From: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>
To: Konstantin Ananyev <konstantin.ananyev@intel.com>,
"dev@dpdk.org" <dev@dpdk.org>
Cc: nd <nd@arm.com>,
Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>,
"Gavin Hu (Arm Technology China)" <Gavin.Hu@arm.com>,
nd <nd@arm.com>
Subject: Re: [dpdk-dev] [PATCH 1/2] rwlock: introduce 'try' semantics for RD and WR locking
Date: Wed, 19 Dec 2018 06:37:37 +0000 [thread overview]
Message-ID: <AM6PR08MB367213976F11F1C407FF195398BE0@AM6PR08MB3672.eurprd08.prod.outlook.com> (raw)
In-Reply-To: <1542130061-3702-2-git-send-email-konstantin.ananyev@intel.com>
>
> This patch targets 19.02 release.
>
> Introduce rte_rwlock_read_trylock() and rte_rwlock_write_trylock().
> Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> ---
> .../common/include/generic/rte_rwlock.h | 54 +++++++++++++++++++
> lib/librte_eal/rte_eal_version.map | 2 +
> 2 files changed, 56 insertions(+)
>
> diff --git a/lib/librte_eal/common/include/generic/rte_rwlock.h
> b/lib/librte_eal/common/include/generic/rte_rwlock.h
> index 5751a0e6d..7e395781e 100644
> --- a/lib/librte_eal/common/include/generic/rte_rwlock.h
> +++ b/lib/librte_eal/common/include/generic/rte_rwlock.h
> @@ -75,6 +75,33 @@ rte_rwlock_read_lock(rte_rwlock_t *rwl)
> }
> }
>
> +/**
Please add the experimental API warning
> + * try to take a read lock.
> + *
> + * @param rwl
> + * A pointer to a rwlock structure.
> + * @return
> + * - zero if the lock is successfully taken
> + * - -EBUSY if lock could not be acquired for reading because a
> + * writer holds the lock
> + */
> +static inline __rte_experimental int
> +rte_rwlock_read_trylock(rte_rwlock_t *rwl) {
> + int32_t x;
> + int success = 0;
> +
> + while (success == 0) {
> + x = rwl->cnt;
> + /* write lock is held */
> + if (x < 0)
> + return -EBUSY;
> + success = rte_atomic32_cmpset((volatile uint32_t *)&rwl->cnt,
> + (uint32_t)x, (uint32_t)(x + 1));
> + }
> + return 0;
> +}
> +
> /**
> * Release a read lock.
> *
> @@ -87,6 +114,33 @@ rte_rwlock_read_unlock(rte_rwlock_t *rwl)
> rte_atomic32_dec((rte_atomic32_t *)(intptr_t)&rwl->cnt); }
>
> +/**
Please add the experimental API warning
> + * try to take a write lock.
> + *
> + * @param rwl
> + * A pointer to a rwlock structure.
> + * @return
> + * - zero if the lock is successfully taken
> + * - -EBUSY if lock could not be acquired for writing because
> + * it was already locked for reading or writing
> + */
> +static inline __rte_experimental int
> +rte_rwlock_write_trylock(rte_rwlock_t *rwl) {
> + int32_t x;
> + int success = 0;
> +
> + while (success == 0) {
> + x = rwl->cnt;
> + /* a lock is held */
> + if (x != 0)
> + return -EBUSY;
> + success = rte_atomic32_cmpset((volatile uint32_t *)&rwl->cnt,
> + 0, (uint32_t)-1);
> + }
> + return 0;
> +}
> +
> /**
> * Take a write lock. Loop until the lock is held.
> *
> diff --git a/lib/librte_eal/rte_eal_version.map
> b/lib/librte_eal/rte_eal_version.map
> index 3fe78260d..8b1593dd8 100644
> --- a/lib/librte_eal/rte_eal_version.map
> +++ b/lib/librte_eal/rte_eal_version.map
> @@ -355,6 +355,8 @@ EXPERIMENTAL {
> rte_mp_request_async;
> rte_mp_sendmsg;
> rte_option_register;
> + rte_rwlock_read_trylock;
> + rte_rwlock_write_trylock;
I do not see the other RW lock APIs in this file.
> rte_service_lcore_attr_get;
> rte_service_lcore_attr_reset_all;
> rte_service_may_be_active;
> --
> 2.17.1
Other than the minor comments,
Reviewed-by: Honnappa Nagarahalli <Honnappa.nagarahalli@arm.com>
next prev parent reply other threads:[~2018-12-19 6:37 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-13 17:27 [dpdk-dev] [PATCH 0/2] Add " Konstantin Ananyev
2018-11-13 17:27 ` [dpdk-dev] [PATCH 1/2] rwlock: introduce " Konstantin Ananyev
2018-12-19 6:37 ` Honnappa Nagarahalli [this message]
2018-12-19 8:30 ` Gavin Hu (Arm Technology China)
2018-12-19 10:28 ` Mattias Rönnblom
2018-12-19 10:56 ` Ananyev, Konstantin
2018-12-19 11:00 ` Bruce Richardson
2018-12-19 12:41 ` Ananyev, Konstantin
2018-12-19 15:11 ` Honnappa Nagarahalli
2018-12-19 16:27 ` Ananyev, Konstantin
2018-11-13 17:27 ` [dpdk-dev] [PATCH 2/2] test: add new test-cases for rwlock autotest Konstantin Ananyev
2018-12-19 8:28 ` Gavin Hu (Arm Technology China)
2018-12-19 2:39 ` [dpdk-dev] [PATCH 0/2] Add 'try' semantics for RD and WR locking Thomas Monjalon
2018-12-19 18:07 ` [dpdk-dev] [PATCH v2 " Konstantin Ananyev
2018-12-19 19:53 ` Thomas Monjalon
2018-12-19 18:07 ` [dpdk-dev] [PATCH v2 1/2] rwlock: introduce " Konstantin Ananyev
2018-12-19 18:07 ` [dpdk-dev] [PATCH v2 2/2] test: add new test-cases for rwlock autotest Konstantin Ananyev
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