static VALUE
cont_capture(volatile int *stat)
{
    rb_context_t *cont;
    rb_thread_t *th = GET_THREAD();
    volatile VALUE contval;

    THREAD_MUST_BE_RUNNING(th);
    rb_vm_stack_to_heap(th);
    cont = cont_new(rb_cContinuation);
    contval = cont->self;

#ifdef CAPTURE_JUST_VALID_VM_STACK
    cont->vm_stack_slen = th->cfp->sp + th->mark_stack_len - th->stack;
    cont->vm_stack_clen = th->stack + th->stack_size - (VALUE*)th->cfp;
    cont->vm_stack = ALLOC_N(VALUE, cont->vm_stack_slen + cont->vm_stack_clen);
    MEMCPY(cont->vm_stack, th->stack, VALUE, cont->vm_stack_slen);
    MEMCPY(cont->vm_stack + cont->vm_stack_slen, (VALUE*)th->cfp, VALUE, cont->vm_stack_clen);
#else
    cont->vm_stack = ALLOC_N(VALUE, th->stack_size);
    MEMCPY(cont->vm_stack, th->stack, VALUE, th->stack_size);
#endif
    cont->saved_thread.stack = 0;

    cont_save_machine_stack(th, cont);

    /* backup ensure_list to array for search in another context */
    {
	rb_ensure_list_t *p;
	int size = 0;
	rb_ensure_entry_t *entry;
	for (p=th->ensure_list; p; p=p->next)
	    size++;
	entry = cont->ensure_array = ALLOC_N(rb_ensure_entry_t,size+1);
	for (p=th->ensure_list; p; p=p->next) {
	    if (!p->entry.marker)
		p->entry.marker = rb_ary_tmp_new(0); /* dummy object */
	    *entry++ = p->entry;
	}
	entry->marker = 0;
    }

    if (ruby_setjmp(cont->jmpbuf)) {
	volatile VALUE value;

	VAR_INITIALIZED(cont);
	value = cont->value;
	if (cont->argc == -1) rb_exc_raise(value);
	cont->value = Qnil;
	*stat = 1;
	return value;
    }
    else {
	*stat = 0;
	return contval;
    }
}

/*
 *  call-seq:
 *     narray.view => narray
 *
 *  Return view of NArray
 */
VALUE
na_make_view(VALUE self)
{
    int i, nd;
    size_t  j;
    size_t *idx1, *idx2;
    ssize_t stride;
    narray_t *na;
    narray_view_t *na1, *na2;
    volatile VALUE view;

    GetNArray(self,na);
    nd = na->ndim;

    view = na_s_allocate_view(CLASS_OF(self));

    na_copy_flags(self, view);
    GetNArrayView(view, na2);

    na_setup_shape((narray_t*)na2, nd, na->shape);
    na2->stridx = ALLOC_N(stridx_t,nd);

    switch(na->type) {
    case NARRAY_DATA_T:
    case NARRAY_FILEMAP_T:
        stride = na_get_elmsz(self);
        for (i=nd; i--;) {
            SDX_SET_STRIDE(na2->stridx[i],stride);
            stride *= na->shape[i];
        }
        na2->offset = 0;
        na2->data = self;
        break;
    case NARRAY_VIEW_T:
        GetNArrayView(self, na1);
        for (i=0; i<nd; i++) {
            if (SDX_IS_INDEX(na1->stridx[i])) {
                idx1 = SDX_GET_INDEX(na1->stridx[i]);
                idx2 = ALLOC_N(size_t,na1->base.shape[i]);
                for (j=0; j<na1->base.shape[i]; j++) {
                    idx2[j] = idx1[j];
                }
                SDX_SET_INDEX(na2->stridx[i],idx2);
            } else {
                na2->stridx[i] = na1->stridx[i];
            }
        }
        na2->offset = na1->offset;
        na2->data = na1->data;
        break;
    }

    return view;
}

void redtree_init_struct(struct redtree* tree) {
  tree->tokens = ALLOC_N(redtree_token, INITIAL_TOKEN_COUNT);
  tree->token_locations = ALLOC_N(struct token_location, INITIAL_TOKEN_COUNT);
  tree->token_size = INITIAL_TOKEN_COUNT;
  tree->token_count = 0;
  tree->sequence = ALLOC_N(redtree_sequence_entry, INITIAL_SEQUENCE_COUNT);
  tree->sequence_size = INITIAL_SEQUENCE_COUNT;
  tree->sequence_count = 0;
  tree->lines = ALLOC_N(VALUE, INITIAL_LINE_COUNT);
  tree->line_size = INITIAL_LINE_COUNT;
  tree->line_count = 0;
  tree->enc = 0;
}

static void
cont_save_machine_stack(rb_thread_t *th, rb_context_t *cont)
{
    size_t size;
    rb_thread_t *sth = &cont->saved_thread;

    SET_MACHINE_STACK_END(&th->machine_stack_end);
#ifdef __ia64
    th->machine_register_stack_end = rb_ia64_bsp();
#endif

    if (th->machine_stack_start > th->machine_stack_end) {
	size = cont->machine_stack_size = th->machine_stack_start - th->machine_stack_end;
	cont->machine_stack_src = th->machine_stack_end;
    }
    else {
	size = cont->machine_stack_size = th->machine_stack_end - th->machine_stack_start;
	cont->machine_stack_src = th->machine_stack_start;
    }

    if (cont->machine_stack) {
	REALLOC_N(cont->machine_stack, VALUE, size);
    }
    else {
	cont->machine_stack = ALLOC_N(VALUE, size);
    }

    FLUSH_REGISTER_WINDOWS;
    MEMCPY(cont->machine_stack, cont->machine_stack_src, VALUE, size);

#ifdef __ia64
    rb_ia64_flushrs();
    size = cont->machine_register_stack_size = th->machine_register_stack_end - th->machine_register_stack_start;
    cont->machine_register_stack_src = th->machine_register_stack_start;
    if (cont->machine_register_stack) {
	REALLOC_N(cont->machine_register_stack, VALUE, size);
    }
    else {
	cont->machine_register_stack = ALLOC_N(VALUE, size);
    }

    MEMCPY(cont->machine_register_stack, cont->machine_register_stack_src, VALUE, size);
#endif

    sth->machine_stack_start = sth->machine_stack_end = 0;
#ifdef __ia64
    sth->machine_register_stack_start = sth->machine_register_stack_end = 0;
#endif
}

/*
 *  call-seq:
 *     narray.expand_dims(dim) => narray view
 *
 *  Expand the shape of an array. Insert a new axis with size=1
 *  at a given dimension.
 *  @param [Integer] dim  dimension at which new axis is inserted.
 *  @return [Numo::NArray]  result narray view.
 */
VALUE
na_expand_dims(VALUE self, VALUE vdim)
{
    int  i, j, nd, dim;
    size_t *shape, *na_shape;
    stridx_t *stridx, *na_stridx;
    narray_t *na;
    narray_view_t *na2;
    VALUE view;

    GetNArray(self,na);
    nd = na->ndim;

    dim = NUM2INT(vdim);
    if (dim < -nd-1 || dim > nd) {
        rb_raise(nary_eDimensionError,"invalid axis (%d for %dD NArray)",
                 dim,nd);
    }
    if (dim < 0) {
        dim += nd+1;
    }

    view = na_make_view(self);
    GetNArrayView(view, na2);

    shape = ALLOC_N(size_t,nd+1);
    stridx = ALLOC_N(stridx_t,nd+1);
    na_shape = na2->base.shape;
    na_stridx = na2->stridx;

    for (i=j=0; i<=nd; i++) {
        if (i==dim) {
            shape[i] = 1;
            SDX_SET_STRIDE(stridx[i],0);
        } else {
            shape[i] = na_shape[j];
            stridx[i] = na_stridx[j];
            j++;
        }
    }

    na2->stridx = stridx;
    xfree(na_stridx);
    na2->base.shape = shape;
    xfree(na_shape);
    na2->base.ndim++;
    return view;
}

sp_error
sp_session_create(const sp_session_config *config, sp_session * *sess)
{
  sp_session *session;

  if (memcmp(config->application_key, "appkey_good", config->application_key_size))
      return SP_ERROR_BAD_APPLICATION_KEY;

  session = *sess = ALLOC(sp_session);

  session->config.api_version       = config->api_version;
  session->config.cache_location    = strclone(config->cache_location);
  session->config.settings_location = strclone(config->settings_location);
  session->config.user_agent        = strclone(config->user_agent);
  session->config.callbacks         = ALLOC(sp_session_callbacks);
  session->config.userdata          = config->userdata;

  session->config.application_key   = ALLOC_N(byte, config->application_key_size);
  memcpy((char *) session->config.application_key, config->application_key, config->application_key_size);

  if (config->callbacks)
  {
    MEMCPY((sp_session_callbacks *) session->config.callbacks, config->callbacks, sp_session_callbacks);
  }

  // sp_session defaults
  session->cache_size = 0;

  // TODO: v0.0.8 (and earlier) directly call `notify_main_thread` callback here, before returning
  if (config->callbacks && config->callbacks->notify_main_thread)
    config->callbacks->notify_main_thread(session);

  return SP_ERROR_OK;
}

/* Construct a finite automaton from REGEXP and return it in *FA.
 *
 * Return NULL if REGEXP is valid, if the regexp REGEXP has syntax errors,
 * return an exception.
 */
static struct value *str_to_fa(struct info *info, const char *pattern,
                               struct fa **fa) {
    int error;
    struct value *exn = NULL;
    size_t re_err_len;
    char *re_str, *re_err;

    error = fa_compile(pattern, strlen(pattern), fa);
    if (error == REG_NOERROR)
        return NULL;

    re_str = escape(pattern, -1);
    if (re_str == NULL) {
        FIXME("Out of memory");
    }
    exn = make_exn_value(info, "Invalid regular expression /%s/", re_str);

    re_err_len = regerror(error, NULL, NULL, 0);
    if (ALLOC_N(re_err, re_err_len) < 0) {
        FIXME("Out of memory");
    }
    regerror(error, NULL, re_err, re_err_len);
    exn_printf_line(exn, "%s", re_err);

    free(re_str);
    free(re_err);
    return exn;
}

static VALUE grpc_rb_hash_convert_to_channel_args0(VALUE as_value) {
  ID id_size = rb_intern("size");
  VALUE grpc_rb_cChannelArgs = rb_define_class("TmpChannelArgs", rb_cObject);
  channel_convert_params* params = (channel_convert_params*)as_value;
  size_t num_args = 0;

  if (!NIL_P(params->src_hash) && TYPE(params->src_hash) != T_HASH) {
    rb_raise(rb_eTypeError, "bad channel args: got:<%s> want: a hash or nil",
             rb_obj_classname(params->src_hash));
    return Qnil;
  }

  if (TYPE(params->src_hash) == T_HASH) {
    num_args = NUM2INT(rb_funcall(params->src_hash, id_size, 0));
    params->dst->num_args = num_args;
    params->dst->args = ALLOC_N(grpc_arg, num_args);
    MEMZERO(params->dst->args, grpc_arg, num_args);
    rb_hash_foreach(params->src_hash,
                    grpc_rb_channel_create_in_process_add_args_hash_cb,
                    Data_Wrap_Struct(grpc_rb_cChannelArgs, GC_NOT_MARKED,
                                     GC_DONT_FREE, params->dst));
    /* reset num_args as grpc_rb_channel_create_in_process_add_args_hash_cb
     * decrements it during has processing */
    params->dst->num_args = num_args;
  }
  return Qnil;
}

static rb_thread_t *
thread_recycle_struct(void)
{
    void *p = ALLOC_N(rb_thread_t, 1);
    memset(p, 0, sizeof(rb_thread_t));
    return p;
}

static VALUE Buffer_alloc(VALUE klass)
{
    msgpack_buffer_t* b = ALLOC_N(msgpack_buffer_t, 1);
    msgpack_buffer_init(b);

    return Data_Wrap_Struct(klass, msgpack_buffer_mark, Buffer_free, b);
}

static void
na_parse_narray_index(VALUE a, int orig_dim, ssize_t size, na_index_arg_t *q)
{
    VALUE idx;
    narray_t *na;
    narray_data_t *nidx;
    size_t k, n;
    ssize_t *nidxp;

    GetNArray(a,na);
    if (NA_NDIM(na) != 1) {
        rb_raise(rb_eIndexError, "should be 1-d NArray");
    }
    n = NA_SIZE(na);
    idx = nary_new(cIndex,1,&n);
    na_store(idx,a);

    GetNArrayData(idx,nidx);
    nidxp   = (ssize_t*)nidx->ptr;
    q->idx  = ALLOC_N(size_t, n);
    for (k=0; k<n; k++) {
        q->idx[k] = na_range_check(nidxp[k], size, orig_dim);
    }
    q->n    = n;
    q->beg  = 0;
    q->step = 1;
    q->reduce = 0;
    q->orig_dim = orig_dim;
}

static char *get_home_dir(uid_t uid) {
    char *strbuf;
    char *result;
    struct passwd pwbuf;
    struct passwd *pw = NULL;
    long val = sysconf(_SC_GETPW_R_SIZE_MAX);
    size_t strbuflen = val;

    if (val < 0)
        return NULL;

    if (ALLOC_N(strbuf, strbuflen) < 0)
        return NULL;

    if (getpwuid_r(uid, &pwbuf, strbuf, strbuflen, &pw) != 0 || pw == NULL) {
        free(strbuf);
        return NULL;
    }

    result = strdup(pw->pw_dir);

    free(strbuf);

    return result;
}

static VALUE
cont_capture(volatile int *stat)
{
    rb_context_t *cont;
    rb_thread_t *th = GET_THREAD(), *sth;
    volatile VALUE contval;

    vm_stack_to_heap(th);
    cont = cont_new(rb_cContinuation);
    contval = cont->self;
    sth = &cont->saved_thread;

    cont->vm_stack = ALLOC_N(VALUE, th->stack_size);
    MEMCPY(cont->vm_stack, th->stack, VALUE, th->stack_size);
    sth->stack = 0;

    cont_save_machine_stack(th, cont);

    if (ruby_setjmp(cont->jmpbuf)) {
	VALUE value;

	value = cont->value;
	cont->value = Qnil;
	*stat = 1;
	return value;
    }
    else {
	*stat = 0;
	return cont->self;
    }
}

VALUE Ashton_PixelCache_init(VALUE self, VALUE owner)
{
    PIXEL_CACHE();

    pixel_cache->rb_owner = owner;

    // Different behaviour depending on what the owning class is.
    if(RTEST(rb_obj_is_kind_of(owner, rb_cTexture)))
    {
        // Ashton::Texture
        pixel_cache->texture_id = NUM2UINT(rb_funcall(owner, rb_intern("id"), 0));
    }
    else if(RTEST(rb_obj_is_kind_of(owner, rb_cImage)))
    {
        // Gosu::Image
        // TODO: this needs to be done completely differently, since the image is a sprite on a texture, 1024x1024.
        VALUE tex_info = rb_funcall(owner, rb_intern("gl_tex_info"), 0);
        pixel_cache->texture_id = NUM2UINT(rb_funcall(tex_info, rb_intern("tex_name"), 0));
    }
    else
    {
        rb_raise(rb_eTypeError, "Can only cache Gosu::Image or Ashton::Texture objects.");
    }

    pixel_cache->width = NUM2UINT(rb_funcall(owner, rb_intern("width"), 0));
    pixel_cache->height = NUM2UINT(rb_funcall(owner, rb_intern("height"), 0));
    pixel_cache->data = ALLOC_N(Color_i, pixel_cache->width * pixel_cache->height);
    cache_texture(pixel_cache);

    return Qnil;
}

static VALUE
ifact_create_items(VALUE self, VALUE ary)
{
    VALUE entry, path, accel, type, func, data, extdata;
    GtkItemFactoryEntry *entries;
    guint i, len, n_menu_entries;

    n_menu_entries = RARRAY_LEN(ary);
    entries = ALLOC_N(GtkItemFactoryEntry, n_menu_entries);

    for (i = 0; i < n_menu_entries; i++) {
        entry = RARRAY_PTR(ary)[i];
        len = RARRAY_LEN(entry);
        Check_Type(entry, T_ARRAY);
        path =  RARRAY_PTR(entry)[0];
        type =  ((len > 1) ? RARRAY_PTR(entry)[1] : Qnil);
        accel = ((len > 2) ? RARRAY_PTR(entry)[2] : Qnil);
        extdata = ((len > 3) ? RARRAY_PTR(entry)[3] : Qnil);
        func =  ((len > 4) ? RARRAY_PTR(entry)[4] : Qnil);
        data =  ((len > 5) ? RARRAY_PTR(entry)[5] : Qnil);

        create_factory_entry(&entries[i], self, path, type, accel, extdata, func, data);
    }

    gtk_item_factory_create_items (_SELF(self), n_menu_entries, entries, NULL);
    g_free(entries);

    return self;
}

static VALUE
pp_leds_allocate( VALUE klass )
{
  int ii;
  ws2811_t *ledstring;

  ledstring = ALLOC_N( ws2811_t, 1 );
  if (!ledstring) {
    rb_raise(rb_eNoMemError, "could not allocate PixelPi::Leds instance");
  }

  ledstring->freq   = WS2811_TARGET_FREQ;
  ledstring->dmanum = 5;
  ledstring->device = NULL;

  for (ii=0; ii<RPI_PWM_CHANNELS; ii++) {
    ledstring->channel[ii].gpionum    = 0;
    ledstring->channel[ii].count      = 0;
    ledstring->channel[ii].invert     = 0;
    ledstring->channel[ii].brightness = 255;
    ledstring->channel[ii].leds       = NULL;
  }

  return Data_Wrap_Struct( klass, NULL, pp_leds_free, ledstring );
}

static sp_error
sp_mock_playlistcontainer_insert(sp_playlistcontainer *pc, int index, sp_playlistcontainer_playlist_t playlist)
{
  sp_playlistcontainer_playlist_t *new_playlists;
  int num_playlists = sp_playlistcontainer_num_playlists(pc);
  int new_num_playlists = num_playlists + 1;
  int i, j;

  if (index > num_playlists || index < 0)
  {
    return SP_ERROR_INDEX_OUT_OF_RANGE;
  }

  new_playlists = ALLOC_N(sp_playlistcontainer_playlist_t, new_num_playlists);
  for (i = 0, j = 0; i < new_num_playlists; i++)
  {
    if (i == index)
    {
      MEMCPY(&new_playlists[i], &playlist, sp_playlistcontainer_playlist_t);
    }
    else
    {
      MEMCPY(&new_playlists[i], &pc->playlists[j++], sp_playlistcontainer_playlist_t);
    }
  }

  free(pc->playlists);
  pc->playlists = new_playlists;
  pc->num_playlists = new_num_playlists;

  return SP_ERROR_OK;
}

sp_error
sp_playlistcontainer_remove_playlist(sp_playlistcontainer *pc, int index)
{
  sp_playlistcontainer_playlist_t *new_playlists;
  int num_playlists = sp_playlistcontainer_num_playlists(pc);
  int new_num_playlists = num_playlists - 1;
  int i, j;

  if (index >= num_playlists || index < 0)
  {
    return SP_ERROR_INDEX_OUT_OF_RANGE;
  }

  new_playlists = ALLOC_N(sp_playlistcontainer_playlist_t, new_num_playlists);
  for (i = 0, j = 0; i < num_playlists; ++i)
  {
    if (i != index)
    {
      MEMCPY(&new_playlists[j++], &pc->playlists[i], sp_playlistcontainer_playlist_t);
    }
  }

  free(pc->playlists);
  pc->playlists = new_playlists;
  pc->num_playlists = new_num_playlists;

  return SP_ERROR_OK;
}

static void rf_extend_if_necessary(RAMFile *rf, int buf_num)
{
    while (rf->bufcnt <= buf_num) {
        REALLOC_N(rf->buffers, uchar *, (rf->bufcnt + 1));
        rf->buffers[rf->bufcnt++] = ALLOC_N(uchar, BUFFER_SIZE);
    }
}

static int run_args(int argc, char **argv) {
    size_t len = 0;
    char *line = NULL;
    int   code;

    for (int i=0; i < argc; i++)
        len += strlen(argv[i]) + 1;
    if (ALLOC_N(line, len + 1) < 0)
        return -1;
    for (int i=0; i < argc; i++) {
        strcat(line, argv[i]);
        strcat(line, " ");
    }
    if (echo_commands)
        printf("%s%s\n", AUGTOOL_PROMPT, line);
    code = run_command(line);
    free(line);
    if (code >= 0 && auto_save)
        if (echo_commands)
            printf("%ssave\n", AUGTOOL_PROMPT);
        code = run_command("save");

    if (code < 0) {
        code = -1;
        print_aug_error();
    }
    return (code >= 0 || code == -2) ? 0 : -1;
}