miniav_ffi_callback_trace library

TRACING FOR NativeCallable LIFETIME BUGS.

Closing a NativeCallable that native code can still invoke aborts the whole process:

runtime_entry.cc: error: Callback invoked after it has been deleted.
... isolate=(nil)

It is uncatchable and prints no Dart stack, so the usual debugging move — find out who did it — is not available. When several packages hand callbacks to native threads, narrowing it down is guesswork unless the closes announce themselves.

Set MINIAV_TRACE_CALLBACKS=1 and every close in this package prints to stderr (not the log port: during a Flutter hot reload the isolate is paused at a safepoint, so port messages are not delivered until after the window in which the crash happens — stderr is written synchronously and survives).

Read the output as an ordering: the last [miniav-cb] close before the abort is the prime suspect. If the abort arrives with NO close line before it, this package did not delete the callback and the culprit is elsewhere.

Functions

traceCallbackClose(String what) → void

Announces that a NativeCallable is about to be closed. what should name the callback precisely enough to act on — module plus role.

traceCallbackOpen(String what) → void

Announces a native-thread callback registration, so the trace shows what was live before a close.