380 lines
13 KiB
Nim
380 lines
13 KiB
Nim
# Nimbus
|
|
# Copyright (c) 2021 Status Research & Development GmbH
|
|
# Licensed under either of
|
|
# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
|
|
# http://www.apache.org/licenses/LICENSE-2.0)
|
|
# * MIT license ([LICENSE-MIT](LICENSE-MIT) or
|
|
# http://opensource.org/licenses/MIT)
|
|
# at your option. This file may not be copied, modified, or distributed
|
|
# except according to those terms.
|
|
|
|
## Sync worker peers scheduler template
|
|
## ====================================
|
|
##
|
|
## Virtual method/interface functions to be provided as `mixin`:
|
|
##
|
|
## *runSetup(ctx: CtxRef[S]; tickerOK: bool): bool*
|
|
## Global set up. This function will be called before any worker peer is
|
|
## started. If that function returns `false`, no worker peers will be run.
|
|
##
|
|
## Also, this function should decide whether the `runDaemon()` job will be
|
|
## started next by controlling the `ctx.daemon` flag (default is `false`.)
|
|
##
|
|
## *runRelease(ctx: CtxRef[S])*
|
|
## Global clean up, done with all the worker peers.
|
|
##
|
|
## *runDaemon(ctx: CtxRef[S]) {.async.}*
|
|
## Global background job that will be re-started as long as the variable
|
|
## `ctx.daemon` is set `true`. If that job was stopped due to re-setting
|
|
## `ctx.daemon` to `false`, it will be restarted next after it was reset
|
|
## as `true` not before there is some activity on the `runPool()`,
|
|
## `runSingle()`, or `runMulti()` functions.
|
|
##
|
|
##
|
|
## *runStart(buddy: BuddyRef[S,W]): bool*
|
|
## Initialise a new worker peer.
|
|
##
|
|
## *runStop(buddy: BuddyRef[S,W])*
|
|
## Clean up this worker peer.
|
|
##
|
|
##
|
|
## *runPool(buddy: BuddyRef[S,W], last: bool): bool*
|
|
## Once started, the function `runPool()` is called for all worker peers in
|
|
## sequence as the body of an iteration as long as the function returns
|
|
## `false`. There will be no other worker peer functions activated
|
|
## simultaneously.
|
|
##
|
|
## This procedure is started if the global flag `buddy.ctx.poolMode` is set
|
|
## `true` (default is `false`.) It is the responsibility of the `runPool()`
|
|
## instance to reset the flag `buddy.ctx.poolMode`, typically at the first
|
|
## peer instance.
|
|
##
|
|
## The argument `last` is set `true` if the last entry is reached.
|
|
##
|
|
## Note:
|
|
## + This function does *not* runs in `async` mode.
|
|
## + The flag `buddy.ctx.poolMode` has priority over the flag
|
|
## `buddy.ctrl.multiOk` which controls `runSingle()` and `runMulti()`.
|
|
##
|
|
##
|
|
## *runSingle(buddy: BuddyRef[S,W]) {.async.}*
|
|
## This worker peer method is invoked if the peer-local flag
|
|
## `buddy.ctrl.multiOk` is set `false` which is the default mode. This flag
|
|
## is updated by the worker peer when deemed appropriate.
|
|
## + For all worker peerss, there can be only one `runSingle()` function
|
|
## active simultaneously.
|
|
## + There will be no `runMulti()` function active for the very same worker
|
|
## peer that runs the `runSingle()` function.
|
|
## + There will be no `runPool()` iterator active.
|
|
##
|
|
## Note that this function runs in `async` mode.
|
|
##
|
|
##
|
|
## *runMulti(buddy: BuddyRef[S,W]) {.async.}*
|
|
## This worker peer method is invoked if the `buddy.ctrl.multiOk` flag is
|
|
## set `true` which is typically done after finishing `runSingle()`. This
|
|
## instance can be simultaneously active for all worker peers.
|
|
##
|
|
## Note that this function runs in `async` mode.
|
|
##
|
|
##
|
|
## Additional import files needed when using this template:
|
|
## * eth/[common, p2p]
|
|
## * chronicles
|
|
## * chronos
|
|
## * stew/[interval_set, sorted_set],
|
|
## * "."/[sync_desc, sync_sched, protocol]
|
|
##
|
|
|
|
import
|
|
std/hashes,
|
|
chronos,
|
|
eth/[common, p2p, p2p/peer_pool, p2p/private/p2p_types],
|
|
stew/keyed_queue,
|
|
"."/[handlers, sync_desc]
|
|
|
|
{.push raises: [Defect].}
|
|
|
|
static:
|
|
# type `EthWireRef` is needed in `initSync()`
|
|
type silenceUnusedhandlerComplaint = EthWireRef # dummy directive
|
|
|
|
type
|
|
ActiveBuddies[S,W] = ##\
|
|
## List of active workers, using `Hash(Peer)` rather than `Peer`
|
|
KeyedQueue[Hash,RunnerBuddyRef[S,W]]
|
|
|
|
RunnerSyncRef*[S,W] = ref object
|
|
## Module descriptor
|
|
ctx*: CtxRef[S] ## Shared data
|
|
pool: PeerPool ## For starting the system
|
|
buddies: ActiveBuddies[S,W] ## LRU cache with worker descriptors
|
|
tickerOk: bool ## Ticker logger
|
|
daemonRunning: bool ## Run global background job
|
|
singleRunLock: bool ## Some single mode runner is activated
|
|
monitorLock: bool ## Monitor mode is activated
|
|
activeMulti: int ## Number of activated runners in multi-mode
|
|
shutdown: bool ## Internal shut down flag
|
|
|
|
RunnerBuddyRef[S,W] = ref object
|
|
## Per worker peer descriptor
|
|
dsc: RunnerSyncRef[S,W] ## Scheduler descriptor
|
|
worker: BuddyRef[S,W] ## Worker peer data
|
|
|
|
const
|
|
execLoopTimeElapsedMin = 50.milliseconds
|
|
## Minimum elapsed time an exec loop needs for a single lap. If it is
|
|
## faster, asynchroneous sleep seconds are added. in order to avoid
|
|
## cpu overload.
|
|
|
|
execLoopTaskSwitcher = 1.nanoseconds
|
|
## Asynchroneous waiting time at the end of an exec loop unless some sleep
|
|
## seconds were added as decribed by `execLoopTimeElapsedMin`, above.
|
|
|
|
execLoopPollingTime = 50.milliseconds
|
|
## Single asynchroneous time interval wait state for event polling
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# Private helpers
|
|
# ------------------------------------------------------------------------------
|
|
|
|
proc hash(peer: Peer): Hash =
|
|
## Needed for `buddies` table key comparison
|
|
peer.remote.id.hash
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# Private functions
|
|
# ------------------------------------------------------------------------------
|
|
|
|
proc daemonLoop[S,W](dsc: RunnerSyncRef[S,W]) {.async.} =
|
|
mixin runDaemon
|
|
|
|
if dsc.ctx.daemon and not dsc.shutdown:
|
|
dsc.daemonRunning = true
|
|
|
|
# Continue until stopped
|
|
while true:
|
|
# Enforce minimum time spend on this loop
|
|
let startMoment = Moment.now()
|
|
|
|
await dsc.ctx.runDaemon()
|
|
|
|
if not dsc.ctx.daemon:
|
|
break
|
|
|
|
# Enforce minimum time spend on this loop so we never each 100% cpu load
|
|
# caused by some empty sub-tasks which are out of this scheduler control.
|
|
let
|
|
elapsed = Moment.now() - startMoment
|
|
suspend = if execLoopTimeElapsedMin <= elapsed: execLoopTaskSwitcher
|
|
else: execLoopTimeElapsedMin - elapsed
|
|
await sleepAsync suspend
|
|
# End while
|
|
|
|
dsc.daemonRunning = false
|
|
|
|
|
|
proc workerLoop[S,W](buddy: RunnerBuddyRef[S,W]) {.async.} =
|
|
mixin runMulti, runSingle, runPool, runStop
|
|
let
|
|
dsc = buddy.dsc
|
|
ctx = dsc.ctx
|
|
worker = buddy.worker
|
|
peer = worker.peer
|
|
|
|
# Continue until stopped
|
|
block taskExecLoop:
|
|
while worker.ctrl.running and not dsc.shutdown:
|
|
# Enforce minimum time spend on this loop
|
|
let startMoment = Moment.now()
|
|
|
|
if dsc.monitorLock:
|
|
discard # suspend some time at the end of loop body
|
|
|
|
# Invoke `runPool()` over all buddies if requested
|
|
elif ctx.poolMode:
|
|
# Grab `monitorLock` (was `false` as checked above) and wait until
|
|
# clear to run as the only activated instance.
|
|
dsc.monitorLock = true
|
|
while 0 < dsc.activeMulti or dsc.singleRunLock:
|
|
await sleepAsync execLoopPollingTime
|
|
if worker.ctrl.stopped:
|
|
dsc.monitorLock = false
|
|
break taskExecLoop
|
|
var count = dsc.buddies.len
|
|
for w in dsc.buddies.nextValues:
|
|
count.dec
|
|
if worker.runPool(count == 0):
|
|
break # `true` => stop
|
|
dsc.monitorLock = false
|
|
|
|
else:
|
|
# Rotate connection table so the most used entry is at the top/right
|
|
# end. So zombies will end up leftish.
|
|
discard dsc.buddies.lruFetch(peer.hash)
|
|
|
|
# Multi mode
|
|
if worker.ctrl.multiOk:
|
|
if not dsc.singleRunLock:
|
|
dsc.activeMulti.inc
|
|
# Continue doing something, work a bit
|
|
await worker.runMulti()
|
|
dsc.activeMulti.dec
|
|
|
|
elif dsc.singleRunLock:
|
|
# Some other process is running single mode
|
|
discard # suspend some time at the end of loop body
|
|
|
|
else:
|
|
# Start single instance mode by grabbing `singleRunLock` (was
|
|
# `false` as checked above).
|
|
dsc.singleRunLock = true
|
|
await worker.runSingle()
|
|
dsc.singleRunLock = false
|
|
|
|
# Dispatch daemon sevice if needed
|
|
if not dsc.daemonRunning and dsc.ctx.daemon:
|
|
asyncSpawn dsc.daemonLoop()
|
|
|
|
# Check for termination
|
|
if worker.ctrl.stopped:
|
|
break taskExecLoop
|
|
|
|
# Enforce minimum time spend on this loop so we never each 100% cpu load
|
|
# caused by some empty sub-tasks which are out of this scheduler control.
|
|
let
|
|
elapsed = Moment.now() - startMoment
|
|
suspend = if execLoopTimeElapsedMin <= elapsed: execLoopTaskSwitcher
|
|
else: execLoopTimeElapsedMin - elapsed
|
|
await sleepAsync suspend
|
|
# End while
|
|
|
|
# Note that `runStart()` was dispatched in `onPeerConnected()`
|
|
worker.runStop()
|
|
|
|
|
|
proc onPeerConnected[S,W](dsc: RunnerSyncRef[S,W]; peer: Peer) =
|
|
mixin runStart, runStop
|
|
# Check for known entry (which should not exist.)
|
|
let
|
|
maxWorkers = dsc.ctx.buddiesMax
|
|
peers = dsc.pool.len
|
|
workers = dsc.buddies.len
|
|
if dsc.buddies.hasKey(peer.hash):
|
|
trace "Reconnecting zombie peer ignored", peer, peers, workers, maxWorkers
|
|
return
|
|
|
|
# Initialise worker for this peer
|
|
let buddy = RunnerBuddyRef[S,W](
|
|
dsc: dsc,
|
|
worker: BuddyRef[S,W](
|
|
ctx: dsc.ctx,
|
|
ctrl: BuddyCtrlRef(),
|
|
peer: peer))
|
|
if not buddy.worker.runStart():
|
|
trace "Ignoring useless peer", peer, peers, workers, maxWorkers
|
|
buddy.worker.ctrl.zombie = true
|
|
return
|
|
|
|
# Check for table overflow. An overflow might happen if there are zombies
|
|
# in the table (though preventing them from re-connecting for a while.)
|
|
if dsc.ctx.buddiesMax <= workers:
|
|
let leastPeer = dsc.buddies.shift.value.data
|
|
if leastPeer.worker.ctrl.zombie:
|
|
trace "Dequeuing zombie peer",
|
|
oldest=leastPeer.worker, peers, workers=dsc.buddies.len, maxWorkers
|
|
discard
|
|
else:
|
|
# This could happen if there are idle entries in the table, i.e.
|
|
# somehow hanging runners.
|
|
trace "Peer table full! Dequeuing least used entry",
|
|
oldest=leastPeer.worker, peers, workers=dsc.buddies.len, maxWorkers
|
|
leastPeer.worker.runStop()
|
|
leastPeer.worker.ctrl.zombie = true
|
|
|
|
# Add peer entry
|
|
discard dsc.buddies.lruAppend(peer.hash, buddy, dsc.ctx.buddiesMax)
|
|
|
|
trace "Running peer worker", peer, peers,
|
|
workers=dsc.buddies.len, maxWorkers
|
|
|
|
asyncSpawn buddy.workerLoop()
|
|
|
|
|
|
proc onPeerDisconnected[S,W](dsc: RunnerSyncRef[S,W], peer: Peer) =
|
|
let
|
|
peers = dsc.pool.len
|
|
maxWorkers = dsc.ctx.buddiesMax
|
|
workers = dsc.buddies.len
|
|
rc = dsc.buddies.eq(peer.hash)
|
|
if rc.isErr:
|
|
debug "Disconnected, unregistered peer", peer, peers, workers, maxWorkers
|
|
return
|
|
if rc.value.worker.ctrl.zombie:
|
|
# Don't disconnect, leave them fall out of the LRU cache. The effect is,
|
|
# that reconnecting might be blocked, for a while.
|
|
trace "Disconnected, zombie", peer, peers, workers, maxWorkers
|
|
else:
|
|
rc.value.worker.ctrl.stopped = true # in case it is hanging somewhere
|
|
dsc.buddies.del(peer.hash)
|
|
trace "Disconnected buddy", peer, peers, workers=dsc.buddies.len, maxWorkers
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# Public functions
|
|
# ------------------------------------------------------------------------------
|
|
|
|
proc initSync*[S,W](
|
|
dsc: RunnerSyncRef[S,W];
|
|
node: EthereumNode;
|
|
chain: Chain,
|
|
slots: int;
|
|
noisy = false) =
|
|
## Constructor
|
|
# Leave one extra slot so that it can holds a *zombie* even if all slots
|
|
# are full. The effect is that a re-connect on the latest zombie will be
|
|
# rejected as long as its worker descriptor is registered.
|
|
dsc.ctx = CtxRef[S](
|
|
ethWireCtx: cast[EthWireRef](node.protocolState protocol.eth),
|
|
buddiesMax: max(1, slots + 1),
|
|
chain: chain)
|
|
dsc.pool = node.peerPool
|
|
dsc.tickerOk = noisy
|
|
dsc.buddies.init(dsc.ctx.buddiesMax)
|
|
|
|
proc startSync*[S,W](dsc: RunnerSyncRef[S,W]): bool =
|
|
## Set up `PeerObserver` handlers and start syncing.
|
|
mixin runSetup
|
|
# Initialise sub-systems
|
|
if dsc.ctx.runSetup(dsc.tickerOk):
|
|
var po = PeerObserver(
|
|
onPeerConnected:
|
|
proc(p: Peer) {.gcsafe.} =
|
|
dsc.onPeerConnected(p),
|
|
onPeerDisconnected:
|
|
proc(p: Peer) {.gcsafe.} =
|
|
dsc.onPeerDisconnected(p))
|
|
|
|
po.setProtocol eth
|
|
dsc.pool.addObserver(dsc, po)
|
|
if dsc.ctx.daemon:
|
|
asyncSpawn dsc.daemonLoop()
|
|
return true
|
|
|
|
proc stopSync*[S,W](dsc: RunnerSyncRef[S,W]) =
|
|
## Stop syncing and free peer handlers .
|
|
mixin runRelease
|
|
dsc.pool.delObserver(dsc)
|
|
|
|
# Gracefully shut down async services
|
|
dsc.shutdown = true
|
|
for buddy in dsc.buddies.nextValues:
|
|
buddy.worker.ctrl.stopped = true
|
|
dsc.ctx.daemon = false
|
|
|
|
# Final shutdown (note that some workers might still linger on)
|
|
dsc.ctx.runRelease()
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# End
|
|
# ------------------------------------------------------------------------------
|