fix(pool): use time.monotonic() instead of time.time() for connection timestamps

[algojogacor]

Description

Replaced all time.time() calls in pool/base.py with time.monotonic() for connection record timestamp tracking. Also updated the comment block that documented the Windows precision caveat.

time.time() on Windows has approximately 16 ms granularity, which can cause soft invalidation checks to fail when _soft_invalidate_time and starttime are captured in the same timer quantum. time.monotonic() is monotonic by definition and provides sub-millisecond precision on all platforms, so the > comparisons between timestamps work correctly regardless of platform timer resolution.

Four sites changed (all in lib/sqlalchemy/pool/base.py):

• Pool._invalidate_time assignment (line 407)
• _ConnectionRecord._soft_invalidate_time assignment (line 812)
• Connection recycle time check in get_connection (line 838)
• _ConnectionRecord.starttime assignment in __connect (line 893)

All comparisons are relative (timestamp vs timestamp or timestamp delta vs timeout), so switching to time.monotonic() preserves existing behavior while fixing the precision issue.

• A short code fix
  • Fixes: Connection pool soft invalidation uses time.time() comparison that can silently fail on low-resolution clocks (e.g. Windows ~16 ms) #13169
  • Existing pool invalidation tests cover the comparison logic

[zzzeek]

I want to do what I propose here which is dont hardcode time functions that are used in this way:

1. note that we also use time.time() in queue.py ; modern cpython correctly uses monotonic
2. other places we use time() for cache invalidation:

   sqlalchemy/lib/sqlalchemy/testing/util.py

   Lines 522 to 534 in 1e1c008

   	@contextlib.contextmanager
   	def skip_if_timeout(seconds: float, cleanup: Any = None):
   	now = time.time()
   	yield
   	sec = time.time() - now
   	if sec > seconds:
   	try:
   	cleanup()
   	finally:
   	config.skip_test(
   	f"test took too long ({sec:.4f} seconds > {seconds})"
   	)

   and three places in asyncpg such as

   sqlalchemy/lib/sqlalchemy/dialects/postgresql/asyncpg.py

   Line 777 in 1e1c008

   self._invalidate_schema_cache_asof = time.time()

steps:

1. add new library function sqlalchemy.util.compat.highres_clock() (or whatever name, but the point is it should be named for the use case, not the implementation)
2. apply to pool/base.py, postgresql/asyncpg.py, util/queue.py, testing/util.py
3. this will be for 2.1 and i think we should have a short changelog
4. thanks!

[zzzeek]

I dont want to lose the note about how >= would eliminate the issue, but would run a theoretical risk of constant re-connects if "time" were not incrementing.