Re: pgbench: option delaying queries till connections establishment?

Hello,

>>> I've merged all time-related stuff (time_t, instr_time, int64) to use a
>>> unique type (pg_time_usec_t) and set of functions/macros, which simplifies
>>> the code somehow.
>>
>> Hm. I'm not convinced it's a good idea for pgbench to do its own thing
>> here.

I really think that the refactoring part is a good thing because cloc and
cost is reduced (time arithmetic is an ugly pain with instr_time).

I have split the patch.

* First patch reworks time measurements in pgbench.

It creates a convenient pg_time_usec_t and use it everywhere, getting rid
of "instr_time_t". The code is somehow simplified wrt what time are taken
and what they mean.

Instead of displaying 2 tps at the end, which is basically insane, it
shows one tps for --connect, which includes reconnection times, and one
tps for the usual one connection at startup which simply ignores the
initial connection time.

This (mostly) refactoring reduces the cloc.

* Second patch adds a barrier before starting the bench

It applies on top of the previous one. The initial imbalance due to thread
creation times is smoothed.

I may add a --start-on option afterwards so that several pgbench (running
on distinct hosts) can be synchronized, which would be implemented as a
delay inserted by thread 0 before the barrier.

The windows implementation is more or less blind, if someone can confirm
that it works, it would be nice.

--
Fabien.