[asterisk-dev] Asterisk 1.4.15 ast_service_stop() function deadlock?

[Paulo Garcia]

Hi,

well, it isn't really a deadlock, but I think it is something wrong....

in my channel driver, I have a fax detection procedure that calls
ast_exists_extensions() to check if there is a 'fax' exten available to jump
for.

My test environment is an Asterisk box with FXO interface and another
non-asterisk box with FXS interface. The FXS side originates the call and
the asterisk box answer the call.

I always used the following dialplan for testing:

exten => s,1,Answer(1000);
exten => s,n,Record(test:ulaw|0|0)
exten => s,n,NoOp(${REMOTESTATIONID})

When the Asterisk side answer the call, the FXS side starts a Fax transmit.
Of course the fax won't be received since there is no Rx application running
on Asterisk side.

The problem is that, when the Asterisk detects the fax signal and calls
ast_exists_extensions(), the function ast_service_stop() only returns when
the call finishes. I followed the stack and it seems that the
ast_service_stop function stay the following point:

00234    /* Wait for it to un-block */00235    while (ast_test_flag
<http://www.asterisk.org/doxygen/1.4/utils_8h.html#0cba63300a5690b7f297b26179882cd9>(chan
<http://www.asterisk.org/doxygen/1.4/structasent.html#24fea160601399d6d7a15f28b22bebd7>,
AST_FLAG_BLOCKING
<http://www.asterisk.org/doxygen/1.4/channel_8h.html#d032a9ab2ed31c90af611a3c6221925306284ba3d5b82164197739aff2f52568>))
00236       usleep(1000);


So, If my call takes 3 minutes, the Asterisk will stay on that point for 3
minutes and return only to hangup.

Also, I tested using Asterisk 1.4.14 and this problem doesn't happen. I saw
that 1.4.15 has a lot of changes on that function, to keep dtmf frames but I
couldn't figure out why these changes starts to cause the problem in
1.4.15since that loop exists on both versions.

Any idea?

*Note: I used the Record() application because it has the same loop to wait
finish that my fax rx application has. I swapped them to be sure that it is
not only a problem in my application.
*
-- 
--------------
Paulo Garcia
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