iphone - 使用 PJSIP 取消 SIP 注册

Question

在我们的应用程序中，当用户将应用程序推送到后台时，我们需要取消用户注册。 我们正在使用 PJSIP。我的应用程序DidEnterBackground:

- (void)applicationDidEnterBackground:(UIApplication *)application {
    NSLog(@"did enter background");


     __block UIBackgroundTaskIdentifier bgTask;

     bgTask = [application beginBackgroundTaskWithExpirationHandler:^{
        [application endBackgroundTask:bgTask];
        bgTask = UIBackgroundTaskInvalid;
    }];


    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        [self deregis];        
        [application endBackgroundTask: bgTask]; //End the task so the system knows that you are done with what you need to perform
        bgTask = UIBackgroundTaskInvalid; //Invalidate the background_task
        NSLog(@"\n\nRunning in the background!\n\n");

    });
     }

注销方法如下:

- (void)deregis {
    if (!pj_thread_is_registered())
    {
        pj_thread_register("ipjsua", a_thread_desc, &a_thread);
   }    
    dereg();

}

解除注册方法如下:

void dereg()
{
    int i;
    for (i=0; i<(int)pjsua_acc_get_count(); ++i) {
        if (!pjsua_acc_is_valid(i))
             pjsua_buddy_del(i);

        pjsua_acc_set_registration(i, PJ_FALSE);
    }
}

当我们将应用程序推送到后台时，dereg 就会被调用。但是，当服务器发回 401 质询时，堆栈不会发回 SIP 调用中的身份验证详细信息，直到我将应用程序带回到前台。 有谁知道为什么会发生这种情况？

谢谢， 赫塔尔

Answer 1

您不想在后台线程中结束后台任务:

例如

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    [self deregis];        
    // don't do below...
    // [application endBackgroundTask: bgTask]; //End the task so the system knows that you are done with what you need to perform
    // bgTask = UIBackgroundTaskInvalid; //Invalidate the background_task
    NSLog(@"\n\nRunning in the background!\n\n");

});

您想要在注册更新时结束后台任务。因此，您需要 Hook pjsua on_reg_state 回调。

例如此示例可能仅假设一个帐户已注销，对于多个帐户，您必须等到所有帐户都已注销

-(void) regStateChanged: (bool)unregistered {
    if (unregistered && bgTask != UIBackgroundTaskInvalid) {
        [application endBackgroundTask: bgTask]; //End the task so the system knows that you are done with what you need to perform
        bgTask = UIBackgroundTaskInvalid; //Invalidate the background_task
    }
}