files, sockets: ignore cleanup exceptions on =destroy

src/sys/private/files_posix.nim

@@ -21,7 +21,11 @@ template closeImpl() {.dirty.} =
   close f.handle
 
 template destroyFileImpl() {.dirty.} =
-  cleanupFile f
+  try:
+    cleanupFile f
+  except CatchableError:
+    discard "Nothing can be done here"
+
   `=destroy` f.handle
 
 template newFileImpl() {.dirty.} =

src/sys/private/files_windows.nim

@@ -29,7 +29,11 @@ template closeImpl() {.dirty.} =
   close f.handle
 
 template destroyFileImpl() {.dirty.} =
-  cleanupFile f
+  try:
+    cleanupFile f
+  except CatchableError:
+    discard "Nothing can be done here"
+
   `=destroy` f.handle
 
 template newFileImpl() {.dirty.} =

src/sys/sockets.nim

@@ -55,21 +55,30 @@
   ## If `s` is invalid, `ClosedHandleDefect` will be raised.
   close s.handle
 
-proc close(s: var AsyncSocketObj) {.inline.}
+template closeAsync(s: untyped) =
+  ## Forward declaration of `close(AsyncSocketObj)` to avoid issues due to
+  ## `=destroy` being implicitly defined at first usage of type
+  unregister s.handle.fd
+  close SocketObj(s)
 
 proc `=destroy`(s: var AsyncSocketObj) =
   ## Destroy the asynchronous socket `s`.
+  ##
+  ## Note that non-fatal errors are ignored, use `close` instead if those should
+  ## be catched.
   if s.handle.fd != InvalidFD:
-    close(s)
+    try:
+      closeAsync(s)
+    except CatchableError:
+      discard "Nothing can be done here"
 
 proc close(s: var AsyncSocketObj) {.inline.} =
   ## Closes and invalidates the socket `s`.
   ##
   ## If `s` is invalid, `ClosedHandleDefect` will be raised.
   ##
   ## The FD associated with `s` will be deregistered from `ioqueue`.
-  unregister s.handle.fd
-  close SocketObj(s)
+  closeAsync(s)
 
 proc close*(s: Socket) {.inline.} =
   ## Closes and invalidates the socket `s`.
@@ -86,7 +95,7 @@
   close s[]
 
 # These are used to ensure correct destructor binding
 {.warning: "compiler bug workaround; see: https://github.com/nim-lang/Nim/issues/19138".}
 proc newSocketAs(T: typedesc[not ref], fd: SocketFD): ref T {.inline.} =
   ## Create a ref socket from `fd`, converted to `T`.
   new result
@@ -498,7 +507,7 @@
   var
     attempted = false
     lastError: ref OSError
   {.warning: "Workaround for nim-works/cps#185".}
   let next: iterator (): IPEndpoint = closureItems(endpoints)
   while true:
     attempted = true