GtK+3.0多线程应用

Question

这是我的问题：我正在开发一个由以下组成的多线程应用程序：

GUI 线程-> GTK
帮助线程 --> 检查与 JACK 服务器的连接
jack 的 RT 线程 --> 做一些声音阐述的东西

我已经实现了一个按钮小部件，它只接收来自助手和 RT 线程的信号，在其回调函数中修改 gui。

所以，我的问题是：谁在修改 GUI？我使用 gtk_main() ?

的 helper/RT 线程或 gui 线程

感谢您的配合！

编辑：我添加了代码 /** @file JPLowPassFilter.c * * @brief 这是一个实现数字低频通过滤波器的简单客户端 */

#include "JPLowPassFilter.h" 
jack_port_t *input_port;
jack_port_t *output_port;

jack_default_audio_sample_t tmp;
int first=1;
appData* mainData;
jack_default_audio_sample_t tmp;

/*Code for port_registration_callback */
void registrationPort(jack_port_id_t port, int reg, void *arg)
{
    return;
}

/*Code for client_registration_callback */
void registrationClient(const char* name, int reg, void *arg)
{
    return;

}
/**
 * The process callback for this JACK application is called in a
 * special realtime thread once for each audio cycle.
 * Must not block!
 */
int process (jack_nframes_t nframes, void *arg)
{ 
    int i;
    float alfa=mainData->alfa;
    jack_default_audio_sample_t *in, *out;
    in = jack_port_get_buffer (input_port, nframes);
    out = jack_port_get_buffer (output_port, nframes);
    for( i=0; i<nframes; i++) {
        if(first==1){
            tmp=in[i];
            first=0;
        }
        else{
            tmp=tmp*alfa+(1.0f-alfa)*in[i];
            //tmp=tmp*(1.0f-alfa)+alfa*in[i];
        }
        out[i]=tmp;
    }
    //fprintf (stderr, ".");
    return 0;      
}

/**
 * JACK calls this shutdow_callback if the server ever shuts down or
 * decides to disconnect the client
 */
void jack_shutdown (void *arg)
{ 
    mainData->state=NOT_WORKING;
    jack_port_unregister(mainData->client,input_port);
    jack_port_unregister(mainData->client, output_port);    
    g_signal_emit_by_name (GTK_BUTTON(mainData->init),"clicked");
}

/* JACK calls this function whenever there is an xrun */
int xrun_function(void *arg)
{
    fprintf (stderr, "--XRUN OCCURRED--\n");    
}

void* threadCode(void* val)
{
    const char *client_name = CLIENT_NAME;
    const char *server_name = NULL;
    mainData=(appData*) val;
    /* if server isn't present, don't start it!*/ 
    jack_options_t options =JackNoStartServer; 
    jack_status_t status;
    do{
        /* try to open a client connection to the JACK server */
        mainData->client = jack_client_open (client_name, options, &status, server_name);
        if (mainData->client == NULL) 
        {
            fprintf (stderr, "jack_client_open() failed, "
                 "status = 0x%2.0x\n", status);
            if (status & JackServerFailed) {
                fprintf (stderr, "Unable to connect to JACK server\n");
            }
            sleep(3);
        }
        else
        {
            fprintf (stderr, "Connected to JACK server\n");
            mainData->state=INIT;
            /*  CALLBACKS*/
            jack_set_process_callback (mainData->client, process, 0);
            jack_on_shutdown (mainData->client, jack_shutdown, mainData);
            jack_set_xrun_callback(mainData->client,xrun_function, 0);  
            jack_set_port_registration_callback (mainData->client, registrationPort,NULL);
            jack_set_client_registration_callback(mainData->client, registrationClient,NULL);

            /* PORTS */
            input_port = jack_port_register (mainData->client, "input", JACK_DEFAULT_AUDIO_TYPE,JackPortIsInput, 0);
            output_port = jack_port_register (mainData->client, "output", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0);
            mainData->state=INIT;
            if ((input_port == NULL) || (output_port == NULL)) 
            {
                fprintf(stderr, "no more JACK ports available\n");
                mainData->state=NOT_WORKING;
            }
            /* STARTS */
            else if (jack_activate (mainData->client)) {
                fprintf (stderr, "cannot activate client");
                jack_port_unregister(mainData->client,input_port);
                jack_port_unregister(mainData->client, output_port); 
                mainData->state=NOT_WORKING; 
            }
            else  
            {
                fprintf (stderr, "Client ready to Run\n");
                mainData->state=WORKING;
                mainData->portsName[0]=jack_port_name(input_port);
                mainData->portsName[1]=jack_port_name(output_port);
            }
             //can be written to
                        mainData->inputList=jack_get_ports(mainData->client,NULL, NULL,JackPortIsInput);
                        //can be read from
            mainData->outputList=jack_get_ports(mainData->client,NULL, NULL,JackPortIsOutput);
            g_signal_emit_by_name (GTK_BUTTON(mainData->init),"clicked");
            while(mainData->state==WORKING)
            {
                sleep(5);
                fprintf (stderr, ".");
            }
            fprintf (stderr, "\n");
                jack_free(mainData->inputList);
            jack_free(mainData->outputList);
            mainData->outputList=NULL;
            mainData->inputList=NULL;
            jack_client_close (mainData->client);       
        }
        fprintf (stderr, "---RECONNECT---\n");
    }while(mainData->state==NOT_WORKING);
    fprintf (stderr, "Ended!\n");

    pthread_exit(NULL);
}

Answer 1

根据评论，建议将 g_signal_emit_by_name 函数替换为 g_async_queue_* 函数。

假设 mainData->init 指向在主线程中创建的 GAsyncQueue 而不是实际按钮。

然后你可以在你的线程上使用：

g_async_queue_push(G_ASYNC_QUEUE(mainData->init), data);

数据可以包含一个简单的标志来指示状态and/or状态变化

然后在您的主线程上，当您设置 UI 时，您可以添加空闲处理程序：

my_queue = g_async_queue_new();
...
g_idle_add ((GSourceFunc) check_async_queue, my_queue);

你的 check_async_queue 可能是这样的：

gboolean check_async_queue (gpointer user_data) {
   gpointer queue_data;

   queue_data = g_async_queue_try_pop (G_ASYNC_QUEUE(user_data));

   if (queue_data != NULL) {
      // We have data, do something with 'queue_data'
      // and update GUI

   } else {
      // no data, probably do nothing

   }

   return TRUE; // can be G_SOURCE_CONTINUE instead of TRUE
}

return值将指示check_async_queue函数是否应保留运行，因此您可以有条件删除该函数。

这将允许您拥有一个简单的单向消息队列，您可以使用它来将信息从工作线程传递到主线程。

GtK+3.0多线程应用

GtK+3.0 multithreaded application

c

jack

gtk3