Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Small fixes to work-stealing-queue #55629

Open
wants to merge 2 commits into
base: master
Choose a base branch
from
+8 −5
Open

Small fixes to work-stealing-queue #55629

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
675bdd5
Prevent overflow of t to be an issue
vchuravy Aug 29, 2024
6aeee18
Change relaxed to acquire
vchuravy Aug 29, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
13 changes: 8 additions & 5 deletions src/work-stealing-queue.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -55,7 +55,8 @@ static inline ws_array_t *ws_queue_push(ws_queue_t *q, void *elt, int32_t eltsz)
int64_t t = jl_atomic_load_acquire(&q->top);
ws_array_t *ary = jl_atomic_load_relaxed(&q->array);
ws_array_t *old_ary = NULL;
if (__unlikely(b - t > ary->capacity - 1)) {
int64_t size = b - t;
if (__unlikely(size > ary->capacity - 1)) {
ws_array_t *new_ary = create_ws_array(2 * ary->capacity, eltsz);
for (int i = 0; i < ary->capacity; i++) {
memcpy(new_ary->buffer + ((t + i) & new_ary->mask) * eltsz, ary->buffer + ((t + i) & ary->mask) * eltsz, eltsz);
Expand All @@ -77,9 +78,10 @@ static inline void ws_queue_pop(ws_queue_t *q, void *dest, int32_t eltsz) JL_NOT
jl_atomic_store_relaxed(&q->bottom, b);
jl_fence();
int64_t t = jl_atomic_load_relaxed(&q->top);
if (__likely(t <= b)) {
int64_t size = b - t + 1;
if (__likely(size > 0)) {
memcpy(dest, ary->buffer + (b & ary->mask) * eltsz, eltsz);
if (t == b) {
if (size == 1) {
if (!jl_atomic_cmpswap(&q->top, &t, t + 1))
memset(dest, 0, eltsz);
jl_atomic_store_relaxed(&q->bottom, b + 1);
Expand All @@ -96,8 +98,9 @@ static inline void ws_queue_steal_from(ws_queue_t *q, void *dest, int32_t eltsz)
int64_t t = jl_atomic_load_acquire(&q->top);
jl_fence();
int64_t b = jl_atomic_load_acquire(&q->bottom);
if (t < b) {
ws_array_t *ary = jl_atomic_load_relaxed(&q->array);
int64_t size = b - t;
if (size > 0) {
ws_array_t *ary = jl_atomic_load_acquire(&q->array); // consume in Le
memcpy(dest, ary->buffer + (t & ary->mask) * eltsz, eltsz);
if (!jl_atomic_cmpswap(&q->top, &t, t + 1))
memset(dest, 0, eltsz);
Expand Down