fix: pr comments

ffi/event_thread.nim

@@ -116,20 +116,24 @@ proc eventRun[T](ctx: ptr FFIContext[T]) {.async.} =
   var hb = HeartbeatMonitor.init(ctx)
   var notifiedStuck = false # latched forever — eventQueueStuck is sticky terminal.
 
-  while ctx.running.load():
+  # Keep draining after `running` flips false until the FFI thread has exited, so
+  # events emitted by an async {.ffiDtor.} teardown are still dispatched.
+  while ctx.running.load() or not ctx.ffiThreadExited.load():
     # Wake on enqueue or tick — whichever first.
     discard await ctx.eventQueueSignal.wait().withTimeout(EventThreadTickInterval)
 
     ctx.drainEventQueue()
 
-    # Fire after drain so reg.lock is free — FFI-thread would deadlock here.
-    if not notifiedStuck and ctx.eventQueueStuck.load():
-      onNotResponding(ctx)
-      notifiedStuck = true
+    # Liveness only applies while running; skip it during the teardown drain.
+    if ctx.running.load():
+      # Fire after drain so reg.lock is free — FFI-thread would deadlock here.
+      if not notifiedStuck and ctx.eventQueueStuck.load():
+        onNotResponding(ctx)
+        notifiedStuck = true
+      hb.check(ctx)
 
-    if not ctx.running.load():
-      break
-    hb.check(ctx)
+  # Catch anything enqueued between the last drain and the FFI thread's exit.
+  ctx.drainEventQueue()
 
 proc eventThreadBody[T](ctx: ptr FFIContext[T]) {.thread.} =
   ## Drains the event queue and runs the FFI-thread heartbeat check.

ffi/ffi_context.nim

@@ -37,6 +37,9 @@ type FFIContext*[T] = object
   ffiHeartbeat*: Atomic[int64]
     # advanced each FFI-thread loop; event thread reads for liveness
   eventQueueStuck*: Atomic[bool] # sticky overflow flag
+  ffiThreadExited*: Atomic[bool]
+    # set once the FFI thread (including any async {.ffiDtor.} teardown) is done;
+    # keeps the event thread draining until then so teardown-emitted events land
   running: Atomic[bool] # To control when the threads are running
   registeredRequests: ptr Table[cstring, FFIRequestProc]
   requestTimeouts: ptr Table[cstring, int]
@@ -126,6 +129,7 @@ proc initContextResources*[T](ctx: ptr FFIContext[T]): Result[void, string] =
   initEventQueue(ctx[].eventQueue)
   ctx.ffiHeartbeat.store(0)
   ctx.eventQueueStuck.store(false)
+  ctx.ffiThreadExited.store(false)
   ctx.defaultRequestTimeout = DefaultRequestTimeout
 
   var success = false
@@ -199,7 +203,7 @@ proc signalStop*[T](ctx: ptr FFIContext[T]): Result[void, string] =
 ## connections) on the FFI thread before it exits — a graceful shutdown can
 ## outlast the default, and being cut short leaks the context instead of waiting.
 ## Override at compile time with `-d:ffiThreadExitTimeoutMs=<ms>`.
-const ThreadExitTimeoutMs* {.intdefine.} = 1500
+const ThreadExitTimeoutMs* {.intdefine: "ffiThreadExitTimeoutMs".} = 1500
 const ThreadExitTimeout* = ThreadExitTimeoutMs.milliseconds
 
 proc stopAndJoinThreads*[T](ctx: ptr FFIContext[T]): Result[void, string] =

ffi/ffi_thread.nim

@@ -150,6 +150,12 @@ proc ffiThreadBody[T](ctx: ptr FFIContext[T]) {.thread.} =
     onFFIThread = false
     # Free handle refs on the FFI thread that allocated them (refc heap is thread-local).
     ctx[].handles.releaseAll()
+    # Teardown has run and no more events will be emitted from this thread; let
+    # the event thread stop draining and exit. Wake it so it notices without
+    # waiting a full tick.
+    ctx.ffiThreadExited.store(true)
+    ctx.eventQueueSignal.fireSync().isOkOr:
+      error "failed to wake event thread on FFI thread exit", err = error
     # Unblocks destroyFFIContext's bounded wait so cleanup can proceed.
     let fireRes = ctx.threadExitSignal.fireSync()
     if fireRes.isErr():

ffi/internal/ffi_macro.nim

@@ -1585,6 +1585,10 @@ macro ffiDtor*(args: varargs[untyped]): untyped =
   ## The wire format follows the library default and can be overridden with
   ## `{.ffiDtor: "abi = c".}` / `{.ffiDtor: "abi = cbor".}`.
   ##
+  ## Example (sync):
+  ##   proc echo_destroy*(e: Echo) {.ffiDtor.} =
+  ##     e.close()
+  ##
   ## Example (async):
   ##   proc waku_destroy*(w: Waku): Future[void] {.ffiDtor.} =
   ##     await w.stop()