#include "moar.h"

/* This representation's function pointer table. */
static const MVMREPROps MVMThread_this_repr;

/* Creates a new type object of this representation, and associates it with
 * the given HOW. */
static MVMObject * type_object_for(MVMThreadContext *tc, MVMObject *HOW) {
    MVMSTable *st  = MVM_gc_allocate_stable(tc, &MVMThread_this_repr, HOW);

    MVMROOT(tc, st, {
        MVMObject *obj = MVM_gc_allocate_type_object(tc, st);
        MVM_ASSIGN_REF(tc, &(st->header), st->WHAT, obj);
        st->size = sizeof(MVMThread);
    });

    return st->WHAT;
}

/* Copies the body of one object to another. */
static void copy_to(MVMThreadContext *tc, MVMSTable *st, void *src, MVMObject *dest_root, void *dest) {
    MVM_exception_throw_adhoc(tc, "Cannot copy object with representation MVMThread");
}

/* Adds held objects to the GC worklist. */
static void gc_mark(MVMThreadContext *tc, MVMSTable *st, void *data, MVMGCWorklist *worklist) {
    MVMThreadBody *body = (MVMThreadBody *)data;
    MVM_gc_worklist_add(tc, worklist, &body->invokee);
    MVM_gc_worklist_add(tc, worklist, &body->next);

    /* Unstarted threads are not yet in the running threads list, so their TC
     * needs marking here. The rest of the time, it's marked due to being in
     * the running threads list. */
    if (MVM_load(&(body->stage)) == MVM_thread_stage_unstarted)
        MVM_gc_root_add_tc_roots_to_worklist(body->tc, worklist, NULL);
}

/* Called by the VM in order to free memory associated with this object. */
static void gc_free(MVMThreadContext *tc, MVMObject *obj) {
    /* The ThreadContext has already been destroyed by the GC. */
    MVMThread *thread = (MVMThread *)obj;
    thread->body.invokee = NULL;
}

static const MVMStorageSpec storage_spec = {
    MVM_STORAGE_SPEC_REFERENCE, /* inlineable */
    0,                          /* bits */
    0,                          /* align */
    MVM_STORAGE_SPEC_BP_NONE,   /* boxed_primitive */
    0,                          /* can_box */
    0,                          /* is_unsigned */
};


/* Gets the storage specification for this representation. */
static const MVMStorageSpec * get_storage_spec(MVMThreadContext *tc, MVMSTable *st) {
    return &storage_spec;
}

/* Compose the representation. */
static void compose(MVMThreadContext *tc, MVMSTable *st, MVMObject *info) {
    /* Nothing to do for this REPR. */
}

/* Initializes the representation. */
const MVMREPROps * MVMThread_initialize(MVMThreadContext *tc) {
    return &MVMThread_this_repr;
}

static const MVMREPROps MVMThread_this_repr = {
    type_object_for,
    MVM_gc_allocate_object,
    NULL, /* initialize */
    copy_to,
    MVM_REPR_DEFAULT_ATTR_FUNCS,
    MVM_REPR_DEFAULT_BOX_FUNCS,
    MVM_REPR_DEFAULT_POS_FUNCS,
    MVM_REPR_DEFAULT_ASS_FUNCS,
    MVM_REPR_DEFAULT_ELEMS,
    get_storage_spec,
    NULL, /* change_type */
    NULL, /* serialize */
    NULL, /* deserialize */
    NULL, /* serialize_repr_data */
    NULL, /* deserialize_repr_data */
    NULL, /* deserialize_stable_size */
    gc_mark,
    gc_free,
    NULL, /* gc_cleanup */
    NULL, /* gc_mark_repr_data */
    NULL, /* gc_free_repr_data */
    compose,
    NULL, /* spesh */
    "VMThread", /* name */
    MVM_REPR_ID_MVMThread,
    NULL, /* unmanaged_size */
    NULL, /* describe_refs */
};