nwaku/library/waku_thread/waku_thread.nim

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{.pragma: exported, exportc, cdecl, raises: [].}
{.pragma: callback, cdecl, raises: [], gcsafe.}
{.passc: "-fPIC".}
import
std/[json,sequtils,times,strformat,options,atomics,strutils,os]
import
chronicles,
chronos,
chronos/threadsync,
taskpools/channels_spsc_single,
stew/results,
stew/shims/net
import
../../../waku/node/waku_node,
../events/[json_error_event,json_message_event,json_base_event],
./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
var ctx {.threadvar.}: ptr Context
# To control when the thread is running
var running: Atomic[bool]
# Every Nim library must have this function called - the name is derived from
# the `--nimMainPrefix` command line option
proc NimMain() {.importc.}
var initialized: Atomic[bool]
proc waku_init() =
if not initialized.exchange(true):
NimMain() # Every Nim library needs to call `NimMain` once exactly
when declared(setupForeignThreadGc): setupForeignThreadGc()
when declared(nimGC_setStackBottom):
var locals {.volatile, noinit.}: pointer
locals = addr(locals)
nimGC_setStackBottom(locals)
proc run(ctx: ptr Context) {.thread.} =
## This is the worker thread body. This thread runs the Waku node
## and attends library user requests (stop, connect_to, etc.)
var node: WakuNode
while running.load == true:
## Trying to get a request from the libwaku main thread
var request: ptr InterThreadRequest
waitFor ctx.reqSignal.wait()
let recvOk = ctx.reqChannel.tryRecv(request)
if recvOk == true:
let resultResponse =
waitFor InterThreadRequest.process(request, addr node)
## 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()
tearDownForeignThreadGc()
proc createWakuThread*(): Result[void, string] =
## This proc is called from the main thread and it creates
## the Waku working thread.
waku_init()
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()
proc stopWakuNodeThread*() =
running.store(false)
joinThread(ctx.thread)
discard ctx.reqSignal.close()
discard ctx.respSignal.close()
freeShared(ctx)
proc sendRequestToWakuThread*(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
waitFor ctx.respSignal.wait()
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)