lgtv_audio_cap/native/src/main.c

// Entry point for the native Luna service.
//
// Nothing interesting happens here: register on the bus, hand control to the
// glib main loop, and make sure a SIGTERM from the service launcher shuts the
// capture down cleanly so sinks get to say goodbye (HyperHDR in particular
// needs its Clear, or the LEDs freeze on the last frame we sent).

#include "common/log.h"
#include "service.h"

#include <glib-unix.h>
#include <glib.h>
#include <luna-service2/lunaservice.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define SERVICE_NAME "org.webosbrew.audiocap.service"

// webOS 3.5 and earlier need the service registered on the public bus too.
// Declared weak so the same binary keeps loading on newer firmware where the
// symbol was removed.
extern bool LSRegisterPubPriv(const char* name, LSHandle** handle, bool public_bus,
    LSError* error) __attribute__((weak));

static gboolean on_signal(gpointer user)
{
    GMainLoop* loop = user;
    INFO("Signal received, shutting down");
    g_main_loop_quit(loop);
    return G_SOURCE_REMOVE;
}

static void log_environment(void)
{
    uid_t uid = getuid();
    INFO("lgtv-audio-cap service starting (uid=%d%s)", (int)uid,
        uid == 0 ? ", root" : ", unprivileged");
    if (uid != 0) {
        // Without root the PulseAudio socket and the ALSA devices are usually
        // out of reach, so say this once rather than leaving the user to
        // decode a permission error later.
        WARN("Not running as root: audio devices are likely inaccessible.");
        WARN("Install the Homebrew Channel 'elevate-service' patch and restart the service.");
    }
}

int main(int argc, char** argv)
{
    bool debug = false;
    for (int i = 1; i < argc; i++) {
        if (strcmp(argv[i], "-d") == 0 || strcmp(argv[i], "--debug") == 0)
            debug = true;
    }

    log_init(debug ? LOG_DEBUG : LOG_INFO);
    log_environment();

    // A client that hangs up mid-stream must not kill the service. Every send
    // path already asks for MSG_NOSIGNAL; this covers the rest.
    signal(SIGPIPE, SIG_IGN);

    GMainLoop* loop = g_main_loop_new(NULL, false);

    LSError lserror;
    LSErrorInit(&lserror);

    LSHandle* handle = NULL;
    bool registered = LSRegisterPubPriv
        ? LSRegisterPubPriv(SERVICE_NAME, &handle, true, &lserror)
        : LSRegister(SERVICE_NAME, &handle, &lserror);
    if (!registered) {
        ERR("Cannot register %s on the Luna bus: %s", SERVICE_NAME, lserror.message);
        LSErrorFree(&lserror);
        g_main_loop_unref(loop);
        return 1;
    }

    if (!LSGmainAttach(handle, loop, &lserror)) {
        ERR("Cannot attach to the main loop: %s", lserror.message);
        LSErrorFree(&lserror);
        LSUnregister(handle, &lserror);
        g_main_loop_unref(loop);
        return 1;
    }

    service_t* service = service_create(handle, loop);
    if (!service) {
        ERR("Cannot create the service");
        LSUnregister(handle, &lserror);
        g_main_loop_unref(loop);
        return 1;
    }

    char err[256] = { 0 };
    if (!service_register(service, err, sizeof(err))) {
        ERR("%s", err);
        service_destroy(service);
        LSUnregister(handle, &lserror);
        g_main_loop_unref(loop);
        return 1;
    }

    g_unix_signal_add(SIGTERM, on_signal, loop);
    g_unix_signal_add(SIGINT, on_signal, loop);

    INFO("Registered as %s", SERVICE_NAME);
    service_autostart(service);

    g_main_loop_run(loop);

    INFO("Shutting down");
    service_destroy(service);

    if (!LSUnregister(handle, &lserror)) {
        ERR("Unregister failed: %s", lserror.message);
        LSErrorFree(&lserror);
    }
    g_main_loop_unref(loop);
    return 0;
}