Shared lock service

Contents

• Shared lock service

  • Setup

  • EAPI methods

    • list

    • lock

    • status

    • unlock

Allows other services to work with shared locks

Setup

Use the template EVA_DIR/share/svc-tpl/svc-tpl-locker.yml:

# Locker service
command: svc/eva-svc-locker
bus:
  path: var/bus.ipc
config:
  locks:
   - lock1
   - lock2
   - lock3
user: nobody

Create the service using eva-shell:

eva svc create eva.svc.locker1 /opt/eva4/share/svc-tpl/svc-tpl-locker.yml

or using the bus CLI client:

cd /opt/eva4
cat DEPLOY.yml | ./bin/yml2mp | \
    ./sbin/bus ./var/bus.ipc rpc call eva.core svc.deploy -

(see eva.core::svc.deploy for more info)

EAPI methods

See EAPI commons for the common information about the bus, types, errors and RPC calls.

list

Description	List status of all locks
Parameters	none
Returns	List of lock status

Return payload example:

[
  {
      "id": "lock1",
      "locked": false
  },
  {
      "id": "lock2",
      "locked": true
  },
]

lock

Description	Acquire a shared lock
Parameters	required
Returns	nothing

Parameters

Name	Type	Description	Required
i	String	lock ID	yes
expires	f64	auto-release timer (seconds)	yes
timeout	f64	max operation timeout (seconds)	no

status

Description	Get status of a lock
Parameters	required
Returns	Lock status (struct)

Parameters

Name	Type	Description	Required
i	String	lock ID	yes

Return payload example:

{
    "id": "lock1",
    "locked": false
}

unlock

Description	Unlock previously acquired lock
Parameters	required
Returns	nothing

Parameters

Name	Type	Description	Required
i	String	lock ID	yes