updates

tests/exampleGcFailures/exFailure.nim

@@ -51,7 +51,7 @@ proc runTest(tp: TaskPool, sig: ThreadSignalPtr) {.async.} =
   tp.spawn worker(addr obj.mockSeq, sig)
 
   ## adding fut.wait(100.milliseconds) creates memory issue
-  await wait(sig).wait(100.milliseconds)
+  await wait(sig)
   ## just doing the wait is fine:
   # await wait(sig)
 
@@ -61,7 +61,7 @@ suite "async tests":
 
   asyncTest "test":
     try:
-      await runTest(tp, sig)
+      await runTest(tp, sig).wait(100.milliseconds)
     except AsyncTimeoutError:
       echo "Run GC"
       GC_fullCollect()

tests/exampleGcFailures/exFailure2.nim

@@ -0,0 +1,81 @@
+import std/os
+import chronos
+import chronos/threadsync
+import chronos/unittest2/asynctests
+import taskpools
+
+## This example mocks up a sequence and uses
+## a finalizer and GC_fullCollect to more
+## deterministically create a memory error.
+## 
+## see `exFailureSeq.nim` for a probablisitc based
+## example using a real seq object.
+## 
+
+type
+  Seq*[T] = object
+    data*: ptr UncheckedArray[T]
+    size*: int
+
+  DataObj = ref object
+    mockSeq: Seq[char]
+
+template toOpenArray*[T](arr: Seq[T]): auto =
+  system.toOpenArray(arr.data, 0, arr.size)
+
+proc worker(data: ptr Seq[char], sig: ThreadSignalPtr) =
+  os.sleep(5_000)
+  echo "running worker: "
+  assert data[].data != nil
+  echo "worker: ", data[].toOpenArray()
+  discard sig.fireSync()
+
+proc finalizer(obj: DataObj) =
+  echo "finalize DataObj and freeing mockSeq"
+  obj.mockSeq.data.dealloc()
+  obj.mockSeq.data = nil
+
+proc initMockSeq(msg: string): Seq[char] =
+  result.data = cast[ptr UncheckedArray[char]](alloc0(13))
+  for i, c in msg:
+    result.data[i] = c
+  result.size = 12
+
+proc runTest(tp: TaskPool, sig: ThreadSignalPtr) {.async.} =
+  ## init
+  var obj: DataObj
+  obj.new(finalizer)
+  obj.mockSeq = initMockSeq("hello world!")
+
+  echo "spawn worker"
+  tp.spawn worker(addr obj.mockSeq, sig)
+
+  ## adding fut.wait(100.milliseconds) creates memory issue
+  try:
+    await wait(sig)
+    echo "runTest got sig"
+  finally:
+    echo "runTest done"
+  ## just doing the wait is fine:
+  # await wait(sig)
+
+proc doFail() {.async.} =
+  await sleepAsync(10.milliseconds)
+  raise newException(CatchableError, "error")
+
+suite "async tests":
+  var tp = Taskpool.new(num_threads = 2) # Default to the number of hardware threads.
+  let sig = ThreadSignalPtr.new().get()
+
+  asyncTest "test":
+    try:
+      await allFutures(
+        runTest(tp, sig),
+        doFail(),
+      )
+    except Defect:
+      echo "Errored out"
+    finally:
+      echo "Run GC"
+      GC_fullCollect()
+      os.sleep(2_000)