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bring inline with C11 atomics; no volatile and cas order of expected/desired

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daan
2020-07-25 22:52:27 -07:00
parent e27422adca
commit 09ade02429
12 changed files with 170 additions and 188 deletions
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11
src/bitmap.inc.c
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@@ -30,7 +30,7 @@ and that the sequence must be smaller or equal to the bits in a field.
#define MI_BITMAP_FIELD_FULL (~((uintptr_t)0)) // all bits set
// An atomic bitmap of `uintptr_t` fields
typedef volatile _Atomic(uintptr_t) mi_bitmap_field_t;
typedef _Atomic(uintptr_t) mi_bitmap_field_t;
typedef mi_bitmap_field_t* mi_bitmap_t;
// A bitmap index is the index of the bit in a bitmap.
@@ -123,7 +123,7 @@ static inline bool mi_bitmap_try_claim_field(mi_bitmap_t bitmap, size_t bitmap_f
uintptr_t field = mi_atomic_read_relaxed(&bitmap[idx]);
if ((field & mask) == 0) { // free?
if (mi_atomic_cas_strong(&bitmap[idx], (field|mask), field)) {
if (mi_atomic_cas_strong(&bitmap[idx], &field, (field|mask))) {
// claimed!
return true;
}
@@ -137,7 +137,7 @@ static inline bool mi_bitmap_try_claim_field(mi_bitmap_t bitmap, size_t bitmap_f
static inline bool mi_bitmap_try_find_claim_field(mi_bitmap_t bitmap, size_t idx, const size_t count, mi_bitmap_index_t* bitmap_idx)
{
mi_assert_internal(bitmap_idx != NULL);
volatile _Atomic(uintptr_t)* field = &bitmap[idx];
_Atomic(uintptr_t)* field = &bitmap[idx];
uintptr_t map = mi_atomic_read(field);
if (map==MI_BITMAP_FIELD_FULL) return false; // short cut
@@ -158,9 +158,8 @@ static inline bool mi_bitmap_try_find_claim_field(mi_bitmap_t bitmap, size_t idx
mi_assert_internal((m >> bitidx) == mask); // no overflow?
const uintptr_t newmap = map | m;
mi_assert_internal((newmap^map) >> bitidx == mask);
if (!mi_atomic_cas_weak(field, newmap, map)) { // TODO: use strong cas here?
// no success, another thread claimed concurrently.. keep going
map = mi_atomic_read(field);
if (!mi_atomic_cas_weak(field, &map, newmap)) { // TODO: use strong cas here?
// no success, another thread claimed concurrently.. keep going (with updated `map`)
continue;
}
else {