add nextSignal using mutex

datastore/threads/threadproxyds.nim

@@ -41,6 +41,7 @@ type
     signal: ThreadSignalPtr
     running: bool ## used to mark when a task worker is running
     cancelled: bool ## used to cancel a task before it's started
+    nextSignal: (Lock, Cond)
 
   TaskCtx*[T] = SharedPtr[TaskCtxObj[T]]
     ## Task context object.
@@ -72,6 +73,13 @@ proc setDone[T](ctx: TaskCtx[T]) =
   # withLock(ctxLock):
     ctx[].running = false
 
+proc waitSync*(sig: var (Lock, Cond)) =
+  withLock(sig[0]):
+    wait(sig[1], sig[0])
+proc fireSync*(sig: var (Lock, Cond)) =
+  withLock(sig[0]):
+    signal(sig[1])
+
 proc acquireSignal(): ?!ThreadSignalPtr =
   let signal = ThreadSignalPtr.new()
   if signal.isErr():

tests/datastore/testthreadproxyds.nim

@@ -24,7 +24,7 @@ import ./querycommontests
 
 const
   NumThreads = 20 # IO threads aren't attached to CPU count
-  ThreadTestLoops {.intdefine.} = 10
+  ThreadTestLoops {.intdefine.} = 100
   N = ThreadTestLoops
 
 for i in 1..N: