site_archiver@lists.apple.com Delivered-To: darwin-kernel@lists.apple.com On Mar 11, 2010, at 6:15 AM, Godfrey van der Linden wrote:
I've now explored every variant I can think of for using kevent with EVFILT_TIMER. If I read kevent(2) properly the default implementation for the TIMER is to set a repeating timeout that can fire every ident timeperiods and delivers a EVFILT_TIMER event.
Yet only ever get one hit, immediately and the event never fires again. Is this a documentation problem or am I missing something?
Here is the code that demonstrates the problem, not that it never returns after the initial immediate and incorrect kevents.
I'm running a vanilla x86_64 macbook pro with 10.6.2.
Please help, this problem has been screwing me over for the last week.
Godfrey
/* gcc -std=c99 -Wall -Wextra -Werror -g -o kevent_timer kevent_timer.c */
#include <sys/cdefs.h>
#include <assert.h> #include <errno.h> #include <stdio.h> #include <stdbool.h> #include <strings.h> #include <sys/time.h>
#include <sys/event.h>
#define kLongTimer_ms (1000) #define kShortTimer_ms ( 10)
static struct timeval sStart; static int sKQ;
static void logKEvent(const struct kevent64_s *kep, int ind, const char * const pfx);
int main(int argc __unused, char *argv[] __unused) { sKQ = kqueue();
gettimeofday(&sStart, NULL);
uintptr_t nch = 0; struct kevent64_s timers[2];
EV_SET64(&timers[nch], kLongTimer_ms, EVFILT_TIMER, EV_ADD, 0, 0, nch, 0, 0); nch++; EV_SET64(&timers[nch], kShortTimer_ms, EVFILT_TIMER, EV_ADD, 0, 0, nch, 0, 0); nch++;
Your code is broken here. The "ident" field of the struct is supposed to contain the timer number, not the time interval- that's put in the "data" field with fflags holding the time units. This is all in the man page. Here is some sample code that works: #include <sys/cdefs.h> #include <assert.h> #include <errno.h> #include <stdio.h> #include <stdbool.h> #include <strings.h> #include <sys/time.h> #include <sys/event.h> #include <stdlib.h> int main() { int akq=kqueue(); struct kevent64_s aTimerEvent; EV_SET64(&aTimerEvent,1,EVFILT_TIMER,EV_ADD|EV_ENABLE,NOTE_SECONDS,1,0,0,0); //add the event int aSuccess=kevent64(akq,&aTimerEvent,1,NULL,0,0,NULL); if(aSuccess<0) abort(); while(1) { struct kevent64_s anEvent; int anEventCount=kevent64(akq,NULL,0,&anEvent,1,0,NULL); if(anEventCount<0) abort(); if(anEventCount==1) { printf("timer!\n"); } } } Cheers, M _______________________________________________ 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: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.a... This email sent to site_archiver@lists.apple.com