feat: introduce Task Manager threadpool

The `TaskManager` threadpool is a memory-safe replacement for the `spawnAndSend` operations that are currently causing memory issues in status-desktop.

From a fundamental memory management point of view, `libstatus/settings`, `libstatus/contracts`, and `libstatus/tokens` (custom tokens) have all been converted to `{.threadvar.}`s and `Atomic[bool]`s to maintain the cache and `dirty` flag across threads, respectively, eliminating the need for thread locks and incorrect `{.gcsafe.}` compiler overrides.

The successful [recyclable threadpool experiment from `nim-task-runner`](https://github.com/status-im/nim-task-runner/blob/test/use-cases/test/use_cases/test_sync.nim) using `AsyncChannel[ThreadSafeString]`s was brought over to `status-desktop` and implemented in somewhat of a hardcoded manner, as we knew this would save some time instead of trying to create a fully fleshed out `nim-task-runner` API and build a miraculous macro that may or may not be able to generate the needed API.

The threadpool is started by the `TaskManager` and both the `TaskManager` and the `TaskManager`'s threadpool are started as early as possible in the application lifecycle (in `nim_status_client.nim`). The `TaskManager` creates a thread to run the threadpool. During its initialization, the threadpool then spools up all the threads it will manage and puts them in an idle thread sequence. This is to prevent expensive thread creation and teardown happening during the app's lifetime as it is quite expensive and blocks the main thread. When tasks comes in to the pool, the task is sent to an idle thread, or put in a queue if all threads are busy. The idle thread is moved to the busy thread sequence. When a task is completed, the thread is taken out of the busy threads sequence and moved back in to the sequence of idle threads, effectively recycling it.

The first `spawnAndSend` we were able to change over to the new threadpool was `estimate`, which estimates the gas of a sticker purchase transaction.

From the consumer point of view, the existing `spawnAndSend` to achieve this looks like:
```nim
  proc estimate*(self: StickersView, packId: int, address: string, price: string, uuid: string) {.slot.} =
    let status_stickers = self.status.stickers
    spawnAndSend(self, "setGasEstimate") do:
      var success: bool
      var estimate = status_stickers.estimateGas(packId, address, price, success)
      if not success:
        estimate = 325000
      let result: tuple[estimate: int, uuid: string] = (estimate, uuid)
      Json.encode(result)
```
And the new syntax looks like this:
```nim
  proc estimate*(self: StickersView, packId: int, address: string, price: string, uuid: string) {.slot.} =
    self.status.taskManager.threadPool.stickers.stickerPackPurchaseGasEstimate(cast[pointer](self.vptr), "setGasEstimate", packId, address, price, uuid)
```
The logic inside the `spawnAndSend` body was moved to [src/status/tasks/stickers.nim](https://github.com/status-im/status-desktop/compare/experiment/tasks-3?expand=1#diff-09e57eef00b0cee5c4abdb9039f948d8372e7003e09e934a9b4c7e9167d47658).

This is just the first migration of `spawnAndSend`, however moving the majority of the remaining `spawnAndSend`s will likely just be an exercise in copy/pasta. There will be one or two that may require a bit more thinking, depending how they rely on data from the model.

Once the `spawnAndSend`s have been converted to the threadpool, we can start implementing the [long-running process from the task runner use case experiments](https://github.com/status-im/nim-task-runner/blob/test/use-cases/test/use_cases/test_long_running.nim).

And finally, we can then implement the [async tasks](https://github.com/status-im/nim-task-runner/blob/test/use-cases/test/use_cases/test_async.nim) if needed.

@michaelsbradleyjr and I spent many hours digging in to the depths of nim's memory management in an attempt to understand it. We have created [a presentation with our task runner experiment findings](https://docs.google.com/presentation/d/1ItCxAfsVTcIoH_E4bgvmHljhbU-tC3T6K2A6ahwAedk/edit?usp=sharing), and @michaelsbradleyjr has spent time [answering questions off the back of that presentation.](https://gist.github.com/michaelsbradleyjr/1eaa9937b3fbb4ffff3fb814f0dd82a9).

We have created a fork of `edn.nim` at `status-im/edn.nim` and we need the PR to be merged and the commit hash updated before we can merge this PR in to `status-desktop`.

.gitignore

@@ -4,6 +4,7 @@ noBackup/
 *.pro.user
 *.pro.autosave
 *.qml.autosave
+.update.timestamp
 .vscode
 bin/
 /bottles/

.gitmodules

@@ -91,3 +91,9 @@
 [submodule "vendor/nim-status-go"]
 	path = vendor/nim-status-go
 	url = https://github.com/status-im/nim-status-go.git
+[submodule "vendor/nim-task-runner"]
+	path = vendor/nim-task-runner
+	url = https://github.com/status-im/nim-task-runner.git
+[submodule "vendor/edn.nim"]
+	path = vendor/edn.nim
+	url = https://github.com/status-im/edn.nim.git

src/app/chat/views/stickers.nim

@@ -5,6 +5,7 @@ import ../../../status/libstatus/stickers as status_stickers
 import ../../../status/libstatus/wallet as status_wallet
 import sticker_pack_list, sticker_list, chat_item
 import json_serialization
+import ../../../status/tasks/task_manager
 
 logScope:
   topics = "stickers-view"
@@ -45,14 +46,7 @@ QtObject:
   proc transactionCompleted*(self: StickersView, success: bool, txHash: string, revertReason: string = "") {.signal.}
 
   proc estimate*(self: StickersView, packId: int, address: string, price: string, uuid: string) {.slot.} =
-    let status_stickers = self.status.stickers
+    self.status.taskManager.threadPool.stickers.stickerPackPurchaseGasEstimate(cast[pointer](self.vptr), "setGasEstimate", packId, address, price, uuid)
-    spawnAndSend(self, "setGasEstimate") do:
-      var success: bool
-      var estimate = status_stickers.estimateGas(packId, address, price, success)
-      if not success:
-        estimate = 325000
-      let result: tuple[estimate: int, uuid: string] = (estimate, uuid)
-      Json.encode(result)
 
   proc gasEstimateReturned*(self: StickersView, estimate: int, uuid: string) {.signal.}
 

src/app/wallet/view.nim

@@ -491,9 +491,8 @@ QtObject:
   proc gasPricePredictionsChanged*(self: WalletView) {.signal.}
 
   proc getGasPricePredictions*(self: WalletView) {.slot.} =
-    let walletModel = self.status.wallet
     spawnAndSend(self, "getGasPricePredictionsResult") do:
-      $ %walletModel.getGasPricePredictions()
+      $ %getGasPricePredictions2()
 
   proc getGasPricePredictionsResult(self: WalletView, gasPricePredictionsJson: string) {.slot.} =
     let prediction = Json.decode(gasPricePredictionsJson, GasPricePrediction)

src/nim_status_client.nim

@@ -10,11 +10,13 @@ import app/onboarding/core as onboarding
 import app/login/core as login
 import app/provider/core as provider
 import status/signals/core as signals
+import status/tasks/task_manager
 import status/libstatus/types
 import status/libstatus/accounts/constants
 import status_go
 import status/status as statuslib
 import ./eventemitter
+import chronos, task_runner
 
 var signalsQObjPointer: pointer
 
@@ -28,7 +30,9 @@ proc mainProc() =
     else:
       "/../fleets.json"
 
-  let status = statuslib.newStatusInstance(readFile(joinPath(getAppDir(), fleets)))
+  let taskManager = newTaskManager()
+  taskManager.init()
+  let status = statuslib.newStatusInstance(taskManager, readFile(joinPath(getAppDir(), fleets)))
   status.initNode()
 
   enableHDPI()
@@ -132,6 +136,7 @@ proc mainProc() =
     wallet.checkPendingTransactions()
     wallet.start()
 
+
   engine.setRootContextProperty("loginModel", login.variant)
   engine.setRootContextProperty("onboardingModel", onboarding.variant)
 
@@ -152,6 +157,7 @@ proc mainProc() =
     profile.delete()
     utilsController.delete()
     browserController.delete()
+    taskManager.teardown()
 
 
   # Initialize only controllers whose init functions
@@ -188,9 +194,7 @@ proc mainProc() =
   # it will be passed as a regular C function to libstatus. This means that
   # we cannot capture any local variables here (we must rely on globals)
   var callback: SignalCallback = proc(p0: cstring) {.cdecl.} =
-    setupForeignThreadGc()
     signal_handler(signalsQObjPointer, p0, "receiveSignal")
-    tearDownForeignThreadGc()
 
   status_go.setSignalEventCallback(callback)
 

src/status/ens.nim

@@ -295,8 +295,10 @@ proc decodeENSContentHash*(value: string): tuple[ensType: ENSType, output: strin
       # 12 = identifies sha2-256 hash
       # 20 = multihash length = 32
       # ...rest = multihash digest
-      let multiHash = MultiHash.init(nimcrypto.fromHex(multiHashStr)).get()
+      let
-      return (ENSType.IPFS, $Cid.init(CIDv0, MultiCodec.codec(codec), multiHash))
+        multiHash = MultiHash.init(nimcrypto.fromHex(multiHashStr)).get()
+        decoded = Cid.init(CIDv0, MultiCodec.codec(codec), multiHash).get()
+      return (ENSType.IPFS, $decoded)
     except Exception as e:
       error "Error decoding ENS contenthash", hash=value, exception=e.msg
       raise

src/status/libstatus/eth/contracts.nim

@@ -1,5 +1,5 @@
 import
-  sequtils, sugar, macros, tables, strutils, locks
+  sequtils, sugar, macros, tables, strutils
 
 import
   web3/ethtypes, stew/byteutils, nimcrypto, json_serialization, chronicles
@@ -16,9 +16,6 @@ export
 logScope:
   topics = "contracts"
 
-var contractsLock: Lock
-initLock(contractsLock)
-
 const ERC20_METHODS = @[
   ("name", Method(signature: "name()")),
   ("symbol", Method(signature: "symbol()")),
@@ -80,7 +77,14 @@ proc newErc721Contract(name: string, network: Network, address: Address, symbol:
   Erc721Contract(name: name, network: network, address: address, symbol: symbol, hasIcon: hasIcon, methods: ERC721_ENUMERABLE_METHODS.concat(addlMethods).toTable)
 
 
-var ALL_CONTRACTS {.guard: contractsLock.}: seq[Contract] = @[
+var 
+  contracts {.threadvar.}: seq[Contract]
+  contractsInited {.threadvar.}: bool
+proc allContracts(): seq[Contract] =
+  if contractsInited:
+    result = contracts
+  else:
+    contracts = @[
       # Mainnet contracts
       newErc20Contract("Status Network Token", Network.Mainnet, parseAddress("0x744d70fdbe2ba4cf95131626614a1763df805b9e"), "SNT", 18, true),
       newErc20Contract("Dai Stablecoin", Network.Mainnet, parseAddress("0x6b175474e89094c44da98b954eedeac495271d0f"), "DAI", 18, true),
@@ -253,12 +257,12 @@ var ALL_CONTRACTS {.guard: contractsLock.}: seq[Contract] = @[
       newErc20Contract("Balancer", Network.Mainnet, parseAddress("0xba100000625a3754423978a60c9317c58a424e3d"), "BAL", 18, true),
       newErc20Contract("Akropolis", Network.Mainnet, parseAddress("0x8ab7404063ec4dbcfd4598215992dc3f8ec853d7"), "AKRO", 18, true),
       newErc20Contract("Orchid", Network.Mainnet, parseAddress("0x4575f41308EC1483f3d399aa9a2826d74Da13Deb"), "OXT", 18, false),
-]
+    ]
+    contractsInited = true
+    result = contracts
 
 proc getContract(network: Network, name: string): Contract =
-  {.gcsafe.}:
+  let found = allContracts().filter(contract => contract.name == name and contract.network == network)
-    withLock contractsLock:
-      let found = ALL_CONTRACTS.filter(contract => contract.name == name and contract.network == network)
   result = if found.len > 0: found[0] else: nil
 
 proc getContract*(name: string): Contract =
@@ -275,26 +279,18 @@ proc getErc20ContractByAddress*(contracts: seq[Erc20Contract], address: Address)
 
 proc getErc20Contract*(symbol: string): Erc20Contract =
   let network = settings.getCurrentNetwork()
-  {.gcsafe.}:
+  result = allContracts().filter(contract => contract.network == network and contract of Erc20Contract).map(contract => Erc20Contract(contract)).getErc20ContractBySymbol(symbol)
-    withLock contractsLock:
-      result = ALL_CONTRACTS.filter(contract => contract.network == network and contract of Erc20Contract).map(contract => Erc20Contract(contract)).getErc20ContractBySymbol(symbol)
 
 proc getErc20Contract*(address: Address): Erc20Contract =
   let network = settings.getCurrentNetwork()
-  {.gcsafe.}:
+  result = allContracts().filter(contract => contract.network == network and contract of Erc20Contract).map(contract => Erc20Contract(contract)).getErc20ContractByAddress(address)
-    withLock contractsLock:
-      result = ALL_CONTRACTS.filter(contract => contract.network == network and contract of Erc20Contract).map(contract => Erc20Contract(contract)).getErc20ContractByAddress(address)
 
 proc getErc20Contracts*(): seq[Erc20Contract] =
   let network = settings.getCurrentNetwork()
-  {.gcsafe.}:
+  result = allContracts().filter(contract => contract of Erc20Contract and contract.network == network).map(contract => Erc20Contract(contract))
-    withLock contractsLock:
-      result = ALL_CONTRACTS.filter(contract => contract of Erc20Contract and contract.network == network).map(contract => Erc20Contract(contract))
 
 proc getErc721Contract(network: Network, name: string): Erc721Contract =
-  {.gcsafe.}:
+  let found = allContracts().filter(contract => contract of Erc721Contract and Erc721Contract(contract).name.toLower == name.toLower and contract.network == network)
-    withLock contractsLock:
-      let found = ALL_CONTRACTS.filter(contract => contract of Erc721Contract and Erc721Contract(contract).name.toLower == name.toLower and contract.network == network)
   result = if found.len > 0: Erc721Contract(found[0]) else: nil
 
 proc getErc721Contract*(name: string): Erc721Contract =
@@ -303,9 +299,7 @@ proc getErc721Contract*(name: string): Erc721Contract =
 
 proc getErc721Contracts*(): seq[Erc721Contract] =
   let network = settings.getCurrentNetwork()
-  {.gcsafe.}:
+  result = allContracts().filter(contract => contract of Erc721Contract and contract.network == network).map(contract => Erc721Contract(contract))
-    withLock contractsLock:
-      result = ALL_CONTRACTS.filter(contract => contract of Erc721Contract and contract.network == network).map(contract => Erc721Contract(contract))
 
 proc getSntContract*(): Erc20Contract =
   if settings.getCurrentNetwork() == Network.Mainnet:

src/status/libstatus/settings.nim

@@ -1,37 +1,46 @@
-import core, ./types, ../signals/types as statusgo_types, ./accounts/constants, ./utils
+import
-import json, tables, sugar, sequtils, strutils
+  json, tables, sugar, sequtils, strutils, atomics
-import json_serialization
-import locks
-import uuids
 
-var settingsLock {.global.}: Lock
+import
-initLock(settingsLock)
+  json_serialization, chronicles, uuids
 
-var settings = %*{}
+import
-var dirty = true
+  ./core, ./types, ../signals/types as statusgo_types, ./accounts/constants,
+  ./utils
+
+var
+  settings {.threadvar.}: JsonNode
+  settingsInited {.threadvar.}: bool
+  dirty: Atomic[bool]
+
+dirty.store(true)
+settings = %* {}
 
 proc saveSetting*(key: Setting, value: string | JsonNode): StatusGoError =
-  withLock settingsLock:
   try:
     let response = callPrivateRPC("settings_saveSetting", %* [key, value])
-      result = Json.decode($response, StatusGoError)
+    let responseResult = $(response.parseJSON(){"result"})
-    except:
+    if responseResult == "null":
-      dirty = true
+      result.error = ""
+    else: result = Json.decode(response, StatusGoError)
+  except Exception as e:
+    error "Error saving setting", key=key, value=value, msg=e.msg
+    dirty.store(true)
 
 proc getWeb3ClientVersion*(): string =
   parseJson(callPrivateRPC("web3_clientVersion"))["result"].getStr
 
 proc getSettings*(useCached: bool = true, keepSensitiveData: bool = false): JsonNode =
-  withLock settingsLock:
+  let cacheIsDirty = (not settingsInited) or dirty.load
-    {.gcsafe.}:
+  if useCached and (not cacheIsDirty) and (not keepSensitiveData):
-      if useCached and not dirty and not keepSensitiveData:
     result = settings
   else: 
     result = callPrivateRPC("settings_getSettings").parseJSON()["result"]
     if not keepSensitiveData:
-          dirty = false
+      dirty.store(false)
       delete(result, "mnemonic")
       settings = result
+      settingsInited = true
 
 proc getSetting*[T](name: Setting, defaultValue: T, useCached: bool = true): T =
   let settings: JsonNode = getSettings(useCached, $name == "mnemonic")

src/status/libstatus/stickers.nim

@@ -47,7 +47,8 @@ proc decodeContentHash*(value: string): string =
     # 20 = multihash length = 32
     # ...rest = multihash digest
     let multiHash = MultiHash.init(nimcrypto.fromHex(multiHashStr)).get()
-    result = $Cid.init(CIDv0, MultiCodec.codec(codec), multiHash)
+    let resultTyped = Cid.init(CIDv0, MultiCodec.codec(codec), multiHash).get()
+    result = $resultTyped
     trace "Decoded sticker hash", cid=result
   except Exception as e:
     error "Error decoding sticker", hash=value, exception=e.msg
@@ -95,7 +96,6 @@ proc getPackCount*(): int =
 
 # Gets sticker pack data
 proc getPackData*(id: Stuint[256]): StickerPack =
-  {.gcsafe.}:
   let
     contract = contracts.getContract("stickers")
     contractMethod = contract.methods["getPackData"]

src/status/libstatus/tokens.nim

@@ -1,26 +1,27 @@
-import json, chronicles, strformat, stint, strutils, sequtils, tables
+import
-import core, wallet
+  json, chronicles, strformat, stint, strutils, sequtils, tables, atomics
-import ./eth/contracts
+
-import web3/[ethtypes, conversions]
+import
-import json_serialization
+  web3/[ethtypes, conversions], json_serialization
-import settings
+
+import 
+  ./settings, ./core, ./wallet, ./eth/contracts
 from types import Setting, Network, RpcResponse, RpcException
 from utils import parseAddress
-import locks
 
 logScope:
   topics = "wallet"
 
-var customTokensLock: Lock
+var
-initLock(customTokensLock)
+  customTokens {.threadvar.}: seq[Erc20Contract]
+  customTokensInited {.threadvar.}: bool
+  dirty: Atomic[bool]
 
-var customTokens {.guard: customTokensLock.}: seq[Erc20Contract] = @[]
+dirty.store(true)
-var dirty {.guard: customTokensLock.}  = true
 
 proc getCustomTokens*(useCached: bool = true): seq[Erc20Contract] =
-  {.gcsafe.}:
+  let cacheIsDirty = not customTokensInited or dirty.load
-    withLock customTokensLock:
+  if useCached and not cacheIsDirty:
-      if useCached and not dirty:
     result = customTokens
   else: 
     let payload = %* []
@@ -31,8 +32,9 @@ proc getCustomTokens*(useCached: bool = true): seq[Erc20Contract] =
     if not response.error.isNil:
       raise newException(RpcException, "Error getting custom tokens: " & response.error.message)
     result = if response.result == "null": @[] else: Json.decode(response.result, seq[Erc20Contract])
-        dirty = false
+    dirty.store(false)
     customTokens = result
+    customTokensInited = true
 
 proc visibleTokensSNTDefault(): JsonNode =
   let currentNetwork = getCurrentNetwork()
@@ -85,14 +87,12 @@ proc getVisibleTokens*(): seq[Erc20Contract] =
 proc addCustomToken*(address: string, name: string, symbol: string, decimals: int, color: string) =
   let payload = %* [{"address": address, "name": name, "symbol": symbol, "decimals": decimals, "color": color}]
   discard callPrivateRPC("wallet_addCustomToken", payload)
-  withLock customTokensLock:
+  dirty.store(true)
-    dirty = true
 
 proc removeCustomToken*(address: string) =
   let payload = %* [address]
   echo callPrivateRPC("wallet_deleteCustomToken", payload)
-  withLock customTokensLock:
+  dirty.store(true)
-    dirty = true
 
 proc getTokensBalances*(accounts: openArray[string], tokens: openArray[string]): JsonNode =
   let payload = %* [accounts, tokens]

src/status/status.nim

@@ -4,6 +4,7 @@ import libstatus/settings as libstatus_settings
 import libstatus/types as libstatus_types
 import chat, accounts, wallet, node, network, mailservers, messages, contacts, profile, stickers, permissions, fleet
 import ../eventemitter
+import tasks/task_manager
 
 export chat, accounts, node, mailservers, messages, contacts, profile, network, permissions, fleet
 
@@ -21,9 +22,11 @@ type Status* = ref object
   network*: NetworkModel
   stickers*: StickersModel
   permissions*: PermissionsModel
+  taskManager*: TaskManager
 
-proc newStatusInstance*(fleetConfig: string): Status =
+proc newStatusInstance*(taskManager: TaskManager, fleetConfig: string): Status =
   result = Status()
+  result.taskManager = taskManager
   result.events = createEventEmitter()
   result.fleet = fleet.newFleetModel(result.events, fleetConfig)
   result.chat = chat.newChatModel(result.events)

src/status/stickers.nim

@@ -42,7 +42,7 @@ proc init*(self: StickersModel) =
     var evArgs = StickerArgs(e)
     self.addStickerToRecent(evArgs.sticker, evArgs.save)
 
-proc buildTransaction(self: StickersModel, packId: Uint256, address: Address, price: Uint256, approveAndCall: var ApproveAndCall[100], sntContract: var Erc20Contract, gas = "", gasPrice = ""): EthSend =
+proc buildTransaction(packId: Uint256, address: Address, price: Uint256, approveAndCall: var ApproveAndCall[100], sntContract: var Erc20Contract, gas = "", gasPrice = ""): EthSend =
   sntContract = status_contracts.getSntContract()
   let
     stickerMktContract = status_contracts.getContract("sticker-market")
@@ -51,11 +51,11 @@ proc buildTransaction(self: StickersModel, packId: Uint256, address: Address, pr
   approveAndCall = ApproveAndCall[100](to: stickerMktContract.address, value: price, data: DynamicBytes[100].fromHex(buyTxAbiEncoded))
   transactions.buildTokenTransaction(address, sntContract.address, gas, gasPrice)
 
-proc estimateGas*(self: StickersModel, packId: int, address: string, price: string, success: var bool): int =
+proc estimateGas*(packId: int, address: string, price: string, success: var bool): int =
   var
     approveAndCall: ApproveAndCall[100]
     sntContract = status_contracts.getSntContract()
-    tx = self.buildTransaction(
+    tx = buildTransaction(
       packId.u256,
       parseAddress(address),
       eth2Wei(parseFloat(price), sntContract.decimals),
@@ -71,7 +71,7 @@ proc buyPack*(self: StickersModel, packId: int, address, price, gas, gasPrice, p
   var
     sntContract: Erc20Contract
     approveAndCall: ApproveAndCall[100]
-    tx = self.buildTransaction(
+    tx = buildTransaction(
       packId.u256,
       parseAddress(address),
       eth2Wei(parseFloat(price), 18), # SNT

src/status/tasks/stickers.nim

@@ -0,0 +1,40 @@
+import
+  chronos, NimQml, json_serialization, task_runner
+
+import
+  ../stickers
+
+type
+  StickerPackPurchaseGasEstimate* = object
+    vptr*: ByteAddress
+    slot*: string
+    packId*: int
+    address*: string
+    price*: string
+    uuid*: string
+  StickersTasks* = ref object
+    chanSendToPool: AsyncChannel[ThreadSafeString]
+
+proc newStickersTasks*(chanSendToPool: AsyncChannel[ThreadSafeString]): StickersTasks =
+  new(result)
+  result.chanSendToPool = chanSendToPool
+
+proc runTask*(stickerPackPurchaseGasEstimate: StickerPackPurchaseGasEstimate) =
+  var success: bool
+  var estimate = estimateGas(
+    stickerPackPurchaseGasEstimate.packId,
+    stickerPackPurchaseGasEstimate.address,
+    stickerPackPurchaseGasEstimate.price,
+    success
+  )
+  if not success:
+    estimate = 325000
+  let result: tuple[estimate: int, uuid: string] = (estimate, stickerPackPurchaseGasEstimate.uuid)
+  let resultPayload = Json.encode(result)
+
+  signal_handler(cast[pointer](stickerPackPurchaseGasEstimate.vptr), resultPayload, stickerPackPurchaseGasEstimate.slot)
+
+proc stickerPackPurchaseGasEstimate*(self: StickersTasks, vptr: pointer, slot: string, packId: int, address: string, price: string, uuid: string) =
+  let task = StickerPackPurchaseGasEstimate(vptr: cast[ByteAddress](vptr), slot: slot, packId: packId, address: address, price: price, uuid: uuid)
+  let payload = task.toJson(typeAnnotations = true)
+  self.chanSendToPool.sendSync(payload.safe)

src/status/tasks/task_manager.nim

@@ -0,0 +1,27 @@
+import # vendor libs
+  chronicles, task_runner
+
+import # status-desktop libs
+  ./threadpool
+
+export threadpool
+
+logScope:
+  topics = "task-manager"
+
+type
+  TaskManager* = ref object
+    threadPool*: ThreadPool
+
+proc newTaskManager*(): TaskManager =
+  new(result)
+  result.threadPool = newThreadPool()
+
+proc init*(self: TaskManager) =
+  self.threadPool.init()
+
+proc teardown*(self: TaskManager) =
+  self.threadPool.teardown()
+
+
+

src/status/tasks/threadpool.nim

@@ -0,0 +1,256 @@
+import
+  chronicles, chronos, json, json_serialization, NimQml, sequtils, tables,
+  task_runner
+
+import
+  ./stickers
+export
+  stickers
+
+logScope:
+  topics = "task-threadpool"
+
+type
+  ThreadPool* = ref object
+    chanRecvFromPool*: AsyncChannel[ThreadSafeString]
+    chanSendToPool*: AsyncChannel[ThreadSafeString]
+    thread: Thread[PoolThreadArg]
+    size: int
+    stickers*: StickersTasks
+  PoolThreadArg* = object
+    chanSendToMain*: AsyncChannel[ThreadSafeString]
+    chanRecvFromMain*: AsyncChannel[ThreadSafeString]
+    size*: int
+  TaskThreadArg = object
+    id: int
+    chanRecvFromPool: AsyncChannel[ThreadSafeString]
+    chanSendToPool: AsyncChannel[ThreadSafeString]
+  ThreadNotification = object
+    id: int
+    notice: string
+  
+
+# forward declarations
+proc poolThread(arg: PoolThreadArg) {.thread.}
+
+const MaxThreadPoolSize = 16
+
+proc newThreadPool*(size: int = MaxThreadPoolSize): ThreadPool =
+  new(result)
+  result.chanRecvFromPool = newAsyncChannel[ThreadSafeString](-1)
+  result.chanSendToPool = newAsyncChannel[ThreadSafeString](-1)
+  result.thread = Thread[PoolThreadArg]()
+  result.size = size
+  result.stickers = newStickersTasks(result.chanSendToPool)
+
+proc init*(self: ThreadPool) =
+  self.chanRecvFromPool.open()
+  self.chanSendToPool.open()
+  let arg = PoolThreadArg(
+    chanSendToMain: self.chanRecvFromPool,
+    chanRecvFromMain: self.chanSendToPool,
+    size: self.size
+  )
+  createThread(self.thread, poolThread, arg)
+
+  # block until we receive "ready"
+  let received = $(self.chanRecvFromPool.recvSync())
+
+proc teardown*(self: ThreadPool) =
+  self.chanSendToPool.sendSync("shutdown".safe)
+  self.chanRecvFromPool.close()
+  self.chanSendToPool.close()
+  joinThread(self.thread)
+
+proc task(arg: TaskThreadArg) {.async.} =
+  arg.chanRecvFromPool.open()
+  arg.chanSendToPool.open()
+
+  let noticeToPool = ThreadNotification(id: arg.id, notice: "ready")
+  info "[threadpool task thread] sending 'ready'", threadid=arg.id
+  await arg.chanSendToPool.send(noticeToPool.toJson(typeAnnotations = true).safe)
+
+  while true:
+    info "[threadpool task thread] waiting for message"
+    let received = $(await arg.chanRecvFromPool.recv())
+
+    if received == "shutdown":
+      info "[threadpool task thread] received 'shutdown'"
+      info "[threadpool task thread] breaking while loop"
+      break
+
+    let
+      jsonNode = parseJson(received)
+      messageType = jsonNode{"$type"}.getStr
+
+    info "[threadpool task thread] received task", messageType=messageType
+    info "[threadpool task thread] initiating task", messageType=messageType,
+      threadid=arg.id
+
+    try:
+      case messageType
+        of "StickerPackPurchaseGasEstimate":
+          let decoded = Json.decode(received, StickerPackPurchaseGasEstimate, allowUnknownFields = true)
+          decoded.runTask()
+        else:
+          error "[threadpool task thread] unknown message", message=received
+    except Exception as e:
+      error "[threadpool task thread] exception", error=e.msg
+
+    let noticeToPool = ThreadNotification(id: arg.id, notice: "done")
+    info "[threadpool task thread] sending 'done' notice to pool",
+      threadid=arg.id
+    await arg.chanSendToPool.send(noticeToPool.toJson(typeAnnotations = true).safe)
+
+  arg.chanRecvFromPool.close()
+  arg.chanSendToPool.close()
+
+proc taskThread(arg: TaskThreadArg) {.thread.} =
+  waitFor task(arg)
+
+proc pool(arg: PoolThreadArg) {.async.} =
+  let
+    chanSendToMain = arg.chanSendToMain
+    chanRecvFromMainOrTask = arg.chanRecvFromMain
+  var threadsBusy = newTable[int, tuple[thr: Thread[TaskThreadArg],
+    chanSendToTask: AsyncChannel[ThreadSafeString]]]()
+  var threadsIdle = newSeq[tuple[id: int, thr: Thread[TaskThreadArg],
+    chanSendToTask: AsyncChannel[ThreadSafeString]]](arg.size)
+  var taskQueue: seq[string] = @[] # FIFO queue
+  var allReady = 0
+  chanSendToMain.open()
+  chanRecvFromMainOrTask.open()
+
+  info "[threadpool] sending 'ready' to main thread"
+  await chanSendToMain.send("ready".safe)
+
+  for i in 0..<arg.size:
+    let id = i + 1
+    let chanSendToTask = newAsyncChannel[ThreadSafeString](-1)
+    chanSendToTask.open()
+    info "[threadpool] adding to threadsIdle", threadid=id
+    threadsIdle[i].id = id
+    createThread(
+      threadsIdle[i].thr,
+      taskThread,
+      TaskThreadArg(id: id, chanRecvFromPool: chanSendToTask,
+        chanSendToPool: chanRecvFromMainOrTask
+      )
+    )
+    threadsIdle[i].chanSendToTask = chanSendToTask
+
+  # when task received and number of busy threads == MaxThreadPoolSize,
+  # then put the task in a queue
+
+  # when task received and number of busy threads < MaxThreadPoolSize, pop
+  # a thread from threadsIdle, track that thread in threadsBusy, and run
+  # task in that thread
+
+  # if "done" received from a thread, remove thread from threadsBusy, and
+  # push thread into threadsIdle
+
+  while true:
+    info "[threadpool] waiting for message"
+    var task = $(await chanRecvFromMainOrTask.recv())
+    info "[threadpool] received message", msg=task
+
+    if task == "shutdown":
+      info "[threadpool] sending 'shutdown' to all task threads"
+      for tpl in threadsIdle:
+        await tpl.chanSendToTask.send("shutdown".safe)
+      for tpl in threadsBusy.values:
+        await tpl.chanSendToTask.send("shutdown".safe)
+      info "[threadpool] breaking while loop"
+      break
+
+    let
+      jsonNode = parseJson(task)
+      messageType = jsonNode{"$type"}.getStr
+    info "[threadpool] determined message type", messageType=messageType
+
+    case messageType
+      of "ThreadNotification":
+        try:
+          let notification = Json.decode(task, ThreadNotification, allowUnknownFields = true)
+          info "[threadpool] received notification",
+            notice=notification.notice, threadid=notification.id
+
+          if notification.notice == "ready":
+            info "[threadpool] received 'ready' from a task thread"
+            allReady = allReady + 1
+
+          elif notification.notice == "done":
+            let tpl = threadsBusy[notification.id]
+            info "[threadpool] adding to threadsIdle",
+                newlength=(threadsIdle.len + 1)
+            threadsIdle.add (notification.id, tpl.thr, tpl.chanSendToTask)
+            info "[threadpool] removing from threadsBusy",
+              newlength=(threadsBusy.len - 1), threadid=notification.id
+            threadsBusy.del notification.id
+
+            if taskQueue.len > 0:
+              info "[threadpool] removing from taskQueue",
+                newlength=(taskQueue.len - 1)
+              task = taskQueue[0]
+              taskQueue.delete 0, 0
+
+              info "[threadpool] removing from threadsIdle",
+                newlength=(threadsIdle.len - 1)
+              let tpl = threadsIdle[0]
+              threadsIdle.delete 0, 0
+              info "[threadpool] adding to threadsBusy",
+                newlength=(threadsBusy.len + 1), threadid=tpl.id
+              threadsBusy.add tpl.id, (tpl.thr, tpl.chanSendToTask)
+              await tpl.chanSendToTask.send(task.safe)
+
+          else:
+            error "[threadpool] unknown notification", notice=notification.notice
+        except Exception as e:
+          warn "[threadpool] unknown error in thread notification", message=task, error=e.msg
+
+      else: # must be a request to do task work
+        if allReady < arg.size or threadsBusy.len == arg.size:
+          # add to queue
+          info "[threadpool] adding to taskQueue",
+            newlength=(taskQueue.len + 1)
+          taskQueue.add task
+
+        # do we have available threads in the threadpool?
+        elif threadsBusy.len < arg.size:
+          # check if we have tasks waiting on queue
+          if taskQueue.len > 0:
+            # remove first element from the task queue
+            info "[threadpool] adding to taskQueue",
+              newlength=(taskQueue.len + 1)
+            taskQueue.add task
+            info "[threadpool] removing from taskQueue",
+              newlength=(taskQueue.len - 1)
+            task = taskQueue[0]
+            taskQueue.delete 0, 0
+
+          info "[threadpool] removing from threadsIdle",
+            newlength=(threadsIdle.len - 1)
+          let tpl = threadsIdle[0]
+          threadsIdle.delete 0, 0
+          info "[threadpool] adding to threadsBusy",
+            newlength=(threadsBusy.len + 1), threadid=tpl.id
+          threadsBusy.add tpl.id, (tpl.thr, tpl.chanSendToTask)
+          await tpl.chanSendToTask.send(task.safe)
+
+
+  var allTaskThreads: seq[Thread[TaskThreadArg]] = @[]
+
+  for tpl in threadsIdle:
+    tpl.chanSendToTask.close()
+    allTaskThreads.add tpl.thr
+  for tpl in threadsBusy.values:
+    tpl.chanSendToTask.close()
+    allTaskThreads.add tpl.thr
+
+  chanSendToMain.close()
+  chanRecvFromMainOrTask.close()
+
+  joinThreads(allTaskThreads)
+
+proc poolThread(arg: PoolThreadArg) {.thread.} =
+  waitFor pool(arg)

src/status/wallet.nim

@@ -349,3 +349,18 @@ proc getGasPricePredictions*(self: WalletModel): GasPricePrediction =
   except Exception as e:
     echo "error getting gas price predictions"
     echo e.msg
+
+proc getGasPricePredictions2*(): GasPricePrediction =
+  if status_settings.getCurrentNetwork() != Network.Mainnet:
+    # TODO: what about other chains like xdai?
+    return GasPricePrediction(safeLow: 1.0, standard: 2.0, fast: 3.0, fastest: 4.0)
+  try:
+    let url: string = fmt"https://etherchain.org/api/gasPriceOracle"
+    let secureSSLContext = newContext()
+    let client = newHttpClient(sslContext = secureSSLContext)
+    client.headers = newHttpHeaders({ "Content-Type": "application/json" })
+    let response = client.request(url)
+    result = Json.decode(response.body, GasPricePrediction)
+  except Exception as e:
+    echo "error getting gas price predictions"
+    echo e.msg

vendor/DOtherSide

@@ -1 +1 @@
-Subproject commit 1cc16aaa5c643d0d33c31f9953fbe4a9f6bde151
+Subproject commit 5177a129d45985bb61471d7afecd397a82ed9d42

vendor/edn.nim

@@ -1 +1 @@
-Subproject commit 4cda60880e108f0cb7efe1c209308f2db03267d9
+Subproject commit 3305e41f9da3f2f21c56bd23b74b0a3589f3bf3e

vendor/nim-libp2p

@@ -1 +1 @@
-Subproject commit 8d9e231a74c1afc76b6745e05020f8d4e33501e7
+Subproject commit 70deac9e0d16f7d00a0d4404ed191042dbf079be

vendor/nim-task-runner

@@ -0,0 +1 @@
+Subproject commit a87f3f85be052fb3332358f95079a059cf1daf15