Re: missing snd_dlclose in timer.c

[Benoit Fouet <benoit.fouet@purplelabs.com>]

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Takashi Iwai wrote:

>At Tue, 25 Apr 2006 11:03:28 +0200,
>Benoit Fouet wrote:
>  
>
>>Hi,
>>
>>I worked on an ARM9E platform with not much memory. We had to
>>dynamically link the libraries we needed.
>>BTW I found out that there was a dlclose missing in ALSA lib in the
>>snd_timer_open_conf function.
>>Find below the diff of my file, if you want to add it in th hg repository.
>>    
>>
>
>A good catch.
>
>I just wonder whether it's safe to call dlclose() there.
>Can the callback functions dynamically registered by open
>(e.g. snd_timer_hw_open) be still accessed safely after dlclose()?
>
>Or should we keep dl handle and dlclose it in snd_timer_close()?
>
>
>Takashi
>  
>
It surely is safer to keep the library opened as long as its symbol are
likely to be used.
I'm afraid I'm not aware enough of how it works to answer more clearly.
btw, the symbols I used were in asound library, and were consequently
still reachable after dlclose as the library was not really unloaded.
Keeping the handle must be the best way to guarantee symbols can be
reached until snd_timer_close.

Ben

>
>  
>
>>Cheers,
>>Ben
>>
>>
>>diff -r 211e55692b5d src/timer/timer.c
>>--- a/src/timer/timer.c Wed Apr 19 12:29:47 2006 +0200
>>+++ b/src/timer/timer.c Tue Apr 25 10:53:04 2006 +0200
>>@@ -171,7 +171,10 @@ static int snd_timer_open_conf(snd_timer
>>        _err:
>>        if (type_conf)
>>                snd_config_delete(type_conf);
>>-       return err >= 0 ? open_func(timer, name, timer_root, timer_conf,
>>mode) : err;
>>+       err = err >= 0 ? open_func(timer, name, timer_root, timer_conf,
>>mode) : err;
>>+       if (h)
>>+               snd_dlclose(h);
>>+       return err;
>> }
>>
>> static int snd_timer_open_noupdate(snd_timer_t **timer, snd_config_t
>>*root, const char *name, int mode)
>>
>>
>>
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>>    
>>
>
>
>-------------------------------------------------------
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