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<div class="moz-cite-prefix">On 09/09/2015 01:31 AM, Siri Hansen
wrote:<br>
</div>
<blockquote
cite="mid:CAGqERUE0MK11fsXqV0Dwz0godKzjxVXykvMiuk++sc=aDJwGcg@mail.gmail.com"
type="cite">
<div dir="ltr">Hi Michael,
<div><br>
</div>
<div>I think that the child spec is kept in the supervisor so
that one is allowed to do supervisor:restart_child/2. This has
been the behavior at least as far back as the git repository
goes. And given that the text was changed as far back as
OTP-R8B, I don't think that the old documentation is a reason
for changing this behavior. <br>
</div>
</div>
</blockquote>
That is fine, but documentation could be added to make sure this
behavior is clear, since it is contrary to the definition of
"transient":<br>
1a passing especially quickly into and out of existence<br>
(<a class="moz-txt-link-freetext" href="http://www.merriam-webster.com/dictionary/transient">http://www.merriam-webster.com/dictionary/transient</a>)<br>
<br>
I assume temporary has a similar problem.<br>
<br>
<blockquote
cite="mid:CAGqERUE0MK11fsXqV0Dwz0godKzjxVXykvMiuk++sc=aDJwGcg@mail.gmail.com"
type="cite">
<div dir="ltr">
<div><br>
</div>
<div>Regards </div>
<div>/siri</div>
<div><br>
</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">2015-07-10 3:53 GMT+02:00 Michael Truog
<span dir="ltr"><<a moz-do-not-send="true"
href="mailto:mjtruog@gmail.com" target="_blank">mjtruog@gmail.com</a>></span>:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000"> <tt>Hi,</tt><tt><br>
</tt><tt><br>
</tt><tt>I have noticed that when the supervisor has a
child process with the childspec restart set to
transient, and the process </tt><tt>terminates in a way
that is not abnormal, the childspec remains within the
supervisor. This appears to be an error based on old
documentation: "</tt><tt>When a </tt><code>temporary</code><tt>
child dies for any reason or a </tt><code>transient</code><tt>
child dies normally, the child is removed from the
supervisor." (<a moz-do-not-send="true"
href="http://www.erlang.org/documentation/doc-4.8.2/lib/stdlib-1.6.1/doc/html/supervisor.html"
target="_blank">http://www.erlang.org/documentation/doc-4.8.2/lib/stdlib-1.6.1/doc/html/supervisor.html</a>).
The new documentation states: "</tt><tt>a </tt><tt><span>transient</span></tt><tt>
child process will be restarted only if it terminates
abnormally, i.e. with another exit reason than </tt><tt><span>normal</span></tt><tt>,
</tt><tt><span>shutdown</span></tt><tt> or </tt><tt><span>{shutdown,Term}"
(<a moz-do-not-send="true"
href="http://www.erlang.org/doc/man/supervisor.html"
target="_blank">http://www.erlang.org/doc/man/supervisor.html</a>),
and this statement is true with the current supervisor
code.<br>
<br>
Is it an error that transient processes that terminate
in a way that is not abnormal do not get removed from
the supervisor? I think it is, but I am not sure if
this was accepted legacy behavior that the
documentation didn't want to contradict. I have an
example below with output:<br>
<br>
-module(test).<br>
-behaviour(supervisor).<br>
-export([start_link/0, test_child/0, test/0, init/1]).<br>
start_link() -><br>
supervisor:start_link({local, ?MODULE}, ?MODULE,
[]).<br>
test_child() -><br>
{ok, erlang:spawn_link(fun() ->
erlang:exit(normal) end)}.<br>
test() -><br>
ChildSpec = {test, {test, test_child, []},
transient, 2000, worker, []},<br>
supervisor:start_child(?MODULE, ChildSpec).<br>
init([]) -><br>
{ok, {{one_for_one, 5, 300}, []}}.<br>
<br>
<br>
Erlang/OTP 18 [erts-7.0] [source] [64-bit] [smp:2:2]
[ds:2:2:10] [async-threads:10] [kernel-poll:false]<br>
<br>
Eshell V7.0 (abort with ^G)<br>
1> {ok, Sup} = test:start_link().<br>
{ok,<0.35.0>}<br>
2> erlang:unlink(Sup).<br>
true<br>
3> {ok, P} = test:test().<br>
{ok,<0.38.0>}<br>
4> erlang:is_process_alive(P).<br>
false<br>
5> supervisor:which_children(test).<br>
[{test,undefined,worker,[]}]<br>
6> test:test().<br>
{error,already_present}<br>
<br>
Isn't keeping the entry in the supervisor, after a
termination that is not abnormal, an error?<br>
</span></tt><tt><span><br>
Thanks,<br>
Michael<br>
</span></tt> </div>
<br>
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</blockquote>
</div>
<br>
</div>
</blockquote>
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