tutorial3.c

Tutorial - Part 3: Forcing a roundtrip

/*
  [title]
  \ref page_tutorial3
  [title]
 */
/* [code] */
#include <pipewire/pipewire.h>
 
/* [roundtrip] */
static int roundtrip(struct pw_core *core, struct pw_main_loop *loop)
{
        struct spa_hook core_listener;
        int pending, done = 0;
        void core_event_done(void *object, uint32_t id, int seq) {
                if (id == PW_ID_CORE && seq == pending) {
                        done = 1;
                        pw_main_loop_quit(loop);
                }
        }
        const struct pw_core_events core_events = {
                PW_VERSION_CORE_EVENTS,
                .done = core_event_done,
        };
 
        spa_zero(core_listener);
        pw_core_add_listener(core, &core_listener,
                                 &core_events, NULL);
 
        pending = pw_core_sync(core, PW_ID_CORE, 0);
 
        while (!done) {
                pw_main_loop_run(loop);
        }
        spa_hook_remove(&core_listener);
        return 0;
}
/* [roundtrip] */
 
static void registry_event_global(void *data, uint32_t id,
                uint32_t permissions, const char *type, uint32_t version,
                const struct spa_dict *props)
{
        printf("object: id:%u type:%s/%d\n", id, type, version);
}
 
static const struct pw_registry_events registry_events = {
        PW_VERSION_REGISTRY_EVENTS,
        .global = registry_event_global,
};
 
int main(int argc, char *argv[])
{
        struct pw_main_loop *loop;
        struct pw_context *context;
        struct pw_core *core;
        struct pw_registry *registry;
        struct spa_hook registry_listener;
 
        pw_init(&argc, &argv);
 
        loop = pw_main_loop_new(NULL /* properties */);
        context = pw_context_new(pw_main_loop_get_loop(loop),
                        NULL /* properties */,
                        0 /* user_data size */);
 
        core = pw_context_connect(context,
                        NULL /* properties */,
                        0 /* user_data size */);
 
        registry = pw_core_get_registry(core, PW_VERSION_REGISTRY,
                        0 /* user_data size */);
 
        spa_zero(registry_listener);
        pw_registry_add_listener(registry, &registry_listener,
                                       &registry_events, NULL);
 
        roundtrip(core, loop);
 
        pw_proxy_destroy((struct pw_proxy*)registry);
        pw_core_disconnect(core);
        pw_context_destroy(context);
        pw_main_loop_destroy(loop);
 
        return 0;
}
/* [code] */