Libraries: Decision Watchdog: refuse yesterday's decision, fail closed, log once

 

Decision Watchdog: refuse yesterday's decision, fail closed, log once:

A daily process writes "today's decision" (which strategy runs, or FLAT) to a file the EAs read at the open. One day the writer did not run. The EAs read yesterday's file, compared its date with TimeCurrent() - the server clock, which had stepped back to the previous day overnight - saw a match, and traded all morning on a 24-hour-old decision. No error anywhere. Two rules, both in this class: 1) staleness is judged against TimeLocal(), which always moves forward; TimeCurrent() is the last tick's stamp - it freezes without ticks and can step back on reconnect. 2) When in doubt the answer is FLAT: missing file, bad date, wrong day, empty line - every failure path returns "do nothing", and each is logged ONCE per state change, not on every tick and not never. File format: line 1 = ISO date, line 2 = decision string. The demo writes a fresh, a stale, a malformed, an empty and a missing file, and shows that only the first is allowed to trade.

Decision Watchdog: refuse yesterday's decision, fail closed, log once

Author: Joao Prata Silva Yglesias