diff options
| -rw-r--r-- | src/include/port/atomics.h | 58 | ||||
| -rw-r--r-- | src/include/port/atomics/generic.h | 36 |
2 files changed, 94 insertions, 0 deletions
diff --git a/src/include/port/atomics.h b/src/include/port/atomics.h index 504349080d4..ff47782cdba 100644 --- a/src/include/port/atomics.h +++ b/src/include/port/atomics.h @@ -238,6 +238,26 @@ pg_atomic_read_u32(volatile pg_atomic_uint32 *ptr) } /* + * pg_atomic_read_membarrier_u32 - read with barrier semantics. + * + * This read is guaranteed to return the current value, provided that the value + * is only ever updated via operations with barrier semantics, such as + * pg_atomic_compare_exchange_u32() and pg_atomic_write_membarrier_u32(). + * While this may be less performant than pg_atomic_read_u32(), it may be + * easier to reason about correctness with this function in less performance- + * sensitive code. + * + * Full barrier semantics. + */ +static inline uint32 +pg_atomic_read_membarrier_u32(volatile pg_atomic_uint32 *ptr) +{ + AssertPointerAlignment(ptr, 4); + + return pg_atomic_read_membarrier_u32_impl(ptr); +} + +/* * pg_atomic_write_u32 - write to atomic variable. * * The write is guaranteed to succeed as a whole, i.e. it's not possible to @@ -275,6 +295,26 @@ pg_atomic_unlocked_write_u32(volatile pg_atomic_uint32 *ptr, uint32 val) } /* + * pg_atomic_write_membarrier_u32 - write with barrier semantics. + * + * The write is guaranteed to succeed as a whole, i.e., it's not possible to + * observe a partial write for any reader. Note that this correctly interacts + * with both pg_atomic_compare_exchange_u32() and + * pg_atomic_read_membarrier_u32(). While this may be less performant than + * pg_atomic_write_u32(), it may be easier to reason about correctness with + * this function in less performance-sensitive code. + * + * Full barrier semantics. + */ +static inline void +pg_atomic_write_membarrier_u32(volatile pg_atomic_uint32 *ptr, uint32 val) +{ + AssertPointerAlignment(ptr, 4); + + pg_atomic_write_membarrier_u32_impl(ptr, val); +} + +/* * pg_atomic_exchange_u32 - exchange newval with current value * * Returns the old value of 'ptr' before the swap. @@ -427,6 +467,15 @@ pg_atomic_read_u64(volatile pg_atomic_uint64 *ptr) return pg_atomic_read_u64_impl(ptr); } +static inline uint64 +pg_atomic_read_membarrier_u64(volatile pg_atomic_uint64 *ptr) +{ +#ifndef PG_HAVE_ATOMIC_U64_SIMULATION + AssertPointerAlignment(ptr, 8); +#endif + return pg_atomic_read_membarrier_u64_impl(ptr); +} + static inline void pg_atomic_write_u64(volatile pg_atomic_uint64 *ptr, uint64 val) { @@ -436,6 +485,15 @@ pg_atomic_write_u64(volatile pg_atomic_uint64 *ptr, uint64 val) pg_atomic_write_u64_impl(ptr, val); } +static inline void +pg_atomic_write_membarrier_u64(volatile pg_atomic_uint64 *ptr, uint64 val) +{ +#ifndef PG_HAVE_ATOMIC_U64_SIMULATION + AssertPointerAlignment(ptr, 8); +#endif + pg_atomic_write_membarrier_u64_impl(ptr, val); +} + static inline uint64 pg_atomic_exchange_u64(volatile pg_atomic_uint64 *ptr, uint64 newval) { diff --git a/src/include/port/atomics/generic.h b/src/include/port/atomics/generic.h index c3b5f6d9a42..6113ab62a31 100644 --- a/src/include/port/atomics/generic.h +++ b/src/include/port/atomics/generic.h @@ -243,6 +243,24 @@ pg_atomic_sub_fetch_u32_impl(volatile pg_atomic_uint32 *ptr, int32 sub_) } #endif +#if !defined(PG_HAVE_ATOMIC_READ_MEMBARRIER_U32) && defined(PG_HAVE_ATOMIC_FETCH_ADD_U32) +#define PG_HAVE_ATOMIC_READ_MEMBARRIER_U32 +static inline uint32 +pg_atomic_read_membarrier_u32_impl(volatile pg_atomic_uint32 *ptr) +{ + return pg_atomic_fetch_add_u32_impl(ptr, 0); +} +#endif + +#if !defined(PG_HAVE_ATOMIC_WRITE_MEMBARRIER_U32) && defined(PG_HAVE_ATOMIC_EXCHANGE_U32) +#define PG_HAVE_ATOMIC_WRITE_MEMBARRIER_U32 +static inline void +pg_atomic_write_membarrier_u32_impl(volatile pg_atomic_uint32 *ptr, uint32 val) +{ + (void) pg_atomic_exchange_u32_impl(ptr, val); +} +#endif + #if !defined(PG_HAVE_ATOMIC_EXCHANGE_U64) && defined(PG_HAVE_ATOMIC_COMPARE_EXCHANGE_U64) #define PG_HAVE_ATOMIC_EXCHANGE_U64 static inline uint64 @@ -399,3 +417,21 @@ pg_atomic_sub_fetch_u64_impl(volatile pg_atomic_uint64 *ptr, int64 sub_) return pg_atomic_fetch_sub_u64_impl(ptr, sub_) - sub_; } #endif + +#if !defined(PG_HAVE_ATOMIC_READ_MEMBARRIER_U64) && defined(PG_HAVE_ATOMIC_FETCH_ADD_U64) +#define PG_HAVE_ATOMIC_READ_MEMBARRIER_U64 +static inline uint64 +pg_atomic_read_membarrier_u64_impl(volatile pg_atomic_uint64 *ptr) +{ + return pg_atomic_fetch_add_u64_impl(ptr, 0); +} +#endif + +#if !defined(PG_HAVE_ATOMIC_WRITE_MEMBARRIER_U64) && defined(PG_HAVE_ATOMIC_EXCHANGE_U64) +#define PG_HAVE_ATOMIC_WRITE_MEMBARRIER_U64 +static inline void +pg_atomic_write_membarrier_u64_impl(volatile pg_atomic_uint64 *ptr, uint64 val) +{ + (void) pg_atomic_exchange_u64_impl(ptr, val); +} +#endif |