Huge latency between onPreExecute and doInBackground in AsyncTask

Question

I have an AsynkTask: ``` new AsyncTask<Void, Void, Void>() { private ProgressDialog mProgressDialog; @Override protected void onPreExecute() { Log.i(TAG, "Pre execute: " + System.currentTimeMillis()); super.onPreExecute(); mProgressDialog = ProgressDialog.show(NewWeatherActivity.this, null, getResources().getString(R.string.weather_is_updating)); mProgressDialog.setCancelable(false); Log.i(TAG, "Pre executed: " + System.currentTimeMillis()); } @Override protected Void doInBackground(Void... voids) { Log.i(TAG, "Do in background: " + System.currentTimeMillis()); // Some actions Log.i(TAG, "Done in background: " + System.currentTimeMillis()); return null; } @Override protected void onPostExecute(Void aVoid) { Log.i(TAG, "Post execute: " + System.currentTimeMillis()); super.onPostExecute(aVoid); mProgressDialog.dismiss(); Log.i(TAG, "Post executed: " + System.currentTimeMillis()); } }.execute(); ``` Log: I/TVLauncher/NewWeatherActivity(21691): Pre execute: 1354798705667 I/TVLauncher/NewW…

Accepted Answer

You are likely calling a framework or some library that is also using an Async Task. This would manifest in a slowdown on later versions of Android.

AsyncTasks are now run sequentially. That means a new async task won't run until the last one was finished. Instead of calling execute try calling `executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, "");`

This will likely reduce the latency to negligible levels.

Huge latency between onPreExecute and doInBackground in AsyncTask

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