* Tally and duration counters for Job Queue tasks and RPC calls
optionally rendered by server_info and server_state, and
optionally printed to a distinct log file.
- Tally each Job Queue task as it is queued, starts, and
finishes running. Track total duration queued and running.
- Tally each RPC call as it starts and either finishes
successfully or throws an exception. Track total running
duration for each.
* Track currently executing Job Queue tasks and RPC methods
along with durations.
* Json-formatted performance log file written by a dedicated
thread, for above-described data.
* New optional parameter, "counters", for server_info and
server_state. If set, render Job Queue and RPC call counters
as well as currently executing tasks.
* New configuration section, "[perf]", to optionally control
performance logging to a file.
* Support optional sub-second periods when rendering human-readable
time points.
All uses of beast::Thread were previously removed from the code
base, so beast::Thread is removed. One piece of beast::Thread
needed to be preserved: the ability to set the current thread's
name. So there's now a beast::CurrentThreadName that allows the
current thread's name to be set and returned.
Thread naming is also cleaned up a bit. ThreadName.h and .cpp
are removed since beast::CurrentThreadName does a better job.
ThreadEntry is also removed, but its terminateHandler() is
preserved in TerminateHandler.cpp. The revised terminateHandler()
uses beast::CurrentThreadName to recover the name of the running
thread.
Finally, the NO_LOG_UNHANDLED_EXCEPTIONS #define is removed since
it was discovered that the MacOS debugger preserves the stack
of the original throw even if the terminateHandler() rethrows.
Log thread name and exception type on unhandled exceptions and use a
terminate handler to get a stack trace that includes the function that
thows the exception.
