diff options
Diffstat (limited to 'ext/unicorn_http/httpdate.c')
| -rw-r--r-- | ext/unicorn_http/httpdate.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/ext/unicorn_http/httpdate.c b/ext/unicorn_http/httpdate.c index b59d038..0faf5da 100644 --- a/ext/unicorn_http/httpdate.c +++ b/ext/unicorn_http/httpdate.c @@ -1,5 +1,6 @@ #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"); @@ -11,6 +12,7 @@ static const char months[] = "Jan\0Feb\0Mar\0Apr\0May\0Jun\0" /* for people on wonky systems only */ #ifndef HAVE_GMTIME_R +# warning using fake gmtime_r static struct tm * my_gmtime_r(time_t *now, struct tm *tm) { struct tm *global = gmtime(now); @@ -42,13 +44,24 @@ 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, |