Re: [libvirt] [PATCH 2/8] Basic framework for lock manager plugins

+/** + * virLockManagerNew: + * @man: the lock manager context + * @type: the type of process to be supervised + * @flags: optional flags, currently unused + * + * Initialize a new context to supervise a process, usually + * a virtual machine. If the lock driver requested a + * private data, the <code>privateData</code> field of + * <code>man</code> will be initialized with a suitable + * pointer. + * + * Returns 0 if successful initialized a new context, -1 on error + */ +typedef int (*virLockDriverNew)(virLockManagerPtr man, + unsigned int type, + unsigned int flags);

+/** + * virLockDriverFree: + * @manager: the lock manager context + * + * Release any resources associated with the lock manager + * context private data + */ +typedef void (*virLockDriverFree)(virLockManagerPtr man);

+/** + * virLockDriverSetParameter: + * @manager: the lock manager context + * @key: the parameter name + * @value: the parameter value + * + * Set a configuration parameter for the managed process. + * A process of VIR_LOCK_MANAGER_START_DOMAIN will be + * given at least 3 parameters: + * + * - id: the domain unique id + * - uuid: the domain uuid + * - name: the domain name + * + * There may be other parameters specific to the lock manager + * plugin that are provided for the managed process + * + * This should only be called prior to the supervised process + * being started. + * + * Returns 0 on success, or -1 on failure + */ +typedef int (*virLockDriverSetParameter)(virLockManagerPtr man, + const char *key, + const char *value);

+/** + * virLockDriverAcquireObject: + * @manager: the lock manager context + * @state: the current lock state + * @flags: optional flags, currently unused + * + * Start managing resources for the object. If the + * object is being transferred from another location + * the current lock state may be passed in. This + * must be called from the PID that represents the + * object to be managed. If the lock is lost at any + * time, the PID will be killed off by the lock manager. + * + * Returns 0 on success, or -1 on failure + */ +typedef int (*virLockDriverAcquireObject)(virLockManagerPtr man, + const char *state, + unsigned int flags);

+/** + * virLockDriverGetState: + * @manager: the lock manager context + * @state: pointer to be filled with lock state + * @flags: optional flags, currently unused + * + * Retrieve the current lock state. The returned + * lock state may be NULL if none is required. The + * caller is responsible for freeing the lock + * state string when it is no longer required + * + * Returns 0 on success, or -1 on failure. + */ +typedef int (*virLockDriverGetState)(virLockManagerPtr man, + char **state, + unsigned int flags);

+/** + * virLockDriverAcquireResource: + * @manager: the lock manager context + * @type: the resource type virLockDriverResourceType + * @name: the resource name + * @flags: the resource access flags + * + * Assign a resource to a managed object. This will + * only be called when the object is already locked + * and active. eg, to hotplug a disk into a VM. + * The format of @name varies according to + * the resource @type. A VIR_LOCK_MANAGER_RESOURCE_TYPE_DISK + * will have a fully qualified file path. + * + * If no flags are given, the resource is assumed to be + * used in exclusive, read-write mode. Access can be + * relaxed to readonly, or shared read-write. + * + * Returns 0 on success, or -1 on failure + */ +typedef int (*virLockDriverAcquireResource)(virLockManagerPtr man, + unsigned int type, + const char *name, + unsigned int flags);