diff options
Diffstat (limited to 'runtime/atomic.h')
| -rw-r--r-- | runtime/atomic.h | 200 |
1 files changed, 71 insertions, 129 deletions
diff --git a/runtime/atomic.h b/runtime/atomic.h index 271e825e..fc3e0b2d 100644 --- a/runtime/atomic.h +++ b/runtime/atomic.h @@ -39,134 +39,29 @@ * They simply came in too late. -- rgerhards, 2008-04-02 */ #ifdef HAVE_ATOMIC_BUILTINS -# define ATOMIC_INC(data) ((void) __sync_fetch_and_add(&(data), 1)) +# define ATOMIC_INC(data, phlpmut) ((void) __sync_fetch_and_add(data, 1)) # define ATOMIC_INC_AND_FETCH(data) __sync_fetch_and_add(&(data), 1) -# define ATOMIC_DEC(data) ((void) __sync_sub_and_fetch(&(data), 1)) -# define ATOMIC_DEC_AND_FETCH(data) __sync_sub_and_fetch(&(data), 1) +# define ATOMIC_DEC(data, phlpmut) ((void) __sync_sub_and_fetch(data, 1)) +# define ATOMIC_DEC_AND_FETCH(data, phlpmut) __sync_sub_and_fetch(data, 1) # define ATOMIC_FETCH_32BIT(data) ((unsigned) __sync_fetch_and_and(&(data), 0xffffffff)) # define ATOMIC_STORE_1_TO_32BIT(data) __sync_lock_test_and_set(&(data), 1) -# define ATOMIC_STORE_0_TO_INT(data) __sync_fetch_and_and(&(data), 0) -# define ATOMIC_STORE_1_TO_INT(data) __sync_fetch_and_or(&(data), 1) +# define ATOMIC_STORE_0_TO_INT(data, phlpmut) __sync_fetch_and_and(data, 0) +# define ATOMIC_STORE_1_TO_INT(data, phlpmut) __sync_fetch_and_or(data, 1) # define ATOMIC_STORE_INT_TO_INT(data, val) __sync_fetch_and_or(&(data), (val)) # define ATOMIC_CAS(data, oldVal, newVal) __sync_bool_compare_and_swap(&(data), (oldVal), (newVal)); -# define ATOMIC_CAS_VAL(data, oldVal, newVal) __sync_val_compare_and_swap(&(data), (oldVal), (newVal)); -#else -#ifdef HAVE_SEMAPHORE_H - /* we use POSIX semaphores instead */ - -#include "rsyslog.h" -#include <semaphore.h> - -extern sem_t atomicSem; -rsRetVal atomicSemInit(void); -void atomicSemExit(void); - -#if HAVE_TYPEOF -#define my_typeof(x) typeof(x) -#else /* sorry, can't determine types, using 'int' */ -#define my_typeof(x) int -#endif - -# define ATOMIC_SUB(data, val) \ -({ \ - my_typeof(data) tmp; \ - sem_wait(&atomicSem); \ - tmp = data; \ - data -= val; \ - sem_post(&atomicSem); \ - tmp; \ -}) - -# define ATOMIC_ADD(data, val) \ -({ \ - my_typeof(data) tmp; \ - sem_wait(&atomicSem); \ - tmp = data; \ - data += val; \ - sem_post(&atomicSem); \ - tmp; \ -}) - -# define ATOMIC_INC_AND_FETCH(data) \ -({ \ - my_typeof(data) tmp; \ - sem_wait(&atomicSem); \ - tmp = data; \ - data += 1; \ - sem_post(&atomicSem); \ - tmp; \ -}) - -# define ATOMIC_INC(data) ((void) ATOMIC_INC_AND_FETCH(data)) - -# define ATOMIC_DEC_AND_FETCH(data) \ -({ \ - sem_wait(&atomicSem); \ - data -= 1; \ - sem_post(&atomicSem); \ - data; \ -}) +# define ATOMIC_CAS_VAL(data, oldVal, newVal, phlpmut) __sync_val_compare_and_swap(data, (oldVal), (newVal)); -# define ATOMIC_DEC(data) ((void) ATOMIC_DEC_AND_FETCH(data)) + /* functions below are not needed if we have atomics */ +# define DEF_ATOMIC_HELPER_MUT(x) +# define INIT_ATOMIC_HELPER_MUT(x) +# define DESTROY_ATOMIC_HELPER_MUT(x) -# define ATOMIC_FETCH_32BIT(data) ((unsigned) ATOMIC_ADD((data), 0xffffffff)) - -# define ATOMIC_STORE_1_TO_32BIT(data) \ -({ \ - my_typeof(data) tmp; \ - sem_wait(&atomicSem); \ - tmp = data; \ - data = 1; \ - sem_post(&atomicSem); \ - tmp; \ -}) - -# define ATOMIC_STORE_0_TO_INT(data) \ -({ \ - my_typeof(data) tmp; \ - sem_wait(&atomicSem); \ - tmp = data; \ - data = 0; \ - sem_post(&atomicSem); \ - tmp; \ -}) - -# define ATOMIC_STORE_1_TO_INT(data) \ -({ \ - my_typeof(data) tmp; \ - sem_wait(&atomicSem); \ - tmp = data; \ - data = 1; \ - sem_post(&atomicSem); \ - tmp; \ -}) - -# define ATOMIC_CAS(data, oldVal, newVal) \ -({ \ - int ret; \ - sem_wait(&atomicSem); \ - if(data != oldVal) ret = 0; \ - else \ - { \ - data = newVal; \ - ret = 1; \ - } \ - sem_post(&atomicSem); \ - ret; \ -}) - -# define ATOMIC_CAS_VAL(data, oldVal, newVal) \ -({ \ - sem_wait(&atomicSem); \ - if(data == oldVal) \ - { \ - data = newVal; \ - } \ - sem_post(&atomicSem); \ - data; \ -}) - -#else /* not HAVE_SEMAPHORE_H */ + /* the following operations should preferrably be done atomic, but it is + * not fatal if not -- that means we can live with some missed updates. So be + * sure to use these macros only if that really does not matter! + */ +# define PREFER_ATOMIC_INC(data) ((void) __sync_fetch_and_add(&(data), 1)) +#else /* note that we gained parctical proof that theoretical problems DO occur * if we do not properly address them. See this blog post for details: * http://blog.gerhards.net/2009/01/rsyslog-data-race-analysis.html @@ -174,16 +69,63 @@ void atomicSemExit(void); * simply go ahead and do without them - use mutexes or other things. The * code needs to be checked against all those cases. -- rgerhards, 2009-01-30 */ + #include <pthread.h> +# define ATOMIC_INC(data, phlpmut) { \ + pthread_mutex_lock(phlpmut); \ + ++(*(data)); \ + pthread_mutex_unlock(phlpmut); \ + } + +# define ATOMIC_STORE_0_TO_INT(data, hlpmut) { \ + pthread_mutex_lock(&hlpmut); \ + *(data) = 0; \ + pthread_mutex_unlock(&hlpmut); \ + } + +# define ATOMIC_STORE_1_TO_INT(data, hlpmut) { \ + pthread_mutex_lock(&hlpmut); \ + *(data) = 1; \ + pthread_mutex_unlock(&hlpmut); \ + } + + static inline int + ATOMIC_CAS_VAL(int *data, int oldVal, int newVal, pthread_mutex_t *phlpmut) { + int val; + pthread_mutex_lock(phlpmut); + if(*data == oldVal) { + *data = newVal; + } + val = *data; + pthread_mutex_unlock(phlpmut); + return(val); + } + +# define ATOMIC_DEC(data, phlpmut) { \ + pthread_mutex_lock(phlpmut); \ + --(*(data)); \ + pthread_mutex_unlock(phlpmut); \ + } + + static inline int + ATOMIC_DEC_AND_FETCH(int *data, pthread_mutex_t *phlpmut) { + int val; + pthread_mutex_lock(phlpmut); + val = --(*data); + pthread_mutex_unlock(phlpmut); + return(val); + } +#if 0 # warning "atomic builtins not available, using nul operations - rsyslogd will probably be racy!" -# define ATOMIC_INC(data) (++(data)) -# define ATOMIC_DEC(data) (--(data)) -# define ATOMIC_DEC_AND_FETCH(data) (--(data)) -# define ATOMIC_FETCH_32BIT(data) (data) -# define ATOMIC_STORE_1_TO_32BIT(data) (data) = 1 -# define ATOMIC_STORE_1_TO_INT(data) (data) = 1 -# define ATOMIC_STORE_0_TO_INT(data) (data) = 0 -# define ATOMIC_CAS_VAL(data, oldVal, newVal) (data) = (newVal) +# define ATOMIC_INC_AND_FETCH(data) (++(data)) +# define ATOMIC_FETCH_32BIT(data) (data) // TODO: del +# define ATOMIC_STORE_1_TO_32BIT(data) (data) = 1 // TODO: del #endif +# define DEF_ATOMIC_HELPER_MUT(x) pthread_mutex_t x +# define INIT_ATOMIC_HELPER_MUT(x) pthread_mutex_init(&(x), NULL) +# define DESTROY_ATOMIC_HELPER_MUT(x) pthread_mutex_init(&(x), NULL) + +# define PREFER_ATOMIC_INC(data) ((void) ++data) + #endif #endif /* #ifndef INCLUDED_ATOMIC_H */ |