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| author | Eric Wong <bofh@yhbt.net> | 2023-06-01 23:58:13 +0000 |
|---|---|---|
| committer | Eric Wong <bofh@yhbt.net> | 2023-06-05 09:17:18 +0000 |
| commit | a6463151bd1db5b9ae7a54985a200f28f543f241 (patch) | |
| tree | 36fd4690072983e38ade3ae8af2a85ca42a4014f /ext | |
| parent | caadb37fed62105fc27494593bfe3a74c309429b (diff) | |
| download | unicorn-a6463151bd1db5b9ae7a54985a200f28f543f241.tar.gz | |
While scanning the git@vger.kernel.org mailing list, I've learned time(2) may return the wrong value in the first 1 to 2.5 ms of every second. While I'm not sure if the Date: response header matters to anyone, returning the correct time seems prudent. Link: https://lore.kernel.org/git/20230320230507.3932018-1-gitster@pobox.com/ Link: https://inbox.sourceware.org/libc-alpha/20230306160321.2942372-1-adhemerval.zanella@linaro.org/T/ Link: https://sourceware.org/bugzilla/show_bug.cgi?id=30200
Diffstat (limited to 'ext')
| -rw-r--r-- | ext/unicorn_http/httpdate.c | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/ext/unicorn_http/httpdate.c b/ext/unicorn_http/httpdate.c index 3f512dd..27a8f51 100644 --- a/ext/unicorn_http/httpdate.c +++ b/ext/unicorn_http/httpdate.c @@ -1,5 +1,5 @@ #include <ruby.h> -#include <time.h> +#include <sys/time.h> #include <stdio.h> static const size_t buf_capa = sizeof("Thu, 01 Jan 1970 00:00:00 GMT"); @@ -43,13 +43,24 @@ static struct tm * my_gmtime_r(time_t *now, struct tm *tm) static VALUE httpdate(VALUE self) { static time_t last; - time_t now = time(NULL); /* not a syscall on modern 64-bit systems */ + struct timeval now; struct tm tm; - if (last == now) + /* + * Favor gettimeofday(2) over time(2), as the latter can return the + * wrong value in the first 1 .. 2.5 ms of every second(!) + * + * https://lore.kernel.org/git/20230320230507.3932018-1-gitster@pobox.com/ + * https://inbox.sourceware.org/libc-alpha/20230306160321.2942372-1-adhemerval.zanella@linaro.org/T/ + * https://sourceware.org/bugzilla/show_bug.cgi?id=30200 + */ + if (gettimeofday(&now, NULL)) + rb_sys_fail("gettimeofday"); + + if (last == now.tv_sec) return buf; - last = now; - gmtime_r(&now, &tm); + last = now.tv_sec; + gmtime_r(&now.tv_sec, &tm); /* we can make this thread-safe later if our Ruby loses the GVL */ snprintf(buf_ptr, buf_capa, |