diff options
Diffstat (limited to 'includes/stg/SMP.h')
| -rw-r--r-- | includes/stg/SMP.h | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/includes/stg/SMP.h b/includes/stg/SMP.h index 389dd95c88..589bde8266 100644 --- a/includes/stg/SMP.h +++ b/includes/stg/SMP.h @@ -52,6 +52,13 @@ EXTERN_INLINE StgWord cas(StgVolatilePtr p, StgWord o, StgWord n); EXTERN_INLINE StgWord8 cas_word8(StgWord8 *volatile p, StgWord8 o, StgWord8 n); /* + * Compare-and-swap + * this uses a seq_cst success memory order and a relaxed failure memory order + */ +EXTERN_INLINE StgWord cas_seq_cst_relaxed(StgVolatilePtr p, StgWord o, StgWord n); + + +/* * Atomic addition by the provided quantity * * atomic_inc(p, n) { @@ -304,6 +311,17 @@ cas_word8(StgWord8 *volatile p, StgWord8 o, StgWord8 n) #endif } +EXTERN_INLINE StgWord +cas_seq_cst_relaxed(StgVolatilePtr p, StgWord o, StgWord n) { +#if defined(HAVE_C11_ATOMICS) + __atomic_compare_exchange_n(p, &o, n, 0, __ATOMIC_SEQ_CST, __ATOMIC_RELAXED); + return o; +#else + return __sync_val_compare_and_swap(p, o, n); +#endif + +} + // RRN: Generalized to arbitrary increments to enable fetch-and-add in // Haskell code (fetchAddIntArray#). // PT: add-and-fetch, returns new value @@ -454,6 +472,9 @@ load_load_barrier(void) { // Non-atomic addition for "approximate" counters that can be lossy #define NONATOMIC_ADD(ptr,val) RELAXED_STORE(ptr, RELAXED_LOAD(ptr) + val) +// compare-and-swap atomic operations +#define SEQ_CST_RELAXED_CAS(p,o,n) cas_seq_cst_relaxed(p,o,n) + // Explicit fences // // These are typically necessary only in very specific cases (e.g. WSDeque) @@ -489,6 +510,9 @@ EXTERN_INLINE void load_load_barrier () {} /* nothing */ // Non-atomic addition for "approximate" counters that can be lossy #define NONATOMIC_ADD(ptr,val) *ptr += val +// compare-and-swap atomic operations +#define SEQ_CST_RELAXED_CAS(p,o,n) cas(p,o,n) + // Fences #define RELEASE_FENCE() #define SEQ_CST_FENCE() |