diff options
| -rw-r--r-- | src/atomic_ops_stack.c | 28 | ||||
| -rw-r--r-- | src/atomic_ops_stack.h | 98 |
2 files changed, 63 insertions, 63 deletions
diff --git a/src/atomic_ops_stack.c b/src/atomic_ops_stack.c index 28eba64..0f23fdf 100644 --- a/src/atomic_ops_stack.c +++ b/src/atomic_ops_stack.c @@ -222,12 +222,14 @@ AO_API void AO_stack_init(AO_stack_t *list) AO_API void AO_stack_push_release(AO_stack_t *list, AO_t *x) { - AO_stack_push_explicit_aux_release(&list->AO_ptr, x, &list->AO_aux); + AO_stack_push_explicit_aux_release(&list->AO_pa.AO_ptr, x, + &list->AO_pa.AO_aux); } AO_API AO_t *AO_stack_pop_acquire(AO_stack_t *list) { - return AO_stack_pop_explicit_aux_acquire(&list->AO_ptr, &list->AO_aux); + return AO_stack_pop_explicit_aux_acquire(&list->AO_pa.AO_ptr, + &list->AO_pa.AO_aux); } #else /* ! USE_ALMOST_LOCK_FREE */ @@ -254,8 +256,8 @@ AO_API void AO_stack_init(AO_stack_t *list) # endif /* !AO_THREAD_SANITIZER */ /* Better names for fields in AO_stack_t. */ -# define ptr AO_val2 -# define version AO_val1 +# define version AO_vp.AO_val1 +# define ptr AO_vp.AO_val2 # if defined(AO_HAVE_compare_double_and_swap_double) \ && !(defined(AO_STACK_PREFER_CAS_DOUBLE) \ @@ -303,9 +305,9 @@ AO_API void AO_stack_init(AO_stack_t *list) if (NULL == cptr) return NULL; next = load_before_cas((AO_t *)cptr); - } while (AO_EXPECT_FALSE(!AO_compare_double_and_swap_double_release(list, - cversion, (AO_t)cptr, - cversion+1, (AO_t)next))); + } while (AO_EXPECT_FALSE(!AO_compare_double_and_swap_double_release( + &list->AO_vp, cversion, (AO_t)cptr, + cversion+1, (AO_t)next))); return cptr; } @@ -319,17 +321,17 @@ AO_API void AO_stack_init(AO_stack_t *list) /* for an unchanged version number, not an unchanged pointer. */ AO_API void AO_stack_push_release(AO_stack_t *list, AO_t *element) { - AO_t version; + AO_t cversion; do { AO_t next_ptr; /* Again version must be loaded first, for different reason. */ - version = AO_load_acquire(&list->version); + cversion = AO_load_acquire(&list->version); next_ptr = AO_load(&list->ptr); store_before_cas(element, next_ptr); - } while (!AO_compare_and_swap_double_release(list, version, version+1, - (AO_t)element)); + } while (!AO_compare_and_swap_double_release(&list->AO_vp, cversion, + cversion+1, (AO_t)element)); } AO_API AO_t *AO_stack_pop_acquire(AO_stack_t *list) @@ -344,10 +346,12 @@ AO_API void AO_stack_init(AO_stack_t *list) if (NULL == cptr) return NULL; next = load_before_cas(cptr); - } while (!AO_compare_double_and_swap_double_release(list, + } while (!AO_compare_double_and_swap_double_release(&list->AO_vp, cversion, (AO_t)cptr, cversion+1, next)); return cptr; } # endif /* AO_HAVE_compare_and_swap_double */ +# undef ptr +# undef version #endif /* ! USE_ALMOST_LOCK_FREE */ diff --git a/src/atomic_ops_stack.h b/src/atomic_ops_stack.h index 642026e..ef54d16 100644 --- a/src/atomic_ops_stack.h +++ b/src/atomic_ops_stack.h @@ -31,6 +31,12 @@ #include "atomic_ops.h" +#ifndef AO_HAVE_double_t + /* Can happen if we are using CAS emulation, since we do not want to */ + /* force that here, in case other atomic_ops clients do not want it. */ +# include "atomic_ops/sysdeps/standard_ao_double_t.h" +#endif + #ifdef __cplusplus extern "C" { #endif @@ -73,31 +79,49 @@ * compare-and-swap operations are available. */ -#ifdef AO_USE_ALMOST_LOCK_FREE +/* AO_stack_aux should be treated as opaque. It is fully defined */ +/* here, so it can be allocated, and also to facilitate debugging. */ +/* Note: changing the value of AO_BL_SIZE leads to the ABI change. */ +#ifndef AO_BL_SIZE +# define AO_BL_SIZE 2 +#endif - /* The number of low order pointer bits we can use for a small */ - /* version number. */ -# if defined(__LP64__) || defined(_LP64) || defined(_WIN64) -# define AO_N_BITS 3 -# else -# define AO_N_BITS 2 -# endif +/* The number of low order pointer bits we can use for a small */ +/* version number. */ +#if defined(__LP64__) || defined(_LP64) || defined(_WIN64) +# define AO_N_BITS 3 +#else +# define AO_N_BITS 2 +#endif -# define AO_BIT_MASK ((1 << AO_N_BITS) - 1) +#define AO_BIT_MASK ((1 << AO_N_BITS) - 1) + +#if AO_BL_SIZE > (1 << AO_N_BITS) +# error AO_BL_SIZE too big +#endif - /* AO_stack_aux should be treated as opaque. It is fully defined */ - /* here, so it can be allocated, and to facilitate debugging. */ -# ifndef AO_BL_SIZE -# define AO_BL_SIZE 2 -# endif +typedef struct AO__stack_aux { + volatile AO_t AO_stack_bl[AO_BL_SIZE]; +} AO_stack_aux; -# if AO_BL_SIZE > (1 << AO_N_BITS) -# error AO_BL_SIZE too big -# endif +struct AO__stack_ptr_aux { + volatile AO_t AO_ptr; + AO_stack_aux AO_aux; +}; - typedef struct AO__stack_aux { - volatile AO_t AO_stack_bl[AO_BL_SIZE]; - } AO_stack_aux; +/* The AO stack type. Should be treated as opaque. */ +/* Note: AO_stack_t variables are not intended to be local ones, */ +/* otherwise it is the client responsibility to ensure they have */ +/* double-word alignment. */ +typedef union AO__stack { + struct AO__stack_ptr_aux AO_pa; + volatile AO_double_t AO_vp; +} AO_stack_t; + +/* The static initializer of the AO stack type. */ +#define AO_STACK_INITIALIZER { /* .AO_pa= */ { 0, { {0} } } } + +#ifdef AO_USE_ALMOST_LOCK_FREE /* The stack implementation knows only about the location of */ /* link fields in nodes, and nothing about the rest of the */ @@ -110,6 +134,7 @@ /* The following two routines should not normally be used directly. */ /* We make them visible here for the rare cases in which it makes */ /* sense to share the AO_stack_aux between stacks. */ + AO_API void AO_stack_push_explicit_aux_release(volatile AO_t *list, AO_t *x, AO_stack_aux *); @@ -117,42 +142,13 @@ AO_API AO_t * AO_stack_pop_explicit_aux_acquire(volatile AO_t *list, AO_stack_aux *); - /* And now AO_stack_t for the real interface: */ - - typedef struct AO__stack { - volatile AO_t AO_ptr; - AO_stack_aux AO_aux; - } AO_stack_t; - -# define AO_STACK_INITIALIZER {0,{{0}}} - /* Convert an AO_stack_t to a pointer to the link field in */ /* the first element. */ -# define AO_REAL_HEAD_PTR(x) AO_REAL_NEXT_PTR((x).AO_ptr) +# define AO_REAL_HEAD_PTR(x) AO_REAL_NEXT_PTR((x).AO_pa.AO_ptr) #else /* Use fully non-blocking data structure, wide CAS. */ -# ifndef AO_HAVE_double_t - /* Can happen if we are using CAS emulation, since we don't want to */ - /* force that here, in case other atomic_ops clients don't want it. */ -# ifdef __cplusplus - } /* extern "C" */ -# endif -# include "atomic_ops/sysdeps/standard_ao_double_t.h" -# ifdef __cplusplus - extern "C" { -# endif -# endif - - typedef volatile AO_double_t AO_stack_t; - /* AO_val1 is version, AO_val2 is pointer. */ - /* Note: AO_stack_t variables are not intended to be local ones, */ - /* otherwise it is the client responsibility to ensure they have */ - /* double-word alignment. */ - -# define AO_STACK_INITIALIZER AO_DOUBLE_T_INITIALIZER - -# define AO_REAL_HEAD_PTR(x) (AO_t *)((x).AO_val2) +# define AO_REAL_HEAD_PTR(x) (AO_t *)((x).AO_vp.AO_val2) # define AO_REAL_NEXT_PTR(x) (AO_t *)(x) #endif /* !AO_USE_ALMOST_LOCK_FREE */ |