diff options
Diffstat (limited to 'erts')
-rw-r--r-- | erts/emulator/beam/erl_process_dict.c | 158 |
1 files changed, 82 insertions, 76 deletions
diff --git a/erts/emulator/beam/erl_process_dict.c b/erts/emulator/beam/erl_process_dict.c index 3c80f0e0f6..aee88841ae 100644 --- a/erts/emulator/beam/erl_process_dict.c +++ b/erts/emulator/beam/erl_process_dict.c @@ -79,6 +79,8 @@ /* Array access macro */ #define ARRAY_GET(PDict, Index) (ASSERT((Index) < (PDict)->arraySize), \ (PDict)->data[Index]) +#define ARRAY_GET_PTR(PDict, Index) (ASSERT((Index) < (PDict)->arraySize), \ + &(PDict)->data[Index]) #define ARRAY_PUT(PDict, Index, Val) (ASSERT((Index) < (PDict)->arraySize), \ (PDict)->data[Index] = (Val)) @@ -92,7 +94,7 @@ static void pd_hash_erase_all(Process *p); static Eterm pd_hash_get_with_hval(Process *p, Eterm bucket, Eterm id); static Eterm pd_hash_get_keys(Process *p, Eterm value); static Eterm pd_hash_get_all_keys(Process *p, ProcDict *pd); -static Eterm pd_hash_get_all(Process *p, ProcDict *pd); +static Eterm pd_hash_get_all(Process *p, ProcDict *pd, int keep_dict); static Eterm pd_hash_put(Process *p, Eterm id, Eterm value); static void shrink(Process *p, Eterm* ret); @@ -281,7 +283,7 @@ BIF_RETTYPE get_0(BIF_ALIST_0) { Eterm ret; PD_CHECK(BIF_P->dictionary); - ret = pd_hash_get_all(BIF_P, BIF_P->dictionary); + ret = pd_hash_get_all(BIF_P, BIF_P->dictionary, 1); PD_CHECK(BIF_P->dictionary); BIF_RET(ret); } @@ -329,7 +331,7 @@ BIF_RETTYPE erase_0(BIF_ALIST_0) { Eterm ret; PD_CHECK(BIF_P->dictionary); - ret = pd_hash_get_all(BIF_P, BIF_P->dictionary); + ret = pd_hash_get_all(BIF_P, BIF_P->dictionary, 0); pd_hash_erase_all(BIF_P); PD_CHECK(BIF_P->dictionary); BIF_RET(ret); @@ -541,29 +543,46 @@ static Eterm pd_hash_get_keys(Process *p, Eterm value) static Eterm -pd_hash_get_all(Process *p, ProcDict *pd) +pd_hash_get_all(Process *p, ProcDict *pd, int keep_dict) { Eterm* hp; + Eterm* tp; Eterm res = NIL; Eterm tmp, tmp2; unsigned int i; unsigned int num; + Uint need; if (pd == NULL) { return res; } num = HASH_RANGE(pd); - hp = HAlloc(p, pd->numElements * 2); - + + /* + * If this is not erase/0, then must copy all key-value tuples + * as they may be mutated by put/2. + */ + need = pd->numElements * (keep_dict ? 2+3 : 2); + hp = HAlloc(p, need); + for (i = 0; i < num; ++i) { tmp = ARRAY_GET(pd, i); if (is_boxed(tmp)) { - ASSERT(is_tuple(tmp)); + if (keep_dict) { + tp = tuple_val(tmp); + tmp = TUPLE2(hp, tp[1], tp[2]); + hp += 3; + } res = CONS(hp, tmp, res); hp += 2; } else if (is_list(tmp)) { while (tmp != NIL) { tmp2 = TCAR(tmp); + if (keep_dict) { + tp = tuple_val(tmp2); + tmp2 = TUPLE2(hp, tp[1], tp[2]); + hp += 3; + } res = CONS(hp, tmp2, res); hp += 2; tmp = TCDR(tmp); @@ -577,11 +596,14 @@ static Eterm pd_hash_put(Process *p, Eterm id, Eterm value) { unsigned int hval; Eterm *hp; + Eterm *tp; + Eterm *bucket; Eterm tpl; Eterm old; + Eterm old_val = am_undefined; Eterm tmp; int needed; - int i = 0; + int new_key = 1; #ifdef DEBUG Eterm *hp_limit; #endif @@ -595,7 +617,8 @@ static Eterm pd_hash_put(Process *p, Eterm id, Eterm value) p->dictionary->numElements = 0; } hval = pd_hash_value(p->dictionary, id); - old = ARRAY_GET(p->dictionary, hval); + bucket = ARRAY_GET_PTR(p->dictionary, hval); + old = *bucket; /* * Calculate the number of heap words needed and garbage @@ -603,32 +626,49 @@ static Eterm pd_hash_put(Process *p, Eterm id, Eterm value) */ needed = 3; /* {Key,Value} tuple */ if (is_boxed(old)) { - /* - * We don't want to compare keys twice, so we'll always - * reserve the space for two CONS cells. - */ - needed += 2+2; + ASSERT(is_tuple(old)); + tp = tuple_val(old); + if (EQ(tp[1], id)) { + old_val = tp[2]; + if (is_immed(value)) { + tp[2] = value; /* DESTRUCTIVE HEAP ASSIGNMENT */ + return old_val; + } + new_key = 0; + } + else { + needed += 2+2; + } } else if (is_list(old)) { - i = 0; - for (tmp = old; tmp != NIL && !EQ(tuple_val(TCAR(tmp))[1], id); tmp = TCDR(tmp)) { - ++i; - } - if (is_nil(tmp)) { - i = -1; - needed += 2; - } else { - needed += 2*(i+1); + Eterm* prev_cdr = bucket; + + needed += 2; + for (tmp = old; tmp != NIL; prev_cdr = &TCDR(tmp), tmp = *prev_cdr) { + tp = tuple_val(TCAR(tmp)); + if (EQ(tp[1], id)) { + old_val = tp[2]; + if (is_immed(value)) { + tp[2] = value; /* DESTRUCTIVE HEAP ASSIGNMENT */ + return old_val; + } + new_key = 0; + /* Unlink old {Key,Value} from list */ + *prev_cdr = TCDR(tmp); /* maybe DESTRUCTIVE HEAP ASSIGNMENT */ + break; + } } } if (HeapWordsLeft(p) < needed) { Eterm root[3]; root[0] = id; root[1] = value; - root[2] = old; + root[2] = old_val; erts_garbage_collect(p, needed, root, 3); id = root[0]; value = root[1]; - old = root[2]; + old_val = root[2]; + ASSERT(bucket == ARRAY_GET_PTR(p->dictionary, hval)); + old = *bucket; } #ifdef DEBUG hp_limit = p->htop + needed; @@ -644,66 +684,29 @@ static Eterm pd_hash_put(Process *p, Eterm id, Eterm value) * Update the dictionary. */ if (is_nil(old)) { - ARRAY_PUT(p->dictionary, hval, tpl); - ++(p->dictionary->numElements); + *bucket = tpl; } else if (is_boxed(old)) { ASSERT(is_tuple(old)); - if (EQ(tuple_val(old)[1],id)) { - ARRAY_PUT(p->dictionary, hval, tpl); - return tuple_val(old)[2]; + if (!new_key) { + ASSERT(EQ(tuple_val(old)[1],id)); + *bucket = tpl; + return old_val; } else { hp = HeapOnlyAlloc(p, 4); tmp = CONS(hp, old, NIL); hp += 2; - ++(p->dictionary->numElements); - ARRAY_PUT(p->dictionary, hval, CONS(hp, tpl, tmp)); + *bucket = CONS(hp, tpl, tmp); hp += 2; ASSERT(hp <= hp_limit); } } else if (is_list(old)) { - if (i == -1) { - /* - * New key. Simply prepend the tuple to the beginning of the list. - */ - hp = HeapOnlyAlloc(p, 2); - ARRAY_PUT(p->dictionary, hval, CONS(hp, tpl, old)); - hp += 2; - ASSERT(hp <= hp_limit); - ++(p->dictionary->numElements); - } else { - /* - * i = Number of CDRs to skip to reach the changed element in the list. - * - * Replace old value in list. To avoid pointers from the old generation - * to the new, we must rebuild the list from the beginning up to and - * including the changed element. - */ - Eterm nlist; - int j; - - hp = HeapOnlyAlloc(p, (i+1)*2); - - /* Find the list element to change. */ - for (j = 0, nlist = old; j < i; j++, nlist = TCDR(nlist)) { - ; - } - ASSERT(EQ(tuple_val(TCAR(nlist))[1], id)); - nlist = TCDR(nlist); /* Unchanged part of list. */ - - /* Rebuild list before the updated element. */ - for (tmp = old; i-- > 0; tmp = TCDR(tmp)) { - nlist = CONS(hp, TCAR(tmp), nlist); - hp += 2; - } - ASSERT(EQ(tuple_val(TCAR(tmp))[1], id)); - - /* Put the updated element first in the new list. */ - nlist = CONS(hp, tpl, nlist); - hp += 2; - ASSERT(hp <= hp_limit); - ARRAY_PUT(p->dictionary, hval, nlist); - return tuple_val(TCAR(tmp))[2]; - } + /* + * Simply prepend the tuple to the beginning of the list. + */ + hp = HeapOnlyAlloc(p, 2); + *bucket = CONS(hp, tpl, *bucket); + hp += 2; + ASSERT(hp <= hp_limit); } else { #ifdef DEBUG erts_fprintf(stderr, @@ -714,10 +717,13 @@ static Eterm pd_hash_put(Process *p, Eterm id, Eterm value) erts_exit(ERTS_ERROR_EXIT, "Damaged process dictionary found during put/2."); } + + p->dictionary->numElements += new_key; + if (HASH_RANGE(p->dictionary) <= p->dictionary->numElements) { grow(p); } - return am_undefined; + return old_val; } /* |