linuxaudio.org

On 06/03/2012 10:52 PM, Brendan Jones wrote:

quoted text
> On 06/01/2012 03:48 PM, David Adler wrote:

>> On Fri, Jun 1, 2012 at 2:52 PM, Robin Gareus wrote:

>>>

>>> It might have to do with Arch's compiler[-flags] and how jack2 uses

>>> unions .. or scoping: JackGlobals vs Engine-Parameters.. although I

>>> don't have an explanation.. all seems good.

>>

>> Compiler flags (for 32bit) are, (from unaltered /etc/makepkg.conf):

>> CXXFLAGS="-march=i686 -mtune=generic -O2 -pipe -fstack-protector

>> --param=ssp-buffer-size=4 -D_FORTIFY_SOURCE=2"

>>

>>> A hunch: it could be caused by using 'server_ptr->verbose.b' (a union)

>>> as boolean. The sever only checks "if (server_ptr->verbose.b)". The

>>> union itself comprises other uninitialized values that could make it

>>> evaluate to true (though it shouldn't, but maybe some compiler

>>> optimization casts it to (int) instead of (bool) )

>>>

>>>

>>> I know this is the '-users' list (I'm ccing jack-devel), but could

>>> someone who experiences the problem try to track it down?

>>>

>>> Basically just add a few printf()'s. Start at: common/JackControlAPI.cpp

>>> - line 926 - before the call to "new JackServer(..)" add

>>>

>>> printf("DEBUG verbose: %s\n",(server_ptr->verbose.b)?"on":"off");

>>>

>>> recompile, launch jackd. If it prints "verbose: on", sth is wrong with

>>> parameter initialization in main() or with using unions. If it's "off"

>>> the problem sits deeper:

>>

>> DEBUG verbose: on

>>

>>> add a line just after common/JackServer.cpp line 66

>>> printf("DEBUG verbose2: %s\n",(JackGlobals::fVerbose)?"on":"off");

>>> ...

>>

>> above, your line number didn't match exactly, so we seem to have

>> different versions (1.9.7 here). Thus, I wasn't exactly sure where to

>> add the prinf() and did the following:

>>

>> ...

>> JackServerGlobals::fUserCount = 1; // One user

>> printf("DEBUG verbose2: %s\n",(JackGlobals::fVerbose)?"on":"off");

>> JackGlobals::fVerbose = verbose;

>> printf("DEBUG verbose3: %s\n",(JackGlobals::fVerbose)?"on":"off");

>> }

>>

>> which prints:

>> DEBUG verbose2: off

>> DEBUG verbose3: on

>>

>>> A crude test for the union() hunch would be to change

>>> common/JackControlAPI.h line 53:

>>> replace

>>> "union jackctl_parameter_value"

>>> with

>>> "struct jackctl_parameter_value"

>>> and compile with '-fpermissive' like this:

>>>

>>> CXXFLAGS="-fpermissive" ./waf configure

>>> ./waf

>>>

>>

>> Again, mismatching line numbers. I assume you meant the line:

>> union jackctl_parameter_value verbose;

>>

>> Changing that to struct fixes both issues I reported,

>> the verbose output and exit on last client close.

>>

>> So we seem to be getting somewhere. Nice.

>>

>>

>> thanks Robin,

>> d

>

> I've come a cross a jackdbus error which seems related. Basically

> jackbus receives a SIGSEGV via the dbus-daemon on account of a bool

> value not being 1 or 0.

>

> The crude workaround below does nothing to explain the issue. Using a

> struct in this instance is also not possible:

>

> diff -Nurp jack-1.9.8.orig/dbus/jackdbus.c jack-1.9.8/dbus/jackdbus.c

> --- jack-1.9.8.orig/dbus/jackdbus.c 2011-12-19 12:54:24.000000000 +0100

> +++ jack-1.9.8/dbus/jackdbus.c 2012-06-03 22:06:16.148799580 +0200

> @@ -418,6 +418,7 @@ jack_dbus_message_append_variant(

> }

>

> /* Append the supplied value. */

> + if (type == DBUS_TYPE_BOOLEAN) *arg = (message_arg_t) ((int*)arg>0);

> if (!dbus_message_iter_append_basic (&sub_iter, type, (const void *) arg))

> {

> dbus_message_iter_close_container (iter, &sub_iter);

>

> Where arg is a pointer to (dbus/jackdbus.h)

> typedef union

> {

> unsigned char byte;

> dbus_bool_t boolean;

> dbus_int16_t int16;

> dbus_uint16_t uint16;

> dbus_int32_t int32;

> dbus_uint32_t uint32;

> dbus_int64_t int64;

> dbus_uint64_t uint64;

> double doubl;

> const char *string;

> } message_arg_t;

>

>

>

In fact this is not a work around at all, it just prevents crashing. The

value is still being cast incorrectly.

_______________________________________________

Linux-audio-user mailing list

Linux-audio-user@lists.linuxaudio.org

http://lists.linuxaudio.org/listinfo/linux-audio-user