# Class type Nethttpd_engine.http_engine_processing_config

    class type http_engine_processing_config = object .. end

    method config_synch_input : (Netchannels.in_obj_channel -> unit) -> Uq_engines.async_in_channel -> unit

The "input synchronizer": It is called as `obj # config_synch_input f ch` to create a synchronous input channel from an asynchronous one, `ch`. The function `f` must be called back by the synchronizer when synchronisation is established, and with the synchronous channel `ch'` as argument. In particular, the task of the synchronizer is to turn blocking reads of `ch'` into non-blocking reads of `ch`. In general there are two ways of implementation:

- Buffer all input from `ch` until the end of the channel is reached, then call `f` with a wrapper channel `ch'` that just reads from the buffer.
- Run `f` in a different thread that blocks whenever there is nothing to read from `ch`.

Both implementations are allowed, i.e. it is allowed that `f` runs in a different thread.

CHECK: How to handle exceptions raised from `f`? Idea: `f` is obliged to close `ch'` in this case, even if `ch` is not yet at the end. The rest of exception handling is up to the user. - The complementary must also be true: When there is an error in the engine, `ch` must be closed to signal the other thread that we have a problem.

    method config_synch_output : (Netchannels.out_obj_channel -> unit) -> Uq_engines.async_out_channel -> unit

The "output synchronizer": It is called as `obj # config_synch_output f ch` to create a synchronous output channel from an asynchronous one, `ch`. The function `f` must be called back by the synchronizer when synchronisation is established, and with the synchronous channel `ch'` as argument. In particular, the task of the synchronizer is to turn blocking writes to `ch'` into non-blocking writes to `ch`. In general there are two ways of implementation:

- Call `f`, then buffer all output to `ch'` until the end of the channel is reached, and finally output the contents of the buffer in an asynchronous way.
- Run `f` in a different thread that blocks whenever there is no space to write to `ch`.

Both implementations are allowed, i.e. it is allowed that `f` runs in a different thread.

CHECK: Exceptions.