When the libc headers used to build mosquitto define CLOCK_BOOTTIME but
the kernel where mosquitto runs does not implement CLOCK_BOOTTIME, all
timestamps are wrong (uninitialized data), because there is no check for
the success of the clock_gettime() calls.
This adds probing for the availability of CLOCK_BOOTTIME from
mosquitto_lib_init(), falling back to CLOCK_MONOTONIC, and then modifies
mosquitto_time() to use the selected clock. Probing at init time avoids
having to do two clock_gettime() calls for every timestamp if
CLOCK_BOOTTIME is not available.
It also fixes a similar problem in mosquitto_lib_init().
Signed-off-by: Diego Santa Cruz <diego.santacruz@spinetix.com>
Diego Santa Cruz
688fa86de4