• Jim Brunner's avatar
    Use H/W Monotonic clock and updates to AE (#7644) · c01e94a4
    Jim Brunner authored
    Update adds a general source for retrieving a monotonic time.
    In addition, AE has been updated to utilize the new monotonic
    clock for timer processing.
    
    This performance improvement is **not** enabled in a default build due to various H/W compatibility
    concerns, see README.md for details. It does however change the default use of gettimeofday with
    clock_gettime and somewhat improves performance.
    
    This update provides the following
    1. An interface for retrieving a monotonic clock. getMonotonicUs returns a uint64_t (aka monotime)
       with the number of micro-seconds from an arbitrary point. No more messing with tv_sec/tv_usec.
       Simple routines are provided for measuring elapsed milli-seconds or elapsed micro-seconds (the
       most common use case for a monotonic timer). No worries about time moving backwards.
    2. High-speed assembler implementation for x86 and ARM. The standard method for retrieving the
       monotonic clock is POSIX.1b (1993): cloc...
    c01e94a4
README.md 20.8 KB