Re: [Qemu-devel] [RFC PATCH V4 0/4] Introduce COLO-compare

[Zhang Chen <zhangchen.fnst@cn.fujitsu.com>]

On 06/20/2016 11:03 AM, Jason Wang wrote:
>
>
> On 2016年06月17日 10:25, Zhang Chen wrote:
>> Hi~ jason.
>>
>> I tried a lot of ways to make it run in compare thread, but it not work.
>>
>> Because that:
>> void g_main_context_push_thread_default (GMainContext *context);
>> Acquires context and sets it as the thread-default context for the 
>> current thread.
>>
>> So, this function g_main_context_push_thread_default() just can set 
>> thread-default context,
>> not the global default context. and I can't find a function to set 
>> global default context in glib.
>> The qemu's QIOChannel uses g_source_attach(source, NULL); to attach 
>> GSource.
>> g_source_attach (GSource *source,
>>                  GMainContext *context);
>>
>> context
>> a GMainContext (if NULL, the default context will be used).
>>
>> But he not say "the default context" is global default context or 
>> thread-default context.
>> So I read glib codes find that:
>> guint
>> g_source_attach (GSource *source,
>>                  GMainContext *context)
>> {
>> .....
>> if (!context)
>>     context = g_main_context_default ();
>> .....
>> }
>>
>> g_main_context_default ()
>> Returns the global default main context.
>>
>> So...I think we can't make qemu_chr_add_handlers() run in colo thread 
>> in this way.
>> Do you have any comments about that? 
>
> How about (like I suggest previously) just use
>
> g_souce_attach(x, g_main_context_get_thread_default());
>
> in qemu's QIOChannel code?
>
>
>

I feel it seems can work, and will try it.
but I don't know how this change in qemu's QIOChannel code
will affect the other code. needs other people confirm it?
If no affect and works good,I will send a independent patch
for this.


Thanks
Zhang Chen

>
>
> .
>

-- 
Thanks
zhangchen