eclipse-archived
protect cellular http api calls by mutex
I noticed a potential hazard in the HTTP service-layer.
The Cellular driver API promises to be thread-safe. To achieve this we simply lock the entire driver API with a mutex. We do this via the helper function Engine_Dispatch(). The idea is to put everything that should be under the mutex' protection into a function and then dispatch said function via this little helper. Note that in-between consecutive Engine_Dispatch() calls we are not protected.
This is what's bugging me about HttpService.c. There we call Engine_Dispatch() multiple times for a single request. Given that HTTP works with intermediate files on the modem's own flash, it is highly recommended to protect the entire request under a single mutex lock (basically just get rid of the individual Engine_Dispatch() calls and stuff everything into a single one).
