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authorEileen M. Uchitelle <[email protected]>2025-03-17 10:42:48 -0400
committerGitHub <[email protected]>2025-03-17 10:42:48 -0400
commitc85dffeee2f1899e0db3bde6a4fb49bc90c90ec2 (patch)
tree5545ed4f48598c820c70b4bf709bb45273367b7c
parent8d6f153fba8ce48a8e31cb22a9c9222bbb1832f6 (diff)
Avoid pinning `storage_head` in `iseq_mark_and_move` (#12880)
* Avoid pinning `storage_head` in `iseq_mark_and_move` This refactor changes the behavior of `iseq_mark_and_move` to avoid pinning the `storage_head`. Previously pinning was required because they could be gc'd during `iseq_set_sequence` it would be possible to end up with a half build array of instructions. However, in order to implement a moving immix algorithm we can't pin these objects so this rafactoring changes the code to mark and move. To accomplish this, it was required to add `iseq_size`, `iseq_encoded`, and the `mark_bits` union to the `iseq_compile_data` struct. In addition `iseq_compile_data` sets a bool for whether there is a single or list of mark bits. While this change is needed for moving immix, it should be better for Ruby's GC as well. * Don't allocate mark_offset_bits for one word If only one word is needed, we don't need to allocate mark_offset_bits and can instead directly write to it. --------- Co-authored-by: Peter Zhu <[email protected]>
Notes
Notes: Merged-By: eileencodes <[email protected]>
-rw-r--r--compile.c32
-rw-r--r--iseq.c45
-rw-r--r--iseq.h12
3 files changed, 60 insertions, 29 deletions
diff --git a/compile.c b/compile.c
index 90efcc93b5..7aac2f9dbc 100644
--- a/compile.c
+++ b/compile.c
@@ -1375,7 +1375,7 @@ new_adjust_body(rb_iseq_t *iseq, LABEL *label, int line)
}
static void
-iseq_insn_each_markable_object(INSN *insn, void (*func)(VALUE, VALUE), VALUE data)
+iseq_insn_each_markable_object(INSN *insn, void (*func)(VALUE *, VALUE), VALUE data)
{
const char *types = insn_op_types(insn->insn_id);
for (int j = 0; types[j]; j++) {
@@ -1386,7 +1386,7 @@ iseq_insn_each_markable_object(INSN *insn, void (*func)(VALUE, VALUE), VALUE dat
case TS_VALUE:
case TS_IC: // constant path array
case TS_CALLDATA: // ci is stored.
- func(OPERAND_AT(insn, j), data);
+ func(&OPERAND_AT(insn, j), data);
break;
default:
break;
@@ -1395,9 +1395,9 @@ iseq_insn_each_markable_object(INSN *insn, void (*func)(VALUE, VALUE), VALUE dat
}
static void
-iseq_insn_each_object_write_barrier(VALUE obj, VALUE iseq)
+iseq_insn_each_object_write_barrier(VALUE * obj, VALUE iseq)
{
- RB_OBJ_WRITTEN(iseq, Qundef, obj);
+ RB_OBJ_WRITTEN(iseq, Qundef, *obj);
}
static INSN *
@@ -2607,16 +2607,21 @@ iseq_set_sequence(rb_iseq_t *iseq, LINK_ANCHOR *const anchor)
iseq_bits_t * mark_offset_bits;
int code_size = code_index;
- iseq_bits_t tmp[1] = {0};
bool needs_bitmap = false;
if (ISEQ_MBITS_BUFLEN(code_index) == 1) {
- mark_offset_bits = tmp;
+ mark_offset_bits = &ISEQ_COMPILE_DATA(iseq)->mark_bits.single;
+ ISEQ_COMPILE_DATA(iseq)->is_single_mark_bit = true;
}
else {
mark_offset_bits = ZALLOC_N(iseq_bits_t, ISEQ_MBITS_BUFLEN(code_index));
+ ISEQ_COMPILE_DATA(iseq)->mark_bits.list = mark_offset_bits;
+ ISEQ_COMPILE_DATA(iseq)->is_single_mark_bit = false;
}
+ ISEQ_COMPILE_DATA(iseq)->iseq_encoded = (void *)generated_iseq;
+ ISEQ_COMPILE_DATA(iseq)->iseq_size = code_index;
+
list = FIRST_ELEMENT(anchor);
insns_info_index = code_index = sp = 0;
@@ -2827,15 +2832,16 @@ iseq_set_sequence(rb_iseq_t *iseq, LINK_ANCHOR *const anchor)
body->iseq_size = code_index;
body->stack_max = stack_max;
- if (ISEQ_MBITS_BUFLEN(body->iseq_size) == 1) {
- body->mark_bits.single = mark_offset_bits[0];
+ if (ISEQ_COMPILE_DATA(iseq)->is_single_mark_bit) {
+ body->mark_bits.single = ISEQ_COMPILE_DATA(iseq)->mark_bits.single;
}
else {
if (needs_bitmap) {
body->mark_bits.list = mark_offset_bits;
}
else {
- body->mark_bits.list = 0;
+ body->mark_bits.list = NULL;
+ ISEQ_COMPILE_DATA(iseq)->mark_bits.list = NULL;
ruby_xfree(mark_offset_bits);
}
}
@@ -12128,13 +12134,13 @@ iseq_build_kw(rb_iseq_t *iseq, VALUE params, VALUE keywords)
}
static void
-iseq_insn_each_object_mark_and_pin(VALUE obj, VALUE _)
+iseq_insn_each_object_mark_and_move(VALUE * obj, VALUE _)
{
- rb_gc_mark(obj);
+ rb_gc_mark_and_move(obj);
}
void
-rb_iseq_mark_and_pin_insn_storage(struct iseq_compile_data_storage *storage)
+rb_iseq_mark_and_move_insn_storage(struct iseq_compile_data_storage *storage)
{
INSN *iobj = 0;
size_t size = sizeof(INSN);
@@ -12159,7 +12165,7 @@ rb_iseq_mark_and_pin_insn_storage(struct iseq_compile_data_storage *storage)
iobj = (INSN *)&storage->buff[pos];
if (iobj->operands) {
- iseq_insn_each_markable_object(iobj, iseq_insn_each_object_mark_and_pin, (VALUE)0);
+ iseq_insn_each_markable_object(iobj, iseq_insn_each_object_mark_and_move, (VALUE)0);
}
pos += (int)size;
}
diff --git a/iseq.c b/iseq.c
index a0c90f398f..4583591b5d 100644
--- a/iseq.c
+++ b/iseq.c
@@ -232,7 +232,30 @@ iseq_scan_bits(unsigned int page, iseq_bits_t bits, VALUE *code, VALUE *original
}
static void
-rb_iseq_mark_and_move_each_value(const rb_iseq_t *iseq, VALUE *original_iseq)
+rb_iseq_mark_and_move_each_compile_data_value(const rb_iseq_t *iseq, VALUE *original_iseq)
+{
+ unsigned int size;
+ VALUE *code;
+ const struct iseq_compile_data *const compile_data = ISEQ_COMPILE_DATA(iseq);
+
+ size = compile_data->iseq_size;
+ code = compile_data->iseq_encoded;
+
+ // Embedded VALUEs
+ if (compile_data->mark_bits.list) {
+ if(compile_data->is_single_mark_bit) {
+ iseq_scan_bits(0, compile_data->mark_bits.single, code, original_iseq);
+ }
+ else {
+ for (unsigned int i = 0; i < ISEQ_MBITS_BUFLEN(size); i++) {
+ iseq_bits_t bits = compile_data->mark_bits.list[i];
+ iseq_scan_bits(i, bits, code, original_iseq);
+ }
+ }
+ }
+}
+static void
+rb_iseq_mark_and_move_each_body_value(const rb_iseq_t *iseq, VALUE *original_iseq)
{
unsigned int size;
VALUE *code;
@@ -280,11 +303,9 @@ rb_iseq_mark_and_move_each_value(const rb_iseq_t *iseq, VALUE *original_iseq)
iseq_scan_bits(0, body->mark_bits.single, code, original_iseq);
}
else {
- if (body->mark_bits.list) {
- for (unsigned int i = 0; i < ISEQ_MBITS_BUFLEN(size); i++) {
- iseq_bits_t bits = body->mark_bits.list[i];
- iseq_scan_bits(i, bits, code, original_iseq);
- }
+ for (unsigned int i = 0; i < ISEQ_MBITS_BUFLEN(size); i++) {
+ iseq_bits_t bits = body->mark_bits.list[i];
+ iseq_scan_bits(i, bits, code, original_iseq);
}
}
}
@@ -327,7 +348,7 @@ rb_iseq_mark_and_move(rb_iseq_t *iseq, bool reference_updating)
if (ISEQ_BODY(iseq)) {
struct rb_iseq_constant_body *body = ISEQ_BODY(iseq);
- rb_iseq_mark_and_move_each_value(iseq, reference_updating ? ISEQ_ORIGINAL_ISEQ(iseq) : NULL);
+ rb_iseq_mark_and_move_each_body_value(iseq, reference_updating ? ISEQ_ORIGINAL_ISEQ(iseq) : NULL);
rb_gc_mark_and_move(&body->variable.coverage);
rb_gc_mark_and_move(&body->variable.pc2branchindex);
@@ -394,14 +415,8 @@ rb_iseq_mark_and_move(rb_iseq_t *iseq, bool reference_updating)
else if (FL_TEST_RAW((VALUE)iseq, ISEQ_USE_COMPILE_DATA)) {
const struct iseq_compile_data *const compile_data = ISEQ_COMPILE_DATA(iseq);
- if (!reference_updating) {
- /* The operands in each instruction needs to be pinned because
- * if auto-compaction runs in iseq_set_sequence, then the objects
- * could exist on the generated_iseq buffer, which would not be
- * reference updated which can lead to T_MOVED (and subsequently
- * T_NONE) objects on the iseq. */
- rb_iseq_mark_and_pin_insn_storage(compile_data->insn.storage_head);
- }
+ rb_iseq_mark_and_move_insn_storage(compile_data->insn.storage_head);
+ rb_iseq_mark_and_move_each_compile_data_value(iseq, reference_updating ? ISEQ_ORIGINAL_ISEQ(iseq) : NULL);
rb_gc_mark_and_move((VALUE *)&compile_data->err_info);
rb_gc_mark_and_move((VALUE *)&compile_data->catch_table_ary);
diff --git a/iseq.h b/iseq.h
index a9af64572e..1cecc6960d 100644
--- a/iseq.h
+++ b/iseq.h
@@ -104,6 +104,16 @@ struct iseq_compile_data {
const VALUE err_info;
const VALUE catch_table_ary; /* Array */
+ /* Mirror fields from ISEQ_BODY so they are accessible during iseq setup */
+ unsigned int iseq_size;
+ VALUE *iseq_encoded; /* half-encoded iseq (insn addr and operands) */
+ bool is_single_mark_bit; /* identifies whether mark bits are single or a list */
+
+ union {
+ iseq_bits_t * list; /* Find references for GC */
+ iseq_bits_t single;
+ } mark_bits;
+
/* GC is not needed */
struct iseq_label_data *start_label;
struct iseq_label_data *end_label;
@@ -194,7 +204,7 @@ VALUE *rb_iseq_original_iseq(const rb_iseq_t *iseq);
void rb_iseq_build_from_ary(rb_iseq_t *iseq, VALUE misc,
VALUE locals, VALUE args,
VALUE exception, VALUE body);
-void rb_iseq_mark_and_pin_insn_storage(struct iseq_compile_data_storage *arena);
+void rb_iseq_mark_and_move_insn_storage(struct iseq_compile_data_storage *arena);
VALUE rb_iseq_load(VALUE data, VALUE parent, VALUE opt);
VALUE rb_iseq_parameters(const rb_iseq_t *iseq, int is_proc);