On 5 Nov 2014, at 23:47, Quinn The Eskimo! <eskimo1@apple.com> wrote:

On 5 Nov 2014, at 16:43, Gerriet M. Denkmann <gerriet@mdenkmann.de> wrote:

...

On 5 Nov 2014, at 20:31, Quinn The Eskimo! <eskimo1@apple.com> wrote:

...

It [i.e. the inode] should change each time the file is saved.

It should, but it does not.

Curious. Alas, the source for ntpd is complex enough that I may be looking at completely the wrong code. On option here is to use fs_usage to see what system calls ntpd is using to make this change and track things from there.

Following your advice I found a way to change a file without DISPATCH_SOURCE_TYPE_VNODE noticing it (same way save_drift_file() in ntp_util.c does it): static void *mmap_addr; static off_t stats_size; if ( mmap_addr == NULL ) { // will receive DISPATCH_VNODE_ATTRIB (sometimes twice) NSLog(@"%s will write %g (case 2: setting mmap_addr)",__FUNCTION__, drift_comp * 1e6); int fd = open(stats_drift_file, O_RDWR); if ( fd < 0 ) ... // error mmap_addr = mmap(0, pageSize, PROT_READ|PROT_WRITE, MAP_FILE|MAP_SHARED, fd, 0); if (mmap_addr == MAP_FAILED) ... // error off_t n = snprintf(mmap_addr, pageSize, "%.3f\n", drift_comp * 1e6); if (n != stats_size) { truncate(stats_drift_file, n); stats_size = n; }; close(fd); } else // stealth-mode { // will receive no DISPATCH_VNODE_XXX at all // does NOT update the change-time of stats_drift_file NSLog(@"%s will write %g (case 3: stealth-mode using mmap)",__FUNCTION__, drift_comp * 1e6); off_t n = snprintf(mmap_addr, pageSize, "%.3f\n", drift_comp * 1e6); if (n != stats_size) // size of ntp.drift changed { truncate(stats_drift_file, n); stats_size = n; }; }; Question: is this the way it should be? Or is this stealth-mode a bug? Kind regards, Gerriet. _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.... This email sent to site_archiver@lists.apple.com