From: Taylor Blau <me@ttaylorr.com>
To: Derrick Stolee via GitGitGadget <gitgitgadget@gmail.com>
Cc: git@vger.kernel.org, gitster@pobox.com,
sandals@crustytoothpaste.net, lenaic@lhuard.fr,
Derrick Stolee <derrickstolee@github.com>
Subject: Re: [PATCH 1/6] maintenance: add get_random_minute()
Date: Mon, 7 Aug 2023 17:20:35 -0400 [thread overview]
Message-ID: <ZNFgIyuhlNd8I9Y2@nand.local> (raw)
In-Reply-To: <fefdaa9457948ee5302e7cbfaae250e0b589d752.1691434300.git.gitgitgadget@gmail.com>
On Mon, Aug 07, 2023 at 06:51:35PM +0000, Derrick Stolee via GitGitGadget wrote:
> diff --git a/builtin/gc.c b/builtin/gc.c
> index f3942188a61..66a972bc292 100644
> --- a/builtin/gc.c
> +++ b/builtin/gc.c
> @@ -1708,6 +1708,23 @@ static int get_schedule_cmd(const char **cmd, int *is_available)
> return 1;
> }
>
> +MAYBE_UNUSED
> +static int get_random_minute(void)
> +{
> + static int random_initialized = 0;
> +
> + /* Use a static value when under tests. */
> + if (!getenv("GIT_TEST_MAINTENANCE_SCHEDULER"))
> + return 13;
> +
> + if (!random_initialized) {
> + srand((unsigned int)getpid());
> + random_initialized = 1;
> + }
I was wondering where else we call srand() within Git, and it looks like
the only other spot is in `lock_file_timeout()`.
I doubt it, but is there a chance that that code depends on only calling
srand() once? I think the answer is "no", since we only use rand()
within that function to generate a random-ish backoff period, so I think
the repeatability of it doesn't matter all that much.
So I think this is kind of outside the scope of your series, but I
wonder if we should have a git_rand() that automatically initializes the
PRNG with the value of getpid()? Then multiple callers can grab random
values at will without reinitializing the PRNG.
Thanks,
Taylor
next prev parent reply other threads:[~2023-08-07 21:20 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-07 18:51 [PATCH 0/6] maintenance: schedule maintenance on a random minute Derrick Stolee via GitGitGadget
2023-08-07 18:51 ` [PATCH 1/6] maintenance: add get_random_minute() Derrick Stolee via GitGitGadget
2023-08-07 21:20 ` Taylor Blau [this message]
2023-08-07 23:53 ` Junio C Hamano
2023-08-08 0:22 ` Junio C Hamano
2023-08-08 14:48 ` Taylor Blau
2023-08-08 16:34 ` Junio C Hamano
2023-08-08 16:49 ` Junio C Hamano
2023-08-08 20:01 ` Taylor Blau
2023-08-08 17:28 ` Derrick Stolee
2023-08-08 20:04 ` Taylor Blau
2023-08-09 12:17 ` Derrick Stolee
2023-08-09 18:50 ` Junio C Hamano
2023-08-09 20:34 ` Taylor Blau
2023-08-07 18:51 ` [PATCH 2/6] maintenance: use random minute in launchctl scheduler Derrick Stolee via GitGitGadget
2023-08-07 21:23 ` Taylor Blau
2023-08-07 18:51 ` [PATCH 3/6] maintenance: use random minute in Windows scheduler Derrick Stolee via GitGitGadget
2023-08-07 18:51 ` [PATCH 4/6] maintenance: use random minute in cron scheduler Derrick Stolee via GitGitGadget
2023-08-07 18:51 ` [PATCH 5/6] maintenance: swap method locations Derrick Stolee via GitGitGadget
2023-08-07 21:24 ` Taylor Blau
2023-08-07 18:51 ` [PATCH 6/6] maintenance: use random minute in systemd scheduler Derrick Stolee via GitGitGadget
2023-08-07 21:31 ` Taylor Blau
2023-08-08 13:49 ` Derrick Stolee
2023-08-08 20:05 ` Taylor Blau
2023-08-08 9:53 ` Phillip Wood
2023-08-08 13:03 ` Phillip Wood
2023-08-08 13:56 ` Derrick Stolee
2023-08-08 17:24 ` Derrick Stolee
2023-08-09 10:03 ` Phillip Wood
2023-08-08 12:08 ` Phillip Wood
2023-08-08 17:06 ` Derrick Stolee
2023-08-08 17:14 ` Derrick Stolee
2023-08-09 10:00 ` Phillip Wood
2023-08-10 20:39 ` [PATCH v2 0/8] maintenance: schedule maintenance on a random minute Derrick Stolee via GitGitGadget
2023-08-10 20:39 ` [PATCH v2 1/8] maintenance: add get_random_minute() Derrick Stolee via GitGitGadget
2023-08-10 21:25 ` Taylor Blau
2023-08-10 20:39 ` [PATCH v2 2/8] maintenance: use random minute in launchctl scheduler Derrick Stolee via GitGitGadget
2023-08-10 20:39 ` [PATCH v2 3/8] maintenance: use random minute in Windows scheduler Derrick Stolee via GitGitGadget
2023-08-10 20:39 ` [PATCH v2 4/8] maintenance: use random minute in cron scheduler Derrick Stolee via GitGitGadget
2023-08-10 20:39 ` [PATCH v2 5/8] maintenance: swap method locations Derrick Stolee via GitGitGadget
2023-08-10 20:39 ` [PATCH v2 6/8] maintenance: use random minute in systemd scheduler Derrick Stolee via GitGitGadget
2023-08-14 11:26 ` Phillip Wood
2023-08-10 20:39 ` [PATCH v2 7/8] maintenance: fix systemd schedule overlaps Derrick Stolee via GitGitGadget
2023-08-10 21:22 ` Junio C Hamano
2023-08-14 11:27 ` Phillip Wood
2023-08-10 20:39 ` [PATCH v2 8/8] maintenance: update schedule before config Derrick Stolee via GitGitGadget
2023-08-14 11:28 ` Phillip Wood
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