add seq destroy example

tests/exampleGcFailures/exNoFailureNoGcCollectSeq.nim

@@ -4,34 +4,16 @@ import chronos/threadsync
 import chronos/unittest2/asynctests
 import taskpools
 
-type
-  Seq*[T] = object
-    data*: ptr UncheckedArray[T]
-    size*: int
-
-  DataObj = ref object
-    mockSeq: Seq[char]
-
-proc worker(data: seq[char], sig: ThreadSignalPtr) =
+proc worker(data: string, sig: ThreadSignalPtr) =
   os.sleep(4_000)
   echo "running worker: "
   echo "worker: ", data
   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 = @"hello world!"
+  var obj = "hello world!"
+  # obj.shallow()
 
   echo "spawn worker"
   tp.spawn worker(obj, sig)

tests/exampleGcFailures/exNoFailureNoGcCollectSeqDestroy.nim

@@ -0,0 +1,48 @@
+import std/os
+import chronos
+import chronos/threadsync
+import chronos/unittest2/asynctests
+import taskpools
+
+type
+  Test* = object
+    count*: int
+
+proc `=destroy`*(obj: var Test) =
+  echo "destroy count: ", obj.count, " thread: ", getThreadId()
+
+proc worker(data: seq[Test], sig: ThreadSignalPtr) =
+  os.sleep(40)
+  echo "running worker: ", getThreadId()
+  echo "worker: ", data
+  discard sig.fireSync()
+
+proc runTest(tp: TaskPool, sig: ThreadSignalPtr) {.async.} =
+  ## init
+  var obj = @[Test(count: 1), Test(count: 2)]
+
+  echo "spawn worker"
+  tp.spawn worker(obj, sig)
+
+  obj[0].count = 10
+  obj[1].count = 20
+  ## adding fut.wait(100.milliseconds) creates memory issue
+  await wait(sig)
+  ## just doing the wait is fine:
+  # await wait(sig)
+
+proc runTests(tp: TaskPool, sig: ThreadSignalPtr) {.async.} =
+  for i in 1..1:
+    try:
+      echo "\n\nrunning main: ", getThreadId()
+      await runTest(tp, sig)
+      os.sleep(200)
+    except AsyncTimeoutError:
+      echo "looping..."
+
+suite "async tests":
+  var tp = Taskpool.new(num_threads = 2) # Default to the number of hardware threads.
+  let sig = ThreadSignalPtr.new().get()
+
+  asyncTest "test":
+    await runTests(tp, sig)