aboutsummaryrefslogblamecommitdiffstats
path: root/lib/kernel/test/heart_SUITE.erl
blob: e63ed349735285b8be08955864d84bdfb23673f3 (plain) (tree)
1
2
3
4
5
6
7
8
9

                   
  
                                                        
  


                                                                   
  






                                                                           
  



                     
                                           
 

                                                                    



                                              
                        
                       
                                                    
 
                                                   
 
                                                                                      


                                   




                                                                    
                                   
           
 
                                   

                           


                                                                            
                                                                           



                                                      
                    





                                                                   


                                 
 


                                           
                                    
                                    
                     
                    

                




                                     
           

                                    
           
 
 
                                              



                                                        
                                     
        
                                             
                              
 
 
                          

                                
                                        

                                                                                 
            
                                                 
        
                             


                                                                
                                                              
        

                                                    
                               

               
                                      


               
                                     
                                                     
                                     
           
                              
                                          
        
                      



                              
                                  
        






                                                     



                                                               
                                       
                                                     
                                      


                           
                 
                                    
        
                      
                                   

                          


                                                              
                                      
                                                     
 
                                       

                                                                    
                                     



                           
                                    
        
                      
                                   

       




                                                                            


                                                                                
                                                                  








                                                                                            

                                                                







                                                       


                                               






                                                                   
               
 
                               
                                                                                                 


                                                                                           
                                                                                 
        
                      
                                   







                                                          


                                                                                
                                                           







                                                                                     

                                                                 


















                                                                   
                                                                                 
        
                       


                                    

                                




                                             

                                      
                                             
                
            
                                      
        

                                                                   
                                       
                                                     
                     
                                                                    
                                     
                                                                      
                                   
                                                
                                     
                                                


                    
                                         
                                                     
                                       

                                                                    
                                     



                           
                                    
        
                      



                                            
                                      

                                       
                                                                       

                                              



                           
                                    
        
                      



                              
                                  
        

       
                                       
                                                     
                 
                                                
                                                   


                    
                                            
                                                     


























                                                                                    
                                          



                    
                                           
                                                     








                                                                                    

                                                                      


                                                  

                                                                      
                                                                          
                                                                      







                                                  
 


                                                              



                                                                     

                                                     

                                                              
 
                        

                               
                                             
                                               
                                             
                                               

                                                           
                                
                                                 
                                                                



                                        
                                                                            







                                                          

                         
                              

                             
          

                               













                                                     

 

                                                              
                                        
                             

                       
                           



                                                             
                                 



                  























                                                                


                        
                                 
                              

                                       



                     

                             


                                               
                                                             











                                            


                                              
 


                                                                   









                                                        
                                               
                                                             
                 

                                                      
                             
































































                                                                      
 
                         
                                                                                                                         









                                              




                                           


                                                            



                                             

                    







                                             
%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%%     http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
-module(heart_SUITE).

-include_lib("common_test/include/ct.hrl").

-export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1, 
	 init_per_group/2,end_per_group/2, start/1, restart/1, 
	 reboot/1,
	 node_start_immediately_after_crash/1,
	 node_start_soon_after_crash/1,
	 set_cmd/1, clear_cmd/1, get_cmd/1,
	 callback_api/1,
         options_api/1,
	 dont_drop/1, kill_pid/1, heart_no_kill/1]).

-export([init_per_testcase/2, end_per_testcase/2]).

-export([start_heart_stress/1, mangle/1, suicide_by_heart/0, non_suicide_by_heart/0]).

-define(DEFAULT_TIMEOUT_SECS, 120).

-define(UNIQ_NODE_NAME,
  list_to_atom(?MODULE_STRING ++ "__" ++
               atom_to_list(?FUNCTION_NAME) ++ "_" ++
	       integer_to_list(erlang:unique_integer([positive])))).

init_per_testcase(_Func, Config) ->
    Config.

end_per_testcase(_Func, _Config) ->
    Nodes = nodes(),
    lists:foreach(fun(X) ->
		NNam = list_to_atom(hd(string:tokens(atom_to_list(X),"@"))),
		case NNam of
		    heart_test ->
			ct:pal(?HI_VERBOSITY, "WARNING: Killed ~p~n", [X]),
			rpc:cast(X, erlang, halt, []);
		    _ ->
			ok
		end
	end, Nodes).

%%-----------------------------------------------------------------
%% Test suite for heart.
%% Should be started in a CC view with:
%% erl -sname master -rsh ctrsh
%%-----------------------------------------------------------------
suite() ->
    [{ct_hooks,[ts_install_cth]},
     {timetrap,{minutes,2}}].

all() -> [
	start, restart, reboot,
	node_start_immediately_after_crash,
	node_start_soon_after_crash,
	set_cmd, clear_cmd, get_cmd,
	callback_api,
        options_api,
	kill_pid
    ].

groups() -> 
    [].

init_per_group(_GroupName, Config) ->
    Config.

end_per_group(_GroupName, Config) ->
    Config.


init_per_suite(Config) when is_list(Config) ->
    case os:type() of
	{win32, windows} ->
	    {skipped, "No use to run on Windows 95/98"};
	_ ->
	    ignore_cores:init(Config)
    end.
end_per_suite(Config) when is_list(Config) ->
    ignore_cores:fini(Config).


start_check(Type, Name) ->
    start_check(Type, Name, []).
start_check(Type, Name, Envs) ->
    Args = case test_server:os_type() of
	{win32,_} ->
	    "+t50000 -heart " ++ env_encode([{"HEART_COMMAND", no_reboot}|Envs]);
	_ ->
	    "+t50000 -heart " ++ env_encode(Envs)
    end,
    {ok, Node} = case Type of
	loose ->
	    loose_node:start(Name, Args, ?DEFAULT_TIMEOUT_SECS);
	_ ->
	    test_server:start_node(Name, Type, [{args, Args}])
    end,
    erlang:monitor_node(Node, true),
    case rpc:call(Node, erlang, whereis, [heart]) of
	Pid when is_pid(Pid) ->
	    ok;
	_ ->
	    ct:fail(heart_not_started)
    end,
    {ok, Node}.

start(Config) when is_list(Config) ->
    {ok, Node} = start_check(slave, ?UNIQ_NODE_NAME),
    rpc:call(Node, init, reboot, []),
    receive
	{nodedown, Node} -> ok
    after 2000 -> ct:fail(node_not_closed)
    end,
    timer:sleep(5000),
    case net_adm:ping(Node) of
	pang ->
	    ok;
	_ -> 
	    ct:fail(node_rebooted)
    end,
    test_server:stop_node(Node).

%% Also test fixed bug in R1B (it was not possible to
%% do init:stop/0 on a restarted system before)
%% Slave executes erlang:halt() on master nodedown.
%% Therefore the slave process has to be killed
%% before restart.

%% restart
%% Purpose:
%%   Check that a node is up and running after a init:restart/0
restart(Config) when is_list(Config) ->
    {ok, Node} = start_check(loose, ?UNIQ_NODE_NAME),
    rpc:call(Node, init, restart, []),
    receive
	{nodedown, Node} ->
	    ok
    after 5000 ->
	    ct:fail(node_not_closed)
    end,
    timer:sleep(5000),
    node_check_up_down(Node, 2000),
    loose_node:stop(Node).

%% reboot
%% Purpose:
%%   Check that a node is up and running after a init:reboot/0
reboot(Config) when is_list(Config) ->
    {ok, Node} = start_check(slave, ?UNIQ_NODE_NAME),

    ok = rpc:call(Node, heart, set_cmd,
			[atom_to_list(lib:progname()) ++ 
			 " -noshell -heart " ++ name(Node) ++ "&"]),
    rpc:call(Node, init, reboot, []),
    receive
	{nodedown, Node} ->
	    ok
    after 2000 ->
	    ct:fail(node_not_closed)
    end,
    timer:sleep(5000),
    node_check_up_down(Node, 2000),
    ok.

%% node_start_immediately_after_crash
%% Purpose:
%%   Check that a node is up and running after a crash.
%%   This test exhausts the atom table on the remote node.
%%   ERL_CRASH_DUMP_SECONDS=0 will force beam not to dump an erl_crash.dump.
%% May currently dump core in beam debug build due to lock-order violation
%% This should be removed when a non-lockad information retriever is implemented
%% for crash dumps
node_start_immediately_after_crash(Config) when is_list(Config) ->
    Config2 = ignore_cores:setup(?MODULE, node_start_immediately_after_crash, Config, true),
    try
	node_start_immediately_after_crash_test(Config2)
    after
	ignore_cores:restore(Config2)
    end.
 

node_start_immediately_after_crash_test(Config) when is_list(Config) ->
    {ok, Node} = start_check(loose, ?UNIQ_NODE_NAME,
			     [{"ERL_CRASH_DUMP_SECONDS", "0"}]),

    ok = rpc:call(Node, heart, set_cmd,
	[atom_to_list(lib:progname()) ++
	    " -noshell -heart " ++ name(Node) ++ "&"]),

    Mod  = exhaust_atoms,

    Code = generate(Mod, [], [
	    "do() -> "
	    "  Set = lists:seq($a,$z), "
	    "  [ list_to_atom([A,B,C,D,E]) || "
	    "  A <- Set, B <- Set, C <- Set, E <- Set, D <- Set ]."
	]),

    %% crash it with atom exhaustion
    rpc:call(Node, erlang, load_module, [Mod, Code]),
    rpc:cast(Node, Mod, do, []),

    T0 = now(),

    receive {nodedown, Node} ->
	    io:format("Took ~.2f s. for node to go down~n", [timer:now_diff(now(), T0)/1000000]),
	    ok
    %% timeout is very liberal here. nodedown is received in about 1 s. on linux (palantir)
    %% and in about 10 s. on solaris (carcharoth)
    after (15000*test_server:timetrap_scale_factor()) -> ct:fail(node_not_closed)
    end,
    timer:sleep(3000),
    node_check_up_down(Node, 2000),
    loose_node:stop(Node).

%% node_start_soon_after_crash
%% Purpose:
%%   Check that a node is up and running after a crash.
%%   This test exhausts the atom table on the remote node.
%%   ERL_CRASH_DUMP_SECONDS=10 will force beam
%%   to only dump an erl_crash.dump for 10 seconds.
%% May currently dump core in beam debug build due to lock-order violation
%% This should be removed when a non-lockad information retriever is implemented
%% for crash dumps
node_start_soon_after_crash(Config) when is_list(Config) ->
    Config2 = ignore_cores:setup(?MODULE, node_start_soon_after_crash, Config, true),
    try
	node_start_soon_after_crash_test(Config2)
    after
	ignore_cores:restore(Config2)
    end.
 
node_start_soon_after_crash_test(Config) when is_list(Config) ->
    {ok, Node} = start_check(loose, ?UNIQ_NODE_NAME,
			     [{"ERL_CRASH_DUMP_SECONDS", "10"}]),

    ok = rpc:call(Node, heart, set_cmd,
	[atom_to_list(lib:progname()) ++
	    " -noshell -heart " ++ name(Node) ++ "&"]),

    Mod  = exhaust_atoms,

    Code = generate(Mod, [], [
	    "do() -> "
	    "  Set = lists:seq($a,$z), "
	    "  [ list_to_atom([A,B,C,D,E]) || "
	    "  A <- Set, B <- Set, C <- Set, E <- Set, D <- Set ]."
	]),

    %% crash it with atom exhaustion
    rpc:call(Node, erlang, load_module, [Mod, Code]),
    rpc:cast(Node, Mod, do, []),

    receive {nodedown, Node} -> ok
    after (15000*test_server:timetrap_scale_factor()) -> ct:fail(node_not_closed)
    end,
    timer:sleep(20000),
    node_check_up_down(Node, 15000),
    loose_node:stop(Node).


node_check_up_down(Node, Tmo) ->
    case net_adm:ping(Node) of
	pong ->
	    erlang:monitor_node(Node, true),
	    rpc:call(Node, init, reboot, []),
	    receive
		{nodedown, Node} -> ok
	    after Tmo ->
		    ct:fail(node_not_closed2)
	    end;
	_ ->
	    ct:fail(node_not_rebooted)
    end.

%% Only tests bad command, correct behaviour is tested in reboot/1.
set_cmd(Config) when is_list(Config) ->
    {ok, Node} = start_check(slave, ?UNIQ_NODE_NAME),
    Cmd = wrong_atom,
    {error, {bad_cmd, Cmd}} = rpc:call(Node, heart, set_cmd, [Cmd]),
    Cmd1 = lists:duplicate(2047, $a),
    {error, {bad_cmd, Cmd1}} = rpc:call(Node, heart, set_cmd, [Cmd1]),
    Cmd2 = lists:duplicate(28, $a),
    ok = rpc:call(Node, heart, set_cmd, [Cmd2]),
    Cmd3 = lists:duplicate(2000, $a),
    ok = rpc:call(Node, heart, set_cmd, [Cmd3]),
    stop_node(Node),
    ok.

clear_cmd(Config) when is_list(Config) ->
    {ok, Node} = start_check(slave, ?UNIQ_NODE_NAME),
    ok = rpc:call(Node, heart, set_cmd,
			[atom_to_list(lib:progname()) ++
			 " -noshell -heart " ++ name(Node) ++ "&"]),
    rpc:call(Node, init, reboot, []),
    receive
	{nodedown, Node} ->
	    ok
    after 2000 ->
	    ct:fail(node_not_closed)
    end,
    timer:sleep(5000),
    case net_adm:ping(Node) of
	pong ->
	    erlang:monitor_node(Node, true);
	_ ->
	    ct:fail(node_not_rebooted)
    end,
    ok = rpc:call(Node, heart, set_cmd,
			["erl -noshell -heart " ++ name(Node) ++ "&"]),
    ok = rpc:call(Node, heart, clear_cmd, []),
    rpc:call(Node, init, reboot, []),
    receive
	{nodedown, Node} ->
	    ok
    after 2000 ->
	    ct:fail(node_not_closed)
    end,
    timer:sleep(5000),
    case net_adm:ping(Node) of
	pang ->
	    ok;
	_ ->
	    ct:fail(node_rebooted)
    end,
    ok.

get_cmd(Config) when is_list(Config) ->
    {ok, Node} = start_check(slave, ?UNIQ_NODE_NAME),
    Cmd = "test",
    ok  = rpc:call(Node, heart, set_cmd, [Cmd]),
    {ok, Cmd} = rpc:call(Node, heart, get_cmd, []),
    stop_node(Node),
    ok.

callback_api(Config) when is_list(Config) ->
    {ok, Node} = start_check(slave, ?UNIQ_NODE_NAME),
    none = rpc:call(Node, heart, get_callback, []),
    M0 = self(),
    F0 = ok,
    {error, {bad_callback, {M0,F0}}} = rpc:call(Node, heart, set_callback, [M0,F0]),
    none = rpc:call(Node, heart, get_callback, []),
    M1 = lists:duplicate(28, $a),
    F1 = lists:duplicate(28, $b),
    {error, {bad_callback, {M1,F1}}} = rpc:call(Node, heart, set_callback, [M1,F1]),
    none = rpc:call(Node, heart, get_callback, []),

    M2 = heart_check_module,
    F2 = cb_ok,
    F3 = cb_error,
    Code0 = generate(M2, [], [
	    atom_to_list(F2) ++ "() -> ok.",
            atom_to_list(F3) ++ "() -> exit(\"callback_error (as intended)\")."
	]),
    {module, M2} = rpc:call(Node, erlang, load_module, [M2, Code0]),
    ok = rpc:call(Node, M2, F2, []),
    ok = rpc:call(Node, heart, set_callback, [M2,F2]),
    {ok, {M2,F2}} = rpc:call(Node, heart, get_callback, []),
    ok = rpc:call(Node, heart, clear_callback, []),
    none = rpc:call(Node, heart, get_callback, []),
    ok = rpc:call(Node, heart, set_callback, [M2,F2]),
    {ok, {M2,F2}} = rpc:call(Node, heart, get_callback, []),
    ok = rpc:call(Node, heart, set_callback, [M2,F3]),
    receive {nodedown, Node} -> ok
    after 5000 -> ct:fail(node_not_killed)
    end,
    stop_node(Node),
    ok.

options_api(Config) when is_list(Config) ->
    {ok, Node} = start_check(slave, ?UNIQ_NODE_NAME),
    none = rpc:call(Node, heart, get_options, []),
    M0 = self(),
    F0 = ok,
    {error, {bad_options, {M0,F0}}} = rpc:call(Node, heart, set_options, [{M0,F0}]),
    none = rpc:call(Node, heart, get_options, []),
    Ls = lists:duplicate(28, $b),
    {error, {bad_options, Ls}} = rpc:call(Node, heart, set_options, [Ls]),
    none = rpc:call(Node, heart, get_options, []),

    ok = rpc:call(Node, heart, set_options, [[check_schedulers]]),
    {ok, [check_schedulers]} = rpc:call(Node, heart, get_options, []),
    ok = rpc:call(Node, heart, set_options, [[]]),
    none = rpc:call(Node, heart, get_options, []),

    ok = rpc:call(Node, heart, set_options, [[check_schedulers]]),
    {ok, [check_schedulers]} = rpc:call(Node, heart, get_options, []),
    {error, {bad_options, Ls}} = rpc:call(Node, heart, set_options, [Ls]),
    {ok, [check_schedulers]} = rpc:call(Node, heart, get_options, []),

    receive after 3000 -> ok end, %% wait 3 secs

    ok = rpc:call(Node, heart, set_options, [[]]),
    none = rpc:call(Node, heart, get_options, []),
    stop_node(Node),
    ok.


%%% Removed as it may crash epmd/distribution in colourful
%%% ways. While we ARE finding out WHY, it would
%%% be nice for others to be able to run the kernel test suite
%%% without "exploding machines", so that's why I removed it for now.

%% Tests that the heart command does not get dropped when
%% set just before halt on very high I/O load..
dont_drop(Config) when is_list(Config) ->
    %%% Have to do it some times to make it happen...
    [ok,ok,ok,ok,ok,ok,ok,ok,ok,ok] = do_dont_drop(Config,10),
    ok.

do_dont_drop(_,0) -> [];
do_dont_drop(Config,N) ->
    %% Name of first slave node
    NN1 = atom_to_list(?MODULE) ++ "slave_1",
    %% Name of node started by heart on failure
    NN2 = atom_to_list(?MODULE) ++ "slave_2",
    %% Name of node started by heart on success
    NN3 = atom_to_list(?MODULE) ++ "slave_3",
    Host = hd(tl(string:tokens(atom_to_list(node()),"@"))),
    %% The initial heart command
    FirstCmd = erl() ++ name(NN2 ++ "@" ++ Host),
    %% Separated the parameters to start_node_run for clarity...
    Name = list_to_atom(NN1),
    Env = [{"HEART_COMMAND", FirstCmd}],
    Func = "start_heart_stress",
    Arg = NN3 ++ "@" ++ Host ++ " " ++
	filename:join(proplists:get_value(data_dir, Config), "simple_echo"),
    start_node_run(Name,Env,Func,Arg),
    case wait_for_any_of(list_to_atom(NN2 ++ "@" ++ Host),
	    list_to_atom(NN3 ++ "@" ++ Host)) of
	2 ->
	    [ok | do_dont_drop(Config,N-1)];
	_ ->
	    false
    end.

wait_for_any_of(N1,N2) ->
    wait_for_any_of(N1,N2,45).

wait_for_any_of(_N1,_N2,0) ->
    false;

wait_for_any_of(N1,N2,Times) ->
    receive after 1000 -> ok end,
    case net_adm:ping(N1) of
	pang ->
	    case net_adm:ping(N2) of
		pang ->
		    wait_for_any_of(N1,N2,Times - 1);
		pong ->
		    rpc:call(N2,init,stop,[]),
		    2
	    end;
	pong ->
	    rpc:call(N1,init,stop,[]),
	    1
    end.


%% Tests that heart kills the old erlang node before executing
%% heart command.
kill_pid(Config) when is_list(Config) ->
    ok = do_kill_pid(Config).

do_kill_pid(_Config) ->
    Name = ?UNIQ_NODE_NAME,
    Env = [{"HEART_COMMAND", "nickeNyfikenFarEttJobb"}],
    {ok,Node} = start_node_run(Name,Env,suicide_by_heart,[]),
    ok = wait_for_node(Node,15),
    erlang:monitor_node(Node, true),
    receive {nodedown,Node} -> ok
    after 30000 ->
	    false
    end.


heart_no_kill(suite) ->
    [];
heart_no_kill(doc) ->
    ["Tests that heart doesn't kill the old erlang node when ",
     "HEART_NO_KILL is set."];
heart_no_kill(Config) when is_list(Config) ->
    ok = do_no_kill(Config).

do_no_kill(_Config) ->
    Name = heart_test,
    {ok,Node} = start_node_run(Name,[],non_suicide_by_heart,[]),
    io:format("Node is ~p~n", [Node]),
    ok = wait_for_node(Node,15),
    io:format("wait_for_node is ~p~n", [ok]),
    erlang:monitor_node(Node, true),
    receive {nodedown,Node} -> false
    after 30000 ->
	    io:format("Node didn't die..\n"),
	    rpc:call(Node,init,stop,[]),
	    io:format("done init:stop..\n"),
	    ok
    end.

wait_for_node(_,0) ->
    false;
wait_for_node(Node,N) ->
    receive after 1000 -> ok end,
    case net_adm:ping(Node) of
	pong -> ok;
	pang -> wait_for_node(Node,N-1)
    end.

erl() ->	   
    case os:type() of
	{win32,_} -> "werl ";
	_ -> "erl "
    end.
    
name(Node) when is_list(Node) -> name(Node,[]);
name(Node) when is_atom(Node) -> name(atom_to_list(Node),[]).

name([$@|Node], Name) ->
    case lists:member($., Node) of
	true ->
	    "-name " ++ lists:reverse(Name);
	_ ->
	    "-sname " ++ lists:reverse(Name)
    end;
name([H|T], Name) ->
    name(T, [H|Name]).


enc(A) when is_atom(A) -> atom_to_list(A);
enc(A) when is_binary(A) -> binary_to_list(A);
enc(A) when is_list(A) -> A.

env_encode([]) -> [];
env_encode([{X,Y}|T]) ->
    "-env " ++ enc(X) ++ " \"" ++ enc(Y) ++ "\" " ++ env_encode(T).

%%%
%%% Starts a node and runs a function in this
%%% module.
%%% Name is the node name as either atom or string,
%%% Env is a list of Tuples containing name-value pairs.
%%% Function is the function to run in this module
%%% Argument is the argument(s) to send through erl -s
%%%
start_node_run(Name, Env, Function, Argument) -> 
    PA = filename:dirname(code:which(?MODULE)),
    Params = "-heart " ++ env_encode(Env) ++ " -pa " ++ PA ++
	" -s " ++
	enc(?MODULE) ++ " " ++ enc(Function) ++ " " ++
	enc(Argument),
    start_node(Name, Params).

start_node(Name, Param) ->
    test_server:start_node(Name, slave, [{args, Param}]).

stop_node(Node) ->
    test_server:stop_node(Node).


%%% This code is run in a slave node to ensure that 
%%% A heart command really gets set syncronously 
%%% and cannot get "dropped".

send_to(_,_,0) ->
    ok;
send_to(Port,D,N) ->
    Port ! {self(),{command,D}},
    send_to(Port,D,N-1).

receive_from(_,_,0) ->
    ok;

receive_from(Port,D,N) ->
    receive
	{Port, {data,{eol,_Data}}} ->
	    receive_from(Port,D,N-1);
	X ->
	    io:format("Got garbage ~p~n",[X])
    end.

mangle(PP) when is_list(PP) ->
    Port = open_port({spawn,PP},[{line,100}]),
    mangle(Port);

mangle(Port) ->
    send_to(Port, "ABCDEFGHIJ" ++ io_lib:nl(),1),
    receive_from(Port,"ABCDEFGHIJ",1),
    mangle(Port).



explode(0,_) ->
    ok;
explode(N,PP) ->
    spawn(?MODULE,mangle,[PP]),
    explode(N-1,PP).

start_heart_stress([NewName,PortProgram]) ->
    explode(10,atom_to_list(PortProgram)),
    NewCmd = erl() ++ name(NewName), 
    %%io:format("~p~n",[NewCmd]),
    receive
    after 10000 ->
	    heart:set_cmd(NewCmd),
	    halt()
    end.

suicide_by_heart() ->
    %%io:format("Suicide starting...~n"),
    open_port({spawn,"heart -ht 11 -pid "++os:getpid()},[{packet,2}]),
    receive X -> X end,
    %% Just hang and wait for heart to timeout
    receive
	{makaronipudding} ->
	    sallad
    end.

non_suicide_by_heart() ->
    P = open_port({spawn,"heart -ht 11 -pid "++os:getpid()},[exit_status, {env, {"HEART_NO_KILL", "TRUE"}}, {packet,2}]),
    receive X -> X end,
    %% Just hang and wait for heart to timeout
    receive
	{P,{exit_status,_}} ->
	    ok
    after
	20000 ->
	    exit(timeout)
    end.


%% generate a module from binary
generate(Module, Attributes, FunStrings) ->
    FunForms = function_forms(FunStrings),
    Forms    = [
	{attribute,a(1),module,Module},
	{attribute,a(2),export,[FA || {FA,_} <- FunForms]}
    ] ++ [{attribute, a(3), A, V}|| {A, V} <- Attributes] ++
    [ Function || {_, Function} <- FunForms],
    {ok, Module, Bin} = compile:forms(Forms),
    Bin.

a(L) ->
    erl_anno:new(L).

function_forms([]) -> [];
function_forms([S|Ss]) ->
    {ok, Ts,_} = erl_scan:string(S),
    {ok, Form} = erl_parse:parse_form(Ts),
    Fun   = element(3, Form),
    Arity = element(4, Form),
    [{{Fun,Arity}, Form}|function_forms(Ss)].