Module Nn_commit_monitor

module Nn_commit_monitor: sig .. end

This monitor ensures that only certain commits can be done in parallel. The model is as follows:

• Each worker process serializes its own commits
• The commits done by two worker commits can usually run in parallel

The criterion whether two commits c1 and c2 can run in parallel:

• Only one of the commits may modify the datastores table
• Only one of the commits may modify data related to the same inode (with the exception inode_upd_time and the exceptions directory names)
• Only one of the commits may modify the same block allocation row

The updates done by inode_upd_time are ignored here - this is only used for updating the mtime of directories if a file is added or deleted. (Or better: The DB will implicitly serialize these updates.)

---

module I64Set: Set.S  with type elt = int64

module BRowSet: Set.S  with type elt = int * int64

type update_characteristics = {

	upd_ds : bool;	(*	whether datastores are updated	*)
	upd_inodes : I64Set.t;	(*	the modified inodes	*)
	upd_blocks : BRowSet.t;	(*	the modified block rows	*)

}

type commit_monitor 

type commit_monitor_shm 

val create_commit_monitor_heap : Netmcore.res_id -> commit_monitor_shm Netmcore_ref.sref

val create_commit_monitor : Netmcore.res_id ->
       commit_monitor_shm Netmcore_ref.sref ->
       Unixqueue.event_system -> commit_monitor

val monitor_e : commit_monitor ->
       update_characteristics ->
       (int -> 'a Uq_engines.engine) -> 'a Uq_engines.engine

val get_update_characteristics : Nn_db.modification Queue.t -> update_characteristics

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