Re: [PATCH 3/9] wrapper: add sleep_nanosec
- From
Junio C Hamano <gitster@pobox.com>
- Date
- May 19, 2026, 23:50 UTC
- Message-ID
- <87qzn7q7qj.fsf@gitster.g>
- In-Reply-To
- <6a8c2093643a385641ef0b2cde33839dc98d8678.1779207350.git.siddh.raman.pant@oracle.com>
Siddh Raman Pant <siddh.raman.pant@oracle.com> writes:
> Signed-off-by: Siddh Raman Pant <siddh.raman.pant@oracle.com> > ---
The space above the signed-off-by line should be utilized to explain why we want this change. For the purpose of this series, why do we want to sleep at nanosecond precision?
Show 83 quoted lines
> wrapper.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
> wrapper.h | 1 +
> 2 files changed, 50 insertions(+)
>
> diff --git a/wrapper.c b/wrapper.c
> index 16f5a63fbb61..1349255f1eb4 100644
> --- a/wrapper.c
> +++ b/wrapper.c
> @@ -10,6 +10,7 @@
> #include "gettext.h"
> #include "strbuf.h"
> #include "trace2.h"
> +#include <time.h>
>
> #ifdef HAVE_RTLGENRANDOM
> /* This is required to get access to RtlGenRandom. */
> @@ -708,6 +709,54 @@ void sleep_millisec(int millisec)
> poll(NULL, 0, millisec);
> }
>
> +#ifdef GIT_WINDOWS_NATIVE
> +/* No nanosleep() on Windows, so fall-back to using sleep_millisec(). */
> +int sleep_nanosec(uint64_t nanosec)
> +{
> + uint64_t ns_in_1ms = 1000000ULL; /* 1 ms = 10^6 ns */
> +
> + uint64_t millisec = nanosec / ns_in_1ms;
> + if (nanosec % ns_in_1ms)
> + millisec++;
> +
> + /* Chunked sleep if we can't represent in integer. */
> + while (millisec > INT_MAX) {
> + sleep_millisec(INT_MAX);
> + millisec -= INT_MAX;
> + }
> +
> + sleep_millisec((int)millisec);
> +
> + return 0;
> +}
> +#else
> +/* Not Windows, so use the more exact nanosleep(). */
> +int sleep_nanosec(uint64_t nanosec)
> +{
> + int ret;
> + struct timespec duration, remaining;
> +
> + /* Construct the duration by dividing the given total (1s = 10^9ns). */
> + duration.tv_sec = nanosec / 1000000000ULL;
> + duration.tv_nsec = nanosec % 1000000000ULL;
> +
> + while(1) {
> + ret = nanosleep(&duration, &remaining);
> +
> + /* Continue sleeping if interrupted. */
> + if (ret == -1 && errno == EINTR) {
> + duration = remaining;
> + continue;
> + }
> +
> + /* Either success or an error. */
> + break;
> + }
> +
> + return ret;
> +}
> +#endif /* GIT_WINDOWS_NATIVE */
> +
> int xgethostname(char *buf, size_t len)
> {
> /*
> diff --git a/wrapper.h b/wrapper.h
> index 15ac3bab6e97..c39992893a81 100644
> --- a/wrapper.h
> +++ b/wrapper.h
> @@ -130,6 +130,7 @@ int warn_on_fopen_errors(const char *path);
> int open_nofollow(const char *path, int flags);
>
> void sleep_millisec(int millisec);
> +int sleep_nanosec(uint64_t nanosec);
>
> enum {
> /*