[dpdk-dev] [PATCH] eal/rwlocks: Try read/write and relock write to read locks added.
Thomas Monjalon
thomas at monjalon.net
Thu Jul 12 15:55:12 CEST 2018
Hi,
Unfortunately, after 2 months, nobody reviewed this patch.
You could motivate some reviews by providing some explanations
or context of use.
21/05/2018 11:08, Leonid Myravjev:
> From: Leonid Myravjev <myravjev at amicon.ru>
>
> Signed-off-by: Leonid Myravjev <myravjev at amicon.ru>
> ---
> lib/librte_eal/common/include/generic/rte_rwlock.h | 61 ++++++++++++++++++++++
> 1 file changed, 61 insertions(+)
>
> diff --git a/lib/librte_eal/common/include/generic/rte_rwlock.h b/lib/librte_eal/common/include/generic/rte_rwlock.h
> index 899e9bc43..11212e2b8 100644
> --- a/lib/librte_eal/common/include/generic/rte_rwlock.h
> +++ b/lib/librte_eal/common/include/generic/rte_rwlock.h
> @@ -76,6 +76,30 @@ rte_rwlock_read_lock(rte_rwlock_t *rwl)
> }
>
> /**
> + * Try take lock a read lock.
> + *
> + * @param rwl
> + * A pointer to a rwlock structure.
> + * @return
> + * 1 if the lock is successfully taken; 0 otherwise.
> + */
> +static inline int
> +rte_rwlock_read_trylock(rte_rwlock_t *rwl)
> +{
> + int32_t x;
> + int success = 0;
> +
> + x = rwl->cnt;
> + /* write lock is held */
> + if (x < 0)
> + return 0;
> + success = rte_atomic32_cmpset((volatile uint32_t *)&rwl->cnt, x, x + 1);
> + if (success == 0)
> + return 0;
> + return 1;
> +}
> +
> +/**
> * Release a read lock.
> *
> * @param rwl
> @@ -110,6 +134,29 @@ rte_rwlock_write_lock(rte_rwlock_t *rwl)
> 0, -1);
> }
> }
> +/**
> + * Try take a write lock.
> + *
> + * @param rwl
> + * A pointer to a rwlock structure.
> + * @return
> + * 1 if the lock is successfully taken; 0 otherwise.
> + */
> +static inline int
> +rte_rwlock_write_trylock(rte_rwlock_t *rwl)
> +{
> + int32_t x;
> + int success = 0;
> +
> + x = rwl->cnt;
> + /* a lock is held */
> + if (x != 0)
> + return 0;
> + success = rte_atomic32_cmpset((volatile uint32_t *)&rwl->cnt, 0, -1);
> + if (success == 0)
> + return 0;
> + return 1;
> +}
>
> /**
> * Release a write lock.
> @@ -124,6 +171,20 @@ rte_rwlock_write_unlock(rte_rwlock_t *rwl)
> }
>
> /**
> + * Relock write lock to read
> + *
> + * @param rwl
> + * A pointer to a rwlock structure.
> + */
> +static inline void
> +rte_rwlock_write_relock_read(rte_rwlock_t *rwl)
> +{
> + rte_atomic32_add((rte_atomic32_t *)(intptr_t)&rwl->cnt, 2);
> +}
> +
> +
> +
> +/**
> * Try to execute critical section in a hardware memory transaction, if it
> * fails or not available take a read lock
> *
>
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