Esempio n. 1
0
static BIF_RETTYPE append(Process* p, Eterm A, Eterm B)
{
    Eterm list;
    Eterm copy;
    Eterm last;
    size_t need;
    Eterm* hp;
    int i;

    //  列表长度小于0
    if ((i = erts_list_length(A)) < 0) {
      BIF_ERROR(p, BADARG);
    }
    if (i == 0) {
	    BIF_RET(B);
    } else if (is_nil(B)) {
	    BIF_RET(A);
    }
    // 先分配 2 * i个大小
    need = 2*i;
    hp = HAlloc(p, need);
    list = A;
    /*
    #define CONS(hp, car, cdr) \
            (CAR(hp)=(car), CDR(hp)=(cdr), make_list(hp))

    #define CAR(x)  ((x)[0])
    #define CDR(x)  ((x)[1])
    */
    /*
      hp[0] = list[0];
      hp[1] = (hp[2] + TAG_PRIMARY_LIST);
      copy = last = (hp + TAG_PRIMARY_LIST);
      list = list[1];
    */
    copy = last = CONS(hp, CAR(list_val(list)), make_list(hp+2));
    list = CDR(list_val(list));
    hp += 2;
    i--;
    // 将A的元素全部都复制一遍
    while(i--) {
	    Eterm* listp = list_val(list);
	    last = CONS(hp, CAR(listp), make_list(hp+2));
	    list = CDR(listp);
	    hp += 2;
    }
    // 将复制后的一个元素直接指向B
    CDR(list_val(last)) = B;
    BIF_RET(copy);
}
Esempio n. 2
0
static void shrink(Process *p, Eterm* ret) 
{
    unsigned int range = HASH_RANGE(p->dictionary);
    unsigned int steps = (range*3) / 10;
    Eterm hi, lo, tmp;
    unsigned int i;
    Eterm *hp;
#ifdef DEBUG
    Eterm *hp_limit;
#endif

    if (range - steps < INITIAL_SIZE) {
	steps = range - INITIAL_SIZE; 
    }

    for (i = 0; i < steps; ++i) {
	ProcDict *pd = p->dictionary;
	if (pd->splitPosition == 0) {
	    pd->homeSize /= 2;
	    pd->splitPosition = pd->homeSize;
	}
	--(pd->splitPosition);
	hi = ARRAY_GET(pd, (pd->splitPosition + pd->homeSize));
	lo = ARRAY_GET(pd, pd->splitPosition);
	if (hi != NIL) {
	    if (lo == NIL) {
		array_put(&(p->dictionary), pd->splitPosition, hi);
	    } else {
		int needed = 4;
		if (is_list(hi) && is_list(lo)) {
		    needed = 2*erts_list_length(hi);
		}
		if (HeapWordsLeft(p) < needed) {
		    BUMP_REDS(p, erts_garbage_collect(p, needed, ret, 1));
		    hi = pd->data[(pd->splitPosition + pd->homeSize)];
		    lo = pd->data[pd->splitPosition];
		}
#ifdef DEBUG
		hp_limit = p->htop + needed;
#endif
		if (is_tuple(lo)) {
		    if (is_tuple(hi)) {
			hp = HeapOnlyAlloc(p, 4);
			tmp = CONS(hp, hi, NIL);
			hp += 2;
			array_put(&(p->dictionary), pd->splitPosition, 
				  CONS(hp,lo,tmp));
			hp += 2;
			ASSERT(hp <= hp_limit);
		    } else { /* hi is a list */
			hp = HeapOnlyAlloc(p, 2);
			array_put(&(p->dictionary), pd->splitPosition, 
				  CONS(hp, lo, hi));
			hp += 2;
			ASSERT(hp <= hp_limit);
		    }
		} else { /* lo is a list */
		    if (is_tuple(hi)) {
			hp = HeapOnlyAlloc(p, 2);
			array_put(&(p->dictionary), pd->splitPosition, 
				  CONS(hp, hi, lo));
			hp += 2;
			ASSERT(hp <= hp_limit);

		    } else { /* Two lists */
			hp = HeapOnlyAlloc(p, needed);
			for (tmp = hi; tmp != NIL; tmp = TCDR(tmp)) {
			    lo = CONS(hp, TCAR(tmp), lo);
			    hp += 2;
			}
			ASSERT(hp <= hp_limit);
			array_put(&(p->dictionary), pd->splitPosition, lo);
		    }
		}
	    }
	}
	array_put(&(p->dictionary), (pd->splitPosition + pd->homeSize), NIL);
    }
    if (HASH_RANGE(p->dictionary) <= (p->dictionary->size / 4)) {
	array_shrink(&(p->dictionary), (HASH_RANGE(p->dictionary) * 3) / 2);
    }
}
Esempio n. 3
0
BIF_RETTYPE
finish_loading_1(BIF_ALIST_1)
{
    Sint i;
    Sint n;
    struct m* p = NULL;
    Uint exceptions;
    Eterm res;
    int is_blocking = 0;
    int do_commit = 0;

    if (!erts_try_seize_code_write_permission(BIF_P)) {
	ERTS_BIF_YIELD1(bif_export[BIF_finish_loading_1], BIF_P, BIF_ARG_1);
    }

    /*
     * Validate the argument before we start loading; it must be a
     * proper list where each element is a magic binary containing
     * prepared (not previously loaded) code.
     *
     * First count the number of elements and allocate an array
     * to keep the elements in.
     */

    n = erts_list_length(BIF_ARG_1);
    if (n < 0) {
    badarg:
	if (p) {
	    erts_free(ERTS_ALC_T_LOADER_TMP, p);
	}
	erts_release_code_write_permission();
	BIF_ERROR(BIF_P, BADARG);
    }
    p = erts_alloc(ERTS_ALC_T_LOADER_TMP, n*sizeof(struct m));

    /*
     * We now know that the argument is a proper list. Validate
     * and collect the binaries into the array.
     */

    for (i = 0; i < n; i++) {
	Eterm* cons = list_val(BIF_ARG_1);
	Eterm term = CAR(cons);
	ProcBin* pb;

	if (!ERTS_TERM_IS_MAGIC_BINARY(term)) {
	    goto badarg;
	}
	pb = (ProcBin*) binary_val(term);
	p[i].code = pb->val;
	p[i].module = erts_module_for_prepared_code(p[i].code);
	if (p[i].module == NIL) {
	    goto badarg;
	}
	BIF_ARG_1 = CDR(cons);
    }

    /*
     * Since we cannot handle atomic loading of a group of modules
     * if one or more of them uses on_load, we will only allow
     * more than one element in the list if none of the modules
     * have an on_load function.
     */

    if (n > 1) {
	for (i = 0; i < n; i++) {
	    if (erts_has_code_on_load(p[i].code) == am_true) {
		erts_free(ERTS_ALC_T_LOADER_TMP, p);
		erts_release_code_write_permission();
		BIF_ERROR(BIF_P, SYSTEM_LIMIT);
	    }
	}
    }

    /*
     * All types are correct. There cannot be a BADARG from now on.
     * Before we can start loading, we must check whether any of
     * the modules already has old code. To avoid a race, we must
     * not allow other process to initiate a code loading operation
     * from now on.
     */

    res = am_ok;
    erts_start_staging_code_ix(n);

    for (i = 0; i < n; i++) {
	p[i].modp = erts_put_module(p[i].module);
	p[i].modp->seen = 0;
    }

    exceptions = 0;
    for (i = 0; i < n; i++) {
	p[i].exception = 0;
	if (p[i].modp->seen) {
	    p[i].exception = 1;
	    exceptions++;
	}
	p[i].modp->seen = 1;
    }
    if (exceptions) {
	res = exception_list(BIF_P, am_duplicated, p, exceptions);
	goto done;
    }

    for (i = 0; i < n; i++) {
	if (p[i].modp->curr.num_breakpoints > 0 ||
	    p[i].modp->curr.num_traced_exports > 0 ||
	    erts_is_default_trace_enabled()) {
	    /* tracing involved, fallback with thread blocking */
	    erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
	    erts_smp_thr_progress_block();
	    is_blocking = 1;
	    break;
	}
    }

    if (is_blocking) {
	for (i = 0; i < n; i++) {
	    if (p[i].modp->curr.num_breakpoints) {
		erts_clear_module_break(p[i].modp);
		ASSERT(p[i].modp->curr.num_breakpoints == 0);
	    }
	}
    }

    exceptions = 0;
    for (i = 0; i < n; i++) {
	p[i].exception = 0;
	if (p[i].modp->curr.code_hdr && p[i].modp->old.code_hdr) {
	    p[i].exception = 1;
	    exceptions++;
	}
    }

    if (exceptions) {
	res = exception_list(BIF_P, am_not_purged, p, exceptions);
    } else {
	/*
	 * Now we can load all code. This can't fail.
	 */

	exceptions = 0;
	for (i = 0; i < n; i++) {
	    Eterm mod;
	    Eterm retval;

	    erts_refc_inc(&p[i].code->refc, 1);
	    retval = erts_finish_loading(p[i].code, BIF_P, 0, &mod);
	    ASSERT(retval == NIL || retval == am_on_load);
	    if (retval == am_on_load) {
		p[i].exception = 1;
		exceptions++;
	    }
	}

	/*
	 * Check whether any module has an on_load_handler.
	 */

	if (exceptions) {
	    res = exception_list(BIF_P, am_on_load, p, exceptions);
	}
	do_commit = 1;
    }

done:
    return staging_epilogue(BIF_P, do_commit, res, is_blocking, p, n);
}
Esempio n. 4
0
static byte* convert_environment(Process* p, Eterm env)
{
    Eterm all;
    Eterm* temp_heap;
    Eterm* hp;
    Uint heap_size;
    Sint n;
    Sint size;
    byte* bytes;
    int encoding = erts_get_native_filename_encoding();

    if ((n = erts_list_length(env)) < 0) {
	return NULL;
    }
    heap_size = 2*(5*n+1);
    temp_heap = hp = (Eterm *) erts_alloc(ERTS_ALC_T_TMP, heap_size*sizeof(Eterm));
    bytes = NULL;		/* Indicating error */

    /*
     * All errors below are handled by jumping to 'done', to ensure that the memory
     * gets deallocated. Do NOT return directly from this function.
     */

    all = CONS(hp, make_small(0), NIL);
    hp += 2;

    while(is_list(env)) {
	Eterm tmp;
	Eterm* tp;

	tmp = CAR(list_val(env));
	if (is_not_tuple_arity(tmp, 2)) {
	    goto done;
	}
	tp = tuple_val(tmp);
	tmp = CONS(hp, make_small(0), NIL);
	hp += 2;
	if (tp[2] != am_false) {
	    tmp = CONS(hp, tp[2], tmp);
	    hp += 2;
	}
	tmp = CONS(hp, make_small('='), tmp);
	hp += 2;
	tmp = CONS(hp, tp[1], tmp);
	hp += 2;
	all = CONS(hp, tmp, all);
	hp += 2;
	env = CDR(list_val(env));
    }
    if (is_not_nil(env)) {
	goto done;
    }

    if ((size = erts_native_filename_need(all,encoding)) < 0) {
	goto done;
    }

    /*
     * Put the result in a binary (no risk for a memory leak that way).
     */
    (void) erts_new_heap_binary(p, NULL, size, &bytes);
    erts_native_filename_put(all,encoding,bytes);

 done:
    erts_free(ERTS_ALC_T_TMP, temp_heap);
    return bytes;
}
Esempio n. 5
0
static Eterm subtract(Process* p, Eterm A, Eterm B)
{
    Eterm  list;
    Eterm* hp;
    Uint  need;
    Eterm  res;
    Eterm small_vec[SMALL_VEC_SIZE];	/* Preallocated memory for small lists */
    Eterm* vec_p;
    Eterm* vp;
    int     i;
    int     n;
    int     m;

    if ((n = erts_list_length(A)) < 0) {
	BIF_ERROR(p, BADARG);
    }
    if ((m = erts_list_length(B)) < 0) {
	BIF_ERROR(p, BADARG);
    }

    if (n == 0)
	BIF_RET(NIL);
    if (m == 0)
	BIF_RET(A);

    /* allocate element vector */
    if (n <= SMALL_VEC_SIZE)
	vec_p = small_vec;
    else
	vec_p = (Eterm*) erts_alloc(ERTS_ALC_T_TMP, n * sizeof(Eterm));

    /* PUT ALL ELEMENTS IN VP */
    vp = vec_p;
    list = A;
    i = n;
    while(i--) {
	Eterm* listp = list_val(list);
	*vp++ = CAR(listp);
	list = CDR(listp);
    }

    /* UNMARK ALL DELETED CELLS */
    list = B;
    m = 0;  /* number of deleted elements */
    while(is_list(list)) {
	Eterm* listp = list_val(list);
	Eterm  elem = CAR(listp);
	i = n;
	vp = vec_p;
	while(i--) {
	    if (is_value(*vp) && eq(*vp, elem)) {
		*vp = THE_NON_VALUE;
		m++;
		break;
	    }
	    vp++;
	}
	list = CDR(listp);
    }

    if (m == n)      /* All deleted ? */
	res = NIL;
    else if (m == 0)  /* None deleted ? */
	res = A;
    else {			/* REBUILD LIST */
	res = NIL;
	need = 2*(n - m);
	hp = HAlloc(p, need);
	vp = vec_p + n - 1;
	while(vp >= vec_p) {
	    if (is_value(*vp)) {
		res = CONS(hp, *vp, res);
		hp += 2;
	    }
	    vp--;
	}
    }
    if (vec_p != small_vec)
	erts_free(ERTS_ALC_T_TMP, (void *) vec_p);
    BIF_RET(res);
}
Esempio n. 6
0
static BIF_RETTYPE append(Process* p, Eterm A, Eterm B)
{
    Eterm list;
    Eterm copy;
    Eterm last;
    Eterm* hp = NULL;
    Sint i;

    list = A;

    if (is_nil(list)) {
        BIF_RET(B);
    }

    if (is_not_list(list)) {
        BIF_ERROR(p, BADARG);
    }

    /* optimistic append on heap first */

    if ((i = HeapWordsLeft(p) / 2) < 4) {
        goto list_tail;
    }

    hp   = HEAP_TOP(p);
    copy = last = CONS(hp, CAR(list_val(list)), make_list(hp+2));
    list = CDR(list_val(list));
    hp  += 2;
    i   -= 2; /* don't use the last 2 words (extra i--;) */

    while(i-- && is_list(list)) {
        Eterm* listp = list_val(list);
        last = CONS(hp, CAR(listp), make_list(hp+2));
        list = CDR(listp);
        hp += 2;
    }

    /* A is proper and B is NIL return A as-is, don't update HTOP */

    if (is_nil(list) && is_nil(B)) {
        BIF_RET(A);
    }

    if (is_nil(list)) {
        HEAP_TOP(p) = hp;
        CDR(list_val(last)) = B;
        BIF_RET(copy);
    }

list_tail:

    if ((i = erts_list_length(list)) < 0) {
        BIF_ERROR(p, BADARG);
    }

    /* remaining list was proper and B is NIL */
    if (is_nil(B)) {
        BIF_RET(A);
    }

    if (hp) {
        /* Note: fall through case, already written
         * on the heap.
         * The last 2 words of the heap is not written yet
         */
        Eterm *hp_save = hp;
        ASSERT(i != 0);
        HEAP_TOP(p) = hp + 2;
        if (i == 1) {
            hp[0] = CAR(list_val(list));
            hp[1] = B;
            BIF_RET(copy);
        }
        hp   = HAlloc(p, 2*(i - 1));
        last = CONS(hp_save, CAR(list_val(list)), make_list(hp));
    } else {
        hp   = HAlloc(p, 2*i);
        copy = last = CONS(hp, CAR(list_val(list)), make_list(hp+2));
        hp  += 2;
    }

    list = CDR(list_val(list));
    i--;

    ASSERT(i > -1);
    while(i--) {
        Eterm* listp = list_val(list);
        last = CONS(hp, CAR(listp), make_list(hp+2));
        list = CDR(listp);
        hp  += 2;
    }

    CDR(list_val(last)) = B;
    BIF_RET(copy);
}