Closes the library handle.
DynamicLibrary implements the explicit resource management protocol, so a library instance can be managed with the using declaration. Leaving the enclosing scope invokes library.close() automatically.
import { DynamicLibrary } from 'node:ffi';
{
using lib = new DynamicLibrary('./mylib.so');
// Use `lib` here; `lib.close()` is called when the block exits.
}
Calling library.close() (or disposing the library) more than once is a no-op.
After a library has been closed:
- Resolved function wrappers become invalid.
- Further symbol and function resolution throws.
- Registered callbacks are invalidated.
Closing a library does not make previously exported callback pointers safe to reuse. Node.js does not track or revoke callback pointers that have already been handed to native code.
If native code still holds a callback pointer after library.close() or after library.unregisterCallback(pointer), invoking that pointer has undefined behavior, is not allowed, and is dangerous: it can crash the process, produce incorrect output, or corrupt memory. Native code must stop using callback addresses before the library is closed or before the callback is unregistered.
Calling library.close() from one of the library's active callbacks is unsupported and dangerous. The callback must return before the library is closed.