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-rw-r--r--lib/stdlib/doc/src/sys.xml73
-rw-r--r--lib/stdlib/src/gen_event.erl37
-rw-r--r--lib/stdlib/src/gen_fsm.erl20
-rw-r--r--lib/stdlib/src/gen_server.erl16
-rw-r--r--lib/stdlib/src/sys.erl65
-rw-r--r--lib/stdlib/test/Makefile2
-rw-r--r--lib/stdlib/test/gen_event_SUITE.erl11
-rw-r--r--lib/stdlib/test/gen_fsm_SUITE.erl20
-rw-r--r--lib/stdlib/test/gen_server_SUITE.erl15
-rw-r--r--lib/stdlib/test/sys_SUITE.erl84
-rw-r--r--lib/stdlib/test/sys_sp1.erl114
-rw-r--r--lib/stdlib/test/sys_sp2.erl107
12 files changed, 511 insertions, 53 deletions
diff --git a/lib/stdlib/doc/src/sys.xml b/lib/stdlib/doc/src/sys.xml
index ab8b380f49..a46fa1289f 100644
--- a/lib/stdlib/doc/src/sys.xml
+++ b/lib/stdlib/doc/src/sys.xml
@@ -246,6 +246,22 @@
<c>{Module, Id, HandlerState}</c>, where <c>Module</c> is the event handler's module name,
<c>Id</c> is the handler's ID (which is the value <c>false</c> if it was registered without
an ID), and <c>HandlerState</c> is the handler's state.</p>
+ <p>If the callback module exports a <c>system_get_state/1</c> function, it will be called in the
+ target process to get its state. Its argument is the same as the <c>Misc</c> value returned by
+ <seealso marker="#get_status-1">get_status/1,2</seealso>, and the <c>system_get_state/1</c>
+ function is expected to extract the callback module's state from it. The <c>system_get_state/1</c>
+ function must return <c>{ok, State}</c> where <c>State</c> is the callback module's state.</p>
+ <p>If the callback module does not export a <c>system_get_state/1</c> function, <c>get_state/1,2</c>
+ assumes the <c>Misc</c> value is the callback module's state and returns it directly instead.</p>
+ <p>If the callback module's <c>system_get_state/1</c> function crashes or throws an exception, the
+ caller exits with error <c>{callback_failed, {Module, system_get_state}, {Class, Reason}}</c> where
+ <c>Module</c> is the name of the callback module and <c>Class</c> and <c>Reason</c> indicate
+ details of the exception.</p>
+ <p>The <c>system_get_state/1</c> function is primarily useful for user-defined
+ behaviours and modules that implement OTP <seealso marker="#special_process">special
+ processes</seealso>. The <c>gen_server</c>, <c>gen_fsm</c>, and <c>gen_event</c> OTP
+ behaviour modules export this function, and so callback modules for those behaviours
+ need not supply their own.</p>
<p>To obtain more information about a process, including its state, see
<seealso marker="#get_status-1">get_status/1</seealso> and
<seealso marker="#get_status-2">get_status/2</seealso>.</p>
@@ -289,6 +305,28 @@
function means that only the state of the particular event handler it was working on when it
failed or crashed is unchanged; it can still succeed in changing the states of other event
handlers registered in the same <c>gen_event</c> process.</p>
+ <p>If the callback module exports a <c>system_replace_state/2</c> function, it will be called in the
+ target process to replace its state using <c>StateFun</c>. Its two arguments are <c>StateFun</c>
+ and <c>Misc</c>, where <c>Misc</c> is the same as the <c>Misc</c> value returned by
+ <seealso marker="#get_status-1">get_status/1,2</seealso>. A <c>system_replace_state/2</c> function
+ is expected to return <c>{ok, NewState, NewMisc}</c> where <c>NewState</c> is the callback module's
+ new state obtained by calling <c>StateFun</c>, and <c>NewMisc</c> is a possibly new value used to
+ replace the original <c>Misc</c> (required since <c>Misc</c> often contains the callback
+ module's state within it).</p>
+ <p>If the callback module does not export a <c>system_replace_state/2</c> function,
+ <c>replace_state/2,3</c> assumes the <c>Misc</c> value is the callback module's state, passes it
+ to <c>StateFun</c> and uses the return value as both the new state and as the new value of
+ <c>Misc</c>.</p>
+ <p>If the callback module's <c>system_replace_state/2</c> function crashes or throws an exception,
+ the caller exits with error <c>{callback_failed, {Module, system_replace_state}, {Class, Reason}}</c>
+ where <c>Module</c> is the name of the callback module and <c>Class</c> and <c>Reason</c> indicate details
+ of the exception. If the callback module does not provide a <c>system_replace_state/2</c> function and
+ <c>StateFun</c> crashes or throws an exception, the caller exits with error
+ <c>{callback_failed, StateFun, {Class, Reason}}</c>.</p>
+ <p>The <c>system_replace_state/2</c> function is primarily useful for user-defined behaviours and
+ modules that implement OTP <seealso marker="#special_process">special processes</seealso>. The
+ <c>gen_server</c>, <c>gen_fsm</c>, and <c>gen_event</c> OTP behaviour modules export this function,
+ and so callback modules for those behaviours need not supply their own.</p>
</desc>
</func>
<func>
@@ -322,7 +360,7 @@
<section>
<title>Process Implementation Functions</title>
- <p>The following functions are used when implementing a
+ <p><marker id="special_process"/>The following functions are used when implementing a
special process. This is an ordinary process which does not use a
standard behaviour, but a process which understands the standard system messages.</p>
</section>
@@ -375,8 +413,9 @@
process continues the execution, or
<c><anno>Module</anno>:system_terminate(Reason, <anno>Parent</anno>, <anno>Debug</anno>, <anno>Misc</anno>)</c> if
the process should terminate. The <c><anno>Module</anno></c> must export
- <c>system_continue/3</c>, <c>system_terminate/4</c>, and
- <c>system_code_change/4</c> (see below).
+ <c>system_continue/3</c>, <c>system_terminate/4</c>,
+ <c>system_code_change/4</c>, <c>system_get_state/1</c> and
+ <c>system_replace_state/2</c> (see below).
</p>
<p>The <c><anno>Misc</anno></c> argument can be used to save internal data
in a process, for example its state. It is sent to
@@ -444,6 +483,34 @@
defined, the atom <c>undefined</c> is sent.</p>
</desc>
</func>
+ <func>
+ <name>Mod:system_get_state(Misc) -> {ok, State}</name>
+ <fsummary>Called when the process should return its current state</fsummary>
+ <type>
+ <v>Misc = term()</v>
+ <v>State = term()</v>
+ </type>
+ <desc>
+ <p>This function is called from <c>sys:handle_system_msg/6</c> when the process
+ should return a term that reflects its current state. <c>State</c> is the
+ value returned by <c>sys:get_state/2</c>.</p>
+ </desc>
+ </func>
+ <func>
+ <name>Mod:system_replace_state(StateFun, Misc) -> {ok, NState, NMisc}</name>
+ <fsummary>Called when the process should replace its current state</fsummary>
+ <type>
+ <v>StateFun = fun((State :: term()) -> NState)</v>
+ <v>Misc = term()</v>
+ <v>NState = term()</v>
+ <v>NMisc = term()</v>
+ </type>
+ <desc>
+ <p>This function is called from <c>sys:handle_system_msg/6</c> when the process
+ should replace its current state. <c>NState</c> is the value returned by
+ <c>sys:replace_state/3</c>.</p>
+ </desc>
+ </func>
</funcs>
</erlref>
diff --git a/lib/stdlib/src/gen_event.erl b/lib/stdlib/src/gen_event.erl
index 7629e88fbf..d39dd89d3a 100644
--- a/lib/stdlib/src/gen_event.erl
+++ b/lib/stdlib/src/gen_event.erl
@@ -40,6 +40,8 @@
system_continue/3,
system_terminate/4,
system_code_change/4,
+ system_get_state/1,
+ system_replace_state/2,
format_status/2]).
-export_type([handler/0, handler_args/0, add_handler_ret/0,
@@ -229,24 +231,6 @@ wake_hib(Parent, ServerName, MSL, Debug) ->
fetch_msg(Parent, ServerName, MSL, Debug, Hib) ->
receive
- {system, From, get_state} ->
- States = [{Mod,Id,State} || #handler{module=Mod, id=Id, state=State} <- MSL],
- sys:handle_system_msg(get_state, From, Parent, ?MODULE, Debug,
- {States, [ServerName, MSL, Hib]}, Hib);
- {system, From, {replace_state, StateFun}} ->
- {NMSL, NStates} =
- lists:unzip([begin
- Cur = {Mod,Id,State},
- try
- NState = {Mod,Id,NS} = StateFun(Cur),
- {HS#handler{state=NS}, NState}
- catch
- _:_ ->
- {HS, Cur}
- end
- end || #handler{module=Mod, id=Id, state=State}=HS <- MSL]),
- sys:handle_system_msg(replace_state, From, Parent, ?MODULE, Debug,
- {NStates, [ServerName, NMSL, Hib]}, Hib);
{system, From, Req} ->
sys:handle_system_msg(Req, From, Parent, ?MODULE, Debug,
[ServerName, MSL, Hib],Hib);
@@ -383,6 +367,23 @@ system_code_change([ServerName, MSL, Hib], Module, OldVsn, Extra) ->
MSL),
{ok, [ServerName, MSL1, Hib]}.
+system_get_state([_ServerName, MSL, _Hib]) ->
+ {ok, [{Mod,Id,State} || #handler{module=Mod, id=Id, state=State} <- MSL]}.
+
+system_replace_state(StateFun, [ServerName, MSL, Hib]) ->
+ {NMSL, NStates} =
+ lists:unzip([begin
+ Cur = {Mod,Id,State},
+ try
+ NState = {Mod,Id,NS} = StateFun(Cur),
+ {HS#handler{state=NS}, NState}
+ catch
+ _:_ ->
+ {HS, Cur}
+ end
+ end || #handler{module=Mod, id=Id, state=State}=HS <- MSL]),
+ {ok, NStates, [ServerName, NMSL, Hib]}.
+
%%-----------------------------------------------------------------
%% Format debug messages. Print them as the call-back module sees
%% them, not as the real erlang messages. Use trace for that.
diff --git a/lib/stdlib/src/gen_fsm.erl b/lib/stdlib/src/gen_fsm.erl
index e9654322f1..e914f7d0b2 100644
--- a/lib/stdlib/src/gen_fsm.erl
+++ b/lib/stdlib/src/gen_fsm.erl
@@ -118,6 +118,8 @@
system_continue/3,
system_terminate/4,
system_code_change/4,
+ system_get_state/1,
+ system_replace_state/2,
format_status/2]).
-import(error_logger, [format/2]).
@@ -422,17 +424,6 @@ wake_hib(Parent, Name, StateName, StateData, Mod, Debug) ->
decode_msg(Msg,Parent, Name, StateName, StateData, Mod, Time, Debug, Hib) ->
case Msg of
- {system, From, get_state} ->
- Misc = [Name, StateName, StateData, Mod, Time],
- sys:handle_system_msg(get_state, From, Parent, ?MODULE, Debug,
- {{StateName, StateData}, Misc}, Hib);
- {system, From, {replace_state, StateFun}} ->
- State = {StateName, StateData},
- NState = {NStateName, NStateData} = try StateFun(State)
- catch _:_ -> State end,
- NMisc = [Name, NStateName, NStateData, Mod, Time],
- sys:handle_system_msg(replace_state, From, Parent, ?MODULE, Debug,
- {NState, NMisc}, Hib);
{system, From, Req} ->
sys:handle_system_msg(Req, From, Parent, ?MODULE, Debug,
[Name, StateName, StateData, Mod, Time], Hib);
@@ -467,6 +458,13 @@ system_code_change([Name, StateName, StateData, Mod, Time],
Else -> Else
end.
+system_get_state([_Name, StateName, StateData, _Mod, _Time]) ->
+ {ok, {StateName, StateData}}.
+
+system_replace_state(StateFun, [Name, StateName, StateData, Mod, Time]) ->
+ Result = {NStateName, NStateData} = StateFun({StateName, StateData}),
+ {ok, Result, [Name, NStateName, NStateData, Mod, Time]}.
+
%%-----------------------------------------------------------------
%% Format debug messages. Print them as the call-back module sees
%% them, not as the real erlang messages. Use trace for that.
diff --git a/lib/stdlib/src/gen_server.erl b/lib/stdlib/src/gen_server.erl
index 5f14e48b0a..202a931fae 100644
--- a/lib/stdlib/src/gen_server.erl
+++ b/lib/stdlib/src/gen_server.erl
@@ -98,6 +98,8 @@
-export([system_continue/3,
system_terminate/4,
system_code_change/4,
+ system_get_state/1,
+ system_replace_state/2,
format_status/2]).
%% Internal exports
@@ -372,13 +374,6 @@ wake_hib(Parent, Name, State, Mod, Debug) ->
decode_msg(Msg, Parent, Name, State, Mod, Time, Debug, Hib) ->
case Msg of
- {system, From, get_state} ->
- sys:handle_system_msg(get_state, From, Parent, ?MODULE, Debug,
- {State, [Name, State, Mod, Time]}, Hib);
- {system, From, {replace_state, StateFun}} ->
- NState = try StateFun(State) catch _:_ -> State end,
- sys:handle_system_msg(replace_state, From, Parent, ?MODULE, Debug,
- {NState, [Name, NState, Mod, Time]}, Hib);
{system, From, Req} ->
sys:handle_system_msg(Req, From, Parent, ?MODULE, Debug,
[Name, State, Mod, Time], Hib);
@@ -687,6 +682,13 @@ system_code_change([Name, State, Mod, Time], _Module, OldVsn, Extra) ->
Else -> Else
end.
+system_get_state([_Name, State, _Mod, _Time]) ->
+ {ok, State}.
+
+system_replace_state(StateFun, [Name, State, Mod, Time]) ->
+ NState = StateFun(State),
+ {ok, NState, [Name, NState, Mod, Time]}.
+
%%-----------------------------------------------------------------
%% Format debug messages. Print them as the call-back module sees
%% them, not as the real erlang messages. Use trace for that.
diff --git a/lib/stdlib/src/sys.erl b/lib/stdlib/src/sys.erl
index 04f8dfb61b..e25cc25f57 100644
--- a/lib/stdlib/src/sys.erl
+++ b/lib/stdlib/src/sys.erl
@@ -102,20 +102,31 @@ get_status(Name, Timeout) -> send_system_msg(Name, get_status, Timeout).
-spec get_state(Name) -> State when
Name :: name(),
State :: term().
-get_state(Name) -> send_system_msg(Name, get_state).
+get_state(Name) ->
+ case send_system_msg(Name, get_state) of
+ {error, Reason} -> error(Reason);
+ State -> State
+ end.
-spec get_state(Name, Timeout) -> State when
Name :: name(),
Timeout :: timeout(),
State :: term().
-get_state(Name, Timeout) -> send_system_msg(Name, get_state, Timeout).
+get_state(Name, Timeout) ->
+ case send_system_msg(Name, get_state, Timeout) of
+ {error, Reason} -> error(Reason);
+ State -> State
+ end.
-spec replace_state(Name, StateFun) -> NewState when
Name :: name(),
StateFun :: fun((State :: term()) -> NewState :: term()),
NewState :: term().
replace_state(Name, StateFun) ->
- send_system_msg(Name, {replace_state, StateFun}).
+ case send_system_msg(Name, {replace_state, StateFun}) of
+ {error, Reason} -> error(Reason);
+ State -> State
+ end.
-spec replace_state(Name, StateFun, Timeout) -> NewState when
Name :: name(),
@@ -123,7 +134,10 @@ replace_state(Name, StateFun) ->
Timeout :: timeout(),
NewState :: term().
replace_state(Name, StateFun, Timeout) ->
- send_system_msg(Name, {replace_state, StateFun}, Timeout).
+ case send_system_msg(Name, {replace_state, StateFun}, Timeout) of
+ {error, Reason} -> error(Reason);
+ State -> State
+ end.
-spec change_code(Name, Module, OldVsn, Extra) -> 'ok' | {error, Reason} when
Name :: name(),
@@ -390,10 +404,11 @@ do_cmd(_, suspend, _Parent, _Mod, Debug, Misc) ->
{suspended, ok, Debug, Misc};
do_cmd(_, resume, _Parent, _Mod, Debug, Misc) ->
{running, ok, Debug, Misc};
-do_cmd(SysState, get_state, _Parent, _Mod, Debug, {State, Misc}) ->
- {SysState, State, Debug, Misc};
-do_cmd(SysState, replace_state, _Parent, _Mod, Debug, {State, Misc}) ->
- {SysState, State, Debug, Misc};
+do_cmd(SysState, get_state, _Parent, Mod, Debug, Misc) ->
+ {SysState, do_get_state(Mod, Misc), Debug, Misc};
+do_cmd(SysState, {replace_state, StateFun}, _Parent, Mod, Debug, Misc) ->
+ {Res, NMisc} = do_replace_state(StateFun, Mod, Misc),
+ {SysState, Res, Debug, NMisc};
do_cmd(SysState, get_status, Parent, Mod, Debug, Misc) ->
Res = get_status(SysState, Parent, Mod, Debug, Misc),
{SysState, Res, Debug, Misc};
@@ -407,6 +422,40 @@ do_cmd(suspended, {change_code, Module, Vsn, Extra}, _Parent,
do_cmd(SysState, Other, _Parent, _Mod, Debug, Misc) ->
{SysState, {error, {unknown_system_msg, Other}}, Debug, Misc}.
+do_get_state(Mod, Misc) ->
+ case erlang:function_exported(Mod, system_get_state, 1) of
+ true ->
+ try
+ {ok, State} = Mod:system_get_state(Misc),
+ State
+ catch
+ Cl:Exc ->
+ {error, {callback_failed,{Mod,system_get_state},{Cl,Exc}}}
+ end;
+ false ->
+ Misc
+ end.
+
+do_replace_state(StateFun, Mod, Misc) ->
+ case erlang:function_exported(Mod, system_replace_state, 2) of
+ true ->
+ try
+ {ok, State, NMisc} = Mod:system_replace_state(StateFun, Misc),
+ {State, NMisc}
+ catch
+ Cl:Exc ->
+ {{error, {callback_failed,{Mod,system_replace_state},{Cl,Exc}}}, Misc}
+ end;
+ false ->
+ try
+ NMisc = StateFun(Misc),
+ {NMisc, NMisc}
+ catch
+ Cl:Exc ->
+ {{error, {callback_failed,StateFun,{Cl,Exc}}}, Misc}
+ end
+ end.
+
get_status(SysState, Parent, Mod, Debug, Misc) ->
PDict = get(),
FmtMisc =
diff --git a/lib/stdlib/test/Makefile b/lib/stdlib/test/Makefile
index af82f22b21..39f6ce423a 100644
--- a/lib/stdlib/test/Makefile
+++ b/lib/stdlib/test/Makefile
@@ -73,6 +73,8 @@ MODULES= \
supervisor_SUITE \
supervisor_bridge_SUITE \
sys_SUITE \
+ sys_sp1 \
+ sys_sp2 \
tar_SUITE \
timer_SUITE \
timer_simple_SUITE \
diff --git a/lib/stdlib/test/gen_event_SUITE.erl b/lib/stdlib/test/gen_event_SUITE.erl
index 5819ef3890..60a1ba8c60 100644
--- a/lib/stdlib/test/gen_event_SUITE.erl
+++ b/lib/stdlib/test/gen_event_SUITE.erl
@@ -974,6 +974,10 @@ get_state(Config) when is_list(Config) ->
[{dummy1_h,false,State1},{dummy1_h,id,State2}] = lists:sort(Result1),
Result2 = sys:get_state(Pid, 5000),
[{dummy1_h,false,State1},{dummy1_h,id,State2}] = lists:sort(Result2),
+ ok = sys:suspend(Pid),
+ Result3 = sys:get_state(Pid),
+ [{dummy1_h,false,State1},{dummy1_h,id,State2}] = lists:sort(Result3),
+ ok = sys:resume(Pid),
ok = gen_event:stop(Pid),
ok.
@@ -998,4 +1002,11 @@ replace_state(Config) when is_list(Config) ->
Replace3 = fun(_) -> exit(fail) end,
[{dummy1_h,false,NState2}] = sys:replace_state(Pid, Replace3),
[{dummy1_h,false,NState2}] = sys:get_state(Pid),
+ %% verify state replaced if process sys suspended
+ NState3 = "replaced again and again",
+ Replace4 = fun({dummy1_h,false,_}=S) -> setelement(3,S,NState3) end,
+ ok = sys:suspend(Pid),
+ [{dummy1_h,false,NState3}] = sys:replace_state(Pid, Replace4),
+ ok = sys:resume(Pid),
+ [{dummy1_h,false,NState3}] = sys:get_state(Pid),
ok.
diff --git a/lib/stdlib/test/gen_fsm_SUITE.erl b/lib/stdlib/test/gen_fsm_SUITE.erl
index fd15838b7d..8aeec07ae8 100644
--- a/lib/stdlib/test/gen_fsm_SUITE.erl
+++ b/lib/stdlib/test/gen_fsm_SUITE.erl
@@ -426,6 +426,14 @@ get_state(Config) when is_list(Config) ->
{idle, State} = sys:get_state(gfsm),
{idle, State} = sys:get_state(gfsm, 5000),
stop_it(Pid2),
+
+ %% check that get_state works when pid is sys suspended
+ {ok, Pid3} = gen_fsm:start(gen_fsm_SUITE, {state_data, State}, []),
+ {idle, State} = sys:get_state(Pid3),
+ ok = sys:suspend(Pid3),
+ {idle, State} = sys:get_state(Pid3, 5000),
+ ok = sys:resume(Pid3),
+ stop_it(Pid3),
ok.
replace_state(Config) when is_list(Config) ->
@@ -442,8 +450,18 @@ replace_state(Config) when is_list(Config) ->
{state0, NState2} = sys:get_state(Pid),
%% verify no change in state if replace function crashes
Replace3 = fun(_) -> error(fail) end,
- {state0, NState2} = sys:replace_state(Pid, Replace3),
+ {'EXIT',{{callback_failed,
+ {gen_fsm,system_replace_state},{error,fail}},_}} =
+ (catch sys:replace_state(Pid, Replace3)),
{state0, NState2} = sys:get_state(Pid),
+ %% verify state replaced if process sys suspended
+ ok = sys:suspend(Pid),
+ Suffix2 = " and again",
+ NState3 = NState2 ++ Suffix2,
+ Replace4 = fun({StateName, _}) -> {StateName, NState3} end,
+ {state0, NState3} = sys:replace_state(Pid, Replace4),
+ ok = sys:resume(Pid),
+ {state0, NState3} = sys:get_state(Pid, 5000),
stop_it(Pid),
ok.
diff --git a/lib/stdlib/test/gen_server_SUITE.erl b/lib/stdlib/test/gen_server_SUITE.erl
index a360a0809b..960e7f60e7 100644
--- a/lib/stdlib/test/gen_server_SUITE.erl
+++ b/lib/stdlib/test/gen_server_SUITE.erl
@@ -1049,6 +1049,9 @@ get_state(Config) when is_list(Config) ->
{ok, Pid} = gen_server:start_link(?MODULE, {state,State}, []),
State = sys:get_state(Pid),
State = sys:get_state(Pid, 5000),
+ ok = sys:suspend(Pid),
+ State = sys:get_state(Pid),
+ ok = sys:resume(Pid),
ok.
%% Verify that sys:replace_state correctly replaces gen_server state
@@ -1075,8 +1078,18 @@ replace_state(Config) when is_list(Config) ->
NState2 = sys:get_state(Pid, 5000),
%% verify no change in state if replace function crashes
Replace3 = fun(_) -> throw(fail) end,
- NState2 = sys:replace_state(Pid, Replace3),
+ {'EXIT',{{callback_failed,
+ {gen_server,system_replace_state},{throw,fail}},_}} =
+ (catch sys:replace_state(Pid, Replace3)),
NState2 = sys:get_state(Pid, 5000),
+ %% verify state replaced if process sys suspended
+ ok = sys:suspend(Pid),
+ Suffix2 = " and again",
+ NState3 = NState2 ++ Suffix2,
+ Replace4 = fun(S) -> S ++ Suffix2 end,
+ NState3 = sys:replace_state(Pid, Replace4),
+ ok = sys:resume(Pid),
+ NState3 = sys:get_state(Pid, 5000),
ok.
%% Test that the time for a huge message queue is not
diff --git a/lib/stdlib/test/sys_SUITE.erl b/lib/stdlib/test/sys_SUITE.erl
index c06ba545e7..f38bc87ae5 100644
--- a/lib/stdlib/test/sys_SUITE.erl
+++ b/lib/stdlib/test/sys_SUITE.erl
@@ -19,7 +19,7 @@
-module(sys_SUITE).
-export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1,
init_per_group/2,end_per_group/2,log/1,log_to_file/1,
- stats/1,trace/1,suspend/1,install/1]).
+ stats/1,trace/1,suspend/1,install/1,special_process/1]).
-export([handle_call/3,terminate/2,init/1]).
-include_lib("test_server/include/test_server.hrl").
@@ -27,14 +27,12 @@
%% Doesn't look into change_code at all
-%% Doesn't address writing your own process that understands
-%% system messages at all.
suite() -> [{ct_hooks,[ts_install_cth]}].
all() ->
- [log, log_to_file, stats, trace, suspend, install].
+ [log, log_to_file, stats, trace, suspend, install, special_process].
groups() ->
[].
@@ -157,6 +155,84 @@ install(Config) when is_list(Config) ->
?line stop(),
ok.
+special_process(suite) -> [];
+special_process(Config) when is_list(Config) ->
+ ok = spec_proc(sys_sp1),
+ ok = spec_proc(sys_sp2).
+
+spec_proc(Mod) ->
+ {ok,_} = Mod:start_link(100),
+ ok = sys:statistics(Mod,true),
+ ok = sys:trace(Mod,true),
+ 1 = Ch = Mod:alloc(),
+ Free = lists:seq(2,100),
+ Replace = case sys:get_state(Mod) of
+ {[Ch],Free} ->
+ fun({A,F}) ->
+ Free = F,
+ {A,[2,3,4]}
+ end;
+ {state,[Ch],Free} ->
+ fun({state,A,F}) ->
+ Free = F,
+ {state,A,[2,3,4]}
+ end
+ end,
+ case sys:replace_state(Mod, Replace) of
+ {[Ch],[2,3,4]} -> ok;
+ {state,[Ch],[2,3,4]} -> ok
+ end,
+ ok = Mod:free(Ch),
+ case sys:get_state(Mod) of
+ {[],[1,2,3,4]} -> ok;
+ {state,[],[1,2,3,4]} -> ok
+ end,
+ {ok,[{start_time,_},
+ {current_time,_},
+ {reductions,_},
+ {messages_in,2},
+ {messages_out,1}]} = sys:statistics(Mod,get),
+ ok = sys:statistics(Mod,false),
+ [] = sys:replace_state(Mod, fun(_) -> [] end),
+ process_flag(trap_exit,true),
+ ok = case catch sys:get_state(Mod) of
+ [] ->
+ ok;
+ {'EXIT',{{callback_failed,
+ {Mod,system_get_state},{throw,fail}},_}} ->
+ ok
+ end,
+ Mod:stop(),
+ WaitForUnregister = fun W() ->
+ case whereis(Mod) of
+ undefined -> ok;
+ _ -> timer:sleep(10), W()
+ end
+ end,
+ WaitForUnregister(),
+ {ok,_} = Mod:start_link(4),
+ ok = case catch sys:replace_state(Mod, fun(_) -> {} end) of
+ {} ->
+ ok;
+ {'EXIT',{{callback_failed,
+ {Mod,system_replace_state},{throw,fail}},_}} ->
+ ok
+ end,
+ Mod:stop(),
+ WaitForUnregister(),
+ {ok,_} = Mod:start_link(4),
+ StateFun = fun(_) -> error(fail) end,
+ ok = case catch sys:replace_state(Mod, StateFun) of
+ {} ->
+ ok;
+ {'EXIT',{{callback_failed,
+ {Mod,system_replace_state},{error,fail}},_}} ->
+ ok;
+ {'EXIT',{{callback_failed,StateFun,{error,fail}},_}} ->
+ ok
+ end,
+ Mod:stop().
+
%%%%%%%%%%%%%%%%%%%%
%% Dummy server
diff --git a/lib/stdlib/test/sys_sp1.erl b/lib/stdlib/test/sys_sp1.erl
new file mode 100644
index 0000000000..e84ffcfa12
--- /dev/null
+++ b/lib/stdlib/test/sys_sp1.erl
@@ -0,0 +1,114 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%%
+%% The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved online at http://www.erlang.org/.
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%%
+%% %CopyrightEnd%
+%%
+-module(sys_sp1).
+-export([start_link/1, stop/0]).
+-export([alloc/0, free/1]).
+-export([init/1]).
+-export([system_continue/3, system_terminate/4,
+ write_debug/3,
+ system_get_state/1, system_replace_state/2]).
+
+%% Implements the ch4 example from the Design Principles doc. Same as
+%% sys_sp2 except this module exports system_get_state/1 and
+%% system_replace_state/2
+
+start_link(NumCh) ->
+ proc_lib:start_link(?MODULE, init, [[self(),NumCh]]).
+
+stop() ->
+ ?MODULE ! stop,
+ ok.
+
+alloc() ->
+ ?MODULE ! {self(), alloc},
+ receive
+ {?MODULE, Res} ->
+ Res
+ end.
+
+free(Ch) ->
+ ?MODULE ! {free, Ch},
+ ok.
+
+init([Parent,NumCh]) ->
+ register(?MODULE, self()),
+ Chs = channels(NumCh),
+ Deb = sys:debug_options([]),
+ proc_lib:init_ack(Parent, {ok, self()}),
+ loop(Chs, Parent, Deb).
+
+loop(Chs, Parent, Deb) ->
+ receive
+ {From, alloc} ->
+ Deb2 = sys:handle_debug(Deb, fun write_debug/3,
+ ?MODULE, {in, alloc, From}),
+ {Ch, Chs2} = alloc(Chs),
+ From ! {?MODULE, Ch},
+ Deb3 = sys:handle_debug(Deb2, fun write_debug/3,
+ ?MODULE, {out, {?MODULE, Ch}, From}),
+ loop(Chs2, Parent, Deb3);
+ {free, Ch} ->
+ Deb2 = sys:handle_debug(Deb, fun write_debug/3,
+ ?MODULE, {in, {free, Ch}}),
+ Chs2 = free(Ch, Chs),
+ loop(Chs2, Parent, Deb2);
+ {system, From, Request} ->
+ sys:handle_system_msg(Request, From, Parent,
+ ?MODULE, Deb, Chs);
+ stop ->
+ sys:handle_debug(Deb, fun write_debug/3,
+ ?MODULE, {in, stop}),
+ ok
+ end.
+
+system_continue(Parent, Deb, Chs) ->
+ loop(Chs, Parent, Deb).
+
+system_terminate(Reason, _Parent, _Deb, _Chs) ->
+ exit(Reason).
+
+system_get_state([]) ->
+ throw(fail);
+system_get_state(Chs) ->
+ {ok, Chs}.
+
+system_replace_state(_StateFun, {}) ->
+ throw(fail);
+system_replace_state(StateFun, Chs) ->
+ NChs = StateFun(Chs),
+ {ok, NChs, NChs}.
+
+write_debug(Dev, Event, Name) ->
+ io:format(Dev, "~p event = ~p~n", [Name, Event]).
+
+channels(NumCh) ->
+ {_Allocated=[], _Free=lists:seq(1,NumCh)}.
+
+alloc({_, []}) ->
+ {error, "no channels available"};
+alloc({Allocated, [H|T]}) ->
+ {H, {[H|Allocated], T}}.
+
+free(Ch, {Alloc, Free}=Channels) ->
+ case lists:member(Ch, Alloc) of
+ true ->
+ {lists:delete(Ch, Alloc), [Ch|Free]};
+ false ->
+ Channels
+ end.
diff --git a/lib/stdlib/test/sys_sp2.erl b/lib/stdlib/test/sys_sp2.erl
new file mode 100644
index 0000000000..56a5e4d071
--- /dev/null
+++ b/lib/stdlib/test/sys_sp2.erl
@@ -0,0 +1,107 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%%
+%% The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved online at http://www.erlang.org/.
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%%
+%% %CopyrightEnd%
+%%
+-module(sys_sp2).
+-export([start_link/1, stop/0]).
+-export([alloc/0, free/1]).
+-export([init/1]).
+-export([system_continue/3, system_terminate/4,
+ write_debug/3]).
+
+%% Implements the ch4 example from the Design Principles doc. Same as
+%% sys_sp1 except this module does not export system_get_state/1 or
+%% system_replace_state/2
+
+start_link(NumCh) ->
+ proc_lib:start_link(?MODULE, init, [[self(),NumCh]]).
+
+stop() ->
+ ?MODULE ! stop,
+ ok.
+
+alloc() ->
+ ?MODULE ! {self(), alloc},
+ receive
+ {?MODULE, Res} ->
+ Res
+ end.
+
+free(Ch) ->
+ ?MODULE ! {free, Ch},
+ ok.
+
+%% can't use 2-tuple for state here as we do in sys_sp1, since the 2-tuple
+%% is not compatible with the backward compatibility handling for
+%% sys:get_state in sys.erl
+-record(state, {alloc,free}).
+
+init([Parent,NumCh]) ->
+ register(?MODULE, self()),
+ Chs = channels(NumCh),
+ Deb = sys:debug_options([]),
+ proc_lib:init_ack(Parent, {ok, self()}),
+ loop(Chs, Parent, Deb).
+
+loop(Chs, Parent, Deb) ->
+ receive
+ {From, alloc} ->
+ Deb2 = sys:handle_debug(Deb, fun write_debug/3,
+ ?MODULE, {in, alloc, From}),
+ {Ch, Chs2} = alloc(Chs),
+ From ! {?MODULE, Ch},
+ Deb3 = sys:handle_debug(Deb2, fun write_debug/3,
+ ?MODULE, {out, {?MODULE, Ch}, From}),
+ loop(Chs2, Parent, Deb3);
+ {free, Ch} ->
+ Deb2 = sys:handle_debug(Deb, fun write_debug/3,
+ ?MODULE, {in, {free, Ch}}),
+ Chs2 = free(Ch, Chs),
+ loop(Chs2, Parent, Deb2);
+ {system, From, Request} ->
+ sys:handle_system_msg(Request, From, Parent,
+ ?MODULE, Deb, Chs);
+ stop ->
+ sys:handle_debug(Deb, fun write_debug/3,
+ ?MODULE, {in, stop}),
+ ok
+ end.
+
+system_continue(Parent, Deb, Chs) ->
+ loop(Chs, Parent, Deb).
+
+system_terminate(Reason, _Parent, _Deb, _Chs) ->
+ exit(Reason).
+
+write_debug(Dev, Event, Name) ->
+ io:format(Dev, "~p event = ~p~n", [Name, Event]).
+
+channels(NumCh) ->
+ #state{alloc=[], free=lists:seq(1,NumCh)}.
+
+alloc(#state{free=[]}=Channels) ->
+ {{error, "no channels available"}, Channels};
+alloc(#state{alloc=Allocated, free=[H|T]}) ->
+ {H, #state{alloc=[H|Allocated], free=T}}.
+
+free(Ch, #state{alloc=Alloc, free=Free}=Channels) ->
+ case lists:member(Ch, Alloc) of
+ true ->
+ #state{alloc=lists:delete(Ch, Alloc), free=[Ch|Free]};
+ false ->
+ Channels
+ end.
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