%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1997-2009. 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(busy_port_SUITE).
-export([all/1, io_to_busy/1, message_order/1, send_3/1,
system_monitor/1, no_trap_exit/1,
no_trap_exit_unlinked/1, trap_exit/1, multiple_writers/1,
hard_busy_driver/1, soft_busy_driver/1]).
-include("test_server.hrl").
%% Internal exports.
-export([init/2]).
all(suite) -> {req, [dynamic_loading],
[io_to_busy, message_order, send_3,
system_monitor, no_trap_exit,
no_trap_exit_unlinked, trap_exit, multiple_writers,
hard_busy_driver, soft_busy_driver]}.
%% Tests I/O operations to a busy port, to make sure a suspended send
%% operation is correctly restarted. This used to crash Beam.
io_to_busy(suite) -> [];
io_to_busy(Config) when is_list(Config) ->
?line Dog = test_server:timetrap(test_server:seconds(30)),
?line start_busy_driver(Config),
?line process_flag(trap_exit, true),
?line Writer = fun_spawn(fun writer/0),
?line Generator = fun_spawn(fun() -> generator(100, Writer) end),
?line wait_for([Writer, Generator]),
?line test_server:timetrap_cancel(Dog),
ok.
generator(N, Writer) ->
generator(N, Writer, lists:duplicate(128, 42)).
generator(0, Writer, _Data) ->
Writer ! stop,
erlang:garbage_collect(),
receive after 2000 -> ok end,
%% Calling process_info(Pid, current_function) on a suspended process
%% used to crash Beam.
{current_function, {erlang, send, 2}} =
process_info(Writer, current_function),
unlock_slave();
generator(N, Writer, Data) ->
Writer ! {exec, Data},
generator(N-1, Writer, [42|Data]).
writer() ->
{Owner, Port} = get_slave(),
Port ! {Owner, {connect, self()}},
X = {a, b, c, d},
forget({element(1, X), element(2, X), element(3, X), element(4, X)}),
writer_loop(Port).
writer_loop(Port) ->
receive
{exec, Data} ->
Port ! {self(), {command, Data}},
writer_loop(Port);
stop ->
erlang:garbage_collect()
end.
forget(_) ->
ok.
%% Test the interaction of busy ports and message sending.
%% This used to cause the wrong message to be received.
message_order(suite) -> {req, dynamic_loading};
message_order(Config) when is_list(Config) ->
?line Dog = test_server:timetrap(test_server:seconds(10)),
?line start_busy_driver(Config),
?line Self = self(),
?line Busy = fun_spawn(fun () -> send_to_busy_1(Self) end),
?line receive after 1000 -> ok end,
?line Busy ! first,
?line Busy ! second,
?line receive after 1 -> ok end,
?line unlock_slave(),
?line Busy ! third,
?line receive
{Busy, first} ->
ok;
Other ->
test_server:fail({unexpected_message, Other})
end,
?line test_server:timetrap_cancel(Dog),
ok.
send_to_busy_1(Parent) ->
{Owner, Slave} = get_slave(),
Slave ! {Owner, {command, "set_me_busy"}},
Slave ! {Owner, {command, "hello"}},
Slave ! {Owner, {command, "hello again"}},
receive
Message ->
Parent ! {self(), Message}
end.
%% Test the bif send/3
send_3(suite) -> {req,dynamic_loading};
send_3(doc) -> ["Test the BIF send/3"];
send_3(Config) when is_list(Config) ->
?line Dog = test_server:timetrap(test_server:seconds(10)),
%%
?line start_busy_driver(Config),
?line {Owner,Slave} = get_slave(),
?line ok = erlang:send(Slave, {Owner,{command,"set busy"}},
[nosuspend]),
?line nosuspend = erlang:send(Slave, {Owner,{command,"busy"}},
[nosuspend]),
?line unlock_slave(),
?line ok = erlang:send(Slave, {Owner,{command,"not busy"}},
[nosuspend]),
?line ok = command(stop),
%%
?line test_server:timetrap_cancel(Dog),
ok.
%% Test the erlang:system_monitor(Pid, [busy_port])
system_monitor(suite) -> {req,dynamic_loading};
system_monitor(doc) -> ["Test erlang:system_monitor({Pid,[busy_port]})."];
system_monitor(Config) when is_list(Config) ->
?line Dog = test_server:timetrap(test_server:seconds(10)),
?line Self = self(),
%%
?line OldMonitor = erlang:system_monitor(Self, [busy_port]),
?line {Self,[busy_port]} = erlang:system_monitor(),
?line Void = make_ref(),
?line start_busy_driver(Config),
?line {Owner,Slave} = get_slave(),
?line Master = command(get_master),
?line Parent = self(),
?line Busy =
spawn_link(
fun() ->
Slave ! {Owner,{command,"set busy"}},
receive {Parent,alpha} -> ok end,
Slave ! {Owner,{command,"busy"}},
Slave ! {Owner,{command,"free"}},
Parent ! {self(),alpha},
command(lock),
receive {Parent,beta} -> ok end,
command({port_command,"busy"}),
command({port_command,"free"}),
Parent ! {self(),beta}
end),
?line Void = rec(Void),
?line Busy ! {self(),alpha},
?line {monitor,Busy,busy_port,Slave} = rec(Void),
?line unlock_slave(),
?line {Busy,alpha} = rec(Void),
?line Void = rec(Void),
?line Busy ! {self(), beta},
?line {monitor,Owner,busy_port,Slave} = rec(Void),
?line Master ! {Owner, {command, "u"}},
?line {Busy,beta} = rec(Void),
?line Void = rec(Void),
?line NewMonitor = erlang:system_monitor(OldMonitor),
?line OldMonitor = erlang:system_monitor(),
?line OldMonitor = erlang:system_monitor(OldMonitor),
%%
?line test_server:timetrap_cancel(Dog),
ok.
rec(Tag) ->
receive X -> X after 1000 -> Tag end.
%% Assuming the following scenario,
%%
%% +---------------+ +-----------+
%% | process with | | |
%% | no trap_exit |------------------| busy port |
%% | (suspended) | | |
%% +---------------+ +-----------+
%%
%% tests that the suspended process is killed if the port is killed.
no_trap_exit(suite) -> [];
no_trap_exit(Config) when is_list(Config) ->
?line Dog = test_server:timetrap(test_server:seconds(10)),
?line process_flag(trap_exit, true),
?line Pid = fun_spawn(fun no_trap_exit_process/3,
[self(), linked, Config]),
?line receive
{Pid, port_created, Port} ->
io:format("Process ~w created port ~w", [Pid, Port]),
?line exit(Port, die);
Other1 ->
test_server:fail({unexpected_message, Other1})
end,
?line receive
{'EXIT', Pid, die} ->
ok;
Other2 ->
test_server:fail({unexpected_message, Other2})
end,
?line test_server:timetrap_cancel(Dog),
ok.
%% The same scenario as above, but the port has been explicitly
%% unlinked from the process.
no_trap_exit_unlinked(suite) -> [];
no_trap_exit_unlinked(Config) when is_list(Config) ->
?line Dog = test_server:timetrap(test_server:seconds(10)),
?line process_flag(trap_exit, true),
?line Pid = fun_spawn(fun no_trap_exit_process/3,
[self(), unlink, Config]),
?line receive
{Pid, port_created, Port} ->
io:format("Process ~w created port ~w", [Pid, Port]),
?line exit(Port, die);
Other1 ->
test_server:fail({unexpected_message, Other1})
end,
?line receive
{'EXIT', Pid, normal} ->
ok;
Other2 ->
test_server:fail({unexpected_message, Other2})
end,
?line test_server:timetrap_cancel(Dog),
ok.
no_trap_exit_process(ResultTo, Link, Config) ->
?line load_busy_driver(Config),
?line _Master = open_port({spawn, "busy_drv master"}, [eof]),
?line Slave = open_port({spawn, "busy_drv slave"}, [eof]),
?line case Link of
linked -> ok;
unlink -> unlink(Slave)
end,
?line Slave ! {self(), {command, "lock port"}},
?line ResultTo ! {self(), port_created, Slave},
?line Slave ! {self(), {command, "suspend me"}},
ok.
%% Assuming the following scenario,
%%
%% +---------------+ +-----------+
%% | process with | | |
%% | trap_exit |------------------| busy port |
%% | (suspended) | | |
%% +---------------+ +-----------+
%%
%% tests that the suspended process is scheduled runnable and
%% receives an 'EXIT' message if the port is killed.
trap_exit(suite) -> [];
trap_exit(Config) when is_list(Config) ->
?line Dog = test_server:timetrap(test_server:seconds(10)),
?line Pid = fun_spawn(fun busy_port_exit_process/2, [self(), Config]),
?line receive
{Pid, port_created, Port} ->
io:format("Process ~w created port ~w", [Pid, Port]),
?line unlink(Pid),
?line {status, suspended} = process_info(Pid, status),
?line exit(Port, die);
Other1 ->
test_server:fail({unexpected_message, Other1})
end,
?line receive
{Pid, ok} ->
ok;
Other2 ->
test_server:fail({unexpected_message, Other2})
end,
?line test_server:timetrap_cancel(Dog),
ok.
busy_port_exit_process(ResultTo, Config) ->
?line process_flag(trap_exit, true),
?line load_busy_driver(Config),
?line _Master = open_port({spawn, "busy_drv master"}, [eof]),
?line Slave = open_port({spawn, "busy_drv slave"}, [eof]),
?line Slave ! {self(), {command, "lock port"}},
?line ResultTo ! {self(), port_created, Slave},
?line Slave ! {self(), {command, "suspend me"}},
receive
{'EXIT', Slave, die} ->
ResultTo ! {self(), ok};
Other ->
ResultTo ! {self(), {unexpected_message, Other}}
end.
%% Tests that several processes suspended by a write to a busy port
%% will start running as soon as the port becamomes ready.
%% This should work even if some of the processes have terminated
%% in the meantime.
multiple_writers(suite) -> [];
multiple_writers(Config) when is_list(Config) ->
?line Dog = test_server:timetrap(test_server:seconds(10)),
?line start_busy_driver(Config),
?line process_flag(trap_exit, true),
%% Start the waiters and make sure they have blocked.
?line W1 = fun_spawn(fun quick_writer/0),
?line W2 = fun_spawn(fun quick_writer/0),
?line W3 = fun_spawn(fun quick_writer/0),
?line W4 = fun_spawn(fun quick_writer/0),
?line W5 = fun_spawn(fun quick_writer/0),
?line test_server:sleep(500), % Make sure writers have blocked.
%% Kill two of the processes.
exit(W1, kill),
receive {'EXIT', W1, killed} -> ok end,
exit(W3, kill),
receive {'EXIT', W3, killed} -> ok end,
%% Unlock the port. The surviving processes should be become runnable.
?line unlock_slave(),
?line wait_for([W2, W4, W5]),
?line test_server:timetrap_cancel(Dog),
ok.
quick_writer() ->
{Owner, Port} = get_slave(),
Port ! {Owner, {command, "port to busy"}},
Port ! {Owner, {command, "lock me"}},
ok.
hard_busy_driver(Config) when is_list(Config) ->
hs_test(Config, true).
soft_busy_driver(Config) when is_list(Config) ->
hs_test(Config, false).
hs_test(Config, HardBusy) when is_list(Config) ->
?line Me = self(),
?line DrvName = case HardBusy of
true -> 'hard_busy_drv';
false -> 'soft_busy_drv'
end,
?line erl_ddll:start(),
?line Path = ?config(data_dir, Config),
case erl_ddll:load_driver(Path, DrvName) of
ok -> ok;
{error, Error} ->
io:format("~s\n", [erl_ddll:format_error(Error)]),
?line ?t:fail()
end,
?line Port = open_port({spawn, DrvName}, []),
NotSuspended = fun (Proc) ->
chk_not_value({status,suspended},
process_info(Proc, status))
end,
NotBusyEnd = fun (Proc, Res, Time) ->
receive
{Port, caller, Proc} -> ok
after
500 -> exit(missing_caller_message)
end,
chk_value({return, true}, Res),
chk_range(0, Time, 100)
end,
ForceEnd = fun (Proc, Res, Time) ->
case HardBusy of
false ->
NotBusyEnd(Proc, Res, Time);
true ->
chk_value({error, notsup}, Res),
chk_range(0, Time, 100),
receive
Msg -> exit({unexpected_msg, Msg})
after
500 -> ok
end
end
end,
BadArg = fun (_Proc, Res, Time) ->
chk_value({error, badarg}, Res),
chk_range(0, Time, 100)
end,
%% Not busy
%% Not busy; nosuspend option
?line hs_busy_pcmd(Port, [nosuspend], NotSuspended, NotBusyEnd),
%% Not busy; force option
?line hs_busy_pcmd(Port, [force], NotSuspended, ForceEnd),
%% Not busy; force and nosuspend option
?line hs_busy_pcmd(Port, [force, nosuspend], NotSuspended, ForceEnd),
%% Not busy; no option
?line hs_busy_pcmd(Port, [], NotSuspended, NotBusyEnd),
%% Not busy; bad option
?line hs_busy_pcmd(Port, [bad_option], NotSuspended, BadArg),
%% Make busy
?line erlang:port_control(Port, $B, []),
%% Busy; nosuspend option
?line hs_busy_pcmd(Port, [nosuspend], NotSuspended,
fun (_Proc, Res, Time) ->
chk_value({return, false}, Res),
chk_range(0, Time, 100),
receive
Msg -> exit({unexpected_msg, Msg})
after
500 -> ok
end
end),
%% Busy; force option
?line hs_busy_pcmd(Port, [force], NotSuspended, ForceEnd),
%% Busy; force and nosuspend option
?line hs_busy_pcmd(Port, [force, nosuspend], NotSuspended, ForceEnd),
%% Busy; bad option
?line hs_busy_pcmd(Port, [bad_option], NotSuspended, BadArg),
%% no option on busy port
?line hs_busy_pcmd(Port, [],
fun (Proc) ->
receive after 1000 -> ok end,
chk_value({status,suspended},
process_info(Proc, status)),
%% Make not busy
erlang:port_control(Port, $N, [])
end,
fun (_Proc, Res, Time) ->
chk_value({return, true}, Res),
chk_range(1000, Time, 2000)
end),
?line true = erlang:port_close(Port),
?line ok = erl_ddll:unload_driver(DrvName),
?line ok = erl_ddll:stop(),
?line ok.
hs_busy_pcmd(Prt, Opts, StartFun, EndFun) ->
Tester = self(),
P = spawn_link(fun () ->
erlang:yield(),
Tester ! {self(), doing_port_command},
Start = os:timestamp(),
Res = try {return,
erlang:port_command(Prt, [], Opts)}
catch Exception:Error -> {Exception, Error}
end,
End = os:timestamp(),
Time = round(timer:now_diff(End, Start)/1000),
Tester ! {self(), port_command_result, Res, Time}
end),
receive
{P, doing_port_command} ->
ok
end,
StartFun(P),
receive
{P, port_command_result, Res, Time} ->
EndFun(P, Res, Time)
end.
%%% Utilities.
chk_range(Min, Val, Max) when Min =< Val, Val =< Max ->
ok;
chk_range(Min, Val, Max) ->
exit({bad_range, Min, Val, Max}).
chk_value(Exp, Exp) ->
ok;
chk_value(Exp, Val) ->
exit({unexpected_value, Val, expected, Exp}).
chk_not_value(NotExp, NotExp) ->
exit({unexpected_not_value, NotExp});
chk_not_value(_, _) ->
ok.
wait_for([]) ->
ok;
wait_for(Pids) ->
io:format("Waiting for ~p", [Pids]),
receive
{'EXIT', Pid, normal} ->
wait_for(lists:delete(Pid, Pids));
Other ->
test_server:fail({bad_exit, Other})
end.
fun_spawn(Fun) ->
fun_spawn(Fun, []).
fun_spawn(Fun, Args) ->
spawn_link(erlang, apply, [Fun, Args]).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% These routines provide a port which will become busy when the
%% the first message is sent to it. The unlock_slave/0 function can
%% be called (from another process) to make the port non-busy.
%%
%% Typical usage:
%%
%% start_busy_driver(Config) Load driver; start server.
%%
%% P r o c e s s O n e
%% {Owner, Port} = get_slave() O Obtain port and its owner.
%% Port ! {Owner, {command, List}} Send to port (will not block
%% but port will become busy).
%% Port ! {Owner, {command, List}} Will block the process.
%%
%% P r o c e s s T w o
%% unlock_slave() Set port to non-busy. Process One
%% will continue executing. Further
%% writes to the port will not block.
%%
%% Any process can call busy_drv:lock() to lock the port again.
%%
%% Note: This module must be used in an installed test suite (outside of
%% clearcase).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
load_busy_driver(Config) when is_list(Config) ->
?line DataDir = ?config(data_dir, Config),
?line erl_ddll:start(),
case erl_ddll:load_driver(DataDir, "busy_drv") of
ok -> ok;
{error, Error} ->
io:format("~s\n", [erl_ddll:format_error(Error)]),
?line ?t:fail()
end.
%%% Interface functions.
start_busy_driver(Config) when is_list(Config) ->
?line Pid = spawn_link(?MODULE, init, [Config, self()]),
?line receive
{Pid, started} ->
ok;
Other ->
test_server:fail({unexpected_message, Other})
end.
unlock_slave() ->
command(unlock).
get_slave() ->
?line command(get_slave).
%% Internal functions.
command(Msg) ->
?line whereis(busy_drv_server) ! {self(), Msg},
?line receive
{busy_drv_reply, Reply} ->
Reply
end.
%%% Server.
init(Config, ReplyTo) ->
register(busy_drv_server, self()),
load_busy_driver(Config),
Driver = "busy_drv",
Master = open_port({spawn, Driver++" master"}, []),
Slave = open_port({spawn, Driver++" slave"}, []),
ReplyTo ! {self(), started},
loop(Master, Slave).
loop(Master, Slave) ->
receive
{Pid, get_master} ->
Pid ! {busy_drv_reply, Master},
loop(Master, Slave);
{Pid, get_slave} ->
Pid ! {busy_drv_reply, {self(), Slave}},
loop(Master, Slave);
{Pid, unlock} ->
Master ! {self(), {command, "u"}},
Pid ! {busy_drv_reply, ok},
loop(Master, Slave);
{Pid, lock} ->
Master ! {self(), {command, "l"}},
Pid ! {busy_drv_reply, ok},
loop(Master, Slave);
{Pid, {port_command,Data}} ->
erlang:port_command(Slave, Data),
Pid ! {busy_drv_reply, ok},
loop(Master, Slave);
{Pid, stop} ->
Pid ! {busy_drv_reply, ok}
end.
