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authorSiri Hansen <[email protected]>2014-03-25 09:46:49 +0100
committerSiri Hansen <[email protected]>2014-03-25 09:47:19 +0100
commitaa2dfd7c30d3ca3318498bcbf4155dad175b6d7e (patch)
tree3b7d38226fe79cc2b19162313e0eac8a44b697f0 /lib/stdlib/test/sys_sp1.erl
parent1eee4ded1b435d3728fc75ad384626c80025bb3b (diff)
parentcbcac6f0d55907dda2e0c385eba44eac2e7923d2 (diff)
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Merge branch 'vinoski/sys-get-rep-state2'
* vinoski/sys-get-rep-state2: remove tuple funs from special process documentation fix sys:get_state/1,2 and sys:replace_state/2,3 when sys suspended OTP-11817
Diffstat (limited to 'lib/stdlib/test/sys_sp1.erl')
-rw-r--r--lib/stdlib/test/sys_sp1.erl114
1 files changed, 114 insertions, 0 deletions
diff --git a/lib/stdlib/test/sys_sp1.erl b/lib/stdlib/test/sys_sp1.erl
new file mode 100644
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+++ 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.