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authorLukas Larsson <[email protected]>2016-02-18 13:52:54 +0100
committerLukas Larsson <[email protected]>2016-04-07 09:54:14 +0200
commit57551877d85ad7659201235e27498be42809fefb (patch)
treed510785967a851f39150331f81da2b3b33b4b87f /erts
parent3f190b62031783ad4fc9bb1fb91703a1b1b40ad7 (diff)
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erts: Add enif_send with NULL as msg env
This is an optimization for reducing the number of heap fragments allocated when sending a message where the majority of the message payload is on the sending process' heap.
Diffstat (limited to 'erts')
-rw-r--r--erts/doc/src/erl_nif.xml4
-rw-r--r--erts/emulator/beam/erl_nif.c36
-rw-r--r--erts/emulator/test/nif_SUITE.erl13
-rw-r--r--erts/emulator/test/nif_SUITE_data/nif_SUITE.c13
4 files changed, 48 insertions, 18 deletions
diff --git a/erts/doc/src/erl_nif.xml b/erts/doc/src/erl_nif.xml
index 1e95634d1b..1bfd98f664 100644
--- a/erts/doc/src/erl_nif.xml
+++ b/erts/doc/src/erl_nif.xml
@@ -1632,7 +1632,7 @@ enif_map_iterator_destroy(env, &amp;iter);
<tag><c>msg_env</c></tag>
<item>The environment of the message term. Must be a process
independent environment allocated with
- <seealso marker="#enif_alloc_env">enif_alloc_env</seealso>.</item>
+ <seealso marker="#enif_alloc_env">enif_alloc_env</seealso> or NULL.</item>
<tag><c>msg</c></tag>
<item>The message term to send.</item>
</taglist>
@@ -1641,6 +1641,8 @@ enif_map_iterator_destroy(env, &amp;iter);
<c>msg</c>) will be invalidated by a successful call to <c>enif_send</c>. The environment
should either be freed with <seealso marker="#enif_free_env">enif_free_env</seealso>
of cleared for reuse with <seealso marker="#enif_clear_env">enif_clear_env</seealso>.</p>
+ <p>If <c>msg_env</c> is set to NULL the <c>msg</c> term is copied and
+ the original term and its environemt is still valid after the call.</p>
<p>This function is only thread-safe when the emulator with SMP support is used.
It can only be used in a non-SMP emulator from a NIF-calling thread.</p>
<note><p>Passing <c>msg_env</c> as <c>NULL</c> is only supported since
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index d3030070b7..1012ced44b 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -312,7 +312,6 @@ int enif_send(ErlNifEnv* env, const ErlNifPid* to_pid,
Process* rp;
Process* c_p;
ErtsMessage *mp;
- ErlHeapFragment* frags;
Eterm receiver = to_pid->pid;
int flush_me = 0;
int scheduler = erts_get_scheduler_id() != 0;
@@ -340,25 +339,32 @@ int enif_send(ErlNifEnv* env, const ErlNifPid* to_pid,
ASSERT(env == NULL || receiver != c_p->common.id);
return 0;
}
- flush_env(msg_env);
- frags = menv->env.heap_frag;
- ASSERT(frags == MBUF(&menv->phony_proc));
- if (frags != NULL) {
- /* Move all offheap's from phony proc to the first fragment.
- Quick and dirty... */
- ASSERT(!is_offheap(&frags->off_heap));
- frags->off_heap = MSO(&menv->phony_proc);
- clear_offheap(&MSO(&menv->phony_proc));
- menv->env.heap_frag = NULL;
- MBUF(&menv->phony_proc) = NULL;
+ if (menv) {
+ flush_env(msg_env);
+ mp = erts_alloc_message(0, NULL);
+ mp->data.heap_frag = menv->env.heap_frag;
+ ASSERT(mp->data.heap_frag == MBUF(&menv->phony_proc));
+ if (mp->data.heap_frag != NULL) {
+ /* Move all offheap's from phony proc to the first fragment.
+ Quick and dirty... */
+ ASSERT(!is_offheap(&mp->data.heap_frag->off_heap));
+ mp->data.heap_frag->off_heap = MSO(&menv->phony_proc);
+ clear_offheap(&MSO(&menv->phony_proc));
+ menv->env.heap_frag = NULL;
+ MBUF(&menv->phony_proc) = NULL;
+ }
+ ASSERT(!is_offheap(&MSO(&menv->phony_proc)));
+ } else {
+ Uint sz = size_object(msg);
+ Eterm *hp;
+ mp = erts_alloc_message(sz, &hp);
+ msg = copy_struct(msg, sz, &hp, &mp->hfrag.off_heap);
+ ASSERT(hp == mp->hfrag.mem+mp->hfrag.used_size);
}
- ASSERT(!is_offheap(&MSO(&menv->phony_proc)));
if (flush_me) {
flush_env(env); /* Needed for ERTS_HOLE_CHECK */
}
- mp = erts_alloc_message(0, NULL);
- mp->data.heap_frag = frags;
erts_queue_message(rp, &rp_locks, mp, msg, am_undefined);
if (c_p == rp)
rp_locks &= ~ERTS_PROC_LOCK_MAIN;
diff --git a/erts/emulator/test/nif_SUITE.erl b/erts/emulator/test/nif_SUITE.erl
index a185b72341..aa512b2360 100644
--- a/erts/emulator/test/nif_SUITE.erl
+++ b/erts/emulator/test/nif_SUITE.erl
@@ -1282,9 +1282,10 @@ send3_make_blob() ->
repeat(N bsr 1,
fun(_) -> grow_blob(MsgEnv,other_term(),rand:uniform(1 bsl 20))
end, void),
- case (N band 1) of
+ case (N band 3) of
0 -> {term,copy_blob(MsgEnv)};
- 1 -> {msgenv,MsgEnv}
+ 1 -> {copy,copy_blob(MsgEnv)};
+ _ -> {msgenv,MsgEnv}
end
end.
@@ -1297,6 +1298,9 @@ send3_send(Pid, Msg) ->
send3_send_nif(Pid, {term,Blob}) ->
%%io:format("~p send term nif\n",[self()]),
send_term(Pid, {blob, Blob}) =:= 1;
+send3_send_nif(Pid, {copy,Blob}) ->
+ %%io:format("~p send term nif\n",[self()]),
+ send_copy_term(Pid, {blob, Blob}) =:= 1;
send3_send_nif(Pid, {msgenv,MsgEnv}) ->
%%io:format("~p send blob nif\n",[self()]),
send3_blob(MsgEnv, Pid, blob) =:= 1.
@@ -1305,6 +1309,10 @@ send3_send_bang(Pid, {term,Blob}) ->
%%io:format("~p send term bang\n",[self()]),
Pid ! {blob, Blob},
true;
+send3_send_bang(Pid, {copy,Blob}) ->
+ %%io:format("~p send term bang\n",[self()]),
+ Pid ! {blob, Blob},
+ true;
send3_send_bang(Pid, {msgenv,MsgEnv}) ->
%%io:format("~p send blob bang\n",[self()]),
Pid ! {blob, copy_blob(MsgEnv)},
@@ -2062,6 +2070,7 @@ send_blob_thread(_,_,_) -> ?nif_stub.
join_send_thread(_) -> ?nif_stub.
copy_blob(_) -> ?nif_stub.
send_term(_,_) -> ?nif_stub.
+send_copy_term(_,_) -> ?nif_stub.
reverse_list(_) -> ?nif_stub.
echo_int(_) -> ?nif_stub.
type_sizes() -> ?nif_stub.
diff --git a/erts/emulator/test/nif_SUITE_data/nif_SUITE.c b/erts/emulator/test/nif_SUITE_data/nif_SUITE.c
index b3c6cc5ba3..e369fb3386 100644
--- a/erts/emulator/test/nif_SUITE_data/nif_SUITE.c
+++ b/erts/emulator/test/nif_SUITE_data/nif_SUITE.c
@@ -1466,6 +1466,18 @@ static ERL_NIF_TERM send_term(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[
return enif_make_int(env, ret);
}
+static ERL_NIF_TERM send_copy_term(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+ ErlNifEnv* menv;
+ ErlNifPid pid;
+ int ret;
+ if (!enif_get_local_pid(env, argv[0], &pid)) {
+ return enif_make_badarg(env);
+ }
+ ret = enif_send(env, &pid, NULL, argv[1]);
+ return enif_make_int(env, ret);
+}
+
static ERL_NIF_TERM reverse_list(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) {
ERL_NIF_TERM rev_list;
@@ -2142,6 +2154,7 @@ static ErlNifFunc nif_funcs[] =
{"join_send_thread", 1, join_send_thread},
{"copy_blob", 1, copy_blob},
{"send_term", 2, send_term},
+ {"send_copy_term", 2, send_copy_term},
{"reverse_list",1, reverse_list},
{"echo_int", 1, echo_int},
{"type_sizes", 0, type_sizes},