erts: Add new module 'atomics'

5 files changed, 270 insertions, 0 deletions

diff --git a/erts/emulator/beam/atom.names b/erts/emulator/beam/atom.names
index 82bb620d62..a14f22b19e 100644
--- a/erts/emulator/beam/atom.names
+++ b/erts/emulator/beam/atom.names
@@ -396,6 +396,7 @@ atom microsecond
 atom microstate_accounting
 atom milli_seconds
 atom millisecond
+atom min
 atom min_heap_size
 atom min_bin_vheap_size
 atom minor
diff --git a/erts/emulator/beam/bif.tab b/erts/emulator/beam/bif.tab
index f1f34ae323..0577c5722f 100644
--- a/erts/emulator/beam/bif.tab
+++ b/erts/emulator/beam/bif.tab
@@ -710,3 +710,12 @@ bif persistent_term:get/0
 bif persistent_term:erase/1
 bif persistent_term:info/0
 bif erts_internal:erase_persistent_terms/0
+
+bif erts_internal:atomics_new/2
+bif atomics:get/2
+bif atomics:put/3
+bif atomics:add/3
+bif atomics:add_get/3
+bif atomics:exchange/3
+bif atomics:compare_exchange/4
+bif atomics:info/1
diff --git a/erts/emulator/beam/erl_alloc.types b/erts/emulator/beam/erl_alloc.types
index 3fc036a13c..aefa04a031 100644
--- a/erts/emulator/beam/erl_alloc.types
+++ b/erts/emulator/beam/erl_alloc.types
@@ -338,6 +338,7 @@ type	GC_INFO_REQ	SHORT_LIVED	SYSTEM		gc_info_request
 type	PORT_DATA_HEAP	STANDARD	SYSTEM		port_data_heap
 type    MSACC           DRIVER          SYSTEM          microstate_accounting
 type	SYS_CHECK_REQ	SHORT_LIVED	SYSTEM		system_check_request
+type	ATOMICS		STANDARD	SYSTEM		erl_bif_atomics
 
 #
 # Types used by system specific code
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);
+}
diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h
index bb22548587..869a575cb4 100644
--- a/erts/emulator/beam/sys.h
+++ b/erts/emulator/beam/sys.h
@@ -325,6 +325,7 @@ typedef long          Sint  erts_align_attribute(sizeof(long));
 #define UWORD_CONSTANT(Const) Const##UL
 #define ERTS_UWORD_MAX ULONG_MAX
 #define ERTS_SWORD_MAX LONG_MAX
+#define ERTS_SWORD_MIN LONG_MIN
 #define ERTS_SIZEOF_ETERM SIZEOF_LONG
 #define ErtsStrToSint strtol
 #elif SIZEOF_VOID_P == SIZEOF_INT
@@ -335,6 +336,7 @@ typedef int          Sint  erts_align_attribute(sizeof(int));
 #define UWORD_CONSTANT(Const) Const##U
 #define ERTS_UWORD_MAX UINT_MAX
 #define ERTS_SWORD_MAX INT_MAX
+#define ERTS_SWORD_MIN INT_MIN
 #define ERTS_SIZEOF_ETERM SIZEOF_INT
 #define ErtsStrToSint strtol
 #elif SIZEOF_VOID_P == SIZEOF_LONG_LONG
@@ -345,6 +347,7 @@ typedef long long          Sint  erts_align_attribute(sizeof(long long));
 #define UWORD_CONSTANT(Const) Const##ULL
 #define ERTS_UWORD_MAX ULLONG_MAX
 #define ERTS_SWORD_MAX LLONG_MAX
+#define ERTS_SWORD_MIN LLONG_MIN
 #define ERTS_SIZEOF_ETERM SIZEOF_LONG_LONG
 #if defined(__WIN32__)
 #define ErtsStrToSint _strtoi64