diff options
Diffstat (limited to 'erts/emulator/beam/erl_bif_atomics.c')
| -rw-r--r-- | erts/emulator/beam/erl_bif_atomics.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/erts/emulator/beam/erl_bif_atomics.c b/erts/emulator/beam/erl_bif_atomics.c new file mode 100644 index 0000000000..092dbb3bd3 --- /dev/null +++ b/erts/emulator/beam/erl_bif_atomics.c @@ -0,0 +1,256 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson AB 2018. All Rights Reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * %CopyrightEnd% + */ + +/* + * Purpose: High performance atomics. + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include <stddef.h> /* offsetof */ + +#include "sys.h" +#include "export.h" +#include "bif.h" +#include "erl_threads.h" +#include "big.h" +#include "erl_binary.h" +#include "erl_bif_unique.h" +#include "erl_map.h" + +typedef struct +{ + int is_signed; + UWord vlen; + erts_atomic64_t v[1]; +}AtomicsRef; + +static int atomics_destructor(Binary *unused) +{ + return 1; +} + +#define OPT_SIGNED (1 << 0) + +BIF_RETTYPE erts_internal_atomics_new_2(BIF_ALIST_2) +{ + AtomicsRef* p; + Binary* mbin; + UWord i, cnt, opts; + Uint bytes; + Eterm* hp; + + if (!term_to_UWord(BIF_ARG_1, &cnt) + || cnt == 0 + || !term_to_UWord(BIF_ARG_2, &opts)) { + + BIF_ERROR(BIF_P, BADARG); + } + + if (cnt > (ERTS_UWORD_MAX / sizeof(p->v[0]))) + BIF_ERROR(BIF_P, SYSTEM_LIMIT); + + bytes = offsetof(AtomicsRef, v) + cnt*sizeof(p->v[0]); + mbin = erts_create_magic_binary_x(bytes, + atomics_destructor, + ERTS_ALC_T_ATOMICS, + 0); + p = ERTS_MAGIC_BIN_DATA(mbin); + p->is_signed = opts & OPT_SIGNED; + p->vlen = cnt; + for (i=0; i < cnt; i++) + erts_atomic64_init_nob(&p->v[i], 0); + hp = HAlloc(BIF_P, ERTS_MAGIC_REF_THING_SIZE); + return erts_mk_magic_ref(&hp, &MSO(BIF_P), mbin); +} + +static ERTS_INLINE int get_ref(Eterm ref, AtomicsRef** pp) +{ + Binary* mbin; + if (!is_internal_magic_ref(ref)) + return 0; + + mbin = erts_magic_ref2bin(ref); + if (ERTS_MAGIC_BIN_DESTRUCTOR(mbin) != atomics_destructor) + return 0; + *pp = ERTS_MAGIC_BIN_DATA(mbin); + return 1; +} + +static ERTS_INLINE int get_ref_ix(Eterm ref, Eterm ix, + AtomicsRef** pp, UWord* ixp) +{ + return (get_ref(ref, pp) + && term_to_UWord(ix, ixp) + && --(*ixp) < (*pp)->vlen); +} + +static ERTS_INLINE int get_value(AtomicsRef* p, Eterm term, erts_aint64_t *valp) +{ + return (p->is_signed ? + term_to_Sint64(term, (Sint64*)valp) : + term_to_Uint64(term, (Uint64*)valp)); +} + +static ERTS_INLINE int get_incr(AtomicsRef* p, Eterm term, erts_aint64_t *valp) +{ + return (term_to_Sint64(term, (Sint64*)valp) + || term_to_Uint64(term, (Uint64*)valp)); +} + +static ERTS_INLINE Eterm bld_atomic(Process* proc, AtomicsRef* p, + erts_aint64_t val) +{ + if (p->is_signed) { + if (IS_SSMALL(val)) + return make_small((Sint) val); + else { + Uint hsz = ERTS_SINT64_HEAP_SIZE(val); + Eterm* hp = HAlloc(proc, hsz); + return erts_sint64_to_big(val, &hp); + } + } + else { + if ((Uint64)val <= MAX_SMALL) + return make_small((Sint) val); + else { + Uint hsz = ERTS_UINT64_HEAP_SIZE(val); + Eterm* hp = HAlloc(proc, hsz); + return erts_uint64_to_big(val, &hp); + } + } +} + +BIF_RETTYPE atomics_put_3(BIF_ALIST_3) +{ + AtomicsRef* p; + UWord ix; + erts_aint64_t val; + + if (!get_ref_ix(BIF_ARG_1, BIF_ARG_2, &p, &ix) + || !get_value(p, BIF_ARG_3, &val)) { + BIF_ERROR(BIF_P, BADARG); + } + erts_atomic64_set_mb(&p->v[ix], val); + return am_ok; +} + +BIF_RETTYPE atomics_get_2(BIF_ALIST_2) +{ + AtomicsRef* p; + UWord ix; + + if (!get_ref_ix(BIF_ARG_1, BIF_ARG_2, &p, &ix)) { + BIF_ERROR(BIF_P, BADARG); + } + return bld_atomic(BIF_P, p, erts_atomic64_read_mb(&p->v[ix])); +} + +BIF_RETTYPE atomics_add_3(BIF_ALIST_3) +{ + AtomicsRef* p; + UWord ix; + erts_aint64_t incr; + + if (!get_ref_ix(BIF_ARG_1, BIF_ARG_2, &p, &ix) + || !get_incr(p, BIF_ARG_3, &incr)) { + BIF_ERROR(BIF_P, BADARG); + } + erts_atomic64_add_mb(&p->v[ix], incr); + return am_ok; +} + +BIF_RETTYPE atomics_add_get_3(BIF_ALIST_3) +{ + AtomicsRef* p; + UWord ix; + erts_aint64_t incr; + + if (!get_ref_ix(BIF_ARG_1, BIF_ARG_2, &p, &ix) + || !get_incr(p, BIF_ARG_3, &incr)) { + BIF_ERROR(BIF_P, BADARG); + } + return bld_atomic(BIF_P, p, erts_atomic64_add_read_mb(&p->v[ix], incr)); +} + +BIF_RETTYPE atomics_exchange_3(BIF_ALIST_3) +{ + AtomicsRef* p; + UWord ix; + erts_aint64_t desired, was; + + if (!get_ref_ix(BIF_ARG_1, BIF_ARG_2, &p, &ix) + || !get_value(p, BIF_ARG_3, &desired)) { + BIF_ERROR(BIF_P, BADARG); + } + was = erts_atomic64_xchg_mb(&p->v[ix], desired); + return bld_atomic(BIF_P, p, was); +} + +BIF_RETTYPE atomics_compare_exchange_4(BIF_ALIST_4) +{ + AtomicsRef* p; + UWord ix; + erts_aint64_t expected, desired, was; + + if (!get_ref_ix(BIF_ARG_1, BIF_ARG_2, &p, &ix) + || !get_value(p, BIF_ARG_3, &expected) + || !get_value(p, BIF_ARG_4, &desired)) { + BIF_ERROR(BIF_P, BADARG); + } + was = erts_atomic64_cmpxchg_mb(&p->v[ix], desired, expected); + return was == expected ? am_ok : bld_atomic(BIF_P, p, was); +} + +BIF_RETTYPE atomics_info_1(BIF_ALIST_1) +{ + AtomicsRef* p; + Uint hsz = MAP4_SZ; + Eterm *hp; + Uint64 max; + Sint64 min; + UWord memory; + Eterm max_val, min_val, sz_val, mem_val; + + if (!get_ref(BIF_ARG_1, &p)) + BIF_ERROR(BIF_P, BADARG); + + max = p->is_signed ? ERTS_SINT64_MAX : ERTS_UINT64_MAX; + min = p->is_signed ? ERTS_SINT64_MIN : 0; + memory = erts_magic_ref2bin(BIF_ARG_1)->orig_size; + + erts_bld_uint64(NULL, &hsz, max); + erts_bld_sint64(NULL, &hsz, min); + erts_bld_uword(NULL, &hsz, p->vlen); + erts_bld_uword(NULL, &hsz, memory); + + hp = HAlloc(BIF_P, hsz); + max_val = erts_bld_uint64(&hp, NULL, max); + min_val = erts_bld_sint64(&hp, NULL, min); + sz_val = erts_bld_uword(&hp, NULL, p->vlen); + mem_val = erts_bld_uword(&hp, NULL, memory); + + return MAP4(hp, am_max, max_val, + am_memory, mem_val, + am_min, min_val, + am_size, sz_val); +} |