Redis Locks

Jedis.redis_lock — Function

redis_lock(fn::Function, lock_key[, lock_value=string(uuid4()); client::Client=get_global_client(), timeout=nothing, seconds_between_checks=0.1])

Enters a redis lock context, blocks if the lock already exists.

Arguments

lock_key: Name of the redis lock key.
lock_value=string(uuid4()): Token value of the redis lock, ensures that only owners of a lock can release it, defaults to UUID.
client::Client=get_global_client(): Redis client instance, defualts to global instance.
timeout=nothing: Timeout of the lock in seconds, if nothing then lock will not timeout.
seconds_between_checks=0.1: Sleep time (seconds) between each lock exists check.

Examples

julia> @async redis_lock("example_lock") do
           sleep(3)  # Lock will exist for 3 seconds
       end

julia> while !isredislocked("example_lock")
           sleep(0.1)  # Ensure async lock is active before proceeding
       end

julia> redis_lock("example_lock") do
           println("This message will be delayed by 3 seconds!")  # Blocked by first lock
       end

source

Jedis.acquire_lock — Function

acquire_lock(lock_key[, lock_value=string(uuid4()); client::Client=get_global_client(), timeout=nothing, seconds_between_checks=0.1])

Creates a redis lock key, blocks if the lock already exists, returns the lock_value.

It is preferred that redis_lock is used instead as it will handle the acquiring and releasing of locks within a do-block context.

Arguments

lock_key: Name of the redis lock key.
lock_value=string(uuid4()): Token value of the redis lock, ensures that only owners of a lock can release it, defaults to UUID.
client::Client=get_global_client(): Redis client instance, defualts to global instance.
timeout=nothing: Timeout of the lock in seconds, if nothing then lock will not timeout.
seconds_between_checks=0.1: Sleep time (seconds) between each lock exists check.

Examples

julia> acquire_lock("example_lock", "lock_token")
"lock_token"

julia> release_lock("example_lock", "wrong_token")
false  # Returns false if the lock value does not match

julia> release_lock("example_lock", "lock_token")
true  # Returns true if the lock value matches and lock was successfully released

source

Jedis.release_lock — Function

release_lock(lock_key, lock_value[; client::Client=get_global_client()])::Bool

Returns true if the lock value matches and lock was successfully released, false otherwise.

It is preferred that redis_lock is used instead as it will handle the acquiring and releasing of locks within a do-block context.

Examples

julia> acquire_lock("example_lock", "lock_token")
"lock_token"

julia> release_lock("example_lock", "wrong_token")
false  # Returns false if the lock value does not match

julia> release_lock("example_lock", "lock_token")
true  # Returns true if the lock value matches and lock was successfully released

source

Jedis.isredislocked — Function

isredislocked(lock_key[; client::Client=get_global_client()])

Returns true if lock_key exists, otherwise false.

source