nwaku/library/waku_thread/waku_thread.nim

117 lines
3.8 KiB
Nim

{.pragma: exported, exportc, cdecl, raises: [].}
{.pragma: callback, cdecl, raises: [], gcsafe.}
{.passc: "-fPIC".}
import std/[options, atomics, os, net]
import
chronicles, chronos, chronos/threadsync, taskpools/channels_spsc_single, stew/results
import
../../../waku/factory/waku,
./inter_thread_communication/waku_thread_request,
./inter_thread_communication/waku_thread_response
type Context* = object
thread: Thread[(ptr Context)]
reqChannel: ChannelSPSCSingle[ptr InterThreadRequest]
reqSignal: ThreadSignalPtr
respChannel: ChannelSPSCSingle[ptr InterThreadResponse]
respSignal: ThreadSignalPtr
userData*: pointer
eventCallback*: pointer
eventUserdata*: pointer
const git_version* {.strdefine.} = "n/a"
const versionString = "version / git commit hash: " & waku.git_version
# To control when the thread is running
# TODO: this should be part of the context so multiple instances can be executed
var running: Atomic[bool]
proc runWaku(ctx: ptr Context) {.async.} =
## This is the worker body. This runs the Waku node
## and attends library user requests (stop, connect_to, etc.)
info "Starting Waku", version = versionString
var waku: Waku
while running.load == true:
await ctx.reqSignal.wait()
# Trying to get a request from the libwaku main thread
var request: ptr InterThreadRequest
let recvOk = ctx.reqChannel.tryRecv(request)
if recvOk == true:
let resultResponse = waitFor InterThreadRequest.process(request, addr waku)
## Converting a `Result` into a thread-safe transferable response type
let threadSafeResp = InterThreadResponse.createShared(resultResponse)
## The error-handling is performed in the main thread
discard ctx.respChannel.trySend(threadSafeResp)
discard ctx.respSignal.fireSync()
proc run(ctx: ptr Context) {.thread.} =
## Launch waku worker
waitFor runWaku(ctx)
proc createWakuThread*(): Result[ptr Context, string] =
## This proc is called from the main thread and it creates
## the Waku working thread.
var ctx = createShared(Context, 1)
ctx.reqSignal = ThreadSignalPtr.new().valueOr:
return err("couldn't create reqSignal ThreadSignalPtr")
ctx.respSignal = ThreadSignalPtr.new().valueOr:
return err("couldn't create respSignal ThreadSignalPtr")
running.store(true)
try:
createThread(ctx.thread, run, ctx)
except ValueError, ResourceExhaustedError:
# and freeShared for typed allocations!
freeShared(ctx)
return err("failed to create the Waku thread: " & getCurrentExceptionMsg())
return ok(ctx)
proc stopWakuThread*(ctx: ptr Context): Result[void, string] =
running.store(false)
let fireRes = ctx.reqSignal.fireSync()
if fireRes.isErr():
return err("error in stopWakuThread: " & $fireRes.error)
discard ctx.reqSignal.close()
discard ctx.respSignal.close()
joinThread(ctx.thread)
freeShared(ctx)
return ok()
proc sendRequestToWakuThread*(
ctx: ptr Context, reqType: RequestType, reqContent: pointer
): Result[string, string] =
let req = InterThreadRequest.createShared(reqType, reqContent)
## Sending the request
let sentOk = ctx.reqChannel.trySend(req)
if not sentOk:
return err("Couldn't send a request to the waku thread: " & $req[])
let fireSyncRes = ctx.reqSignal.fireSync()
if fireSyncRes.isErr():
return err("failed fireSync: " & $fireSyncRes.error)
if fireSyncRes.get() == false:
return err("Couldn't fireSync in time")
# Waiting for the response
let res = waitSync(ctx.respSignal)
if res.isErr():
return err("Couldnt receive response signal")
var response: ptr InterThreadResponse
var recvOk = ctx.respChannel.tryRecv(response)
if recvOk == false:
return err("Couldn't receive response from the waku thread: " & $req[])
## Converting the thread-safe response into a managed/CG'ed `Result`
return InterThreadResponse.process(response)