database/postgres
database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-05-12 16:21:30 +03:00
Code

Update obsolete comment about pg_usleep() accuracy.

Browse Source 
There are still some systems that use traditional tick-based sleep
timing, but many including Linux, FreeBSD and macOS started using high
resolution timer hardware more directly a decade or two ago.  Update our
comment about that.  Also highlight that Windows is like the older
Unixen in that respect.

Author: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://postgr.es/m/CA%2BhUKG%2BogAon8_V223Ldv6taPR2uKH3X_UJ_A7LJAf3-VRARPA%40mail.gmail.com
This commit is contained in:
Thomas Munro 2023-03-15 16:14:36 +13:00
parent 805b821e77
commit e4da2a44c1
1 changed files with 4 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
src/port/pgsleep.c
View File

@ -25,9 +25,10 @@
/* /*
* pg_usleep --- delay the specified number of microseconds. * pg_usleep --- delay the specified number of microseconds.
* *
* NOTE: although the delay is specified in microseconds, the effective * NOTE: Although the delay is specified in microseconds, older Unixen and
* resolution is only 1/HZ, or 10 milliseconds, on most Unixen. Expect * Windows use periodic kernel ticks to wake up, which might increase the delay
* the requested delay to be rounded up to the next resolution boundary. * time significantly. We've observed delay increases as large as 20
* milliseconds on supported platforms.
* *
* On machines where "long" is 32 bits, the maximum delay is ~2000 seconds. * On machines where "long" is 32 bits, the maximum delay is ~2000 seconds.
* *