diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/atomic.h | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/include/atomic.h b/include/atomic.h index bd2e2f13f7..340c6e6bfb 100644 --- a/include/atomic.h +++ b/include/atomic.h @@ -21,6 +21,26 @@ #ifndef _ATOMIC_H #define _ATOMIC_H 1 +/* This header defines three types of macros: + + - atomic arithmetic and logic operation on memory. They all + have the prefix "atomic_". + + - conditionally atomic operations of the same kinds. These + always behave identical but can be faster when atomicity + is not really needed since only one thread has access to + the memory location. In that case the code is slower in + the multi-thread case. The interfaces have the prefix + "catomic_". + + - support functions like barriers. They also have the preifx + "atomic_". + + Architectures must provide a few lowlevel macros (the compare + and exchange definitions). All others are optional. They + should only be provided if the architecture has specific + support for the operation. */ + #include <stdlib.h> #include <bits/atomic.h> @@ -70,12 +90,29 @@ #endif +#if !defined catomic_compare_and_exchange_val_acq \ + && defined __arch_c_compare_and_exchange_val_32_acq +# define catomic_compare_and_exchange_val_acq(mem, newval, oldval) \ + __atomic_val_bysize (__arch_c_compare_and_exchange_val,acq, \ + mem, newval, oldval) +#else +# define catomic_compare_and_exchange_val_acq(mem, newval, oldval) \ + atomic_compare_and_exchange_val_acq (mem, newval, oldval) +#endif + + #ifndef atomic_compare_and_exchange_val_rel # define atomic_compare_and_exchange_val_rel(mem, newval, oldval) \ atomic_compare_and_exchange_val_acq (mem, newval, oldval) #endif +#ifndef catomic_compare_and_exchange_val_rel +# define catomic_compare_and_exchange_val_rel(mem, newval, oldval) \ + atomic_compare_and_exchange_val_acq (mem, newval, oldval) +#endif + + /* Atomically store NEWVAL in *MEM if *MEM is equal to OLDVAL. Return zero if *MEM was changed or non-zero if no exchange happened. */ #ifndef atomic_compare_and_exchange_bool_acq @@ -94,12 +131,34 @@ #endif +#ifndef catomic_compare_and_exchange_bool_acq +# ifdef __arch_c_compare_and_exchange_bool_32_acq +# define catomic_compare_and_exchange_bool_acq(mem, newval, oldval) \ + __atomic_bool_bysize (__arch_c_compare_and_exchange_bool,acq, \ + mem, newval, oldval) +# else +# define catomic_compare_and_exchange_bool_acq(mem, newval, oldval) \ + ({ /* Cannot use __oldval here, because macros later in this file might \ + call this macro with __oldval argument. */ \ + __typeof (oldval) __old = (oldval); \ + catomic_compare_and_exchange_val_acq (mem, newval, __old) != __old; \ + }) +# endif +#endif + + #ifndef atomic_compare_and_exchange_bool_rel # define atomic_compare_and_exchange_bool_rel(mem, newval, oldval) \ atomic_compare_and_exchange_bool_acq (mem, newval, oldval) #endif +#ifndef catomic_compare_and_exchange_bool_rel +# define catomic_compare_and_exchange_bool_rel(mem, newval, oldval) \ + catomic_compare_and_exchange_bool_acq (mem, newval, oldval) +#endif + + /* Store NEWVALUE in *MEM and return the old value. */ #ifndef atomic_exchange_acq # define atomic_exchange_acq(mem, newvalue) \ @@ -141,6 +200,23 @@ #endif +#ifndef catomic_exchange_and_add +# define catomic_exchange_and_add(mem, value) \ + ({ __typeof (*(mem)) __oldv; \ + __typeof (mem) __memp = (mem); \ + __typeof (*(mem)) __value = (value); \ + \ + do \ + __oldv = *__memp; \ + while (__builtin_expect (catomic_compare_and_exchange_bool_acq (__memp, \ + __oldv \ + + __value,\ + __oldv), \ + 0)); \ + \ + __oldv; }) +#endif + #ifndef atomic_max # define atomic_max(mem, value) \ @@ -159,6 +235,25 @@ } while (0) #endif + +#ifndef catomic_max +# define catomic_max(mem, value) \ + do { \ + __typeof (*(mem)) __oldv; \ + __typeof (mem) __memp = (mem); \ + __typeof (*(mem)) __value = (value); \ + do { \ + __oldv = *__memp; \ + if (__oldv >= __value) \ + break; \ + } while (__builtin_expect (catomic_compare_and_exchange_bool_acq (__memp, \ + __value,\ + __oldv),\ + 0)); \ + } while (0) +#endif + + #ifndef atomic_min # define atomic_min(mem, value) \ do { \ @@ -176,21 +271,38 @@ } while (0) #endif + #ifndef atomic_add # define atomic_add(mem, value) (void) atomic_exchange_and_add ((mem), (value)) #endif +#ifndef catomic_add +# define catomic_add(mem, value) \ + (void) catomic_exchange_and_add ((mem), (value)) +#endif + + #ifndef atomic_increment # define atomic_increment(mem) atomic_add ((mem), 1) #endif +#ifndef catomic_increment +# define catomic_increment(mem) catomic_add ((mem), 1) +#endif + + #ifndef atomic_increment_val # define atomic_increment_val(mem) (atomic_exchange_and_add ((mem), 1) + 1) #endif +#ifndef catomic_increment_val +# define catomic_increment_val(mem) (catomic_exchange_and_add ((mem), 1) + 1) +#endif + + /* Add one to *MEM and return true iff it's now zero. */ #ifndef atomic_increment_and_test # define atomic_increment_and_test(mem) \ @@ -203,11 +315,21 @@ #endif +#ifndef catomic_decrement +# define catomic_decrement(mem) catomic_add ((mem), -1) +#endif + + #ifndef atomic_decrement_val # define atomic_decrement_val(mem) (atomic_exchange_and_add ((mem), -1) - 1) #endif +#ifndef catomic_decrement_val +# define catomic_decrement_val(mem) (catomic_exchange_and_add ((mem), -1) - 1) +#endif + + /* Subtract 1 from *MEM and return true iff it's now zero. */ #ifndef atomic_decrement_and_test # define atomic_decrement_and_test(mem) \ @@ -327,6 +449,23 @@ } while (0) #endif +#ifndef catomic_or +# define catomic_or(mem, mask) \ + do { \ + __typeof (*(mem)) __oldval; \ + __typeof (mem) __memp = (mem); \ + __typeof (*(mem)) __mask = (mask); \ + \ + do \ + __oldval = (*__memp); \ + while (__builtin_expect (catomic_compare_and_exchange_bool_acq (__memp, \ + __oldval \ + | __mask, \ + __oldval),\ + 0)); \ + } while (0) +#endif + /* Atomically *mem |= mask and return the old value of *mem. */ #ifndef atomic_or_val # define atomic_or_val(mem, mask) \ |