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authorRickard Green <[email protected]>2015-11-11 10:20:18 +0100
committerRickard Green <[email protected]>2015-11-12 15:25:48 +0100
commit3e490ee1b43140ffcd8cb3fc3ccfe4339c08584e (patch)
tree544e8211359459ef2eab2389f3ceecf43d560cd6
parent9c6f45b901ee701553afe34c0b33b7d931d73fd9 (diff)
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Improve yield strategy for list_to_binary()/binary_to_list()
Avoid yield in the BIF when input is small. This either yielding before beginning to work in the BIF, or by allowing some more reductions before yielding.
-rw-r--r--erts/emulator/beam/binary.c81
1 files changed, 74 insertions, 7 deletions
diff --git a/erts/emulator/beam/binary.c b/erts/emulator/beam/binary.c
index e670fbf31c..d3e481c7f9 100644
--- a/erts/emulator/beam/binary.c
+++ b/erts/emulator/beam/binary.c
@@ -34,6 +34,9 @@
#include "erl_binary.h"
#include "erl_bits.h"
+#define L2B_B2L_MIN_EXEC_REDS (CONTEXT_REDS/4)
+#define L2B_B2L_RESCHED_REDS (CONTEXT_REDS/40)
+
static Export binary_to_list_continue_export;
static Export list_to_binary_continue_export;
@@ -415,10 +418,10 @@ binary_to_list_chunk(Process *c_p,
}
static ERTS_INLINE BIF_RETTYPE
-binary_to_list(Process *c_p, Eterm *hp, Eterm tail, byte *bytes, Uint size, Uint bitoffs)
+binary_to_list(Process *c_p, Eterm *hp, Eterm tail, byte *bytes,
+ Uint size, Uint bitoffs, int reds_left, int one_chunk)
{
- int reds_left = ERTS_BIF_REDS_LEFT(c_p);
- if (size < reds_left*ERTS_B2L_BYTES_PER_REDUCTION) {
+ if (one_chunk) {
Eterm res;
BIF_RETTYPE ret;
int bump_reds = (size - 1)/ERTS_B2L_BYTES_PER_REDUCTION + 1;
@@ -472,11 +475,29 @@ BIF_RETTYPE binary_to_list_1(BIF_ALIST_1)
Uint size;
Uint bitsize;
Uint bitoffs;
+ int reds_left;
+ int one_chunk;
if (is_not_binary(BIF_ARG_1)) {
goto error;
}
+
size = binary_size(BIF_ARG_1);
+ reds_left = ERTS_BIF_REDS_LEFT(BIF_P);
+ one_chunk = size < reds_left*ERTS_B2L_BYTES_PER_REDUCTION;
+ if (!one_chunk) {
+ if (size < L2B_B2L_MIN_EXEC_REDS*ERTS_B2L_BYTES_PER_REDUCTION) {
+ if (reds_left <= L2B_B2L_RESCHED_REDS) {
+ /* Yield and do it with full context reds... */
+ ERTS_BIF_YIELD1(bif_export[BIF_binary_to_list_1],
+ BIF_P, BIF_ARG_1);
+ }
+ /* Allow a bit more reductions... */
+ one_chunk = 1;
+ reds_left = L2B_B2L_MIN_EXEC_REDS;
+ }
+ }
+
ERTS_GET_REAL_BIN(BIF_ARG_1, real_bin, offset, bitoffs, bitsize);
if (bitsize != 0) {
goto error;
@@ -486,7 +507,8 @@ BIF_RETTYPE binary_to_list_1(BIF_ALIST_1)
} else {
Eterm* hp = HAlloc(BIF_P, 2 * size);
byte* bytes = binary_bytes(real_bin)+offset;
- return binary_to_list(BIF_P, hp, NIL, bytes, size, bitoffs);
+ return binary_to_list(BIF_P, hp, NIL, bytes, size,
+ bitoffs, reds_left, one_chunk);
}
error:
@@ -505,6 +527,8 @@ BIF_RETTYPE binary_to_list_3(BIF_ALIST_3)
Uint start;
Uint stop;
Eterm* hp;
+ int reds_left;
+ int one_chunk;
if (is_not_binary(BIF_ARG_1)) {
goto error;
@@ -513,6 +537,21 @@ BIF_RETTYPE binary_to_list_3(BIF_ALIST_3)
goto error;
}
size = binary_size(BIF_ARG_1);
+ reds_left = ERTS_BIF_REDS_LEFT(BIF_P);
+ one_chunk = size < reds_left*ERTS_B2L_BYTES_PER_REDUCTION;
+ if (!one_chunk) {
+ if (size < L2B_B2L_MIN_EXEC_REDS*ERTS_B2L_BYTES_PER_REDUCTION) {
+ if (reds_left <= L2B_B2L_RESCHED_REDS) {
+ /* Yield and do it with full context reds... */
+ ERTS_BIF_YIELD3(bif_export[BIF_binary_to_list_3],
+ BIF_P, BIF_ARG_1, BIF_ARG_2, BIF_ARG_3);
+ }
+ /* Allow a bit more reductions... */
+ one_chunk = 1;
+ reds_left = L2B_B2L_MIN_EXEC_REDS;
+ }
+ }
+
ERTS_GET_BINARY_BYTES(BIF_ARG_1, bytes, bitoffs, bitsize);
if (start < 1 || start > size || stop < 1 ||
stop > size || stop < start ) {
@@ -520,7 +559,8 @@ BIF_RETTYPE binary_to_list_3(BIF_ALIST_3)
}
i = stop-start+1;
hp = HAlloc(BIF_P, 2*i);
- return binary_to_list(BIF_P, hp, NIL, bytes+start-1, i, bitoffs);
+ return binary_to_list(BIF_P, hp, NIL, bytes+start-1, i,
+ bitoffs, reds_left, one_chunk);
error:
BIF_ERROR(BIF_P, BADARG);
}
@@ -537,11 +577,27 @@ BIF_RETTYPE bitstring_to_list_1(BIF_ALIST_1)
byte* bytes;
Eterm previous = NIL;
Eterm* hp;
+ int reds_left;
+ int one_chunk;
if (is_not_binary(BIF_ARG_1)) {
BIF_ERROR(BIF_P, BADARG);
}
size = binary_size(BIF_ARG_1);
+ reds_left = ERTS_BIF_REDS_LEFT(BIF_P);
+ one_chunk = size < reds_left*ERTS_B2L_BYTES_PER_REDUCTION;
+ if (!one_chunk) {
+ if (size < L2B_B2L_MIN_EXEC_REDS*ERTS_B2L_BYTES_PER_REDUCTION) {
+ if (reds_left <= L2B_B2L_RESCHED_REDS) {
+ /* Yield and do it with full context reds... */
+ ERTS_BIF_YIELD1(bif_export[BIF_bitstring_to_list_1],
+ BIF_P, BIF_ARG_1);
+ }
+ /* Allow a bit more reductions... */
+ one_chunk = 1;
+ reds_left = L2B_B2L_MIN_EXEC_REDS;
+ }
+ }
ERTS_GET_REAL_BIN(BIF_ARG_1, real_bin, offset, bitoffs, bitsize);
bytes = binary_bytes(real_bin)+offset;
if (bitsize == 0) {
@@ -566,7 +622,8 @@ BIF_RETTYPE bitstring_to_list_1(BIF_ALIST_1)
hp += 2;
}
- return binary_to_list(BIF_P, hp, previous, bytes, size, bitoffs);
+ return binary_to_list(BIF_P, hp, previous, bytes, size,
+ bitoffs, reds_left, one_chunk);
}
@@ -795,8 +852,19 @@ static BIF_RETTYPE list_to_binary_continue(BIF_ALIST_1)
BIF_RETTYPE erts_list_to_binary_bif(Process *c_p, Eterm arg, Export *bif)
{
+ int orig_reds_left = ERTS_BIF_REDS_LEFT(c_p);
BIF_RETTYPE ret;
+ if (orig_reds_left < L2B_B2L_MIN_EXEC_REDS) {
+ if (orig_reds_left <= L2B_B2L_RESCHED_REDS) {
+ /* Yield and do it with full context reds... */
+ ERTS_BIF_PREP_YIELD1(ret, bif, c_p, arg);
+ return ret;
+ }
+ /* Allow a bit more reductions... */
+ orig_reds_left = L2B_B2L_MIN_EXEC_REDS;
+ }
+
if (is_nil(arg))
ERTS_BIF_PREP_RET(ret, new_binary(c_p, (byte *) "", 0));
else if (is_not_list(arg))
@@ -818,7 +886,6 @@ BIF_RETTYPE erts_list_to_binary_bif(Process *c_p, Eterm arg, Export *bif)
bif,
erts_iolist_size_yielding,
erts_iolist_to_buf_yielding);
- int orig_reds_left = ERTS_BIF_REDS_LEFT(c_p);
/*
* First try to do it all at once without having to use