libuv thread

libuv is not thread safe in this way. You should use uv_async to signal the loop to exit. uv_async is the only thread-safe facility that libuv has.

It would look something like this:

uv_async_t exit_handle;

void exit_async_cb(uv_async_t* handle, int status) {
  /* After closing the async handle, it will no longer keep the loop alive. */
  uv_close((uv_handle_t*) &exit_handle, NULL);
}

void thread_function() {
  uv_loop_t *loop = uv_loop_new();
  /* The existence of the async handle will keep the loop alive. */
  uv_async_init(loop, &exit_handle, exit_async_cb);
  uv_run(loop);
}

 

Now from the other thread you can signal this loop to exit by calling

uv_async_send(&exit_handle);

 

You need to take care to not call uv_async_send() before the other thread has finished setting up the loop and the uv_async handle. Recent version of libuv include the uv_barrier synchronization primitives that you could use; but the libuv version that ships with Node.js 0.8 doesn't support this yet, so you probably need to use pthread facilities to make this work.

On a side note, you seem to be calling uv_ref and uv_unref with a loop reference as the argument. In recent versions of libuv this has changed, you are now supposed to uv_ref and uv_unref a specific handle. See uv.h for details.