Queue tracing

[aggarg (Gaurav Aggarwal)]

@schilkp

The tracer has no way of knowing the previous size of the queue without on-device book keeping, so it cannot directly determine if the send increased the queue size or not. Instead it would have to transmit the queue length with every queue send trace call because it may or may not have changed. If the tracer were to have access to the value of xCopyPosition it could instead emit either a queue send or queue overwrite event which only has the queue identifier as metadata, and only differ in trace event ID.

Thank you for explaining your use case. I think we can add traceQUEUE_SEND_EXT as per your proposal. The following should make it backward compatible:

#ifndef traceQUEUE_SEND_EXT
    #define traceQUEUE_SEND_EXT( pxQueue, xCopyPosition )    traceQUEUE_SEND( pxQueue )
#endif

The call to traceQUEUE_SEND( pxQueue ); can be replaced with traceQUEUE_SEND_EXT( pxQueue, xCopyPosition ); in queue.c.

@schilkp

Providing a traceQUEUE_RESET(xQueue) would be a backwards-compatible change that provides this information in a simple fashion.

Sounds good. Please raise a PR.