealso>
+ to exit with the specified <c><anno>Reason</anno></c>
+ and waits for it to terminate.
+ The <c>gen_statem</c> calls
+ <seealso marker="#Module:terminate/3"><c>Module:terminate/3</c></seealso>
+ before exiting.
+ </p>
+ <p>
+ This function returns <c>ok</c> if the server 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 through
+ <seealso marker="kernel:error_logger#format/2"><c>error_logger:format/2</c></seealso>.
+ The default <c><anno>Reason</anno></c> is <c>normal</c>.
+ </p>
+ <p>
+ <c><anno>Timeout</anno></c> is an integer &gt; 0,
+ which specifies how many milliseconds to wait for the server to
+ terminate, or the atom <c>infinity</c> to wait indefinitely.
+ Defaults to <c>infinity</c>.
+ If the server does not terminate 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>
+ </funcs>
<section>
- <title>CALLBACK FUNCTIONS</title>
+ <title>Callback Functions</title>
<p>
- The following functions should be exported from a
+ The following functions are to be exported from a
<c>gen_statem</c> callback module.
</p>
</section>
+
<funcs>
+ <func>
+ <name>Module:code_change(OldVsn, OldState, OldData, Extra) ->
+ Result
+ </name>
+ <fsummary>Update the internal state during upgrade/downgrade.</fsummary>
+ <type>
+ <v>OldVsn = Vsn | {down,Vsn}</v>
+ <v>&nbsp;&nbsp;Vsn = term()</v>
+ <v>OldState = NewState = term()</v>
+ <v>Extra = term()</v>
+ <v>Result = {NewCallbackMode,NewState,NewData} | Reason</v>
+ <v>
+ NewCallbackMode =
+ <seealso marker="#type-callback_mode">callback_mode()</seealso>
+ </v>
+ <v>
+ OldState = NewState =
+ <seealso marker="#type-state">state()</seealso>
+ </v>
+ <v>
+ OldData = NewData =
+ <seealso marker="#type-data">data()</seealso>
+ </v>
+ <v>Reason = term()</v>
+ </type>
+ <desc>
+ <p>
+ This function is called by a <c>gen_statem</c> when it is to
+ update its internal state during a release upgrade/downgrade,
+ that is, when the instruction <c>{update,Module,Change,...}</c>,
+ where <c>Change={advanced,Extra}</c>, is specified in the
+ <seealso marker="sasl:appup"><c>appup</c></seealso>
+ file. For more information, see
+ <seealso marker="doc/design_principles:release_handling#instr">OTP Design Principles</seealso>.
+ </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>
+ <note>
+ <p>
+ If you would dare to change
+ <seealso marker="#type-callback_mode"><em>callback mode</em></seealso>
+ during release upgrade/downgrade, the upgrade is no problem,
+ as the new code surely knows what <em>callback mode</em>
+ it needs. However, for a downgrade this function must
+ know from argument <c>Extra</c> that comes from the
+ <seealso marker="sasl:appup"><c>sasl:appup</c></seealso>
+ file what <em>callback mode</em> the old code did use.
+ It can also be possible to figure this out
+ from argument <c>{down,Vsn}</c>, as <c>Vsn</c>
+ in effect defines the old callback module version.
+ </p>
+ </note>
+ <p>
+ <c>OldState</c> and <c>OldData</c> is the internal state
+ of the <c>gen_statem</c>.
+ </p>
+ <p>
+ <c>Extra</c> is passed "as is" from the <c>{advanced,Extra}</c>
+ part of the update instruction.
+ </p>
+ <p>
+ If successful, the function must return the updated
+ internal state in an
+ <c>{NewCallbackMode,NewState,NewData}</c> tuple.
+ </p>
+ <p>
+ If the function returns <c>Reason</c>, the ongoing
+ upgrade fails and rolls back to the old release.</p>
+ <p>
+ This function can use
+ <seealso marker="erts:erlang#throw/1"><c>erlang:throw/1</c></seealso>
+ to return <c>Result</c> or <c>Reason</c>.
+ </p>
+ </desc>
+ </func>
<func>
<name>Module:init(Args) -> Result</name>
- <fsummary>Initialize process and internal state</fsummary>
+ <fsummary>Initialize process and internal state.</fsummary>
<type>
<v>Args = term()</v>
<v>Result = {CallbackMode,State,Data}</v>
@@ -1316,25 +1358,25 @@ handle_event(_, _, State, Data) ->
<v>Reason = term()</v>
</type>
<desc>
- <marker id="Module:init-1" />
- <p>
+ <marker id="Module:init-1"/>
+ <p>
Whenever a <c>gen_statem</c> is started using
- <seealso marker="#start_link/3"><c>start_link/3,4</c></seealso>
+ <seealso marker="#start_link/3"><c>start_link/3,4</c></seealso>
or
- <seealso marker="#start/3"><c>start/3,4</c></seealso>,
- this function is called by the new process to initialize
+ <seealso marker="#start/3"><c>start/3,4</c></seealso>,
+ this function is called by the new process to initialize
the implementation state and server data.
</p>
- <p>
+ <p>
<c>Args</c> is the <c>Args</c> argument provided to the start
- function.
+ function.
</p>
- <p>
- If the initialization is successful, the function should
- return <c>{CallbackMode,State,Data}</c> or
+ <p>
+ If the initialization is successful, the function is to
+ return <c>{CallbackMode,State,Data}</c> or
<c>{CallbackMode,State,Data,Actions}</c>.
<c>CallbackMode</c> selects the
- <seealso marker="#type-callback_mode"><em>callback mode</em></seealso>.
+ <seealso marker="#type-callback_mode"><em>callback mode</em></seealso>
of the <c>gen_statem</c>.
<c>State</c> is the initial
<seealso marker="#type-state"><c>state()</c></seealso>
@@ -1347,28 +1389,127 @@ handle_event(_, _, State, Data) ->
<seealso marker="#type-state">state</seealso> just as for a
<seealso marker="#state_function">state function</seealso>.
</p>
- <p>
- If something goes wrong during the initialization
- the function should return <c>{stop,Reason}</c>
- or <c>ignore</c>. See
+ <p>
+ If the initialization fails,
+ the function is to return <c>{stop,Reason}</c>
+ or <c>ignore</c>; see
<seealso marker="#start_link/3"><c>start_link/3,4</c></seealso>.
</p>
<p>
- This function may use
- <seealso marker="erts:erlang#throw/1"><c>throw/1</c></seealso>
+ This function can use
+ <seealso marker="erts:erlang#throw/1"><c>erlang:throw/1</c></seealso>
to return <c>Result</c>.
</p>
</desc>
</func>
<func>
+ <name>Module:format_status(Opt, [PDict,State,Data]) ->
+ Status
+ </name>
+ <fsummary>Optional function for providing a term describing the
+ current <c>gen_statem</c> status.</fsummary>
+ <type>
+ <v>Opt = normal | terminate</v>
+ <v>PDict = [{Key, Value}]</v>
+ <v>
+ State =
+ <seealso marker="#type-state">state()</seealso>
+ </v>
+ <v>
+ Data =
+ <seealso marker="#type-data">data()</seealso>
+ </v>
+ <v>Key = term()</v>
+ <v>Value = term()</v>
+ <v>Status = term()</v>
+ </type>
+ <desc>
+ <note>
+ <p>
+ This callback is optional, so a callback module does not need
+ to export it. The <c>gen_statem</c> module provides a default
+ implementation of this function that returns
+ <c>{State,Data}</c>. If this callback fails, the default
+ function returns <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
+ any of the following apply:</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_statem</c> status. <c>Opt</c> is set
+ to the atom <c>normal</c> for this case.
+ </item>
+ <item>
+ The <c>gen_statem</c> 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_statem</c> status for these cases. A
+ callback module wishing to change the
+ <seealso marker="sys#get_status/1"><c>sys:get_status/1,2</c></seealso>
+ return value and how
+ its status appears in termination error logs exports an
+ instance of <c>format_status/2</c>, which returns a term
+ describing the current status of the <c>gen_statem</c>.
+ </p>
+ <p>
+ <c>PDict</c> is the current value of the process dictionary
+ of the <c>gen_statem</c>.
+ </p>
+ <p>
+ <seealso marker="#type-state"><c>State</c></seealso>
+ is the internal state of the <c>gen_statem</c>.
+ </p>
+ <p>
+ <seealso marker="#type-data"><c>Data</c></seealso>
+ is the internal server data of the <c>gen_statem</c>.
+ </p>
+ <p>
+ The function is to return <c>Status</c>, a term that
+ changes the details of the current state and status of
+ the <c>gen_statem</c>. There are no restrictions on the
+ form <c>Status</c> can take, but for the
+ <seealso marker="sys#get_status/1"><c>sys:get_status/1,2</c></seealso>
+ case (when <c>Opt</c>
+ is <c>normal</c>), the recommended form for
+ the <c>Status</c> value is <c>[{data, [{"State",
+ Term}]}]</c>, where <c>Term</c> provides relevant details of
+ the <c>gen_statem</c> state. Following this recommendation is not
+ required, but it makes the callback module status
+ consistent with the rest of the
+ <seealso marker="sys#get_status/1"><c>sys:get_status/1,2</c></seealso>
+ return value.
+ </p>
+ <p>
+ One use for this function is to return compact alternative
+ state representations to avoid having large state terms
+ printed in log files. Another use is to hide sensitive data from
+ being written to the error log.
+ </p>
+ <p>
+ This function can use
+ <seealso marker="erts:erlang#throw/1"><c>erlang:throw/1</c></seealso>
+ to return <c>Status</c>.
+ </p>
+ </desc>
+ </func>
+
+ <func>
<name>Module:StateName(EventType, EventContent, Data) ->
- StateFunctionResult
+ StateFunctionResult
</name>
<name>Module:handle_event(EventType, EventContent,
- State, Data) -> HandleEventResult
+ State, Data) -> HandleEventResult
</name>
- <fsummary>Handle an event</fsummary>
+ <fsummary>Handle an event.</fsummary>
<type>
<v>
EventType =
@@ -1385,59 +1526,55 @@ handle_event(_, _, State, Data) ->
</v>
<v>
StateFunctionResult =
- <seealso marker="#type-state_function_result">
- state_function_result()
- </seealso>
+ <seealso marker="#type-state_function_result">state_function_result()</seealso>
</v>
<v>
HandleEventResult =
- <seealso marker="#type-handle_event_result">
- handle_event_result()
- </seealso>
+ <seealso marker="#type-handle_event_result">handle_event_result()</seealso>
</v>
</type>
<desc>
- <p>
+ <p>
Whenever a <c>gen_statem</c> receives an event from
- <seealso marker="#call/2"><c>call/2</c></seealso>,
- <seealso marker="#cast/2"><c>cast/2</c></seealso> or
- as a normal process message one of these functions is called. If
+ <seealso marker="#call/2"><c>call/2</c></seealso>,
+ <seealso marker="#cast/2"><c>cast/2</c></seealso>, or
+ as a normal process message, one of these functions is called. If
<seealso marker="#type-callback_mode"><em>callback mode</em></seealso>
- is <c>state_functions</c> then <c>Module:StateName/3</c> is called,
- and if it is <c>handle_event_function</c>
- then <c>Module:handle_event/4</c> is called.
+ is <c>state_functions</c>, <c>Module:StateName/3</c> is called,
+ and if it is <c>handle_event_function</c>,
+ <c>Module:handle_event/4</c> is called.
</p>
<p>
If <c>EventType</c> is
- <seealso marker="#type-event_type"><c>{call,From}</c></seealso>
- the caller is waiting for a reply. The reply can be sent
+ <seealso marker="#type-event_type"><c>{call,From}</c></seealso>,
+ the caller waits for a reply. The reply can be sent
from this or from any other
<seealso marker="#state_function">state function</seealso>
by returning with <c>{reply,From,Reply}</c> in
<seealso marker="#type-action"><c>Actions</c></seealso>, in
- <seealso marker="#type-reply_action"><c>Replies</c></seealso>
+ <seealso marker="#type-reply_action"><c>Replies</c></seealso>,
or by calling
<seealso marker="#reply/2"><c>reply(From, Reply)</c></seealso>.
</p>
<p>
If this function returns with a next state that
- does not match equal (<c>=/=</c>) to the current state
- all postponed events will be retried in the next state.
+ does not match equal (<c>=/=</c>) to the current state,
+ all postponed events are retried in the next state.
</p>
<p>
The only difference between <c>StateFunctionResult</c> and
<c>HandleEventResult</c> is that for <c>StateFunctionResult</c>
- the next state has to be an atom but for <c>HandleEventResult</c>
+ the next state must be an atom, but for <c>HandleEventResult</c>
there is no restriction on the next state.
</p>
<p>
- See <seealso marker="#type-action"><c>action()</c></seealso>
- for options that can be set and actions that can be done
- by <c>gen_statem</c> after returning from this function.
+ For options that can be set and actions that can be done
+ by <c>gen_statem</c> after returning from this function,
+ see <seealso marker="#type-action"><c>action()</c></seealso>.
</p>
<p>
- These functions may use
- <seealso marker="erts:erlang#throw/1"><c>throw/1</c></seealso>,
+ These functions can use
+ <seealso marker="erts:erlang#throw/1"><c>erlang:throw/1</c></seealso>,
to return the result.
</p>
</desc>
@@ -1445,7 +1582,7 @@ handle_event(_, _, State, Data) ->
<func>
<name>Module:terminate(Reason, State, Data) -> Ignored</name>
- <fsummary>Clean up before termination</fsummary>
+ <fsummary>Clean up before termination.</fsummary>
<type>
<v>Reason = normal | shutdown | {shutdown,term()} | term()</v>
<v>State = <seealso marker="#type-state">state()</seealso></v>
@@ -1453,272 +1590,82 @@ handle_event(_, _, State, Data) ->
<v>Ignored = term()</v>
</type>
<desc>
- <p>
+ <p>
This function is called by a <c>gen_statem</c>
- when it is about to terminate. It should be the opposite of
+ 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_statem</c> terminates with <c>Reason</c>. The return
- value is ignored.</p>
- <p>
+ and do any necessary cleaning up. When it returns,
+ the <c>gen_statem</c> terminates with <c>Reason</c>. The return
+ value is ignored.</p>
+ <p>
<c>Reason</c> is a term denoting the stop reason and
- <seealso marker="#type-state"><c>State</c></seealso>
+ <seealso marker="#type-state"><c>State</c></seealso>
is the internal state of the <c>gen_statem</c>.
</p>
- <p>
+ <p>
<c>Reason</c> depends on why the <c>gen_statem</c>
is terminating.
- If it is because another callback function has returned a
- stop tuple <c>{stop,Reason}</c> in
+ If it is because another callback function has returned, a
+ stop tuple <c>{stop,Reason}</c> in
<seealso marker="#type-action"><c>Actions</c></seealso>,
- <c>Reason</c> will have the value specified in that tuple.
- If it is due to a failure, <c>Reason</c> is the error reason.
+ <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_statem</c> is part of a supervision tree and is
- ordered by its supervisor to terminate, this function will be
- called with <c>Reason = shutdown</c> if the following
+ ordered by its supervisor to terminate, this function is
+ called with <c>Reason = shutdown</c> if both the following
conditions apply:</p>
<list type="bulleted">
<item>
- the <c>gen_statem</c> has been set
- to trap exit signals, and
+ <p>
+ The <c>gen_statem</c> has been set
+ to trap exit signals.
+ </p>
</item>
<item>
- the shutdown strategy as defined in the supervisor's
- child specification is an integer timeout value, not
- <c>brutal_kill</c>.
+ <p>
+ The shutdown strategy as defined in the supervisor's
+ child specification is an integer time-out value, not
+ <c>brutal_kill</c>.
+ </p>
</item>
</list>
<p>
Even if the <c>gen_statem</c> is <em>not</em>
- part of a supervision tree, this function will be called
+ part of a supervision tree, this function is called
if it receives an <c>'EXIT'</c> message from its parent.
- <c>Reason</c> will be the same as
+ <c>Reason</c> is the same as
in the <c>'EXIT'</c> message.
</p>
<p>
- Otherwise, the <c>gen_statem</c> will be immediately terminated.
+ Otherwise, the <c>gen_statem</c> is immediately terminated.
</p>
<p>
- Note that for any other reason than <c>normal</c>,
- <c>shutdown</c>, or <c>{shutdown,Term}</c>
- the <c>gen_statem</c> is assumed to terminate due to an error
+ Notice that for any other reason than <c>normal</c>,
+ <c>shutdown</c>, or <c>{shutdown,Term}</c>,
+ the <c>gen_statem</c> 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>
+ <seealso marker="kernel:error_logger#format/2"><c>error_logger:format/2</c></seealso>.
</p>
<p>
- This function may use
- <seealso marker="erts:erlang#throw/1"><c>throw/1</c></seealso>
+ This function can use
+ <seealso marker="erts:erlang#throw/1"><c>erlang:throw/1</c></seealso>
to return <c>Ignored</c>, which is ignored anyway.
</p>
</desc>
</func>
-
- <func>
- <name>Module:code_change(OldVsn, OldState, OldData, Extra) ->
- Result
- </name>
- <fsummary>Update the internal state during upgrade/downgrade</fsummary>
- <type>
- <v>OldVsn = Vsn | {down,Vsn}</v>
- <v>&nbsp;&nbsp;Vsn = term()</v>
- <v>OldState = NewState = term()</v>
- <v>Extra = term()</v>
- <v>Result = {NewCallbackMode,NewState,NewData} | Reason</v>
- <v>
- NewCallbackMode =
- <seealso marker="#type-callback_mode">callback_mode()</seealso>
- </v>
- <v>
- OldState = NewState =
- <seealso marker="#type-state">state()</seealso>
- </v>
- <v>
- OldData = NewData =
- <seealso marker="#type-data">data()</seealso>
- </v>
- <v>Reason = term()</v>
- </type>
- <desc>
- <p>
- This function is called by a <c>gen_statem</c> when it should
- update its internal state during a release upgrade/downgrade,
- that is when the instruction <c>{update,Module,Change,...}</c>
- where <c>Change={advanced,Extra}</c> is given in the
- <seealso marker="sasl:appup"><c>appup</c></seealso>
- file. See
- <seealso marker="doc/design_principles:release_handling#instr">
- OTP Design Principles
- </seealso>
- for more information.
- </p>
- <p>
- In the case of an upgrade, <c>OldVsn</c> is <c>Vsn</c>, and
- in the case of 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>
- <note>
- <p>
- If you would dare to change
- <seealso marker="#type-callback_mode">
- <em>callback mode</em>
- </seealso>
- during release upgrade/downgrade, the upgrade is no problem
- since the new code surely knows what <em>callback mode</em>
- it needs, but for a downgrade this function will have to
- know from the <c>Extra</c> argument that comes from the
- <seealso marker="sasl:appup"><c>appup</c></seealso>
- file what <em>callback mode</em> the old code did use.
- It may also be possible to figure this out
- from the <c>{down,Vsn}</c> argument since <c>Vsn</c>
- in effect defines the old callback module version.
- </p>
- </note>
- <p>
- <c>OldState</c> and <c>OldData</c> is the internal state
- of the <c>gen_statem</c>.
- </p>
- <p>
- <c>Extra</c> is passed as-is from the <c>{advanced,Extra}</c>
- part of the update instruction.
- </p>
- <p>
- If successful, the function shall return the updated
- internal state in an
- <c>{NewCallbackMode,NewState,NewData}</c> tuple.
- </p>
- <p>
- If the function returns <c>Reason</c>, the ongoing
- upgrade will fail and roll back to the old release.</p>
- <p>
- This function may use
- <seealso marker="erts:erlang#throw/1"><c>throw/1</c></seealso>
- to return <c>Result</c> or <c>Reason</c>.
- </p>
- </desc>
- </func>
-
- <func>
- <name>Module:format_status(Opt, [PDict,State,Data]) ->
- Status
- </name>
- <fsummary>Optional function for providing a term describing the
- current <c>gen_statem</c> status</fsummary>
- <type>
- <v>Opt = normal | terminate</v>
- <v>PDict = [{Key, Value}]</v>
- <v>
- State =
- <seealso marker="#type-state">state()</seealso>
- </v>
- <v>
- Data =
- <seealso marker="#type-data">data()</seealso>
- </v>
- <v>Key = term()</v>
- <v>Value = term()</v>
- <v>Status = term()</v>
- </type>
- <desc>
- <note>
- <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
- <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>
- <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_statem</c> status. <c>Opt</c> is set
- to the atom <c>normal</c> for this case.
- </item>
- <item>
- The <c>gen_statem</c> 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 customising the form and
- appearance of the <c>gen_statem</c> status for these cases. A
- callback module wishing to customise the
- <seealso marker="sys#get_status/1">
- <c>sys:get_status/1,2</c>
- </seealso>
- 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_statem</c>.
- </p>
- <p>
- <c>PDict</c> is the current value of the <c>gen_statem</c>'s
- process dictionary.
- </p>
- <p>
- <seealso marker="#type-state"><c>State</c></seealso>
- is the internal state of the <c>gen_statem</c>.
- </p>
- <p>
- <seealso marker="#type-data"><c>Data</c></seealso>
- is the internal server data of the <c>gen_statem</c>.
- </p>
- <p>
- The function should return <c>Status</c>, a term that
- customises the details of the current state and status of
- the <c>gen_statem</c>. There are no restrictions on the
- form <c>Status</c> can take, but for the
- <seealso marker="sys#get_status/1">
- <c>sys:get_status/1,2</c>
- </seealso>
- case (when <c>Opt</c>
- is <c>normal</c>), the recommended form for
- the <c>Status</c> value is <c>[{data, [{"State",
- Term}]}]</c> where <c>Term</c> provides relevant details of
- the <c>gen_statem</c> state. Following this recommendation isn't
- required, but doing so will make the callback module status
- consistent with the rest of the
- <seealso marker="sys#get_status/1">
- <c>sys:get_status/1,2</c>
- </seealso>
- return value.
- </p>
- <p>
- One use for this function is to return compact alternative
- state representations to avoid having large state terms
- 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/1</c></seealso>
- to return <c>Status</c>.
- </p>
- </desc>
- </func>
-
</funcs>
<section>
- <title>SEE ALSO</title>
- <p><seealso marker="gen_event"><c>gen_event(3)</c></seealso>,
+ <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_server"><c>gen_server(3)</c></seealso>,
- <seealso marker="supervisor"><c>supervisor(3)</c></seealso>,
<seealso marker="proc_lib"><c>proc_lib(3)</c></seealso>,
- <seealso marker="sys"><c>sys(3)</c></seealso></p>
+ <seealso marker="supervisor"><c>supervisor(3)</c></seealso>,
+ <seealso marker="sys"><c>sys(3)</c></seealso>.
+ </p>
</section>
</erlref>
diff --git a/lib/stdlib/doc/src/proc_lib.xml b/lib/stdlib/doc/src/proc_lib.xml
index 245580b1ba..f02b1f0651 100644
--- a/lib/stdlib/doc/src/proc_lib.xml
+++ b/lib/stdlib/doc/src/proc_lib.xml
@@ -73,6 +73,13 @@
<name name="priority_level"/>
</datatype>
<datatype>
+ <name name="max_heap_size"/>
+ <desc>
+ <p>See <seealso marker="erts:erlang#process_flag_max_heap_size">
+ erlang:process_flag(max_heap_size, MaxHeapSize)</seealso>.</p>
+ </desc>
+ </datatype>
+ <datatype>
<name name="dict_or_pid"/>
</datatype>
</datatypes>
diff --git a/lib/stdlib/src/epp.erl b/lib/stdlib/src/epp.erl
index 55a818e87c..73934e0e3c 100644
--- a/lib/stdlib/src/epp.erl
+++ b/lib/stdlib/src/epp.erl
@@ -53,6 +53,8 @@
| {atom(),non_neg_integer()}
| tokens().
+-type warning_info() :: {erl_anno:location(), module(), term()}.
+
-define(DEFAULT_ENCODING, utf8).
%% Epp state record.
@@ -158,11 +160,13 @@ scan_erl_form(Epp) ->
epp_request(Epp, scan_erl_form).
-spec parse_erl_form(Epp) ->
- {'ok', AbsForm} | {'eof', Line} | {error, ErrorInfo} when
+ {'ok', AbsForm} | {error, ErrorInfo} |
+ {'warning',WarningInfo} | {'eof',Line} when
Epp :: epp_handle(),
AbsForm :: erl_parse:abstract_form(),
Line :: erl_anno:line(),
- ErrorInfo :: erl_scan:error_info() | erl_parse:error_info().
+ ErrorInfo :: erl_scan:error_info() | erl_parse:error_info(),
+ WarningInfo :: warning_info().
parse_erl_form(Epp) ->
case epp_request(Epp, scan_erl_form) of
@@ -219,6 +223,10 @@ format_error({illegal_function_usage,Macro}) ->
io_lib:format("?~s must not begin a form", [Macro]);
format_error({'NYI',What}) ->
io_lib:format("not yet implemented '~s'", [What]);
+format_error({error,Term}) ->
+ io_lib:format("-error(~p).", [Term]);
+format_error({warning,Term}) ->
+ io_lib:format("-warning(~p).", [Term]);
format_error(E) -> file:format_error(E).
-spec parse_file(FileName, IncludePath, PredefMacros) ->
@@ -263,9 +271,11 @@ parse_file(Ifile, Options) ->
-spec parse_file(Epp) -> [Form] when
Epp :: epp_handle(),
- Form :: erl_parse:abstract_form() | {'error', ErrorInfo} | {'eof',Line},
+ Form :: erl_parse:abstract_form() | {'error', ErrorInfo} |
+ {'warning',WarningInfo} | {'eof',Line},
Line :: erl_anno:line(),
- ErrorInfo :: erl_scan:error_info() | erl_parse:error_info().
+ ErrorInfo :: erl_scan:error_info() | erl_parse:error_info(),
+ WarningInfo :: warning_info().
parse_file(Epp) ->
case parse_erl_form(Epp) of
@@ -273,6 +283,8 @@ parse_file(Epp) ->
[Form|parse_file(Epp)];
{error,E} ->
[{error,E}|parse_file(Epp)];
+ {warning,W} ->
+ [{warning,W}|parse_file(Epp)];
{eof,Location} ->
[{eof,erl_anno:new(Location)}]
end.
@@ -752,6 +764,10 @@ scan_toks([{'-',_Lh},{atom,_Ld,define}=Define|Toks], From, St) ->
scan_define(Toks, Define, From, St);
scan_toks([{'-',_Lh},{atom,_Ld,undef}=Undef|Toks], From, St) ->
scan_undef(Toks, Undef, From, St);
+scan_toks([{'-',_Lh},{atom,_Ld,error}=Error|Toks], From, St) ->
+ scan_err_warn(Toks, Error, From, St);
+scan_toks([{'-',_Lh},{atom,_Ld,warning}=Warn|Toks], From, St) ->
+ scan_err_warn(Toks, Warn, From, St);
scan_toks([{'-',_Lh},{atom,_Li,include}=Inc|Toks], From, St) ->
scan_include(Toks, Inc, From, St);
scan_toks([{'-',_Lh},{atom,_Li,include_lib}=IncLib|Toks], From, St) ->
@@ -807,6 +823,24 @@ scan_extends([{atom,Ln,A}=ModAtom,{')',_Lr}|_Ts], Ms0) ->
Ms#{'BASE_MODULE_STRING':={none,[{string,Ln,ModString}]}};
scan_extends(_Ts, Ms) -> Ms.
+scan_err_warn([{'(',_}|_]=Toks0, {atom,_,Tag}=Token, From, St) ->
+ try expand_macros(Toks0, St) of
+ Toks when is_list(Toks) ->
+ case erl_parse:parse_term(Toks) of
+ {ok,Term} ->
+ epp_reply(From, {Tag,{loc(Token),epp,{Tag,Term}}});
+ {error,_} ->
+ epp_reply(From, {error,{loc(Token),epp,{bad,Tag}}})
+ end
+ catch
+ _:_ ->
+ epp_reply(From, {error,{loc(Token),epp,{bad,Tag}}})
+ end,
+ wait_req_scan(St);
+scan_err_warn(_Toks, {atom,_,Tag}=Token, From, St) ->
+ epp_reply(From, {error,{loc(Token),epp,{bad,Tag}}}),
+ wait_req_scan(St).
+
%% scan_define(Tokens, DefineToken, From, EppState)
scan_define([{'(',_Lp},{Type,_Lm,_}=Mac|Toks], Def, From, St)
@@ -933,9 +967,15 @@ scan_include(_Toks, Inc, From, St) ->
%% normal search path, if not we assume that the first directory name
%% is a library name, find its true directory and try with that.
-find_lib_dir(NewName) ->
- [Lib | Rest] = filename:split(NewName),
- {code:lib_dir(list_to_atom(Lib)), Rest}.
+expand_lib_dir(Name) ->
+ try
+ [App|Path] = filename:split(Name),
+ LibDir = code:lib_dir(list_to_atom(App)),
+ {ok,fname_join([LibDir|Path])}
+ catch
+ _:_ ->
+ error
+ end.
scan_include_lib([{'(',_Llp},{string,_Lf,_NewName0},{')',_Lrp},{dot,_Ld}],
Inc, From, St)
@@ -950,12 +990,11 @@ scan_include_lib([{'(',_Llp},{string,_Lf,NewName0},{')',_Lrp},{dot,_Ld}],
{ok,NewF,Pname} ->
wait_req_scan(enter_file2(NewF, Pname, From, St, Loc));
{error,_E1} ->
- case catch find_lib_dir(NewName) of
- {LibDir, Rest} when is_list(LibDir) ->
- LibName = fname_join([LibDir | Rest]),
- case file:open(LibName, [read]) of
+ case expand_lib_dir(NewName) of
+ {ok,Header} ->
+ case file:open(Header, [read]) of
{ok,NewF} ->
- wait_req_scan(enter_file2(NewF, LibName, From,
+ wait_req_scan(enter_file2(NewF, Header, From,
St, Loc));
{error,_E2} ->
epp_reply(From,
@@ -963,7 +1002,7 @@ scan_include_lib([{'(',_Llp},{string,_Lf,NewName0},{')',_Lrp},{dot,_Ld}],
{include,lib,NewName}}}),
wait_req_scan(St)
end;
- _Error ->
+ error ->
epp_reply(From, {error,{loc(Inc),epp,
{include,lib,NewName}}}),
wait_req_scan(St)
diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl
index f9e2e5f7d2..23bddafeed 100644
--- a/lib/stdlib/src/gen_statem.erl
+++ b/lib/stdlib/src/gen_statem.erl
@@ -97,7 +97,7 @@
%% * Postponing the current event is performed
%% iff 'postpone' is 'true'.
%% * A state timer is started iff 'timeout' is set.
- %% * Pending events are processed or if there are
+ %% * Pending events are handled or if there are
%% no pending events the server goes into receive
%% or hibernate (iff 'hibernate' is 'true')
%%
@@ -282,16 +282,6 @@ event_type(Type) ->
STACKTRACE(),
try throw(ok) catch _ -> erlang:get_stacktrace() end).
--define(
- TERMINATE(Class, Reason, Debug, S, Q),
- terminate(
- begin Class end,
- begin Reason end,
- ?STACKTRACE(),
- begin Debug end,
- begin S end,
- begin Q end)).
-
%%%==========================================================================
%%% API
@@ -300,11 +290,11 @@ event_type(Type) ->
| {'via', RegMod :: module(), Name :: term()}
| {'local', atom()}.
-type server_ref() ::
- {'global', GlobalName :: term()}
- | {'via', RegMod :: module(), ViaName :: term()}
+ pid()
| (LocalName :: atom())
| {Name :: atom(), Node :: atom()}
- | pid().
+ | {'global', GlobalName :: term()}
+ | {'via', RegMod :: module(), ViaName :: term()}.
-type debug_opt() ::
{'debug',
Dbgs ::
@@ -523,12 +513,15 @@ send(Proc, Msg) ->
ok
end.
-%% Here init_it/6 and enter_loop/5,6,7 functions converge
+%% Here the init_it/6 and enter_loop/5,6,7 functions converge
enter(Module, Opts, CallbackMode, State, Data, Server, Actions, Parent) ->
%% The values should already have been type checked
Name = gen:get_proc_name(Server),
Debug = gen:debug_options(Name, Opts),
- PrevState = make_ref(), % Will be discarded by loop_event_actions/9
+ P = Events = [],
+ Event = {internal,initial_state},
+ %% We enforce {postpone,false} to ensure that
+ %% our fake Event gets discarded, thought it might get logged
NewActions =
if
is_list(Actions) ->
@@ -540,15 +533,17 @@ enter(Module, Opts, CallbackMode, State, Data, Server, Actions, Parent) ->
callback_mode => CallbackMode,
module => Module,
name => Name,
- state => PrevState,
+ %% All fields below will be replaced according to the arguments to
+ %% loop_event_actions/10 when it finally loops back to loop/3
+ state => State,
data => Data,
- timer => undefined,
- postponed => [],
- hibernate => false},
+ postponed => P,
+ hibernate => false,
+ timer => undefined},
+ NewDebug = sys_debug(Debug, S, State, {enter,Event,State}),
loop_event_actions(
- Parent, Debug, S, [],
- {event,undefined}, % Will be discarded thanks to {postpone,false}
- PrevState, State, Data, NewActions).
+ Parent, NewDebug, S, Events,
+ State, Data, P, Event, State, NewActions).
%%%==========================================================================
%%% gen callbacks
@@ -617,8 +612,12 @@ init_result(Starter, Parent, ServerRef, Module, Result, Opts) ->
system_continue(Parent, Debug, S) ->
loop(Parent, Debug, S).
-system_terminate(Reason, _Parent, Debug, S) ->
- ?TERMINATE(exit, Reason, Debug, S, []).
+system_terminate(
+ Reason, _Parent, Debug,
+ #{state := State, data := Data, postponed := P} = S) ->
+ terminate(
+ exit, Reason, ?STACKTRACE(),
+ Debug, S, [], State, Data, P).
system_code_change(
#{module := Module,
@@ -634,7 +633,10 @@ system_code_change(
{NewCallbackMode,NewState,NewData} ->
callback_mode(NewCallbackMode) orelse
error({callback_mode,NewCallbackMode}),
- {ok,S#{state := NewState, data := NewData}};
+ {ok,
+ S#{callback_mode := NewCallbackMode,
+ state := NewState,
+ data := NewData}};
{ok,_} = Error ->
error({case_clause,Error});
Error ->
@@ -654,7 +656,7 @@ system_replace_state(
format_status(
Opt,
[PDict,SysState,Parent,Debug,
- #{name := Name, postponed := P} = S]) ->
+ #{name := Name, postponed := P, state := State, data := Data} = S]) ->
Header = gen:format_status_header("Status for state machine", Name),
Log = sys:get_debug(log, Debug, []),
[{header,Header},
@@ -663,7 +665,7 @@ format_status(
{"Parent",Parent},
{"Logged Events",Log},
{"Postponed",P}]} |
- case format_status(Opt, PDict, S) of
+ case format_status(Opt, PDict, S, State, Data) of
L when is_list(L) -> L;
T -> [T]
end].
@@ -673,21 +675,21 @@ format_status(
%% them, not as the real erlang messages. Use trace for that.
%%---------------------------------------------------------------------------
-print_event(Dev, {in,Event}, #{name := Name}) ->
+print_event(Dev, {in,Event}, {Name,_}) ->
io:format(
Dev, "*DBG* ~p received ~s~n",
[Name,event_string(Event)]);
-print_event(Dev, {out,Reply,{To,_Tag}}, #{name := Name}) ->
+print_event(Dev, {out,Reply,{To,_Tag}}, {Name,_}) ->
io:format(
Dev, "*DBG* ~p sent ~p to ~p~n",
[Name,Reply,To]);
-print_event(Dev, {Tag,Event,NewState}, #{name := Name, state := State}) ->
+print_event(Dev, {Tag,Event,NextState}, {Name,State}) ->
StateString =
- case NewState of
+ case NextState of
State ->
io_lib:format("~p", [State]);
_ ->
- io_lib:format("~p => ~p", [State,NewState])
+ io_lib:format("~p => ~p", [State,NextState])
end,
io:format(
Dev, "*DBG* ~p ~w ~s in state ~s~n",
@@ -697,16 +699,17 @@ event_string(Event) ->
case Event of
{{call,{Pid,_Tag}},Request} ->
io_lib:format("call ~p from ~w", [Request,Pid]);
- {Tag,Content} ->
- io_lib:format("~w ~p", [Tag,Content])
+ {EventType,EventContent} ->
+ io_lib:format("~w ~p", [EventType,EventContent])
end.
-sys_debug(Debug, S, Entry) ->
+sys_debug(Debug, #{name := Name}, State, Entry) ->
case Debug of
[] ->
Debug;
_ ->
- sys:handle_debug(Debug, fun print_event/3, S, Entry)
+ sys:handle_debug(
+ Debug, fun print_event/3, {Name,State}, Entry)
end.
%%%==========================================================================
@@ -720,7 +723,7 @@ wakeup_from_hibernate(Parent, Debug, S) ->
%%% State Machine engine implementation of proc_lib/gen server
%% Server loop, consists of all loop* functions
-%% and some detours through sys and proc_lib
+%% and detours through sys:handle_system_message/7 and proc_lib:hibernate/3
%% Entry point for system_continue/3
loop(Parent, Debug, #{hibernate := Hibernate} = S) ->
@@ -749,12 +752,16 @@ loop_receive(Parent, Debug, #{timer := Timer} = S) ->
sys:handle_system_msg(
Req, Pid, Parent, ?MODULE, Debug, S, Hibernate);
{'EXIT',Parent,Reason} = EXIT ->
+ #{state := State, data := Data, postponed := P} = S,
%% EXIT is not a 2-tuple and therefore
%% not an event and has no event_type(),
%% but this will stand out in the crash report...
- ?TERMINATE(exit, Reason, Debug, S, [EXIT]);
+ terminate(
+ exit, Reason, ?STACKTRACE(),
+ Debug, S, [EXIT], State, Data, P);
{timeout,Timer,Content} when Timer =/= undefined ->
- loop_event(Parent, Debug, S, {timeout,Content});
+ loop_receive_result(
+ Parent, Debug, S, {timeout,Content});
_ ->
%% Cancel Timer if running
case Timer of
@@ -782,30 +789,81 @@ loop_receive(Parent, Debug, #{timer := Timer} = S) ->
_ ->
{info,Msg}
end,
- loop_event(Parent, Debug, S, Event)
+ loop_receive_result(Parent, Debug, S, Event)
end
end.
-loop_event(Parent, Debug, S, Event) ->
- %% The timer field and the hibernate flag in S
- %% are now invalid and ignored until we get back to loop/3
- NewDebug = sys_debug(Debug, S, {in,Event}),
- %% Here the queue of not yet processed events is created
- loop_events(Parent, NewDebug, S, [Event], false).
-
-%% Process first the event queue, or if it is empty
-%% loop back to receive a new event
-loop_events(Parent, Debug, S, [], _Hibernate) ->
- loop(Parent, Debug, S);
+loop_receive_result(
+ Parent, Debug,
+ #{state := State,
+ data := Data,
+ postponed := P} = S,
+ Event) ->
+ %% The engine state map S is now dismantled
+ %% and will not be restored until we return to loop/3.
+ %%
+ %% The fields 'callback_mode', 'module', and 'name' are still valid.
+ %% The fields 'state', 'data', and 'postponed' are held in arguments.
+ %% The fields 'timer' and 'hibernate' will be recalculated.
+ %%
+ NewDebug = sys_debug(Debug, S, State, {in,Event}),
+ %% Here the queue of not yet handled events is created
+ Events = [],
+ Hibernate = false,
+ loop_event(
+ Parent, NewDebug, S, Events, State, Data, P, Event, Hibernate).
+
+%% Process the event queue, or if it is empty
+%% loop back to loop/3 to receive a new event
+loop_events(
+ Parent, Debug, S, [Event|Events],
+ State, Data, P, Hibernate, _Timeout) ->
+ %%
+ %% If there was a state timer requested we just ignore that
+ %% since we have events to handle which cancels the timer
+ loop_event(
+ Parent, Debug, S, Events, State, Data, P, Event, Hibernate);
loop_events(
+ Parent, Debug, S, [],
+ State, Data, P, Hibernate, Timeout) ->
+ case Timeout of
+ {timeout,0,EventContent} ->
+ %% Immediate timeout - simulate it
+ %% so we do not get the timeout message
+ %% after any received event
+ loop_event(
+ Parent, Debug, S, [],
+ State, Data, P, {timeout,EventContent}, Hibernate);
+ {timeout,Time,EventContent} ->
+ %% Actually start a timer
+ Timer = erlang:start_timer(Time, self(), EventContent),
+ loop_events_done(
+ Parent, Debug, S, Timer, State, Data, P, Hibernate);
+ undefined ->
+ %% No state timeout has been requested
+ Timer = undefined,
+ loop_events_done(
+ Parent, Debug, S, Timer, State, Data, P, Hibernate)
+ end.
+%%
+loop_events_done(Parent, Debug, S, Timer, State, Data, P, Hibernate) ->
+ NewS =
+ S#{
+ state := State,
+ data := Data,
+ postponed := P,
+ hibernate := Hibernate,
+ timer := Timer},
+ loop(Parent, Debug, NewS).
+
+loop_event(
Parent, Debug,
#{callback_mode := CallbackMode,
- module := Module,
- state := State,
- data := Data} = S,
- [{Type,Content} = Event|Events] = Q,
- Hibernate) ->
- %% If the Hibernate flag is true here it can only be
+ module := Module} = S,
+ Events,
+ State, Data, P, {Type,Content} = Event, Hibernate) ->
+ %%
+ %% If Hibernate is true here it can only be
%% because it was set from an event action
%% and we did not go into hibernation since there
%% were events in queue, so we do what the user
@@ -813,6 +871,7 @@ loop_events(
%% would have happened if we actually hibernated
%% and immediately was awakened
Hibernate andalso garbage_collect(),
+ %%
try
case CallbackMode of
state_functions ->
@@ -822,11 +881,11 @@ loop_events(
end of
Result ->
loop_event_result(
- Parent, Debug, S, Events, Event, Result)
+ Parent, Debug, S, Events, State, Data, P, Event, Result)
catch
Result ->
loop_event_result(
- Parent, Debug, S, Events, Event, Result);
+ Parent, Debug, S, Events, State, Data, P, Event, Result);
error:badarg when CallbackMode =:= state_functions ->
case erlang:get_stacktrace() of
[{erlang,apply,[Module,State,_],_}|Stacktrace] ->
@@ -835,9 +894,11 @@ loop_events(
error,
{undef_state_function,{Module,State,Args}},
Stacktrace,
- Debug, S, Q);
+ Debug, S, [Event|Events], State, Data, P);
Stacktrace ->
- terminate(error, badarg, Stacktrace, Debug, S, Q)
+ terminate(
+ error, badarg, Stacktrace,
+ Debug, S, [Event|Events], State, Data, P)
end;
error:undef ->
%% Process an undef to check for the simple mistake
@@ -852,7 +913,7 @@ loop_events(
error,
{undef_state_function,{Module,State,Args}},
Stacktrace,
- Debug, S, Q);
+ Debug, S, [Event|Events], State, Data, P);
[{Module,handle_event,
[Type,Content,State,Data]=Args,
_}
@@ -860,86 +921,85 @@ loop_events(
when CallbackMode =:= handle_event_function ->
terminate(
error,
- {undef_state_function,
- {Module,handle_event,Args}},
+ {undef_state_function,{Module,handle_event,Args}},
Stacktrace,
- Debug, S, Q);
+ Debug, S, [Event|Events], State, Data, P);
Stacktrace ->
- terminate(error, undef, Stacktrace, Debug, S, Q)
+ terminate(
+ error, undef, Stacktrace,
+ Debug, S, [Event|Events], State, Data, P)
end;
Class:Reason ->
Stacktrace = erlang:get_stacktrace(),
- terminate(Class, Reason, Stacktrace, Debug, S, Q)
+ terminate(
+ Class, Reason, Stacktrace,
+ Debug, S, [Event|Events], State, Data, P)
end.
%% Interpret all callback return variants
loop_event_result(
- Parent, Debug,
- #{state := State, data := Data} = S,
- Events, Event, Result) ->
- %% From now until we loop back to the loop_events/4
- %% the state and data fields in S are old
+ Parent, Debug, S, Events, State, Data, P, Event, Result) ->
case Result of
stop ->
- ?TERMINATE(exit, normal, Debug, S, [Event|Events]);
+ terminate(
+ exit, normal, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, Data, P);
{stop,Reason} ->
- ?TERMINATE(exit, Reason, Debug, S, [Event|Events]);
+ terminate(
+ exit, Reason, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, Data, P);
{stop,Reason,NewData} ->
- NewS = S#{data := NewData},
- Q = [Event|Events],
- ?TERMINATE(exit, Reason, Debug, NewS, Q);
+ terminate(
+ exit, Reason, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, NewData, P);
{stop_and_reply,Reason,Replies} ->
Q = [Event|Events],
- [Class,NewReason,Stacktrace,NewDebug] =
- reply_then_terminate(
- exit, Reason, ?STACKTRACE(), Debug, S, Q, Replies),
- %% Since we got back here Replies was bad
- terminate(Class, NewReason, Stacktrace, NewDebug, S, Q);
+ reply_then_terminate(
+ exit, Reason, ?STACKTRACE(),
+ Debug, S, Q, State, Data, P, Replies);
{stop_and_reply,Reason,Replies,NewData} ->
- NewS = S#{data := NewData},
Q = [Event|Events],
- [Class,NewReason,Stacktrace,NewDebug] =
- reply_then_terminate(
- exit, Reason, ?STACKTRACE(), Debug, NewS, Q, Replies),
- %% Since we got back here Replies was bad
- terminate(Class, NewReason, Stacktrace, NewDebug, NewS, Q);
+ reply_then_terminate(
+ exit, Reason, ?STACKTRACE(),
+ Debug, S, Q, State, NewData, P, Replies);
{next_state,NextState,NewData} ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, []);
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, []);
{next_state,NextState,NewData,Actions} ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, Actions);
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, Actions);
{keep_state,NewData} ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, State, NewData, []);
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, State, []);
{keep_state,NewData,Actions} ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, State, NewData, Actions);
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, State, Actions);
keep_state_and_data ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, State, Data, []);
+ Parent, Debug, S, Events,
+ State, Data, P, Event, State, []);
{keep_state_and_data,Actions} ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, State, Data, Actions);
+ Parent, Debug, S, Events,
+ State, Data, P, Event, State, Actions);
_ ->
- ?TERMINATE(
- error, {bad_return_value,Result}, Debug, S, [Event|Events])
+ terminate(
+ error, {bad_return_value,Result}, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, Data, P)
end.
loop_event_actions(
- Parent, Debug, S, Events, Event, State, NextState, NewData, Actions) ->
- Postpone = false, % Shall we postpone this event, true or false
+ Parent, Debug, S, Events, State, NewData, P, Event, NextState, Actions) ->
+ Postpone = false, % Shall we postpone this event; boolean()
Hibernate = false,
Timeout = undefined,
NextEvents = [],
loop_event_actions(
- Parent, Debug, S, Events, Event, State, NextState, NewData,
+ Parent, Debug, S, Events, State, NewData, P, Event, NextState,
if
is_list(Actions) ->
Actions;
@@ -948,97 +1008,103 @@ loop_event_actions(
end,
Postpone, Hibernate, Timeout, NextEvents).
%%
-%% Process all action()s
+%% Process all actions
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, [Action|Actions],
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, [Action|Actions],
Postpone, Hibernate, Timeout, NextEvents) ->
case Action of
%% Actual actions
{reply,From,Reply} ->
case from(From) of
true ->
- NewDebug = do_reply(Debug, S, From, Reply),
+ NewDebug = do_reply(Debug, S, State, From, Reply),
loop_event_actions(
- Parent, NewDebug, S, Events, Event,
- State, NextState, NewData, Actions,
+ Parent, NewDebug, S, Events,
+ State, NewData, P, Event, NextState, Actions,
Postpone, Hibernate, Timeout, NextEvents);
false ->
- ?TERMINATE(
- error, {bad_action,Action}, Debug, S, [Event|Events])
+ terminate(
+ error, {bad_action,Action}, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, NewData, P)
end;
{next_event,Type,Content} ->
case event_type(Type) of
true ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, Actions,
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, Actions,
Postpone, Hibernate, Timeout,
[{Type,Content}|NextEvents]);
false ->
- ?TERMINATE(
- error, {bad_action,Action}, Debug, S, [Event|Events])
+ terminate(
+ error, {bad_action,Action}, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, NewData, P)
end;
%% Actions that set options
{postpone,NewPostpone} when is_boolean(NewPostpone) ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, Actions,
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, Actions,
NewPostpone, Hibernate, Timeout, NextEvents);
{postpone,_} ->
- ?TERMINATE(
- error, {bad_action,Action}, Debug, S, [Event|Events]);
+ terminate(
+ error, {bad_action,Action}, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, NewData, P);
postpone ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, Actions,
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, Actions,
true, Hibernate, Timeout, NextEvents);
{hibernate,NewHibernate} when is_boolean(NewHibernate) ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, Actions,
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, Actions,
Postpone, NewHibernate, Timeout, NextEvents);
{hibernate,_} ->
- ?TERMINATE(
- error, {bad_action,Action}, Debug, S, [Event|Events]);
+ terminate(
+ error, {bad_action,Action}, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, NewData, P);
hibernate ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, Actions,
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, Actions,
Postpone, true, Timeout, NextEvents);
{timeout,infinity,_} -> % Clear timer - it will never trigger
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, Actions,
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, Actions,
Postpone, Hibernate, undefined, NextEvents);
{timeout,Time,_} = NewTimeout when is_integer(Time), Time >= 0 ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, Actions,
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, Actions,
Postpone, Hibernate, NewTimeout, NextEvents);
{timeout,_,_} ->
- ?TERMINATE(
- error, {bad_action,Action}, Debug, S, [Event|Events]);
+ terminate(
+ error, {bad_action,Action}, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, NewData, P);
infinity -> % Clear timer - it will never trigger
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, Actions,
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, Actions,
Postpone, Hibernate, undefined, NextEvents);
Time when is_integer(Time), Time >= 0 ->
NewTimeout = {timeout,Time,Time},
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, Actions,
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, Actions,
Postpone, Hibernate, NewTimeout, NextEvents);
_ ->
- ?TERMINATE(
- error, {bad_action,Action}, Debug, S, [Event|Events])
+ terminate(
+ error, {bad_action,Action}, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, NewData, P)
end;
%%
%% End of actions list
loop_event_actions(
- Parent, Debug, #{postponed := P0} = S, Events, Event,
- State, NextState, NewData, [],
+ Parent, Debug, S, Events,
+ State, NewData, P0, Event, NextState, [],
Postpone, Hibernate, Timeout, NextEvents) ->
%%
%% All options have been collected and next_events are buffered.
@@ -1059,89 +1125,62 @@ loop_event_actions(
{lists:reverse(P1, Events),[]}
end,
%% Place next events first in queue
- Q3 = lists:reverse(NextEvents, Q2),
+ Q = lists:reverse(NextEvents, Q2),
%%
NewDebug =
sys_debug(
- Debug, S,
+ Debug, S, State,
case Postpone of
true ->
{postpone,Event,NextState};
false ->
{consume,Event,NextState}
end),
- %% Have a peek on the event queue so we can avoid starting
- %% the state timer unless we have to
- {Q,Timer} =
- case Timeout of
- undefined ->
- %% No state timeout has been requested
- {Q3,undefined};
- {timeout,Time,EventContent} ->
- %% A state timeout has been requested
- case Q3 of
- [] when Time =:= 0 ->
- %% Immediate timeout - simulate it
- %% so we do not get the timeout message
- %% after any received event
- {[{timeout,EventContent}],undefined};
- [] ->
- %% Actually start a timer
- {Q3,erlang:start_timer(Time, self(), EventContent)};
- _ ->
- %% Do not start a timer since any queued
- %% event cancels the state timer so we pretend
- %% that the timer has been started and cancelled
- {Q3,undefined}
- end
- end,
- %% Loop to top of event queue loop; process next event
loop_events(
- Parent, NewDebug,
- S#{
- state := NextState,
- data := NewData,
- timer := Timer,
- postponed := P,
- hibernate := Hibernate},
- Q, Hibernate).
+ Parent, NewDebug, S, Q, NextState, NewData, P, Hibernate, Timeout).
%%---------------------------------------------------------------------------
%% Server helpers
-reply_then_terminate(Class, Reason, Stacktrace, Debug, S, Q, Replies) ->
+reply_then_terminate(
+ Class, Reason, Stacktrace,
+ Debug, S, Q, State, Data, P, Replies) ->
if
is_list(Replies) ->
do_reply_then_terminate(
- Class, Reason, Stacktrace, Debug, S, Q, Replies);
+ Class, Reason, Stacktrace,
+ Debug, S, Q, State, Data, P, Replies);
true ->
do_reply_then_terminate(
- Class, Reason, Stacktrace, Debug, S, Q, [Replies])
+ Class, Reason, Stacktrace,
+ Debug, S, Q, State, Data, P, [Replies])
end.
%%
-do_reply_then_terminate(Class, Reason, Stacktrace, Debug, S, Q, []) ->
- terminate(Class, Reason, Stacktrace, Debug, S, Q);
do_reply_then_terminate(
- Class, Reason, Stacktrace, Debug, S, Q, [R|Rs]) ->
+ Class, Reason, Stacktrace, Debug, S, Q, State, Data, P, []) ->
+ terminate(Class, Reason, Stacktrace, Debug, S, Q, State, Data, P);
+do_reply_then_terminate(
+ Class, Reason, Stacktrace, Debug, S, Q, State, Data, P, [R|Rs]) ->
case R of
{reply,{_To,_Tag}=From,Reply} ->
- NewDebug = do_reply(Debug, S, From, Reply),
+ NewDebug = do_reply(Debug, S, State, From, Reply),
do_reply_then_terminate(
- Class, Reason, Stacktrace, NewDebug, S, Q, Rs);
+ Class, Reason, Stacktrace,
+ NewDebug, S, Q, State, Data, P, Rs);
_ ->
- [error,{bad_action,R},?STACKTRACE(),Debug]
+ terminate(
+ error, {bad_action,R}, ?STACKTRACE(),
+ Debug, S, Q, State, Data, P)
end.
-do_reply(Debug, S, From, Reply) ->
+do_reply(Debug, S, State, From, Reply) ->
reply(From, Reply),
- sys_debug(Debug, S, {out,Reply,From}).
+ sys_debug(Debug, S, State, {out,Reply,From}).
terminate(
- Class, Reason, Stacktrace, Debug,
- #{module := Module,
- state := State, data := Data} = S,
- Q) ->
+ Class, Reason, Stacktrace,
+ Debug, #{module := Module} = S, Q, State, Data, P) ->
try Module:terminate(Reason, State, Data) of
_ -> ok
catch
@@ -1149,8 +1188,8 @@ terminate(
C:R ->
ST = erlang:get_stacktrace(),
error_info(
- C, R, ST, Debug, S, Q,
- format_status(terminate, get(), S)),
+ C, R, ST, Debug, S, Q, P,
+ format_status(terminate, get(), S, State, Data)),
erlang:raise(C, R, ST)
end,
case Reason of
@@ -1159,8 +1198,8 @@ terminate(
{shutdown,_} -> ok;
_ ->
error_info(
- Class, Reason, Stacktrace, Debug, S, Q,
- format_status(terminate, get(), S))
+ Class, Reason, Stacktrace, Debug, S, Q, P,
+ format_status(terminate, get(), S, State, Data))
end,
case Stacktrace of
[] ->
@@ -1171,9 +1210,8 @@ terminate(
error_info(
Class, Reason, Stacktrace, Debug,
- #{name := Name, callback_mode := CallbackMode,
- state := State, postponed := P},
- Q, FmtData) ->
+ #{name := Name, callback_mode := CallbackMode},
+ Q, P, FmtData) ->
{FixedReason,FixedStacktrace} =
case Stacktrace of
[{M,F,Args,_}|ST]
@@ -1202,46 +1240,49 @@ error_info(
error_logger:format(
"** State machine ~p terminating~n" ++
case Q of
- [] ->
- "";
- _ ->
- "** Last event = ~p~n"
+ [] -> "";
+ _ -> "** Last event = ~p~n"
end ++
- "** When Server state = ~p~n" ++
+ "** When server state = ~p~n" ++
"** Reason for termination = ~w:~p~n" ++
- "** State = ~p~n" ++
"** Callback mode = ~p~n" ++
- "** Queued/Postponed = ~w/~w~n" ++
+ case Q of
+ [_,_|_] -> "** Queued = ~p~n";
+ _ -> ""
+ end ++
+ case P of
+ [] -> "";
+ _ -> "** Postponed = ~p~n"
+ end ++
case FixedStacktrace of
- [] ->
- "";
- _ ->
- "** Stacktrace =~n"
- "** ~p~n"
+ [] -> "";
+ _ -> "** Stacktrace =~n** ~p~n"
end,
[Name |
case Q of
- [] ->
- [];
- [Event|_] ->
- [Event]
+ [] -> [];
+ [Event|_] -> [Event]
end] ++
[FmtData,Class,FixedReason,
- State,CallbackMode,length(Q),length(P)] ++
+ CallbackMode] ++
+ case Q of
+ [_|[_|_] = Events] -> [Events];
+ _ -> []
+ end ++
+ case P of
+ [] -> [];
+ _ -> [P]
+ end ++
case FixedStacktrace of
- [] ->
- [];
- _ ->
- [FixedStacktrace]
+ [] -> [];
+ _ -> [FixedStacktrace]
end),
sys:print_log(Debug),
ok.
%% Call Module:format_status/2 or return a default value
-format_status(
- Opt, PDict,
- #{module := Module, state := State, data := Data}) ->
+format_status(Opt, PDict, #{module := Module}, State, Data) ->
case erlang:function_exported(Module, format_status, 2) of
true ->
try Module:format_status(Opt, [PDict,State,Data])
diff --git a/lib/stdlib/src/otp_internal.erl b/lib/stdlib/src/otp_internal.erl
index 7a59523f06..c3ad261daa 100644
--- a/lib/stdlib/src/otp_internal.erl
+++ b/lib/stdlib/src/otp_internal.erl
@@ -35,7 +35,7 @@
obsolete(Module, Name, Arity) ->
case obsolete_1(Module, Name, Arity) of
{deprecated=Tag,{_,_,_}=Replacement} ->
- {Tag,Replacement,"in a future release"};
+ {Tag,Replacement,"a future release"};
{_,String}=Ret when is_list(String) ->
Ret;
{_,_,_}=Ret ->
diff --git a/lib/stdlib/src/proc_lib.erl b/lib/stdlib/src/proc_lib.erl
index fdc2ae4070..4a19603ec2 100644
--- a/lib/stdlib/src/proc_lib.erl
+++ b/lib/stdlib/src/proc_lib.erl
@@ -43,9 +43,14 @@
%%-----------------------------------------------------------------------------
-type priority_level() :: 'high' | 'low' | 'max' | 'normal'.
+-type max_heap_size() :: non_neg_integer() |
+ #{ size => non_neg_integer(),
+ kill => true,
+ error_logger => true}.
-type spawn_option() :: 'link'
| 'monitor'
| {'priority', priority_level()}
+ | {'max_heap_size', max_heap_size()}
| {'min_heap_size', non_neg_integer()}
| {'min_bin_vheap_size', non_neg_integer()}
| {'fullsweep_after', non_neg_integer()}
diff --git a/lib/stdlib/test/epp_SUITE.erl b/lib/stdlib/test/epp_SUITE.erl
index ef2c912c57..4078513e38 100644
--- a/lib/stdlib/test/epp_SUITE.erl
+++ b/lib/stdlib/test/epp_SUITE.erl
@@ -27,7 +27,8 @@
pmod/1, not_circular/1, skip_header/1, otp_6277/1, otp_7702/1,
otp_8130/1, overload_mac/1, otp_8388/1, otp_8470/1,
otp_8562/1, otp_8665/1, otp_8911/1, otp_10302/1, otp_10820/1,
- otp_11728/1, encoding/1, extends/1, function_macro/1]).
+ otp_11728/1, encoding/1, extends/1, function_macro/1,
+ test_error/1, test_warning/1]).
-export([epp_parse_erl_form/2]).
@@ -67,7 +68,7 @@ all() ->
not_circular, skip_header, otp_6277, otp_7702, otp_8130,
overload_mac, otp_8388, otp_8470, otp_8562,
otp_8665, otp_8911, otp_10302, otp_10820, otp_11728,
- encoding, extends, function_macro].
+ encoding, extends, function_macro, test_error, test_warning].
groups() ->
[{upcase_mac, [], [upcase_mac_1, upcase_mac_2]},
@@ -1055,7 +1056,65 @@ ifdef(Config) ->
],
[] = run(Config, Ts).
+%% OTP-12847: Test the -error directive.
+test_error(Config) ->
+ Cs = [{error_c1,
+ <<"-error(\"string and macro: \" ?MODULE_STRING).\n"
+ "-ifdef(NOT_DEFINED).\n"
+ " -error(\"this one will be skipped\").\n"
+ "-endif.\n">>,
+ {errors,[{1,epp,{error,"string and macro: epp_test"}}],[]}},
+
+ {error_c2,
+ <<"-ifdef(CONFIG_A).\n"
+ " t() -> a.\n"
+ "-else.\n"
+ "-ifdef(CONFIG_B).\n"
+ " t() -> b.\n"
+ "-else.\n"
+ "-error(\"Neither CONFIG_A nor CONFIG_B are available\").\n"
+ "-endif.\n"
+ "-endif.\n">>,
+ {errors,[{7,epp,{error,"Neither CONFIG_A nor CONFIG_B are available"}}],[]}},
+
+ {error_c3,
+ <<"-error(a b c).\n">>,
+ {errors,[{1,epp,{bad,error}}],[]}}
+ ],
+
+ [] = compile(Config, Cs),
+ ok.
+
+%% OTP-12847: Test the -warning directive.
+test_warning(Config) ->
+ Cs = [{warn_c1,
+ <<"-warning({a,term,?MODULE}).\n"
+ "-ifdef(NOT_DEFINED).\n"
+ "-warning(\"this one will be skipped\").\n"
+ "-endif.\n">>,
+ {warnings,[{1,epp,{warning,{a,term,epp_test}}}]}},
+
+ {warn_c2,
+ <<"-ifdef(CONFIG_A).\n"
+ " t() -> a.\n"
+ "-else.\n"
+ "-ifdef(CONFIG_B).\n"
+ " t() -> b.\n"
+ "-else.\n"
+ " t() -> c.\n"
+ "-warning(\"Using fallback\").\n"
+ "-endif.\n"
+ "-endif.\n">>,
+ {warnings,[{8,epp,{warning,"Using fallback"}}]}},
+
+ {warn_c3,
+ <<"-warning(a b c).\n">>,
+ {errors,[{1,epp,{bad,warning}}],[]}}
+ ],
+
+ [] = compile(Config, Cs),
+ ok.
%% Advanced test on overloading macros.
overload_mac(Config) when is_list(Config) ->
diff --git a/lib/stdlib/test/erl_lint_SUITE.erl b/lib/stdlib/test/erl_lint_SUITE.erl
index b0214e5238..d916eb3eef 100644
--- a/lib/stdlib/test/erl_lint_SUITE.erl
+++ b/lib/stdlib/test/erl_lint_SUITE.erl
@@ -2003,7 +2003,7 @@ otp_5362(Config) when is_list(Config) ->
{error,
[{5,erl_lint,{call_to_redefined_old_bif,{spawn,1}}}],
[{4,erl_lint,{deprecated,{erlang,hash,2},{erlang,phash2,2},
- "in a future release"}}]}},
+ "a future release"}}]}},
{otp_5362_5,
<<"-compile(nowarn_deprecated_function).
@@ -2063,7 +2063,7 @@ otp_5362(Config) when is_list(Config) ->
{nowarn_bif_clash,{spawn,1}}]}, % has no effect
{warnings,
[{5,erl_lint,{deprecated,{erlang,hash,2},{erlang,phash2,2},
- "in a future release"}}]}},
+ "a future release"}}]}},
{otp_5362_9,
<<"-include_lib(\"stdlib/include/qlc.hrl\").
@@ -2093,7 +2093,7 @@ otp_5362(Config) when is_list(Config) ->
[],
{warnings,
[{1,erl_lint,{deprecated,{erlang,hash,2},
- {erlang,phash2,2},"in a future release"}}]}},
+ {erlang,phash2,2},"a future release"}}]}},
{call_removed_function,
<<"t(X) -> regexp:match(X).">>,
diff --git a/lib/stdlib/test/gen_statem_SUITE.erl b/lib/stdlib/test/gen_statem_SUITE.erl
index 3deb5fd986..364314f91b 100644
--- a/lib/stdlib/test/gen_statem_SUITE.erl
+++ b/lib/stdlib/test/gen_statem_SUITE.erl
@@ -634,12 +634,14 @@ sys1(Config) ->
stop_it(Pid).
code_change(Config) ->
+ Mode = handle_event_function,
{ok,Pid} = gen_statem:start(?MODULE, start_arg(Config, []), []),
{idle,data} = sys:get_state(Pid),
sys:suspend(Pid),
- sys:change_code(Pid, ?MODULE, old_vsn, state_functions),
+ sys:change_code(Pid, ?MODULE, old_vsn, Mode),
sys:resume(Pid),
- {idle,{old_vsn,data,state_functions}} = sys:get_state(Pid),
+ {idle,{old_vsn,data,Mode}} = sys:get_state(Pid),
+ Mode = gen_statem:call(Pid, get_callback_mode),
stop_it(Pid).
call_format_status(Config) ->
@@ -1478,6 +1480,8 @@ next_events(Type, Content, Data) ->
end.
+handle_common_events({call,From}, get_callback_mode, _, _) ->
+ {keep_state_and_data,{reply,From,state_functions}};
handle_common_events({call,From}, get, State, Data) ->
{keep_state,Data,
[{reply,From,{state,State,Data}}]};
@@ -1501,6 +1505,8 @@ handle_common_events(cast, {'alive?',Pid}, _, Data) ->
handle_common_events(_, _, _, _) ->
undefined.
+handle_event({call,From}, get_callback_mode, _, _) ->
+ {keep_state_and_data,{reply,From,handle_event_function}};
%% Wrapper state machine that uses a map state machine spec
handle_event(
Type, Event, State, [Data|Machine])
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-09 21:59:24 +0000