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);
}
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);
}
}
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);
}
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;
}
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);
}
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);
}