[pulseaudio-discuss] [PATCH 40/56] bluetooth: Track devices in module-bluez5-discover

[João Paulo Rechi Vita]

On Mon, Jul 22, 2013 at 11:36 AM, Tanu Kaskinen
<tanu.kaskinen at linux.intel.com> wrote:
> On Fri, 2013-07-12 at 15:06 -0300, jprvita at gmail.com wrote:
>> From: João Paulo Rechi Vita <jprvita at openbossa.org>
>>
>> ---
>>  src/modules/bluetooth/module-bluez5-discover.c | 68 ++++++++++++++++++++++++++
>>  1 file changed, 68 insertions(+)
>>
>> diff --git a/src/modules/bluetooth/module-bluez5-discover.c b/src/modules/bluetooth/module-bluez5-discover.c
>> index 8409bd3..4c90744 100644
>> --- a/src/modules/bluetooth/module-bluez5-discover.c
>> +++ b/src/modules/bluetooth/module-bluez5-discover.c
>> @@ -24,6 +24,7 @@
>>  #endif
>>
>>  #include <pulsecore/core.h>
>> +#include <pulsecore/core-util.h>
>>  #include <pulsecore/macro.h>
>>  #include <pulsecore/module.h>
>>
>> @@ -39,9 +40,57 @@ PA_MODULE_LOAD_ONCE(true);
>>  struct userdata {
>>      pa_module *module;
>>      pa_core *core;
>> +    pa_hashmap *device_modules;
>> +    pa_hook_slot *device_connection_changed_slot;
>>      pa_bluetooth_discovery *discovery;
>>  };
>>
>> +struct module_info {
>> +    char *path;
>> +    uint32_t module;
>
> It seems that the module index is not actually used for anything. So
> device_modules could store just the paths, and there's no need for
> module_info.
>

Makes sense, this was also legacy logic from the BlueZ 4 modules.

>> +};
>> +
>> +static pa_hook_result_t device_connection_changed_cb(pa_bluetooth_discovery *y, const pa_bluetooth_device *d, struct userdata *u) {
>> +    struct module_info *mi;
>> +
>> +    pa_assert(d);
>> +    pa_assert(u);
>> +
>> +    mi = pa_hashmap_get(u->device_modules, d->path);
>> +
>> +    if (mi && !pa_bluetooth_device_any_transport_connected(d)) {
>> +        /* disconnection, the module unloads itself */
>> +        pa_log_debug("Unregistering module for %s", d->path);
>> +        pa_hashmap_remove(u->device_modules, mi->path);
>> +        pa_xfree(mi->path);
>> +        pa_xfree(mi);
>> +        return PA_HOOK_OK;
>> +    }
>> +
>> +    if (!mi && pa_bluetooth_device_any_transport_connected(d)) {
>> +        /* a new device has been connected */
>> +        pa_module *m;
>> +        char *args = pa_sprintf_malloc("path=%s", d->path);
>> +
>> +        pa_log_debug("Loading module-bluez5-device %s", args);
>> +        m = pa_module_load(u->module->core, "module-bluez5-device", args);
>> +        pa_xfree(args);
>> +
>> +        if (m) {
>> +            mi = pa_xnew(struct module_info, 1);
>> +            mi->module = m->index;
>> +            mi->path = pa_xstrdup(d->path);
>> +
>> +            pa_hashmap_put(u->device_modules, mi->path, mi);
>> +        } else
>> +            pa_log_warn("Failed to load module for device %s", d->path);
>> +
>> +        return PA_HOOK_OK;
>> +    }
>> +
>> +    return PA_HOOK_OK;
>> +}
>> +
>>  int pa__init(pa_module* m) {
>>      struct userdata *u;
>>
>> @@ -50,10 +99,15 @@ int pa__init(pa_module* m) {
>>      m->userdata = u = pa_xnew0(struct userdata, 1);
>>      u->module = m;
>>      u->core = m->core;
>> +    u->device_modules = pa_hashmap_new(pa_idxset_string_hash_func, pa_idxset_string_compare_func);
>>
>>      if (!(u->discovery = pa_bluetooth_discovery_get(u->core)))
>>          goto fail;
>>
>> +    u->device_connection_changed_slot =
>> +        pa_hook_connect(pa_bluetooth_discovery_hook(u->discovery, PA_BLUETOOTH_HOOK_DEVICE_CONNECTION_CHANGED),
>> +                        PA_HOOK_NORMAL, (pa_hook_cb_t) device_connection_changed_cb, u);
>
> If the discovery object already existed, and it contains devices,
> module-bluez5-discover should load module-bluez5-device modules for
> those devices. It's possible that the device modules are already loaded,
> though, so there needs to be some way of checking whether a device
> module actually needs to be loaded. pa_bluetooth_discovery could have a
> registry for loaded modules, perhaps. Or pa_bluetooth_device could have
> a module_loaded boolean field.
>

The discovery object will only exist if a module-bluez5-device has
been loaded before module-bluez5-discover (I'm not considering the
possibility of clash between bluez4/bluez5 discovery objects, since
this is a different problem). And as you mentioned in the comments of
patch 41/56, manually loading the device module doesn't work anymore
(and I really don't remember if it ever worked). So perhaps we should
explicitly not support manually loading it, is there a way to enforce
this via PulseAudio's module-loading system?

-- 
João Paulo Rechi Vita
http://about.me/jprvita