Prosody application note: simultaneous use of Prosody by multiple processes

Multiple processes can use the Prosody API simultaneously. If two processes never use the same Prosody processor module, then they will be unaware of each other (unless, of course they interact through other shared resources, such as timeslots on the H.100 bus), because Prosody has no resources shared between modules (except, of course, the clocking on the timeslots, which comes from the switch matrix controlled by the switch driver).

Module resources that are shared

These are the resources associated with a module which are shared between all processes using that module:

• All channel resources - these are the resoures which dictate the number of channels that can be used simultaneously. The limits described in Prosody TiNG channel limits apply to the module itself.
• Downloaded firmware - anything downloaded is visible to all processes.
• Downloaded word models for Isolated Word Recognition - but note that a process can only use models which it has downloaded, so a model must be downloaded by every process which uses it but only one copy is stored on the DSP.

Module resources that are not shared

Resources on this list are private to each process, so the amount used by one process does not reduce the amount available to other processes using the same module.

• All parameter adjustments performed on individual channels.
• Input component frequencies, tones, and tone sets.
• Input call progess tones.
• Output component frequencies and tones.
• Parameter adjustments controlled by sm_adjust_input_tone_set().
• Parameter adjustments controlled by sm_config_module_switching().
• Parameter adjustments controlled by sm_adjust_catsig_module_params().

Note that in Prosody version 1 all the above resources, except for parameters adjusted per channel, were shared and physically located on the Prosody processor module itself. In version 2 (TiNG), they are kept in the API library, so, in addition to permitting different processes to have different configurations, it means that generally these items are only limited by the size of the application's memory.

Document reference: AN 1399