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

The process-local part of the monitor

type commit_monitor_shm

The shm part of the monitor

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

monitor_e cm uc f: Tries to get a slot for doing a commit described by uc. When the commit can be done, f commit_id is called, and the result is returned.

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

Extract uc from a queue of DB updates