diff options
Diffstat (limited to 'src/include/port/atomics/fallback.h')
| -rw-r--r-- | src/include/port/atomics/fallback.h | 87 |
1 files changed, 2 insertions, 85 deletions
diff --git a/src/include/port/atomics/fallback.h b/src/include/port/atomics/fallback.h index 2e3eef4acaf..8ffd1a8fd32 100644 --- a/src/include/port/atomics/fallback.h +++ b/src/include/port/atomics/fallback.h @@ -1,7 +1,7 @@ /*------------------------------------------------------------------------- * * fallback.h - * Fallback for platforms without spinlock and/or atomics support. Slower + * Fallback for platforms without 64 bit atomics support. Slower * than native atomics support, but not unusably slow. * * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group @@ -49,50 +49,6 @@ extern void pg_extern_compiler_barrier(void); #endif -/* - * If we have atomics implementation for this platform, fall back to providing - * the atomics API using a spinlock to protect the internal state. Possibly - * the spinlock implementation uses semaphores internally... - * - * We have to be a bit careful here, as it's not guaranteed that atomic - * variables are mapped to the same address in every process (e.g. dynamic - * shared memory segments). We can't just hash the address and use that to map - * to a spinlock. Instead assign a spinlock on initialization of the atomic - * variable. - */ -#if !defined(PG_HAVE_ATOMIC_FLAG_SUPPORT) && !defined(PG_HAVE_ATOMIC_U32_SUPPORT) - -#define PG_HAVE_ATOMIC_FLAG_SIMULATION -#define PG_HAVE_ATOMIC_FLAG_SUPPORT - -typedef struct pg_atomic_flag -{ - /* - * To avoid circular includes we can't use s_lock as a type here. Instead - * just reserve enough space for all spinlock types. Some platforms would - * be content with just one byte instead of 4, but that's not too much - * waste. - */ - int sema; - volatile bool value; -} pg_atomic_flag; - -#endif /* PG_HAVE_ATOMIC_FLAG_SUPPORT */ - -#if !defined(PG_HAVE_ATOMIC_U32_SUPPORT) - -#define PG_HAVE_ATOMIC_U32_SIMULATION - -#define PG_HAVE_ATOMIC_U32_SUPPORT -typedef struct pg_atomic_uint32 -{ - /* Check pg_atomic_flag's definition above for an explanation */ - int sema; - volatile uint32 value; -} pg_atomic_uint32; - -#endif /* PG_HAVE_ATOMIC_U32_SUPPORT */ - #if !defined(PG_HAVE_ATOMIC_U64_SUPPORT) #define PG_HAVE_ATOMIC_U64_SIMULATION @@ -100,49 +56,10 @@ typedef struct pg_atomic_uint32 #define PG_HAVE_ATOMIC_U64_SUPPORT typedef struct pg_atomic_uint64 { - /* Check pg_atomic_flag's definition above for an explanation */ int sema; volatile uint64 value; } pg_atomic_uint64; -#endif /* PG_HAVE_ATOMIC_U64_SUPPORT */ - -#ifdef PG_HAVE_ATOMIC_FLAG_SIMULATION - -#define PG_HAVE_ATOMIC_INIT_FLAG -extern void pg_atomic_init_flag_impl(volatile pg_atomic_flag *ptr); - -#define PG_HAVE_ATOMIC_TEST_SET_FLAG -extern bool pg_atomic_test_set_flag_impl(volatile pg_atomic_flag *ptr); - -#define PG_HAVE_ATOMIC_CLEAR_FLAG -extern void pg_atomic_clear_flag_impl(volatile pg_atomic_flag *ptr); - -#define PG_HAVE_ATOMIC_UNLOCKED_TEST_FLAG -extern bool pg_atomic_unlocked_test_flag_impl(volatile pg_atomic_flag *ptr); - -#endif /* PG_HAVE_ATOMIC_FLAG_SIMULATION */ - -#ifdef PG_HAVE_ATOMIC_U32_SIMULATION - -#define PG_HAVE_ATOMIC_INIT_U32 -extern void pg_atomic_init_u32_impl(volatile pg_atomic_uint32 *ptr, uint32 val_); - -#define PG_HAVE_ATOMIC_WRITE_U32 -extern void pg_atomic_write_u32_impl(volatile pg_atomic_uint32 *ptr, uint32 val); - -#define PG_HAVE_ATOMIC_COMPARE_EXCHANGE_U32 -extern bool pg_atomic_compare_exchange_u32_impl(volatile pg_atomic_uint32 *ptr, - uint32 *expected, uint32 newval); - -#define PG_HAVE_ATOMIC_FETCH_ADD_U32 -extern uint32 pg_atomic_fetch_add_u32_impl(volatile pg_atomic_uint32 *ptr, int32 add_); - -#endif /* PG_HAVE_ATOMIC_U32_SIMULATION */ - - -#ifdef PG_HAVE_ATOMIC_U64_SIMULATION - #define PG_HAVE_ATOMIC_INIT_U64 extern void pg_atomic_init_u64_impl(volatile pg_atomic_uint64 *ptr, uint64 val_); @@ -153,4 +70,4 @@ extern bool pg_atomic_compare_exchange_u64_impl(volatile pg_atomic_uint64 *ptr, #define PG_HAVE_ATOMIC_FETCH_ADD_U64 extern uint64 pg_atomic_fetch_add_u64_impl(volatile pg_atomic_uint64 *ptr, int64 add_); -#endif /* PG_HAVE_ATOMIC_U64_SIMULATION */ +#endif /* PG_HAVE_ATOMIC_U64_SUPPORT */ |