Socket sigio usage

Mbed OS
,
1

Board: NUCLEO-H743ZI2.

I want to use sigio for tracking TCPSocket state by nsapi_error codes.

I’m not familiar with sigio and how to use it with mbed.
I read #3620 and #11025.

I try to do someting like this:

Code 
#include "mbed.h"
#include "EthernetInterface.h"
#include "nsapi_types.h"

static constexpr char IP_ADDR[] = "192.168.088.254";
static constexpr uint16_t PORT = 3333;

EthernetInterface net;
SocketAddress a;
TCPSocket socket;
nsapi_size_or_error_t socket_response;
Mutex print_mutex;
char socket_buffer[250] = {};

void safe_print(const char *msg /*format*/, ...);
void status_callback(nsapi_event_t status, intptr_t param);
void tcp_handler();

int main()
{
    nsapi_error_t socket_connect, socket_open;

    socket.sigio(&tcp_handler);

    net.add_event_listener(&status_callback);
    safe_print("connecting...\r\n");
    net.connect();
    safe_print("Connecting started...\r\n");
    net.get_ip_address(&a);
    printf("IP address: %s\n", a.get_ip_address() ? a.get_ip_address() : "None");
    socket_open = socket.open(&net);
    safe_print("socket_open: %d\n",socket_open);
    net.gethostbyname(IP_ADDR, &a);
    a.set_port(PORT);
    socket_connect = socket.connect(a);
    safe_print("socket_connect: %d\n\r", socket_connect);

    while(true)
    {

    }

    socket.close();
    net.disconnect();
    return 0;
}

void safe_print(const char *msg /*format*/, ...)
{
    print_mutex.lock();
    printf(msg);
    print_mutex.unlock();
}

void status_callback(nsapi_event_t status, intptr_t param)
{
    safe_print("Connection status changed!\r\n");
    switch (param) {
        case NSAPI_STATUS_LOCAL_UP:
            safe_print("Local IP address set!\r\n");
            break;
        case NSAPI_STATUS_GLOBAL_UP:
            safe_print("Global IP address set!\r\n");
            break;
        case NSAPI_STATUS_DISCONNECTED:
            safe_print("No connection to network!\r\n");
            break;
        case NSAPI_STATUS_CONNECTING:
            safe_print("Connecting to network!\r\n");
            break;
        default:
            safe_print("Not supported\r\n");
            break;
    }
}

void tcp_handler()
{
    printf("sigio called\n");
    socket_response = socket.recv(socket_buffer, sizeof socket_buffer);
    printf("%d\n",socket_response);
    if (socket_response == NSAPI_ERROR_WOULD_BLOCK) {
        safe_print("Would_Block\n\r");
    } else if (socket_response < 0) {
        safe_print("%d\n\r", socket_response);
    } else if (socket_response == 0) {
        safe_print("=0\n\r");
    }
}

tcp_handler called after socket_open and then all freezes.
Here my serial output:

connecting...
Connection status changed!
Connecting to network!
Connection status changed!
Global IP address set!
Connecting started...
IP address: 192.168.88.253
socket_open: 0
sigio called

Can anyone explain me how to use sigio correctly? Or using sigio in my case is wrong?

2

have you made some progress? I’ve just read the mentioned issues. It is recommended to use an EventQueue because sigio() maybe called in interrupt context and the printf() or other functions will make problems.